Glimmer DSL for LibUI 0.12.5

If You Liked Shoes, You'll Love Glimmer!

(Fukuoka Ruby Award Competition 2022 Special Award Winner [Award Announcement])

(RubyConf 2023 Workshop - How To Build Desktop Applications in Ruby)

(RubyConf 2022 Talk - Building Native GUI Apps in Ruby)

(Ruby Rogues Podcast Interview - Desktop Apps in Ruby ft. Andy)

Glimmer DSL for LibUI is a Fukuoka Award Winning prerequisite-free MRI Ruby desktop development cross-platform native GUI (Graphical User Interface) library. No need to pre-install any prerequisites. Just install the gem and have cross-platform native GUI that just works on Mac, Windows, and Linux!

Mac	Windows	Linux

LibUI is a relatively new C GUI library that renders native controls on every platform (similar to SWT, but without the heavy weight of the Java Virtual Machine). Applications built with Glimmer DSL for LibUI will provide the familiar native look, feel, and behavior of GUI on Mac, Windows, and Linux.

The main trade-off in using Glimmer DSL for LibUI as opposed to Glimmer DSL for SWT or Glimmer DSL for Tk is the fact that SWT and Tk are more mature than mid-alpha libui as GUI toolkits. Still, if there is only a need to build a small simple application, Glimmer DSL for LibUI could be a good convenient choice due to having zero prerequisites (beyond Ruby and the dependencies included in the Ruby gem). Also, just like Glimmer DSL for Tk, its apps start instantly and have a small memory footprint. LibUI is a promising new GUI toolkit that might prove quite worthy in the future.

Glimmer DSL for LibUI aims to provide a DSL similar to the Glimmer DSL for SWT to enable more productive desktop development in Ruby with:

• Declarative DSL syntax that visually maps to the GUI control hierarchy
• Convention over configuration via smart defaults and automation of low-level details
• Requiring the least amount of syntax possible to build GUI
• Custom Component support (Custom Controls, Custom Windows, and Custom Shapes), including Component Slots and external Ruby gems (e.g. Graphs and Charts)
• Bidirectional/Unidirectional Data-Binding to declaratively wire and automatically synchronize GUI Views with Models
• Scaffolding for new custom windows/controls, apps, and gems
• [Far Future Plan] Native-Executable packaging on Mac, Windows, and Linux.

Hello, World!

require 'glimmer-dsl-libui'

include Glimmer

window('hello world').show

Mac	Windows	Linux

Basic Button

require 'glimmer-dsl-libui'

include Glimmer

window('hello world', 300, 200) {
  button('Button') {
    on_clicked do
      msg_box('Information', 'You clicked the button')
    end
  }
}.show

Basic Table Progress Bar

Mac	Windows	Linux

require 'glimmer-dsl-libui'

include Glimmer

data = [
  ['task 1', 0],
  ['task 2', 15],
  ['task 3', 100],
  ['task 4', 75],
  ['task 5', -1],
]

window('Task Progress', 300, 200) {
  vertical_box {
    table {
      text_column('Task')
      progress_bar_column('Progress')

      cell_rows data # implicit data-binding
    }
    
    button('Mark All As Done') {
      stretchy false
      
      on_clicked do
        data.each_with_index do |row_data, row|
          data[row][1] = 100 # automatically updates table due to implicit data-binding
        end
      end
    }
  }
}.show

Mac	Windows	Linux

Form Table

require 'glimmer-dsl-libui'

class FormTable
  Contact = Struct.new(:name, :email, :phone, :city, :state)
  
  include Glimmer
  
  attr_accessor :contacts, :name, :email, :phone, :city, :state, :filter_value
  
  def initialize
    @contacts = [
      Contact.new('Lisa Sky', 'lisa@sky.com', '720-523-4329', 'Denver', 'CO'),
      Contact.new('Jordan Biggins', 'jordan@biggins.com', '617-528-5399', 'Boston', 'MA'),
      Contact.new('Mary Glass', 'mary@glass.com', '847-589-8788', 'Elk Grove Village', 'IL'),
      Contact.new('Darren McGrath', 'darren@mcgrath.com', '206-539-9283', 'Seattle', 'WA'),
      Contact.new('Melody Hanheimer', 'melody@hanheimer.com', '213-493-8274', 'Los Angeles', 'CA'),
    ]
  end
  
  def launch
    window('Contacts', 600, 600) {
      margined true
      
      vertical_box {
        form {
          stretchy false
          
          entry {
            label 'Name'
            text <=> [self, :name] # bidirectional data-binding between entry text and self.name
          }
          
          entry {
            label 'Email'
            text <=> [self, :email]
          }
          
          entry {
            label 'Phone'
            text <=> [self, :phone]
          }
          
          entry {
            label 'City'
            text <=> [self, :city]
          }
          
          entry {
            label 'State'
            text <=> [self, :state]
          }
        }
        
        button('Save Contact') {
          stretchy false
          
          on_clicked do
            new_row = [name, email, phone, city, state]
            if new_row.map(&:to_s).include?('')
              msg_box_error('Validation Error!', 'All fields are required! Please make sure to enter a value for all fields.')
            else
              @contacts << Contact.new(*new_row) # automatically inserts a row into the table due to explicit data-binding
              @unfiltered_contacts = @contacts.dup
              self.name = '' # automatically clears name entry through explicit data-binding
              self.email = ''
              self.phone = ''
              self.city = ''
              self.state = ''
            end
          end
        }
        
        search_entry {
          stretchy false
          # bidirectional data-binding of text to self.filter_value with after_write option
          text <=> [self, :filter_value,
            after_write: ->(filter_value) { # execute after write to self.filter_value
              @unfiltered_contacts ||= @contacts.dup
              # Unfilter first to remove any previous filters
              self.contacts = @unfiltered_contacts.dup # affects table indirectly through explicit data-binding
              # Now, apply filter if entered
              unless filter_value.empty?
                self.contacts = @contacts.filter do |contact| # affects table indirectly through explicit data-binding
                  contact.members.any? do |attribute|
                    contact[attribute].to_s.downcase.include?(filter_value.downcase)
                  end
                end
              end
            }
          ]
        }
        
        table {
          text_column('Name')
          text_column('Email')
          text_column('Phone')
          text_column('City')
          text_column('State')
    
          editable true
          cell_rows <=> [self, :contacts] # explicit data-binding to self.contacts Modal Array, auto-inferring model attribute names from underscored table column names by convention
          
          on_changed do |row, type, row_data|
            puts "Row #{row} #{type}: #{row_data}"
            $stdout.flush # for Windows
          end
          
          on_edited do |row, row_data| # only fires on direct table editing
            puts "Row #{row} edited: #{row_data}"
            $stdout.flush # for Windows
          end
        }
      }
    }.show
  end
end

FormTable.new.launch

Mac	Windows	Linux

Area Gallery

require 'glimmer-dsl-libui'

include Glimmer

window('Area Gallery', 400, 400) {
  area {
    path { # declarative stable path (explicit path syntax for multiple shapes sharing attributes)
      square(0, 0, 100)
      square(100, 100, 400)
      
      fill r: 102, g: 102, b: 204
    }
    
    path { # declarative stable path (explicit path syntax for multiple shapes sharing attributes)
      rectangle(0, 100, 100, 400)
      rectangle(100, 0, 400, 100)
      
      # linear gradient (has x0, y0, x1, y1, and stops)
      fill x0: 10, y0: 10, x1: 350, y1: 350, stops: [{pos: 0.25, r: 204, g: 102, b: 204}, {pos: 0.75, r: 102, g: 102, b: 204}]
    }
    
    polygon(100, 100, 100, 400, 400, 100, 400, 400) { # declarative stable path (implicit path syntax for a single shape nested directly under area)
      fill r: 202, g: 102, b: 104, a: 0.5
      stroke r: 0, g: 0, b: 0
    }
    
    polybezier(0, 0,
               200, 100, 100, 200, 400, 100,
               300, 100, 100, 300, 100, 400,
               100, 300, 300, 100, 400, 400) { # declarative stable path (implicit path syntax for a single shape nested directly under area)
      fill r: 202, g: 102, b: 204, a: 0.5
      stroke r: 0, g: 0, b: 0, thickness: 2, dashes: [50, 10, 10, 10], dash_phase: -50.0
    }
    
    polyline(100, 100, 400, 100, 100, 400, 400, 400, 0, 0) { # declarative stable path (implicit path syntax for a single shape nested directly under area)
      stroke r: 0, g: 0, b: 0, thickness: 2
    }
    
    arc(404, 216, 190, 90, 90, false) { # declarative stable path (implicit path syntax for a single shape nested directly under area)
      # radial gradient (has an outer_radius in addition to x0, y0, x1, y1, and stops)
      fill outer_radius: 90, x0: 0, y0: 0, x1: 500, y1: 500, stops: [{pos: 0.25, r: 102, g: 102, b: 204, a: 0.5}, {pos: 0.75, r: 204, g: 102, b: 204}]
      stroke r: 0, g: 0, b: 0, thickness: 2, dashes: [50, 10, 10, 10], dash_phase: -50.0
    }
    
    circle(200, 200, 90) { # declarative stable path (implicit path syntax for a single shape nested directly under area)
      fill r: 202, g: 102, b: 204, a: 0.5
      stroke r: 0, g: 0, b: 0, thickness: 2
    }
    
    text(161, 40, 100) { # declarative stable text
      string('Area Gallery') {
        font family: 'Arial', size: (OS.mac? ? 14 : 11)
        color :black
      }
    }
    
    on_mouse_event do |area_mouse_event|
      p area_mouse_event
    end
    
    on_mouse_moved do |area_mouse_event|
      puts 'moved'
    end
    
    on_mouse_down do |area_mouse_event|
      puts 'mouse down'
    end
    
    on_mouse_up do |area_mouse_event|
      puts 'mouse up'
    end
    
    on_mouse_drag_started do |area_mouse_event|
      puts 'drag started'
    end
    
    on_mouse_dragged do |area_mouse_event|
      puts 'dragged'
    end
    
    on_mouse_dropped do |area_mouse_event|
      puts 'dropped'
    end
    
    on_mouse_entered do
      puts 'entered'
    end
    
    on_mouse_exited do
      puts 'exited'
    end
    
    on_key_event do |area_key_event|
      p area_key_event
    end
    
    on_key_up do |area_key_event|
      puts 'key up'
    end
    
    on_key_down do |area_key_event|
      puts 'key down'
    end
  }
}.show

Mac	Windows	Linux

Check out many more examples over here!

Check out many real apps built with Glimmer DSL for LibUI over here!

NOTE: Glimmer DSL for LibUI is regularly catching up with changes in the C libui-ng library API and in beta mode. The C libui-ng is still mid-alpha, which is why Glimmer DSL for LibUI cannot be declared v1.0.0 yet. Please help make better by contributing, adopting for small or low risk projects, and providing feedback. The more feedback and issues you report the better.

Learn more about the differences between various Glimmer DSLs by looking at the Glimmer DSL Comparison Table.

• Glimmer DSL for LibUI
  • Setup
  • Usage
    • Experimentation Usage
    • Prototyping Usage
    • Serious Usage
  • Glimmer Command
    • Run Application
    • Run Examples
    • Scaffold Application
    • Scaffold Custom Control
    • Scaffold Custom Window
    • Scaffold Custom Shape
    • Scaffold Custom Control Gem
    • Scaffold Custom Window Gem
    • Scaffold Custom Shape Gem
    • List Custom Control Gems
    • List Custom Window Gems
    • List Custom Shape Gems
    • List Glimmer DSLs
  • Girb (Glimmer IRB)
  • Glimmer GUI DSL Concepts
  • API
    • Supported Keywords
    • Common Control Properties
    • Common Control Operations
    • LibUI Operations
    • Extra Dialogs
    • Extra Operations
    • Table API
    • Area API
      • Scrolling Area
      • Area Path Shapes
      • Area Text
      • Area Image
      • Colors
      • Area Draw Params
      • Area Listeners
      • Area Methods/Attributes
      • Area Transform Matrix
      • Area Composite Shape
      • Area Animation
    • Smart Defaults and Conventions
    • Custom Components
      • Method-Based Custom Components
      • Class-Based Custom Components
    • Observer Pattern
    • Data-Binding
      • Bidirectional (Two-Way) Data-Binding
        • Table Data-Binding
      • Unidirectional (One-Way) Data-Binding
      • Data-Binding API
      • Data-Binding Gotchas
    • API Gotchas
    • Original API
  • Packaging
  • Glimmer Style Guide
  • Examples
    • Basic Examples
    • Advanced Examples
  • Applications
    • Manga2PDF
    • Befunge98 GUI
    • i3off Gtk Ruby
    • Chess
    • RubyCrumbler
    • Rubio-Radio
    • PMV Calc
  • Design Principles
  • Glimmer Process
  • Resources
  • Help
    • Issues
    • Chat
  • Planned Features and Feature Suggestions
  • Change Log
  • Contributing
  • Contributors
  • License

Note: the newest Ruby 3.3 is not fully supported yet.

Install glimmer-dsl-libui gem directly into a maintained Ruby version:

gem install glimmer-dsl-libui

Or install via Bundler Gemfile:

gem 'glimmer-dsl-libui', '~> 0.12.5'

Test that installation worked by running the Glimmer Meta-Example:

glimmer examples

Or alternatively, run using the explicit Ruby command:

ruby -r glimmer-dsl-libui -e "require 'examples/meta_example'"

Mac	Windows	Linux

Start by requiring the glimmer-dsl-libui Ruby gem, whether through a Ruby require 'glimmer-dsl-libui statement or Bundler.

Afterwards, to access the Glimmer GUI DSL:

• If you are learning/experimenting/prototyping with Glimmer DSL for LibUI, include the Glimmer module into the top-level scope or a Ruby class.
• If you are building a serious application, include Glimmer::LibUI::Application into the main view Ruby class
• If you are building a custom control, include Glimmer::LibUI::CustomControl into a Ruby class
• If you are building a cusotm window, include Glimmer::LibUI::CustomWindow into a Ruby class
• If you are building a custom shape, include Glimmer::LibUI::CustomShape into a Ruby class.

You may learn more about the different options above with basic examples in the following subsections: Experimentation Usage, Prototyping Usage, Serious Usage.

If you are new to Glimmer DSL for LibUI (beginner), after going through the subsections below, check out the RubyConf 2022 talk "Building Native GUI Apps in Ruby", Glimmer GUI DSL Concepts, Glimmer Style Guide, Glimmer Command (just the basics, how to run an app, and how to run examples to start), Girb and Examples to quickly learn through copy/paste. It is very important for beginners to go through all the Examples from the most basic to the most advanced while reading the README topics that relate to the examples. Alternatively, beginners can learn from the RubyConf 2023 workshop "How To Build Desktop Applications in Ruby", which includes 27 step-by-step exercises. You may refer to the API once you have gotten your feet wet with Glimmer DSL for LibUI and need a more detailed reference.

If you encounter any issues with the documentation, get stuck with code you do not understand, or notice some out-of-date information, you may contact the project maintainers on the Glimmer Gitter Chat. Also, this could be your opportunity to be a good steward of Open-Source Software by contributing a documentation fix in a GitHub Pull Request or reporting a GitHub Issue at least.

For integration with a Relational Database (SQL) via ActiveRecord, you may refer to the blog post that was written about using ActiveRecord with SQLite DB and Glimmer DSL for SWT (altering to fit CRuby and Glimmer DSL for LibUI). Also, @chip created a prototype Git repo for starting a Glimmer DSL for LibUI project with SQLite DB and ActiveRecord: https://github.com/chip/glimmer_dsl_with_active_record

For experimenting and learning, add include Glimmer into the top-level main object and start using the Glimmer GUI DSL directly.

Example including Glimmer at the top-level scope just for some prototyping/demoing/testing (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer
  
window('hello world', 300, 200) {
  button('Button') {
    on_clicked do
      puts 'Button Clicked'
    end
  }
}.show

For prototyping, add include Glimmer into an actual class and start using the Glimmer GUI DSL in instance methods.

Example including Glimmer and manually implementing the #launch method (you may copy/paste in girb):

require 'glimmer-dsl-libui'

class SomeGlimmerApp
  include Glimmer
  
  def launch
    window('hello world', 300, 200) {
      button('Button') {
        on_clicked do
          puts 'Button Clicked'
        end
      }
    }.show
  end
end

SomeGlimmerApp.new.launch

For more serious usage, add include Glimmer::LibUI::Application into an actual class (it automatically includes the Glimmer module) to conveniently declare the GUI underneath a body block (with the option of implementing before_body and after_body hooks) and take advantage of the inherited SomeClass::launch method implementation that automatically calls window.show for you.

Example including Glimmer::LibUI::Application (you may copy/paste in girb):

require 'glimmer-dsl-libui'

class SomeGlimmerApp
  include Glimmer::LibUI::Application
  
  body {
    window('hello world', 300, 200) {
      button('Button') {
        on_clicked do
          puts 'Button Clicked'
        end
      }
    }
  }
end

SomeGlimmerApp.launch

(note: Glimmer::LibUI::Application is an alias for Glimmer::LibUI::CustomWindow since that is what it represents)

The glimmer command allows you to conveniently run applications (glimmer app_path), run examples (glimmer examples), and scaffold applications (glimmer "scaffold[app_name]").

You can bring up usage instructions by running the glimmer command without arguments:

glimmer

Glimmer DSL for LibUI (Prerequisite-Free Ruby Desktop Development Cross-Platform Native GUI Library) - Ruby Gem: glimmer-dsl-libui v0.8.0

Usage: glimmer [--bundler] [--pd] [--quiet] [--debug] [--log-level=VALUE] [[ENV_VAR=VALUE]...] [[-ruby-option]...] (application.rb or task[task_args])

Runs Glimmer applications and tasks.

When applications are specified, they are run using Ruby,
automatically preloading the glimmer-dsl-libui Ruby gem.

Optionally, extra Glimmer options, Ruby options, and/or environment variables may be passed in.

Glimmer options:
- "--bundler=GROUP"   : Activates gems in Bundler default group in Gemfile
- "--pd=BOOLEAN"      : Requires puts_debuggerer to enable pd method
- "--quiet=BOOLEAN"   : Does not announce file path of Glimmer application being launched
- "--debug"           : Displays extra debugging information and enables debug logging
- "--log-level=VALUE" : Sets Glimmer's Ruby logger level ("ERROR" / "WARN" / "INFO" / "DEBUG"; default is none)

Tasks are run via rake. Some tasks take arguments in square brackets (surround with double-quotes if using Zsh).

Available tasks are below (if you do not see any, please add `require 'glimmer/rake_task'` to Rakefile and rerun or run rake -T):

Select a Glimmer task to run: (Press ↑/↓ arrow to move, Enter to select and letters to filter)
‣ glimmer examples                                            # Brings up the Glimmer Meta-Sample app to allow browsing, running, and viewing code of Glimmer samples
  glimmer list:gems:customcontrol[query]                      # List Glimmer custom control gems available at rubygems.org (query is optional) [alt: list:gems:cc]
  glimmer list:gems:customshape[query]                        # List Glimmer custom shape gems available at rubygems.org (query is optional) [alt: list:gems:cs]
  glimmer list:gems:customwindow[query]                       # List Glimmer custom window gems available at rubygems.org (query is optional) [alt: list:gems:cw]
  glimmer list:gems:dsl[query]                                # List Glimmer DSL gems available at rubygems.org (query is optional)
  glimmer run[app_path]                                       # Runs Glimmer app or custom window gem in the current directory, unless app_path is specified, then runs it instead (app_path is optional)
  glimmer scaffold[app_name]                                  # Scaffold Glimmer application directory structure to build a new app
  glimmer scaffold:customcontrol[name,namespace]              # Scaffold Glimmer::UI::CustomControl subclass (part of a view) under app/views (namespace is optional) [alt: scaffold:cc]
  glimmer scaffold:customshape[name,namespace]                # Scaffold Glimmer::UI::CustomShape subclass (part of a view) under app/views (namespace is optional) [alt: scaffold:cs]
  glimmer scaffold:customwindow[name,namespace]               # Scaffold Glimmer::UI::CustomWindow subclass (full window view) under app/views (namespace is optional) [alt: scaffold:cw]
  glimmer scaffold:gem:customcontrol[name,namespace]          # Scaffold Glimmer::UI::CustomControl subclass (part of a view) under its own Ruby gem project (namespace is required) [alt: scaffold:gem:cc]
  glimmer scaffold:gem:customshape[name,namespace]            # Scaffold Glimmer::UI::CustomShape subclass (part of a view) under its own Ruby gem project (namespace is required) [alt: scaffold:gem:cs]
  glimmer scaffold:gem:customwindow[name,namespace]           # Scaffold Glimmer::UI::CustomWindow subclass (full window view) under its own Ruby gem + app project (namespace is required) [alt: scaffold:gem:cw]

On Mac and Linux, it brings up a TUI (Text-based User Interface) for interactive navigation and execution of Glimmer tasks (courtesy of rake-tui).

On Windows and ARM64 machines, it simply lists the available Glimmer tasks at the end (courtsey of rake).

Note: If you encounter an issue running the glimmer command, run bundle exec glimmer instead.

Run Glimmer DSL for LibUI applications via this command:

glimmer app_path

For example, from a cloned glimmer-dsl-libui repository:

glimmer examples/basic_window.rb

Mac	Windows	Linux

Run Glimmer DSL for LibUI included examples via this command:

glimmer examples

That brings up the Glimmer Meta-Example)

Mac	Windows	Linux

Application scaffolding enables automatically generating the directories/files of a new desktop GUI application that follows the MVC architecture and can be packaged as a Ruby gem that includes an executable script for running the app conveniently. It also ensures that software engineers follow the recommended Glimmer DSL for LibUI conventions and best practices. Application Scaffolding greatly improves software engineering productivity when building desktop applications with Glimmer DSL for LibUI.

Application Scaffolding relies on the juwelier Ruby gem, which expects a local Git config of user.name (git config --global user.name "FirstName LastName") and github.user (git config --global github.user githubusername).

Scaffold Glimmer DSL for LibUI application with this command:

glimmer "scaffold[app_name]"

That will automatically generate the general MVC structure of a new Glimmer DSL for LibUI application and launch the application when done.

For example, if we run:

glimmer "scaffold[hello_world]"

The following files are generated and reported by the glimmer command:

Created hello_world/.gitignore
Created hello_world/.ruby-version
Created hello_world/.ruby-gemset
Created hello_world/VERSION
Created hello_world/LICENSE.txt
Created hello_world/Gemfile
Created hello_world/Rakefile
Created hello_world/app/hello_world.rb
Created hello_world/app/hello_world/view/hello_world.rb
Created hello_world/app/hello_world/model/greeting.rb
Created hello_world/icons/windows/Hello World.ico
Created hello_world/icons/macosx/Hello World.icns
Created hello_world/icons/linux/Hello World.png
Created hello_world/app/hello_world/launch.rb
Created hello_world/bin/hello_world

They include a basic Hello, World! application with menus and about/preferences dialogs.

Views live under app/app_name/view (e.g. app/hello_world/view)

Models live under app/app_name/model (e.g. app/hello_world/model)

The application runs automatically once scaffolding is done.

Once you step into the application directory, you can run it in one of multiple ways:

bin/app_name

For example:

bin/hello_world

Or using the Glimmer generic command for running applications, which will automatically detect the application running script:

glimmer run

The application comes with the juwelier gem for auto-generating an application gem from the app Rakefile and Gemfile configuration (no need to manually declare gems in a gemspec... just use Gemfile normally and juwelier takes care of the rest by generating an app gemspec automatically from Gemfile).

You can package the newly scaffolded app as a Ruby gem by running this command:

glimmer package:gem

Or by using the raw rake command:

rake build

You can generate the application gemspec explicitly if needed with this command (though it is not needed to build the gem):

glimmer package:gemspec

Or by using the raw rake command:

rake gemspec:generate

Once you install the gem (e.g. gem install hello_world), you can simply run the app with its executable script:

app_name

For example:

hello_world

When you are in a scaffolded application, you can scaffold a new custom control (a control that you can put anything in to represent a view concept in your application) by running this command:

glimmer scaffold:customcontrol[name,namespace]

The name represents the custom control view class name (it can be underscored, and Glimmer will automatically classify it).

The namespace is optional and represents the module that the custom control view class will live under. If left off, the main application class namespace is used (e.g. the top-level HelloWorld class namespace for a hello_world application).

You can also use the shorter cc alias for customcontrol:

glimmer scaffold:cc[name,namespace]

For example by running this command under a hello_world application:

glimmer scaffold:cc[model_form]

That will generate this class under app/hello_world/view/model_form:

class HelloWorld
  module View
    class ModelForm
      include Glimmer::LibUI::CustomControl
  
      ## Add options like the following to configure CustomControl by outside consumers
      #
      # options :custom_text, :background_color
      # option :foreground_color, default: :red
      
      # Replace example options with your own options
      option :model
      option :attributes
  
      ## Use before_body block to pre-initialize variables to use in body
      #
      #
      before_body do
        # Replace example code with your own before_body code
        default_model_attributes = [:first_name, :last_name, :email]
        default_model_class = Struct.new(*default_model_attributes)
        self.model ||= default_model_class.new
        self.attributes ||= default_model_attributes
      end
  
      ## Use after_body block to setup observers for controls in body
      #
      # after_body do
      #
      # end
  
      ## Add control content under custom control body
      ##
      ## If you want to add a window as the top-most control,
      ## consider creating a custom window instead
      ## (Glimmer::LibUI::CustomWindow offers window convenience methods, like show and hide)
      #
      body {
        # Replace example content (model_form custom control) with your own custom control content.
        form {
          attributes.each do |attribute|
            entry { |e|
              label attribute.to_s.underscore.split('_').map(&:capitalize).join(' ')
              text <=> [model, attribute]
            }
          end
        }
      }
  
    end
  end
end

When the generated file is required in another view (e.g. require 'hello_world/view/model_form'), the custom control keyword model_form become available and reusable, like by calling:

window {
  vertical_box {
    label('Form:')
    model_form(model: some_model, attributes: array_of_attributes)
  }
}

Here is an example that generates a custom control with a namespace:

glimmer scaffold:cc[model_form,common]

That will generate this class under app/common/view/model_form:

module Common
  module View
    class ModelForm
      include Glimmer::LibUI::CustomControl
  
      ## Add options like the following to configure CustomControl by outside consumers
      #
      # options :custom_text, :background_color
      # option :foreground_color, default: :red
      
      # Replace example options with your own options
      option :model
      option :attributes
  
      ## Use before_body block to pre-initialize variables to use in body
      #
      #
      before_body do
        # Replace example code with your own before_body code
        default_model_attributes = [:first_name, :last_name, :email]
        default_model_class = Struct.new(*default_model_attributes)
        self.model ||= default_model_class.new
        self.attributes ||= default_model_attributes
      end
  
      ## Use after_body block to setup observers for controls in body
      #
      # after_body do
      #
      # end
  
      ## Add control content under custom control body
      ##
      ## If you want to add a window as the top-most control,
      ## consider creating a custom window instead
      ## (Glimmer::LibUI::CustomWindow offers window convenience methods, like show and hide)
      #
      body {
        # Replace example content (model_form custom control) with your own custom control content.
        form {
          attributes.each do |attribute|
            entry { |e|
              label attribute.to_s.underscore.split('_').map(&:capitalize).join(' ')
              text <=> [model, attribute]
            }
          end
        }
      }
  
    end
  end
end

When that file is required in another view (e.g. require 'common/view/model_form'), the model_form keyword becomes available:

window {
  vertical_box {
    label('Form:')
    model_form(model: some_model, attributes: array_of_attributes)
  }
}

If for whatever reason, you end up with 2 custom control views having the same name with different namespaces, then you can invoke the specific custom control you want by including the Ruby namespace in underscored format separated by double-underscores:

window {
  vertical_box {
    label('Form:')
    common__view__model_form(model: some_model, attributes: array_of_attributes)
  }
}

Or another model_form custom control view:

window {
  vertical_box {
    label('Form:')
    hello_world__view__model_form(model: some_model, attributes: array_of_attributes)
  }
}

A custom window is a specialization of a custom control that has a window as its body root.

When you are in a scaffolded application, you can scaffold a new custom window (a window that you can put anything in to represent a view concept in your application) by running this command:

glimmer scaffold:customwindow[name,namespace]

The name represents the custom window view class name (it can be underscored, and Glimmer will automatically classify it).

The namespace is optional and represents the module that the custom window view class will live under. If left off, the main application class namespace is used (e.g. the top-level HelloWorld class namespace for a hello_world application).

You can also use the shorter cw alias for customwindow:

glimmer scaffold:cw[name,namespace]

For example by running this command under a hello_world application:

glimmer scaffold:cw[greeting_window]

That will generate this class under app/hello_world/view/greeting_window:

class HelloWorld
  module View
    class GreetingWindow
      include Glimmer::LibUI::CustomWindow
    
          
      ## Add options like the following to configure CustomWindow by outside consumers
      #
      # options :title, :background_color
      # option :width, default: 320
      # option :height, default: 240
  
      ## Use before_body block to pre-initialize variables to use in body and
      #  to setup application menu
      #
      # before_body do
      #
      # end
  
      ## Use after_body block to setup observers for controls in body
      #
      # after_body do
      #
      # end
  
      ## Add control content inside custom window body
      ## Top-most control must be a window or another custom window
      #
      body {
        window {
          # Replace example content below with custom window content
          content_size 240, 240
          title 'Hello World'
          
          margined true
          
          label {
            text 'Hello World'
          }
        }
      }
    end
  end
end

When the generated file is required in another view (e.g. require 'hello_world/view/greeting_window'), the custom window keyword greeting_window become available and reusable, like by calling:

greeting_window.show

Here is an example that generates a custom window with a namespace:

glimmer scaffold:cw[train,station]

That will generate this class under app/station/view/train:

module Station
  module View
    class Train
      include Glimmer::LibUI::CustomWindow
    
          
      ## Add options like the following to configure CustomWindow by outside consumers
      #
      # options :title, :background_color
      # option :width, default: 320
      # option :height, default: 240
  
      ## Use before_body block to pre-initialize variables to use in body and
      #  to setup application menu
      #
      # before_body do
      #
      # end
  
      ## Use after_body block to setup observers for controls in body
      #
      # after_body do
      #
      # end
  
      ## Add control content inside custom window body
      ## Top-most control must be a window or another custom window
      #
      body {
        window {
          # Replace example content below with custom window content
          content_size 240, 240
          title 'Station'
          
          margined true
          
          label {
            text 'Station'
          }
        }
      }
    end
  end
end

When that file is required in another view (e.g. require 'station/view/train'), the train keyword becomes available:

train.show

If for whatever reason, you end up with 2 custom window views having the same name with different namespaces, then you can invoke the specific custom window you want by including the Ruby namespace in underscored format separated by double-underscores:

station__view__train.show

Or another train custom window view:

hello_world__view__train.show

When you are in a scaffolded application, you can scaffold a new custom shape (a shape that you can put anything in to represent a view concept in your application) by running this command:

glimmer scaffold:customshape[name,namespace]

The name represents the custom shape view class name (it can be underscored, and Glimmer will automatically classify it).

The namespace is optional and represents the module that the custom shape view class will live under. If left off, the main application class namespace is used (e.g. the top-level HelloWorld class namespace for a hello_world application).

You can also use the shorter cs alias for customshape:

glimmer scaffold:cs[name,namespace]

For example by running this command under a hello_world application:

glimmer scaffold:cs[heart]

That will generate this class under app/hello_world/view/heart:

class HelloWorld
  module View
    class Heart
      include Glimmer::LibUI::CustomShape
  
      ## Add options like the following to configure CustomShape by outside consumers
      #
      # options :option1, option2, option3
      option :background_color, default: :red
      option :size_width, default: 100
      option :size_height, default: 100
      option :location_x, default: 0
      option :location_y, default: 0
  
      ## Use before_body block to pre-initialize variables to use in body
      #
      #
      # before_body do
      #
      # end
  
      ## Use after_body block to setup observers for shapes in body
      #
      # after_body do
      #
      # end
  
      ## Add shape content under custom shape body
      #
      body {
        # Replace example content below (heart shape) with custom shape content
        shape(location_x, location_y) {
          # This fill color is shared under all direct children of `shape`
          fill background_color
          
          bezier(
            size_width - size_width*0.66, size_height/2 - size_height*0.33,
            size_width*0.65 - size_width*0.66, 0 - size_height*0.33,
            size_width/2 - size_width*0.66, size_height*0.75 - size_height*0.33,
            size_width - size_width*0.66, size_height - size_height*0.33
          )
          
          bezier(
            size_width - size_width*0.66, size_height/2 - size_height*0.33,
            size_width*1.35 - size_width*0.66, 0 - size_height*0.33,
            size_width*1.5 - size_width*0.66, size_height*0.75 - size_height*0.33,
            size_width - size_width*0.66, size_height - size_height*0.33
          )
        }
      }
  
    end
  end
end

When the generated file is required in another view (e.g. require 'hello_world/view/heart'), the custom shape keyword heart become available and reusable, like by calling:

window {
  area {
    heart
  }
}

You can pass heart options (as defined with option near the top of the class):

window {
  area {
    heart(location_x: 25, location_y: 50)
  }
}

Here is an example that generates a custom shape with a namespace:

glimmer scaffold:cs[heart,acme]

That will generate this class under app/acme/view/heart:

module Acme
  module View
    class Heart
      include Glimmer::LibUI::CustomShape
  
      ## Add options like the following to configure CustomShape by outside consumers
      #
      # options :option1, option2, option3
      option :background_color, default: :red
      option :size_width, default: 100
      option :size_height, default: 100
      option :location_x, default: 0
      option :location_y, default: 0
  
      ## Use before_body block to pre-initialize variables to use in body
      #
      #
      # before_body do
      #
      # end
  
      ## Use after_body block to setup observers for shapes in body
      #
      # after_body do
      #
      # end
  
      ## Add shape content under custom shape body
      #
      body {
        # Replace example content below (heart shape) with your own custom shape content
        shape(location_x, location_y) {
          # This fill color is shared under all direct children of `shape`
          fill background_color
          
          bezier(
            size_width - size_width*0.66, size_height/2 - size_height*0.33,
            size_width*0.65 - size_width*0.66, 0 - size_height*0.33,
            size_width/2 - size_width*0.66, size_height*0.75 - size_height*0.33,
            size_width - size_width*0.66, size_height - size_height*0.33
          )
          
          bezier(
            size_width - size_width*0.66, size_height/2 - size_height*0.33,
            size_width*1.35 - size_width*0.66, 0 - size_height*0.33,
            size_width*1.5 - size_width*0.66, size_height*0.75 - size_height*0.33,
            size_width - size_width*0.66, size_height - size_height*0.33
          )
        }
      }
  
    end
  end
end

When that file is required in another view (e.g. require 'acme/view/heart'), the heart keyword becomes available:

window {
  area {
    heart
  }
}

If for whatever reason, you end up with 2 custom shape views having the same name with different namespaces, then you can invoke the specific custom shape you want by including the Ruby namespace in underscored format separated by double-underscores:

window {
  area {
    acme__view__heart
  }
}

Or another heart custom shape view:

window {
  area {
    hello_world__view__heart
  }
}

You can scaffold a Ruby gem around a reusable custom control to expose publicly and make available for multiple projects by running this command:

glimmer scaffold:gem:customcontrol[name,namespace]

That will generate a custom control gem project under the naming convention: glimmer-libui-cc-name-namespace

The naming convention helps with discoverability of Ruby gems using the command glimmer list:gems:customcontrol[query] (or alias: glimmer list:gems:cc[query]) where filtering query is optional.

The name is the custom control class name, which must not contain dashes by convention (multiple words can be concatenated or can use underscores between them).

The namespace is needed to avoid clashing with other custom control gems that other software engineers might have thought of. It is recommended not to include dashes between words in it by convention yet concatenated words or underscores between them.

Here is a shorter alias for the custom control gem scaffolding command:

glimmer scaffold:gem:cc[name,namespace]

You can package the newly scaffolded project as a Ruby gem by running this command:

glimmer package:gem

Or by using the raw rake command:

rake build

You can generate the application gemspec explicitly if needed with this command (though it is not needed to build the gem):

glimmer package:gemspec

Or by using the raw rake command:

rake gemspec:generate

Typically, consumers of the gem would include it in their own project, which makes the gem keyword available in the Glimmer GUI DSL anywhere Glimmer. Glimmer::LibUI::Application, Glimmer::LibUI::CustomWindow, Glimmer::LibUI::CustomControl, or Glimmer::LibUI::CustomShape is mixed.

For example:

require 'glimmer-libui-cc-model_form-acme'

...
window {
  vertical_box {
    label('Form:')
    
    model_form(model: some_model, attributes: some_attributes)
  }
}
...

A real external Custom Control Gem is Graphs and Charts.

A custom window is a specialization of a custom control that has a window as its body root.

You can scaffold a Ruby gem around a reusable custom window to expose publicly and make available for multiple projects by running this command:

glimmer scaffold:gem:customwindow[name,namespace]

That will generate a custom window gem project under the naming convention: glimmer-libui-cw-name-namespace

The naming convention helps with discoverability of Ruby gems using the command glimmer list:gems:customwindow[query] (or alias: glimmer list:gems:cw[query]) where filtering query is optional.

The name is the custom window class name, which must not contain dashes by convention (multiple words can be concatenated or can use underscores between them).

The namespace is needed to avoid clashing with other custom window gems that other software engineers might have thought of. It is recommended not to include dashes between words in it by convention yet concatenated words or underscores between them.

Here is a shorter alias for the custom window gem scaffolding command:

glimmer scaffold:gem:cw[name,namespace]

You can package the newly scaffolded project as a Ruby gem by running this command:

glimmer package:gem

Or by using the raw rake command:

rake build

You can generate the application gemspec explicitly if needed with this command (though it is not needed to build the gem):

glimmer package:gemspec

Or by using the raw rake command:

rake gemspec:generate

The project optionally allows you to run the custom window as its own separate app with a executable script (bin/gem_name) to see it, which helps with prototyping it.

But, typically consumers of the gem would include it in their own project, which makes the gem keyword available in the Glimmer GUI DSL anywhere Glimmer. Glimmer::LibUI::Application, Glimmer::LibUI::CustomWindow, Glimmer::LibUI::CustomControl, or Glimmer::LibUI::CustomShape is mixed.

For example:

require 'glimmer-libui-cw-greeter-acme'

...
greeter.show
...

You can scaffold a Ruby gem around a reusable custom shape to expose publicly and make available for multiple projects by running this command:

glimmer scaffold:gem:customshape[name,namespace]

That will generate a custom shape gem project under the naming convention: glimmer-libui-cc-name-namespace

The naming convention helps with discoverability of Ruby gems using the command glimmer list:gems:customshape[query] (or alias: glimmer list:gems:cs[query]) where filtering query is optional.

The name is the custom shape class name, which must not contain dashes by convention (multiple words can be concatenated or can use underscores between them).

The namespace is needed to avoid clashing with other custom shape gems that other software engineers might have thought of. It is recommended not to include dashes between words in it by convention yet concatenated words or underscores between them.

Here is a shorter alias for the custom shape gem scaffolding command:

glimmer scaffold:gem:cs[name,namespace]

You can package the newly scaffolded project as a Ruby gem by running this command:

glimmer package:gem

Or by using the raw rake command:

rake build

You can generate the application gemspec explicitly if needed with this command (though it is not needed to build the gem):

glimmer package:gemspec

Or by using the raw rake command:

rake gemspec:generate

Typically, consumers of the gem would include it in their own project, which makes the gem keyword available in the Glimmer GUI DSL anywhere Glimmer. Glimmer::LibUI::Application, Glimmer::LibUI::CustomWindow, Glimmer::LibUI::CustomControl, or Glimmer::LibUI::CustomShape is mixed.

For example:

require 'glimmer-libui-cs-heart-acme'

...
window {
  area {
    heart
  }
}
...

Custom control gems are scaffolded to follow the naming convention: glimmer-libui-cc-name-namespace

The naming convention helps with discoverability of Ruby gems using the command:

glimmer list:gems:customcontrol[query]

Or by using the shorter alias:

glimmer list:gems:cc[query]

The filtering query is optional.

Custom window gems are scaffolded to follow the naming convention: glimmer-libui-cw-name-namespace

The naming convention helps with discoverability of Ruby gems using the command:

glimmer list:gems:customwindow[query]

Or by using the shorter alias:

glimmer list:gems:cw[query]

The filtering query is optional.

Custom shape gems are scaffolded to follow the naming convention: glimmer-libui-cs-name-namespace

The naming convention helps with discoverability of Ruby gems using the command:

glimmer list:gems:customshape[query]

Or by using the shorter alias:

glimmer list:gems:cs[query]

The filtering query is optional.

Glimmer DSLs can be listed with this command:

glimmer list:gems:dsl[query]

The filtering query is optional.

You can run the girb command (bin/girb if you cloned the project locally) to do some quick and dirty experimentation and learning:

girb

This gives you irb with the glimmer-dsl-libui gem loaded and the Glimmer module mixed into the main object for easy experimentation with GUI.

For a more advanced code editing tool, check out the Meta-Example (The Example of Examples).

Gotcha: On the Mac, when you close a window opened in girb, it remains open until you enter exit or open another GUI window.

The Glimmer GUI DSL provides object-oriented declarative hierarchical syntax for LibUI that:

• Supports smart defaults (e.g. automatic on_closing listener that quits window)
• Automates wiring of controls (e.g. button is automatically set as child of window)
• Hides lower-level details (e.g. LibUI.main loop is started automatically when triggering show on window)
• Nests controls according to their visual hierarchy
• Requires the minimum amount of syntax needed to describe an app's GUI

The Glimmer GUI DSL follows these simple concepts in mapping from LibUI syntax:

Keyword(args): LibUI controls may be declared by lower-case underscored name (aka keyword from list of supported keywords) (e.g. window or button). Behind the scenes, they are represented by keyword methods that map to corresponding LibUI.new_keyword methods receiving args (e.g. window('hello world', 300, 200, true)).

Content Block (Properties/Listeners/Controls): Any keyword may be optionally followed by a Ruby curly-brace multi-line content block containing properties (attributes), listeners, and/or nested controls.

Example:

window {
  title 'hello world' # property
  
  on_closing do # listener (always has a do; end block to signify logic)
    puts 'Bye'
  end
  
  button('greet') { # nested control
    on_clicked do
      puts 'hello world'
    end
  }
}

Content block optionally receives one arg representing the controll

Example:

button('greet') { |b|
  on_clicked do
    puts b.text
  end
}

If there is ever a need to add more content to a control, you can re-open its content with the control.content { ... } method.

Example:

box1 = vertical_box {
  label('First Name')
}
# re-open content of box1 and add another control
box1.content {
  entry {
    text 'fill in your first name'
  }
}

Content Data-Binding also allows you to use data-binding with content blocks to generate content dynamically based on changes in a model attribute. The only difference in syntax in this case would be to wrap the content with an explicit content(*binding_args) { ... } block (like content(model, attribute) { somecontrols } ) that includes data-binding arguments for a model attribute.

Example:

form {
  stretchy false
  
  content(@user, :customizable_attributes) {
    # this content will be re-rendered whenever @user.customizable_attributes changes
    @user.customizable_attributes.each do |attribute|
      entry {
        label attribute.to_s.split('_').map(&:capitalize).join(' ')
        text <=> [@user, attribute]
      }
    end
  }
}

The form above will only display fields for a model's customizable attributes, so if they change, the form content will change too.

If you need to rebuild (re-render) content upon changes to multiple model attributes, you can use the computed_by option.

Example:

form {
  stretchy false
  
  content(@user, :address, computed_by: [:street, :city, :zipcode]) {
    @user.address_attributes.each do |attribute|
      entry {
        label attribute.to_s.split('_').map(&:capitalize).join(' ')
        text <=> [@user, attribute]
      }
    end
  }
}

Now, the content block will get called when changes occur to any of User address ,street, city, or zipcode.

If you do not have a main attribute that is computed by other attributes, you can leave the main attribute out while using computed_by.

Example:

form {
  stretchy false
  
  content(@user, computed_by: [:street, :city, :zipcode]) {
    @user.address_attributes.each do |attribute|
      entry {
        label attribute.to_s.split('_').map(&:capitalize).join(' ')
        text <=> [@user, attribute]
      }
    end
  }
}

Now, the content block will get called (rerendered) when changes occur to any of User street, city, or zipcode.

Learn more about Content Data-Binding at the Dynamic Form example.

Property: Control properties may be declared inside keyword blocks with lower-case underscored name followed by property value args (e.g. title "hello world" inside group). Behind the scenes, properties correspond to LibUI.control_set_property methods.

Listener: Control listeners may be declared inside keyword blocks with listener lower-case underscored name beginning with on_ and receiving required block handler (always followed by a do; end style block to signify logic).

Example:

button('click') {
  on_clicked do
    puts 'clicked'
  end
}

Optionally, the listener block can receive an arg representing the control.

button('click') {
  on_clicked do |btn|
    puts btn.text
  end
}

Behind the scenes, listeners correspond to LibUI.control_on_event methods.

Method: Controls have methods that invoke certain operations on them. For example, window has a #show method that shows the window GUI. More methods are mentioned under API

Example of an app written in LibUI's procedural imperative syntax:

require 'libui'

UI = LibUI

UI.init

main_window = UI.new_window('hello world', 300, 200, 1)

button = UI.new_button('Button')

UI.button_on_clicked(button) do
  UI.msg_box(main_window, 'Information', 'You clicked the button')
end

UI.window_on_closing(main_window) do
  puts 'Bye Bye'
  UI.control_destroy(main_window)
  UI.quit
  0
end

UI.window_set_child(main_window, button)
UI.control_show(main_window)

UI.main
UI.quit

Example of the same app written in Glimmer object-oriented declarative hierarchical syntax:

require 'glimmer-dsl-libui'

include Glimmer

window('hello world', 300, 200) {
  button('Button') {
    on_clicked do
      msg_box('Information', 'You clicked the button')
    end
  }
  
  on_closing do
    puts 'Bye Bye'
  end
}.show

Make sure that you follow the Glimmer Style Guide when writing any Glimmer GUI DSL code.

Any control returned by a Glimmer GUI DSL keyword declaration can be introspected for its properties and updated via object-oriented attributes (standard Ruby attr/attr= or set_attr).

Example (you may copy/paste in girb):

w = window('hello world')
puts w.title # => hello world
w.title = 'howdy'
puts w.title # => howdy
w.set_title 'aloha'
puts w.title # => aloha

Controls are wrapped as Ruby proxy objects, having a #libui method to obtain the wrapped LibUI Fiddle pointer object. Ruby proxy objects rely on composition (via Proxy Design Pattern) instead of inheritance to shield consumers from having to deal with lower-level details unless absolutely needed. That said, you can invoke any LibUI operation on the Glimmer proxy object directly and it gets proxied automatically to the wrapped Fiddle pointer object (e.g. window_proxy.title gets proxied to LibUI.window_title(window_proxy.libui).to_s automatically), so you rarely have to refer to the wrapped #libui Fiddle pointer object directly.

Example (you may copy/paste in girb):

w = window('hello world') # => #<Glimmer::LibUI::WindowProxy:0x00007fde4ea39fb0
w.libui # => #<Fiddle::Pointer:0x00007fde53997980 ptr=0x00007fde51352a60 size=0 free=0x0000000000000000>
w.title == LibUI.window_title(w.libui).to_s # => true

These are all the supported keywords. Note that some keywords do not represent controls. For example, some keywords produce objects that are used as the property values of controls (e.g. image can be used as a control under area or alternatively build objects to use in cell_rows for a table with an image_column)

• enabled (Boolean)
• libui (Fiddle::Pointer): returns wrapped LibUI object
• parent_proxy (Glimmer::LibUI::ControlProxy or subclass)
• parent (Fiddle::Pointer)
• toplevel [read-only] (Boolean)
• visible (Boolean)
• stretchy [dsl-only] (Boolean) [default=true]: available in Glimmer GUI DSL when nested under horizontal_box, vertical_box, or form
• left [dsl-only] (Integer) [default=0]: available in Glimmer GUI DSL when nested under grid
• top [dsl-only] (Integer) [default=0]: available in Glimmer GUI DSL when nested under grid
• xspan [dsl-only] (Integer) [default=1]: available in Glimmer GUI DSL when nested under grid
• yspan [dsl-only] (Integer) [default=1]: available in Glimmer GUI DSL when nested under grid
• hexpand [dsl-only] (Boolean) [default=false]: available in Glimmer GUI DSL when nested under grid
• halign [dsl-only] (:fill, :start, :center, or :end) [default=:fill]: available in Glimmer GUI DSL when nested under grid
• vexpand [dsl-only] (Boolean) [default=false]: available in Glimmer GUI DSL when nested under grid
• valign [dsl-only] (:fill, :start, :center, or :end) [default=:fill]: available in Glimmer GUI DSL when nested under grid

• destroy (note that for closing a window, in addition to calling somewindow.destroy, you also have to call ::LibUI.quit)
• disable
• enable
• hide
• show

All operations that could normally be called on LibUI can also be called on Glimmer::LibUI, but some have enhancements as detailed below.

• Glimmer::LibUI::queue_main(&block): queues an operation to be run on the main event loop at the earliest opportunity possible. When writing multi-threaded code, it is required to wrap all code interacting with GUI objects (like window or button) from another Thread with Glimmer::LibUI::queue_main { ... }. See Glimmer Meta-Example for an example of using Glimmer::LibUI::queue_main { ... } inside another Thread.
• Glimmer::LibUI::timer(time_in_seconds=0.1, repeat: true, &block): calls block after time_in_seconds has elapsed, repeating indefinitely unless repeat is false or an Integer for finite number of repeats. Block can return false or true to override next repetition.

There are additional useful Glimmer::LibUI operations that are not found in LibUI, which mostly help if you would like to do advanced lower level LibUI programming:

• Glimmer::LibUI::integer_to_boolean(int, allow_nil: true)
• Glimmer::LibUI::boolean_to_integer(int, allow_nil: true)
• Glimmer::LibUI::degrees_to_radians(degrees)
• Glimmer::LibUI::interpret_color(value): interprets a color in any form like String, Symbol, or hex into an rgb Hash (including 0x1f3b5d, '0x1f3b5d', '#1f3b5d', and 3-char hex-shorthand variations)
• Glimmer::LibUI::hex_to_rgb(value): converts a hex color to an rgb Hash (including 0x1f3b5d, '0x1f3b5d', '#1f3b5d', and 3-char hex-shorthand variations)
• Glimmer::LibUI::enum_names: provides all possible enum names to use with Glimmer::LibUI::enum_symbols(enum_name)
• Glimmer::LibUI::enum_symbols(enum_name): returns all possible values for an enum. enum_name can be:
  • :draw_brush_type: [:solid, :linear_gradient, :radial_gradient, :image]
  • :draw_line_cap: [:flat, :round, :square]
  • :draw_line_join: [:miter, :round, :bevel]
  • :draw_fill_mode: [:winding, :alternate]
  • :attribute_type: attributes for attributed strings: [:family, :size, weight, :italic, :stretch, :color, :background, :underline, :underline_color, :features]
  • :text_weight: [:minimum, :thin, :ultra_light, :light, :book, :normal, :medium, :semi_bold, :bold, :ultra_bold, :heavy, :ultra_heavy, :maximum]
  • :text_italic: [:normal, :oblique, :italic]
  • :text_stretch: [:ultra_condensed, :extra_condensed, :condensed, :semi_condensed, :normal, :semi_expanded, :expanded, :extra_expanded, :ultra_expanded]
  • :underline: [:none, :single, :double, :suggestion, :color_custom, :color_spelling, :color_grammar, :color_auxiliary]
  • :underline_color: [:custom, :spelling, :grammar, :auxiliary]
  • :draw_text_align: [:left, :center, :right]
  • :modifier: [:ctrl, :alt, :shift, :super]
  • :ext_key: [:escape, :insert, :delete, :home, :end, :page_up, :page_down, :up, :down, :left, :right, :f1, :f2, :f3, :f4, :f5, :f6, :f7, :f8, :f9, :f10, :f11, :f12, :n0, :n1, :n2, :n3, :n4, :n5, :n6, :n7, :n8, :n9, :n_dot, :n_enter, :n_add, :n_subtract, :n_multiply, :n_divide]
  • :at: for inserting grid controls: [:leading, :top, :trailing, :bottom]
  • :align: [:fill, :start, :center, :end]
  • :table_value_type: [:string, :image, :int, :color]
  • :table_model_column: [:never_editable, :always_editable]
• Glimmer::LibUI::enum_symbol_to_value(enum_name, enum_symbol, default_symbol: nil, default_index: 0)
• Glimmer::LibUI::enum_value_to_symbol(enum_name, enum_value)
• Glimmer::LibUI::x11_colors: returns all X11 colors: [:alice_blue, :antique_white, :aqua, :aquamarine, :azure, :beige, :bisque, :rebecca_purple, :becca_purple, :blanched_almond, :blue, :blue_violet, :brown, :burly_wood, :burlywood, :cadet_blue, :carnation, :cayenne, :chartreuse, :chocolate, :coral, :cornflower_blue, :cornsilk, :crimson, :cyan, :dark_blue, :dark_cyan, :dark_golden_rod, :dark_goldenrod, :dark_gray, :dark_grey, :dark_green, :dark_khaki, :dark_magenta, :dark_olive_green, :darkolive_green, :dark_orange, :dark_orchid, :dark_red, :dark_salmon, :darksalmon, :dark_sea_green, :dark_slate_blue, :dark_slate_gray, :dark_slate_grey, :dark_turquoise, :dark_violet, :darkorange, :deep_pink, :deep_sky_blue, :dim_gray, :dim_grey, :dodger_blue, :feldspar, :fire_brick, :firebrick, :floral_white, :forest_green, :fuchsia, :gainsboro, :ghost_white, :gold, :golden_rod, :goldenrod, :gray, :grey, :gray10, :grey10, :gray20, :grey20, :gray30, :grey30, :gray40, :grey40, :gray50, :grey50, :gray60, :grey60, :gray70, :grey70, :gray80, :grey80, :gray90, :grey90, :green, :green_yellow, :honey_dew, :honeydew, :hot_pink, :indian_red, :indigo, :ivory, :khaki, :lavender, :lavender_blush, :lawn_green, :lemon_chiffon, :light_blue, :light_coral, :light_cyan, :light_golden_rod_yellow, :light_goldenrod_yellow, :light_gray, :light_grey, :light_green, :light_pink, :light_salmon, :lightsalmon, :light_sea_green, :light_sky_blue, :light_slate_blue, :light_slate_gray, :light_slate_grey, :light_steel_blue, :lightsteel_blue, :light_yellow, :lime, :lime_green, :linen, :magenta, :maroon, :medium_aqua_marine, :medium_aquamarine, :medium_blue, :medium_orchid, :medium_purple, :medium_sea_green, :medium_slate_blue, :medium_spring_green, :medium_turquoise, :medium_violet_red, :midnight_blue, :mint_cream, :misty_rose, :moccasin, :navajo_white, :navy, :old_lace, :olive, :olive_drab, :olivedrab, :orange, :orange_red, :orchid, :pale_golden_rod, :pale_goldenrod, :pale_green, :pale_turquoise, :pale_violet_red, :papaya_whip, :peach_puff, :peachpuff, :peru, :pink, :plum, :powder_blue, :purple, :red, :rosy_brown, :royal_blue, :saddle_brown, :salmon, :sandy_brown, :sea_green, :sea_shell, :seashell, :sienna, :silver, :sky_blue, :slate_blue, :slate_gray, :slate_grey, :snow, :spring_green, :steel_blue, :tan, :teal, :thistle, :tomato, :turquoise, :violet, :violet_red, :wheat, :white_smoke, :yellow, :yellow_green, :metallic, :white, :black, :gray_scale, :grey_scale]

• open_file(window as Glimmer::LibUI::WindowProxy = ControlProxy::main_window_proxy): returns selected file (String) or nil if cancelled
• open_folder(window as Glimmer::LibUI::WindowProxy = ControlProxy::main_window_proxy): returns selected folder/directory (String) or nil if cancelled
• save_file(window as Glimmer::LibUI::WindowProxy = ControlProxy::main_window_proxy): returns selected file (String) or nil if cancelled

• ControlProxy::control_proxies: returns all instantiated control proxies in the application
• ControlProxy::menu_proxies: returns all instantiated menu proxies in the application
• ControlProxy::image_proxies: returns all instantiated image proxies in the application
• ControlProxy::main_window_proxy: returns the first window proxy instantiated in the application
• ControlProxy#window_proxy: returns the window proxy parent for a control
• ControlProxy#content {...}: re-opens control's content to add more nested controls or properties

The table control must first declare its columns via one of these column keywords (mentioned in Supported Keywords):

• background_color_column: expects color cell values
• button_column: expects String cell values and a nested on_clicked listener that gets triggerd when a button is clicked
• checkbox_column: expects Boolean cell values
• checkbox_text_column: expects dual-element Array of Boolean and String cell values
• checkbox_text_color_column: expects triple-element Array of Boolean, String, and color cell values
• image_column: expects image cell values (produced by image and image_part keywords as per Supported Keywords)
• image_text_column: expects dual-element Array of image and String cell values
• image_text_color_column: expects triple-element Array of image, String, and color cell values
• text_column: expects String cell values
• text_color_column: expects dual-element Array of String and color cell values
• progress_bar_column: expects Integer cell values

Afterwards, it must declare its cell_rows array (Array of Arrays of column cell values) and whether it is editable (Boolean) for all its columns.

Note that the cell_rows property declaration results in "implicit data-binding" between the table control and Array of Arrays (a new innovation) to provide convenience automatic support for:

• Deleting cell rows: Calling Array#delete, Array#delete_at, Array#delete_if, or any filtering/deletion Array method automatically deletes rows in actual table control
• Inserting cell rows: Calling Array#<<, Array#push, Array#prepend, or any insertion/addition Array method automatically inserts rows in actual table control
• Changing cell rows: Calling Array#[]=, Array#map!, or any update Array method automatically updates rows in actual table control

More details about table data-binding can be found in examples/basic_table.rb or other table basic examples and advanced examples.

The table control supports table selection and table sorting automatically as smart defaults, which can also be configured if needed as per the options below.

There are other properties that table supports:

• selection_mode (Symbol) [default: :zero_or_one]: sets selection mode to :one, :zero_or_one, :zero_or_many, or :none
• selection (Integer or Array of Integers): a single Integer row index for :one and :zero_or_one selection modes, or an Array of Integer row indexes if selection mode is :zero_or_many
• header_visible (Boolean): shows or hides column headers
• sortable (Boolean) [default: true]: enables automatic table sorting support
• on_changed {|row, type, row_data| ...}: triggered upon a change to a row that happens outside the table in the model
• on_edited {|row, row_data| ...}: triggered upon a change to a row that happens in the table GUI through editing.
• on_row_clicked {|table, row| }: triggered upon clicking a table row
• on_row_double_clicked {|table, row| }: triggered upon double-clicking a table row
• on_selection_changed {|table, selection, added_selection, removed_selection| }: triggered upon selecting a table row

To handle table sorting manually, the following can be set inside a table column:

• sort_indicator (Symbol): sets sort indicator to ascending or descending with the value being :ascending, :descending, :asc, :desc, :a, or :d
• on_clicked (Proc): this listener is triggered when a table column is clicked

More details about table selection and table sorting can be found in examples/basic_table_selection.rb.

(explicit data-binding supports everything available with implicit data-binding too)

Example (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer

data = [
  ['Lisa Sky', 'lisa@sky.com', '720-523-4329', 'Denver', 'CO'],
  ['Jordan Biggins', 'jordan@biggins.com', '617-528-5399', 'Boston', 'MA'],
  ['Mary Glass', 'mary@glass.com', '847-589-8788', 'Elk Grove Village', 'IL'],
  ['Darren McGrath', 'darren@mcgrath.com', '206-539-9283', 'Seattle', 'WA'],
  ['Melody Hanheimer', 'melody@hanheimer.com', '213-493-8274', 'Los Angeles', 'CA'],
]

window('Contacts', 600, 600) {
  margined true
  
  vertical_box {
    form {
      stretchy false
      
      @name_entry = entry {
        label 'Name'
      }
      
      @email_entry = entry {
        label 'Email'
      }
      
      @phone_entry = entry {
        label 'Phone'
      }
      
      @city_entry = entry {
        label 'City'
      }
      
      @state_entry = entry {
        label 'State'
      }
    }
    
    button('Save Contact') {
      stretchy false
      
      on_clicked do
        new_row = [@name_entry.text, @email_entry.text, @phone_entry.text, @city_entry.text, @state_entry.text]
        if new_row.map(&:to_s).include?('')
          msg_box_error('Validation Error!', 'All fields are required! Please make sure to enter a value for all fields.')
        else
          data << new_row # automatically inserts a row into the table due to implicit data-binding
          @unfiltered_data = data.dup
          @name_entry.text = ''
          @email_entry.text = ''
          @phone_entry.text = ''
          @city_entry.text = ''
          @state_entry.text = ''
        end
      end
    }
    
    search_entry { |se|
      stretchy false
      
      on_changed do
        filter_value = se.text
        @unfiltered_data ||= data.dup
        # Unfilter first to remove any previous filters
        data.replace(@unfiltered_data) # affects table indirectly through implicit data-binding
        # Now, apply filter if entered
        unless filter_value.empty?
          data.filter! do |row_data| # affects table indirectly through implicit data-binding
            row_data.any? do |cell|
              cell.to_s.downcase.include?(filter_value.downcase)
            end
          end
        end
      end
    }
    
    table {
      text_column('Name')
      text_column('Email')
      text_column('Phone')
      text_column('City')
      text_column('State')

      editable true
      cell_rows data # implicit data-binding to raw data Array of Arrays
      
      on_changed do |row, type, row_data|
        puts "Row #{row} #{type}: #{row_data}"
        $stdout.flush # for Windows
      end
      
      on_edited do |row, row_data| # only fires on direct table editing
        puts "Row #{row} edited: #{row_data}"
        $stdout.flush # for Windows
      end
    }
  }
}.show

Mac	Windows	Linux

Learn more by checking out examples.

[EARLY ALPHA FEATURE]

refined_table is a custom control provided exclusively by Glimmer DSL for LibUI that includes filtering and pagination support out of the box and can handle very large amounts of data (e.g. 50,000 rows).

It is currently an early alpha feature, so please test-drive and report issues if you encounter any. And, please keep in mind that the API might undergo big changes.

Options (passed as kwargs hash):

• model_array (Array): array of models for which attributes map to table columns
• filter_query (String): query term to filter table by; AND-matching multiple words against all columns (e.g. John Illinois returns John Doe from Illinois, USA), a double-quoted exact term match against all columns (e.g. "Urbana Champaign" returns only results from the town of "Urbana Champaign"), or a match against specific columns (e.g. first_name:John, "first name":John, first_name:"John Doe", or "first name":"john doe"). You may mix and match different types of filter queries. All matches are case-insensitive. To customize filtering differently, you may set the filter option explained below.
• table_columns (Hash): this maps column types to symbols (e.g. text_column becomes :text) with hash options per column
• table_editable (Boolean) [default: false]: this indicates if all table columns are editable or not.
• per_page (Integer) [default: 10]: number of rows per page
• page (Integer) [default: 1]: initial page displayed
• pagination (Boolean) [default: true]: pagination is enabled (disabling still keeps the filter field)
• visible_page_count (Boolean) [default: false]: shows "of PAGE_COUNT pages" after page entry field
• filter (Lambda) [default: Glimmer::LibUI::CustomControl::RefinedTable::FILTER_DEFAULT]: enables setting custom filter that accepts row_hash (mapping table column names to row values) and query string as arguments, and it is supposed to return true or false for whether to show a row or filter it out.

API:

• refined_model_array (Array): model_array with filtering and pagination applied (useful to grab a table row model by index).
• filtered_model_array (Array): model_array with filtering applied, but without pagination
• table_proxy: control proxy object for the table contained in the refined_table custom control

If the initial model_array has no more than a single page of data, then pagination buttons are hidden (but, the filter field remains).

Example code:

refined_table(
  model_array: contacts,
  table_columns: {
    'Name'  => {button: {on_clicked: ->(row) {puts row}}},
    'Colored Email' => :text_color,
    'Phone' => {text: {editable: true}},
    'City'  => :text,
    'State' => :text,
  },
  table_editable: true, # default value is false
  per_page: 20, # row count per page
  # page: 1, # initial page is 1
  # visible_page_count: true, # page count can be shown if preferred
)

Mac	Windows	Linux

Learn more in the Paginated Refined Table example.

The area control is a canvas-like control for drawing paths that can be used in one of two ways:

• Retained Mode (declaratively via stable shape structures): useful for stable paths that will not change often later on. Simply nest path and figures like rectangle and all drawing logic is generated automatically. Path proxy objects are preserved across redraws assuming there would be relatively few stable paths (mostly for decorative reasons).
• Immediate Mode (semi-declaratively via on_draw listener dynamic shapes): useful for more dynamic paths that will definitely change very often. Open an on_draw listener block that receives an area_draw_params argument and nest path and figures like rectangle and all drawing logic is generated automatically. Path proxy objects are destroyed (thrown-away) at the end of drawing, thus having less memory overhead for drawing thousands of dynamic paths.

Note that when nesting an area directly underneath window (without a layout control like vertical_box), it is automatically reparented with vertical_box in between the window and area since it would not show up on Linux otherwise.

Also, note that Canvas graphics performance is a bit slow today due to the Ruby LibUI binding making Canvas drawing calls with FFI. There is currently work under way to re-implement the Canvas drawing calls with C Native Extensions, which should speed up performance by 10x-100x once fully implemented. Still, if the area control is needed to paint simple or mostly static graphics that do not change much (not updating more than once a second), then current area performance should be more than fast enough for those needs.

Here is an example of a declarative area with a stable path (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer

window('Basic Area', 400, 400) {
  margined true
  
  vertical_box {
    area {
      path { # a stable path is added declaratively
        rectangle(0, 0, 400, 400)
        
        fill r: 102, g: 102, b: 204, a: 1.0
      }
    }
  }
}.show

Mac	Windows	Linux

Here is the same example using a semi-declarative area with on_draw listener that receives a area_draw_params argument and a dynamic path (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer

window('Basic Area', 400, 400) {
  margined true
  
  vertical_box {
    area {
      on_draw do |area_draw_params|
        path { # a dynamic path is added semi-declaratively inside on_draw block
          rectangle(0, 0, 400, 400)
          
          fill r: 102, g: 102, b: 204, a: 1.0
        }
      end
    }
  }
}.show

Check examples/dynamic_area.rb for a more detailed semi-declarative example.

In Retained Mode, you can still generate area shapes dynamically by relying on Content Data-Binding.

require 'glimmer-dsl-libui'

class LineCollection
  attr_accessor :line_count
  
  def initialize
    @line_count = 3
  end
end

class View
  include Glimmer::LibUI::Application
  
  before_body do
    @line_collection = LineCollection.new
  end
  
  body {
    window('Area Shapes - Line', 400, 400) {
      vertical_box {
        button('Generate Lines') {
          stretchy false
          
          on_clicked do
            @line_collection.line_count = rand(3..10)
          end
        }
        area {
          content(@line_collection, :line_count) { # generated dynamically
            point_range = (50..350)
            color_range = (0..255)
            @line_collection.line_count.times do
              line(rand(point_range), rand(point_range), rand(point_range), rand(point_range)) {
                stroke rand(color_range), rand(color_range), rand(color_range), thickness: 3
              }
            end
          }
        }
      }
    }
  }
end

View.launch

scrolling_area(width as Numeric = main_window.width, height as Numeric = main_window.height) is similar to area, but has the following additional methods:

• scroll_to(x as Numeric, y as Numeric, width as Numeric = main_window.width, height as Numeric = main_window.height): scrolls to x/y location with width and height viewport size.
• set_size(width as Numeric, height as Numeric): set size of scrolling area, which must must exceed that of visible viewport in order for scrolling to be enabled.

Mac	Windows	Linux

Check examples/basic_scrolling_area.rb for a more detailed example.

area can have geometric shapes drawn by adding path elements.

To add path shapes under an area, you can do so:

• Explicitly: by adding path under area and nesting shapes (e.g. rectangle) underneath that share the same fill/stroke/transform properties
• Implicitly: by adding shapes directly under area when the shapes have unique fill/stroke/transform properties (Glimmer DSL for LibUI automatically constructs paths as intermediary parents for shapes directly added under area)

path can receive a draw_fill_mode argument that can accept values :winding or :alternate and defaults to :winding.

Available path shapes (that can be nested explicitly under path or implicitly under area directly):

• rectangle(x as Numeric, y as Numeric, width as Numeric, height as Numeric)
• square(x as Numeric, y as Numeric, length as Numeric)
• arc(x_center as Numeric, y_center as Numeric, radius as Numeric, start_angle as Numeric, sweep as Numeric, is_negative as Boolean)
• circle(x_center as Numeric, y_center as Numeric, radius as Numeric)
• line(x as Numeric, y as Numeric, end_x = nil as Numeric, end_y = nil as Numeric): must be placed in a figure if only x/y are specified or have end_x/end_y otherwise if outside of figure (check polyline/polygon alternatives that do not require a figure)
• bezier(x = nil as Numeric, y = nil as Numeric, c1_x as Numeric, c1_y as Numeric, c2_x as Numeric, c2_y as Numeric, end_x as Numeric, end_y as Numeric): must be placed in a figure if x/y are not specified or have x/y as start point otherwise if outside of figure (check polybezier alternative that does not require a figure)
• polygon(point_array as Array of Arrays of Numeric or Array of Numeric): shortcut for a closed figure of lines; can receive points as [[x1, y1], [x2, y2], ...] or [x1, y1, x2, y2, ...]
• polyline(point_array as Array of Arrays of Numeric or Array of Numeric): shortcut for an open figure of lines; can receive points as [[x1, y1], [x2, y2], ...] or [x1, y1, x2, y2, ...]
• polybezier(point_array as Array of Arrays of Numeric or Array of Numeric): shortcut for an open figure of beziers; can receive points as [[start_x1, start_y1], [c1_x2, c1_y2, c2_x2, c2_y2, end_x2, end_y2], [c1_x3, c1_y3, c2_x3, c2_y3, end_x3, end_y3], ...] or [start_x1, start_y1, c1_x2, c1_y2, c2_x2, c2_y2, end_x2, end_y2, c1_x3, c1_y3, c2_x3, c2_y3, end_x3, end_y3, ...]
• figure(x=nil as Numeric, y=nil as Numeric) (composite that can contain other shapes) (can set closed true to connect last point to first point automatically)

Check examples/area_gallery.rb for an overiew of all path shapes.

Mac	Windows	Linux

• ::parameters: returns parameters of a shape class
• #bounding_box: returns Array containing [min_x, min_y, width, height]
• #contain?(*point, outline: false, distance_tolerance: 0): Returns if point ([x, y] Array or args) is inside the shape when outline is false or on the outline when outline is true. distance_tolerance is used when outline is true as a fuzz factor for declaring a point on the outline of the shape (e.g. helps users select a shape from its outline more easily).
• #include?(*point): Returns if point ([x, y] Array or args) is inside the shape when filled (having fill value) or on the outline when stroked (not having fill value yet stroke value only)
• #perfect_shape: returns PerfectShape object matching the libui-ng shape.
• #move_by(x_delta, y_delta) (alias: translate): moves (translates) shape by x,y delta
• #move(x, y): moves (translates) shape to x,y coordinates (in the top-left x,y corner of the shape)
• #min_x: minimum x coordinate of shape (of top-left corner)
• #min_y: minimum y coordinate of shape (of top-left corner)
• #max_x: maximum x coordinate of shape (of bottom-right corner)
• #max_y: maximum y coordinate of shape (of bottom-right corner)
• #center_point (Array of x,y): center point of shape
• #center_x: center x coordinate of shape
• #center_y: center y coordinate of shape

To draw text in an area, you simply nest a text(x, y, width) control directly under area or inside a on_draw listener, and then nest attributed string {[attributes]; string_value} controls underneath it returning an actual String (think of them as the <span> or <p> element in html, which contains a string of text). Alternatively, you can nest attributed string(string_value) {[attributes]} if string_value is a short single-line string. An attributed string value can be changed dynamically via its string property.

text has the following properties:

• default_font:
• align: :left (default), :center, or :right (align currently seems not to work on the Mac)
• x: x coordinate in relation to parent area top-left corner
• y: y coordinate in relation to parent area top-left corner
• width (default: area width - x*2): width of text to display

string has the following properties:

• font: font descriptor hash consisting of :family, :size, :weight ([:minimum, :thin, :ultra_light, :light, :book, :normal, :medium, :semi_bold, :bold, :ultra_bold, :heavy, :ultra_heavy, :maximum]), :italic ([:normal, :oblique, :italic]), and :stretch ([:ultra_condensed, :extra_condensed, :condensed, :semi_condensed, :normal, :semi_expanded, :expanded, :extra_expanded, :ultra_expanded]) key values
• color: rgba, hex, or X11 color
• background: rgba, hex, or X11 color
• underline: one of :none, :single, :double, :suggestion, :color_custom, :color_spelling, :color_grammar, :color_auxiliary
• underline_color: one of :spelling, :grammar, :auxiliary, rgba, hex, or X11 color
• open_type_features: Open Type Features (https://www.microsoft.com/typography/otspec/featuretags.htm) consist of open_type_tags nested in content block, which accept (a, b, c, d, Integer) arguments.
• string: string value (String)

Example (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer

window('area text drawing') {
  area {
    text {
      default_font family: 'Helvetica', size: 12, weight: :normal, italic: :normal, stretch: :normal
        
      string('This ') {
        font size: 20, weight: :bold, italic: :normal, stretch: :normal
        color r: 128, g: 0, b: 0, a: 1
      }
        
      string('is ') {
        font size: 20, weight: :bold, italic: :normal, stretch: :normal
        color r: 0, g: 128, b: 0, a: 1
      }
        
      string('a ') {
        font size: 20, weight: :bold, italic: :normal, stretch: :normal
        color r: 0, g: 0, b: 128, a: 1
      }
        
      string('short ') {
        font size: 20, weight: :bold, italic: :italic, stretch: :normal
        color r: 128, g: 128, b: 0, a: 1
      }
        
      string('attributed ') {
        font size: 20, weight: :bold, italic: :normal, stretch: :normal
        color r: 0, g: 128, b: 128, a: 1
      }
        
      string("string \n\n") {
        font size: 20, weight: :bold, italic: :normal, stretch: :normal
        color r: 128, g: 0, b: 128, a: 1
      }
        
      string {
        font family: 'Georgia', size: 13, weight: :medium, italic: :normal, stretch: :normal
        color r: 0, g: 128, b: 255, a: 1
        background r: 255, g: 255, b: 0, a: 0.5
        underline :single
        underline_color :spelling
        open_type_features {
          open_type_tag 'l', 'i', 'g', 'a', 0
          open_type_tag 'l', 'i', 'g', 'a', 1
        }
        
        "This is a demonstration\n" \
        "of a very long\n" \
        "attributed string\n" \
        "spanning multiple lines\n\n"
      }
    }
  }
}.show

You may checkout examples/basic_draw_text.rb and examples/custom_draw_text.rb for examples of using text inside area.

Mac	Windows	Linux

(ALPHA FEATURE)

libui-ng does not support image rendering outside of table yet. However, Glimmer DSL for LibUI adds a special image(file as String path or web URL, width as Numeric, height as Numeric) custom control that renders an image unto an area pixel by pixel (and when possible to optimize, line by line).

Given that it is very new and is not a libui-ng-native control, please keep these notes in mind:

• It only supports the .png file format.
• libui-ng pixel-by-pixel rendering performance is slow.
• Including an image inside an area on_draw listener improves performance due to not retaining pixel/line data in memory.
• Supplying width and height options greatly improves performance when shrinking image (e.g. image('somefile.png', width: 24, height: 24)). You can also supply one of the two dimensions, and the other one gets calculated automatically while preserving original aspect ratio (e.g. image('somefile.png', height: 24))
• Glimmer DSL for LibUI lets you optionally specify x and y in addition to file, width and height (5 arguments total) to offset image location.

Currently, it is recommended to use image with very small width and height values only (e.g. 24x24).

Setting a transform matrix is supported under image just like it is under path and text inside area.

Example of using image declaratively (you may copy/paste in girb):

Mac	Windows	Linux

require 'glimmer-dsl-libui'

include Glimmer

window('Basic Image', 96, 96) {
  area {
    image(File.expand_path('icons/glimmer.png', __dir__), height: 96) # width is automatically calculated from height while preserving original aspect ratio
#     image(File.expand_path('icons/glimmer.png', __dir__), width: 96, height: 96) # you can specify both width and height options
#     image(File.expand_path('icons/glimmer.png', __dir__), 96, 96) # you can specify width, height as args
#     image(File.expand_path('../icons/glimmer.png', __dir__), 0, 0, 96, 96) # you can specify x, y, width, height args as alternative
#     image(File.expand_path('../icons/glimmer.png', __dir__), x: 0, y: 0, width: 96, height: 96) # you can specify x, y, width, height options as alternative
  }
}.show

Example of better performance via on_draw (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer

window('Basic Image', 96, 96) {
  area {
    on_draw do |area_draw_params|
      image(File.expand_path('icons/glimmer.png', __dir__), 96, 96)
    end
  }
}.show

Example of using image declaratively with explicit properties (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer

window('Basic Image', 96, 96) {
  area {
    image {
      file File.expand_path('icons/glimmer.png', __dir__)
#       x 0 # default
#       y 0 # default
      width 96
      height 96
    }
  }
}.show

Example of better performance via on_draw with explicit properties (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer

window('Basic Image', 96, 96) {
  area {
    on_draw do |area_draw_params|
      image {
        file File.expand_path('icons/glimmer.png', __dir__)
        width 96
        height 96
      }
    end
  }
}.show

If you need to render an image pixel by pixel (e.g. to support a format other than .png) for very exceptional scenarios, you may use this example as a guide, including a line-merge optimization for neighboring horizontal pixels with the same color:

# This is the manual way of rendering an image unto an area control.
# It could come in handy in special situations.
# Otherwise, it is recommended to simply utilize the `image` control that
# can be nested under area or area on_draw listener to automate all this work.

require 'glimmer-dsl-libui'
require 'chunky_png'

include Glimmer

puts 'Parsing image...'; $stdout.flush

f = File.open(File.expand_path('icons/glimmer.png', __dir__))
canvas = ChunkyPNG::Canvas.from_io(f)
f.close
canvas.resample_nearest_neighbor!(96, 96)
data = canvas.to_rgba_stream
width = canvas.width
height = canvas.height
puts "Image width: #{width}"
puts "Image height: #{height}"

puts 'Parsing colors...'; $stdout.flush

color_maps = height.times.map do |y|
  width.times.map do |x|
    r = data[(y*width + x)*4].ord
    g = data[(y*width + x)*4 + 1].ord
    b = data[(y*width + x)*4 + 2].ord
    a = data[(y*width + x)*4 + 3].ord
    {x: x, y: y, color: {r: r, g: g, b: b, a: a}}
  end
end.flatten
puts "#{color_maps.size} pixels to render..."; $stdout.flush

puts 'Parsing shapes...'; $stdout.flush

shape_maps = []
original_color_maps = color_maps.dup
indexed_original_color_maps = Hash[original_color_maps.each_with_index.to_a]
color_maps.each do |color_map|
  index = indexed_original_color_maps[color_map]
  @rectangle_start_x ||= color_map[:x]
  @rectangle_width ||= 1
  if color_map[:x] < width - 1 && color_map[:color] == original_color_maps[index + 1][:color]
    @rectangle_width += 1
  else
    if color_map[:x] > 0 && color_map[:color] == original_color_maps[index - 1][:color]
      shape_maps << {x: @rectangle_start_x, y: color_map[:y], width: @rectangle_width, height: 1, color: color_map[:color]}
    else
      shape_maps << {x: color_map[:x], y: color_map[:y], width: 1, height: 1, color: color_map[:color]}
    end
    @rectangle_width = 1
    @rectangle_start_x = color_map[:x] == width - 1 ? 0 : color_map[:x] + 1
  end
end
puts "#{shape_maps.size} shapes to render..."; $stdout.flush

puts 'Rendering image...'; $stdout.flush

window('Basic Image', 96, 96) {
  area {
    on_draw do |area_draw_params|
      shape_maps.each do |shape_map|
        path {
          rectangle(shape_map[:x], shape_map[:y], shape_map[:width], shape_map[:height])

          fill shape_map[:color]
        }
      end
    end
  }
}.show

One final note is that in Linux, table images grow and shrink with the image size unlike on the Mac where table row heights are constant regardless of image sizes. As such, you may be able to repurpose a table with a single image column and a single row as an image control with more native libui rendering if you are only targeting Linux with your app.

Check out examples/basic_image.rb (all versions) for examples of using image Glimmer custom control.

fill and stroke accept X11 color Symbols/Strings like :skyblue and 'sandybrown' or 6-char hex or 3-char hex-shorthand (as Integer or String with or without 0x prefix)

Available X11 colors can be obtained through Glimmer::LibUI.x11_colors method.

Check Basic Transform example for use of X11 colors.

Check Histogram example for use of hex colors.

The area_draw_params Hash argument for on_draw block is a hash consisting of the following keys:

• :context: the drawing context object
• :area_width: area width
• :area_height: area height
• :clip_x: clip region top-left x coordinate
• :clip_y: clip region top-left y coordinate
• :clip_width: clip region width
• :clip_height: clip region height

In general, it is recommended to use declarative stable paths whenever feasible since they require less code and simpler maintenance. But, in more advanced cases, semi-declarative dynamic paths could be used instead, especially if there are thousands of dynamic paths that need maximum performance and low memory footprint.

area supports a number of keyboard and mouse listeners to enable observing the control for user interaction to execute some logic.

The same listeners can be nested directly under area shapes like rectangle and circle, and Glimmer DSL for LibUI will automatically detect when the mouse lands within those shapes to constrain triggering the listeners by the shape regions.

area supported listeners are:

• on_key_event {|area_key_event| ...}: general catch-all key event (recommend using fine-grained key events below instead)
• on_key_down {|area_key_event| ...}
• on_key_up {|area_key_event| ...}
• on_mouse_event {|area_mouse_event| ...}: general catch-all mouse event (recommend using fine-grained mouse events below instead)
• on_mouse_down {|area_mouse_event| ...}
• on_mouse_up {|area_mouse_event| ...}
• on_mouse_drag_started {|area_mouse_event| ...}
• on_mouse_dragged {|area_mouse_event| ...}
• on_mouse_dropped {|area_mouse_event| ...}
• on_mouse_entered {...}
• on_mouse_exited {...}
• on_mouse_crossed {|left| ...} (NOT RECOMMENDED; it does what on_mouse_entered and on_mouse_exited do by returning a left argument indicating if mouse left area)
• on_drag_broken {...} (NOT RECOMMENDED; varies per platforms; use on_mouse_dropped instead)

The area_mouse_event Hash argument for mouse events that receive it (e.g. on_mouse_up, on_mouse_dragged) consist of the following hash keys:

• :x: mouse x location in relation to area's top-left-corner
• :y: mouse y location in relation to area's top-left-corner
• :area_width: area current width
• :area_height: area current height
• :down: mouse pressed button (e.g. 1 is left button, 3 is right button)
• :up: mouse depressed button (e.g. 1 is left button, 3 is right button)
• :count: count of mouse clicks (e.g. 2 for double-click, 1 for single-click)
• :modifers: Array of Symbols from one of the following: [:command, :shift, :alt, :control]
• :held: mouse held button during dragging (e.g. 1 is left button, 4 is right button)

The area_key_event Hash argument for keyboard events that receive it (e.g. on_key_up, on_key_down) consist of the following hash keys:

• :key: key character (String)
• :key_value (alias: :key_code): key code value (Integer). Useful in rare cases for numeric processing of keys instead of dealing with as :key character String
• :ext_key: non-character extra key (Symbol) from Glimmer::LibUI.enum_symbols(:ext_key) such as :left, :right, :escape, :insert
• :ext_key_value: non-character extra key value (Integer). Useful in rare cases for numeric processing of extra keys instead of dealing with as :ext_key Symbol
• :modifier: modifier key pressed alone (e.g. :shift or :control)
• :modifiers: modifier keys pressed simultaneously with :key, :ext_key, or :modifier
• :up: indicates if key has been released or not (Boolean)

To redraw an area, you may call the #queue_redraw_all method, or simply #redraw.

area has the following Glimmer-added API methods/attributes:

• request_auto_redraw: requests auto redraw upon changes to nested stable path or shapes
• pause_auto_redraw: pause auto redraw upon changes to nested stable path or shapes (useful to avoid too many micro-change redraws, to group all redraws as one after many micro-changes)
• resume_auto_redraw: resume auto redraw upon changes to nested stable path or shapes
• auto_redraw_enabled/auto_redraw_enabled?/auto_redraw_enabled=: an attribute to disable/enable auto redraw on an area upon changes to nested stable path or shapes

A transform matrix can be set on a path by building a matrix(m11 = nil, m12 = nil, m21 = nil, m22 = nil, m31 = nil, m32 = nil) {operations} proxy object and then setting via transform property, or alternatively by building and setting the matrix in one call to transform(m11 = nil, m12 = nil, m21 = nil, m22 = nil, m31 = nil, m32 = nil) {operations} passing it the matrix arguments and/or content operations.

When instantiating a matrix object, it always starts with identity matrix.

Here are the following operations that can be performed in a matrix body:

• identity [alias: set_identity]: resets matrix to identity matrix
• translate(x as Numeric, y as Numeric)
• scale(x_center = 0 as Numeric, y_center = 0 as Numeric, x as Numeric, y as Numeric)
• skew(x = 0 as Numeric, y = 0 as Numeric, x_amount as Numeric, y_amount as Numeric)
• rotate(x = 0 as Numeric, y = 0 as Numeric, degrees as Numeric)

Example of using transform matrix (you may copy/paste in girb):

require 'glimmer-dsl-libui'

include Glimmer

window('Basic Transform', 350, 350) {
  area {
    path {
      square(0, 0, 350)
      
      fill r: 255, g: 255, b: 0
    }
    40.times do |n|
      path {
        square(0, 0, 100)
        
        fill r: [255 - n*5, 0].max, g: [n*5, 255].min, b: 0, a: 0.5
        stroke :black, thickness: 2
        transform {
          skew 0.15, 0.15
          translate 50, 50
          rotate 100, 100, -9 * n
          scale 1.1, 1.1
        }
      }
    end
  }
}.show

Keep in mind that this part could be written differently when there is a need to reuse the matrix:

transform {
  translate 100, 100
  rotate 100, 100, -9 * n
}

Alternatively:

m1 = matrix {
  translate 100, 100
  rotate 100, 100, -9 * n
}
transform m1
# and then reuse m1 elsewhere too

You can set a matrix/transform on area directly to conveniently apply to all nested paths too.

Note that area, path, and nested shapes are all truly declarative, meaning they do not care about the ordering of calls to fill, stroke, and transform. Furthermore, any transform that is applied is reversed at the end of the block, so you never have to worry about the ordering of transform calls among different paths. You simply set a transform on the paths that need it and it is guaranteed to be called before all its content is drawn, and then undone afterwards to avoid affecting later paths. Matrix transform can be set on an entire area too, applying to all nested paths.

If you would like to build a composite shape that contains smaller sub-shapes, which would all get treated as a single unit, you can use the shape (or composite_shape) keyword, and wrap all the sub-shapes within the composite shape.

If you specify the fill, stroke, and transform at the shape level, they will get inherited by all sub-shapes that do not specify values for fill, stroke, or transform (though if they do, they override their parent's value).

When you use the include?(x, y) or contain?(x, y) method on a composite shape, it automatically includes all its aggregated shapes in the inclusion or containment check using the corresponding PerfectShape object.

Example of a cube method-based custom shape built using the composite shape keyword:

require 'glimmer-dsl-libui'

class BasicCompositeShape
  include Glimmer::LibUI::Application
  
  body {
    window {
      title 'Basic Composite Shape'
      content_size 200, 225
    
      @area = area {
        rectangle(0, 0, 200, 225) {
          fill :white
        }
        
        7.times do |n|
          x_location = (rand*125).to_i%200 + (rand*15).to_i
          y_location = (rand*125).to_i%200 + (rand*15).to_i
          shape_color = [rand*125 + 130, rand*125 + 130, rand*125 + 130]
          shape_size = 20+n

          cube(
            location_x: x_location,
            location_y: y_location,
            rectangle_width: shape_size*2,
            rectangle_height: shape_size,
            cube_height: shape_size*2,
            background_color: shape_color,
            line_thickness: 2
          ) { |the_shape|
            on_mouse_up do |area_mouse_event|
              # Change color on mouse up without dragging
              if @drag_shape.nil?
                background_color = [rand(255), rand(255), rand(255)]
                the_shape.fill = background_color
              end
            end
            
            on_mouse_drag_start do |area_mouse_event|
              @drag_shape = the_shape
              @drag_x = area_mouse_event[:x]
              @drag_y = area_mouse_event[:y]
            end
                        
            on_mouse_drag do |area_mouse_event|
              if @drag_shape && @drag_x && @drag_y
                drag_distance_width = area_mouse_event[:x]  - @drag_x
                drag_distance_height = area_mouse_event[:y] - @drag_y
                @drag_shape.x += drag_distance_width
                @drag_shape.y += drag_distance_height
                @drag_x = area_mouse_event[:x]
                @drag_y = area_mouse_event[:y]
              end
            end
            
            on_mouse_drop do |area_mouse_event|
              @drag_shape = nil
              @drag_x = nil
              @drag_y = nil
            end
          }
        end
        
        # this general area on_mouse_drag listener is needed to ensure that dragging a shape
        # outside of its boundaries would still move the dragged shape
        on_mouse_drag do |area_mouse_event|
          if @drag_shape && @drag_x && @drag_y
            drag_distance_width = area_mouse_event[:x]  - @drag_x
            drag_distance_height = area_mouse_event[:y] - @drag_y
            @drag_shape.x += drag_distance_width
            @drag_shape.y += drag_distance_height
            @drag_x = area_mouse_event[:x]
            @drag_y = area_mouse_event[:y]
          end
        end
        
        on_mouse_drop do |area_mouse_event|
          @drag_shape = nil
          @drag_x = nil
          @drag_y = nil
        end
      }
    }
  }
  
  # method-based custom shape using `shape` keyword as a composite shape containing nested shapes
  # that are declared with relative positioning
  def cube(location_x: 0,
           location_y: 0,
           rectangle_width: nil,
           rectangle_height: nil,
           cube_height: nil,
           background_color: :brown,
           line_thickness: 1,
           &content_block)
    default_size = 28
    rectangle_width ||= rectangle_height || cube_height || default_size
    rectangle_height ||= rectangle_width || cube_height || default_size
    cube_height ||= rectangle_width || rectangle_height || default_size
    foreground_color = [0, 0, 0, thickness: line_thickness]
    
    # the shape keyword (alias for composite_shape) enables building a composite shape that is treated as one shape
    # like a cube containing polygons, a polyline, a rectangle, and a line
    # with the fill and stroke colors getting inherited by all children that do not specify them
    shape(location_x, location_y) { |the_shape|
      fill background_color
      stroke foreground_color
    
      bottom = polygon(0, cube_height + rectangle_height / 2.0,
              rectangle_width / 2.0, cube_height,
              rectangle_width, cube_height + rectangle_height / 2.0,
              rectangle_width / 2.0, cube_height + rectangle_height) {
        # inherits fill property from parent shape if not set
        # inherits stroke property from parent shape if not set
      }
      body = rectangle(0, rectangle_height / 2.0, rectangle_width, cube_height) {
        # inherits fill property from parent shape if not set
        # stroke is overridden to ensure a different value from parent
        stroke thickness: 0
      }
      polyline(0, rectangle_height / 2.0 + cube_height,
               0, rectangle_height / 2.0,
               rectangle_width, rectangle_height / 2.0,
               rectangle_width, rectangle_height / 2.0 + cube_height) {
        # inherits stroke property from parent shape if not set
      }
      top = polygon(0, rectangle_height / 2.0,
              rectangle_width / 2.0, 0,
              rectangle_width, rectangle_height / 2.0,
              rectangle_width / 2.0, rectangle_height) {
        # inherits fill property from parent shape if not set
        # inherits stroke property from parent shape if not set
      }
      line(rectangle_width / 2.0, cube_height + rectangle_height,
           rectangle_width / 2.0, rectangle_height) {
        # inherits stroke property from parent shape if not set
      }
      
      content_block&.call(the_shape)
    }
  end
end

BasicCompositeShape.launch
        

If you need to animate area vector graphics, you just have to use the Glimmer::LibUI::timer method along with making changes to shape attributes.

Spinner example that has a fully customizable method-based custom control called spinner, which is destroyed if you click on it (you may copy/paste in girb):

require 'glimmer-dsl-libui'

class SpinnerExample
  include Glimmer
  
  SIZE = 120
  
  def initialize
    create_gui
  end
  
  def launch
    @main_window.show
  end
  
  def create_gui
    @main_window = window {
      title 'Spinner'
      content_size SIZE*2, SIZE*2
      
      horizontal_box {
        padded false
        
        vertical_box {
          padded false
          
          spinner(size: SIZE)
          spinner(size: SIZE, fill_color: [42, 153, 214])
        }
        
        vertical_box {
          padded false
          
          spinner(size: SIZE/2.0, fill_color: :orange)
          spinner(size: SIZE/2.0, fill_color: {x0: 0, y0: 0, x1: SIZE/2.0, y1: SIZE/2.0, stops: [{pos: 0.25, r: 204, g: 102, b: 204}, {pos: 1, r: 2, g: 2, b: 254}]})
          spinner(size: SIZE/2.0, fill_color: :green, unfilled_color: :yellow)
          spinner(size: SIZE/2.0, fill_color: :white, unfilled_color: :gray, background_color: :black)
        }
      }
    }
  end
  
  def spinner(size: 40.0, fill_color: :gray, background_color: :white, unfilled_color: {r: 243, g: 243, b: 243}, donut_percentage: 0.25)
    arc1 = arc2 = nil
    area { |the_area|
      rectangle(0, 0, size, size) {
        fill background_color
      }
      circle(size/2.0, size/2.0, size/2.0) {
        fill fill_color
      }
      arc1 = arc(size/2.0, size/2.0, size/2.0, 0, 180) {
        fill unfilled_color
      }
      arc2 = arc(size/2.0, size/2.0, size/2.0, 90, 180) {
        fill unfilled_color
      }
      circle(size/2.0, size/2.0, (size/2.0)*(1.0 - donut_percentage)) {
        fill background_color
      }
      
      on_mouse_up do
        the_area.destroy
      end
    }.tap do
      Glimmer::LibUI.timer(0.05) do
        delta = 10
        arc1.start_angle += delta
        arc2.start_angle += delta
      end
    end
  end
end

SpinnerExample.new.launch

• horizontal_box, vertical_box, grid, and form controls have padded as true upon instantiation to ensure more user-friendly GUI by default
• group controls have margined as true upon instantiation to ensure more user-friendly GUI by default
• All controls nested under a horizontal_box, vertical_box, and form have stretchy property (fill maximum space) as true by default (passed to box_append/form_append method)
• If an event listener is repeated under a control (e.g. two on_clicked {} listeners under button), it does not overwrite the previous listener, yet it is added to an Array of listeners for the event. Glimmer DSL for LibUI provides multiple-event-listener support unlike LibUI
• window instatiation args can be left off, having the following defaults when unspecified: title as '', width as 190, height as 150, and has_menubar as true)
• window has an on_closing listener by default that quits application upon hitting close button if window is the main window, not a child window (the behavior can be overridden with a manual on_closing implementation that returns integer 1/true for closing and 0/false for remaining open).
• group has title property default to '' if not specified in instantiation args, so it can be instantiated without args with title property specified in nested block (e.g. group {title 'Address'; ...})
• button, checkbox, and label have text default to '' if not specified in instantiation args, so they can be instantiated without args with text property specified in nested block (e.g. button {text 'Greet'; on_clicked {puts 'Hello'}})
• quit_menu_item has an on_clicked listener by default that quits application upon selecting the quit menu item (can be overridden with a manual on_clicked implementation that returns integer 0 for success)
• If an on_closing listener was defined on window and it does not return an integer, default exit behavior is assumed (window.destroy is called followed by LibUI.quit, returning 0).
• If multiple on_closing listeners were added for window, and none return an integer, they are all executed. On the other hand, if one of them returns an integer, it is counted as the final return value and stops the chain of listener execution.
• If an on_clicked listener was defined on quit_menu_item and it does not return an integer, default exit behavior is assumed (quit_menu_item.destroy and main_window.destroy are called followed by LibUI.quit, returning 0).
• If multiple on_clicked listeners were added for quit_menu_item, and none return an integer, they are all executed. On the other hand, if one of them returns an integer, it is counted as the final return value and stops the chain of listener execution.
• All boolean property readers return true or false in Ruby instead of the libui-ng original 0 or 1 in C.
• All boolean property writers accept true/false in addition to 1/0 in Ruby
• All string property readers return a String object in Ruby instead of the libui-ng Fiddle pointer object.
• Automatically allocate font descriptors upon instantiating font_button controls and free them when destroying font_button controls
• Automatically allocate color value pointers upon instantiating color_button controls and free them when destroying color_button controls
• On the Mac, if no menu items were added, an automatic quit_menu_item is added to enable quitting with CTRL+Q
• When destroying a control nested under a horizontal_box or vertical_box, it is automatically deleted from the box's children
• When destroying a control nested under a form, it is automatically deleted from the form's children
• When destroying a control nested under a window or group, it is automatically unset as their child to allow successful destruction
• When destroying a control that has a data-binding to a model attribute, the data-binding observer registration is automatically deregistered
• For date_time_picker, date_picker, and time_picker, make sure time hash values for mon, wday, and yday are 1-based instead of libui-ng original 0-based values, and return dst as Boolean instead of isdst as 1/0
• Smart defaults for grid child properties are left (0), top (0), xspan (1), yspan (1), hexpand (false), halign (:fill), vexpand (false), and valign (:fill)
• The table control automatically constructs required TableModelHandler, TableModel, and TableParams, calculating all their arguments from cell_rows and editable properties (e.g. NumRows) as well as nested columns (e.g. text_column)
• Table model instances are automatically freed from memory after window is destroyed.
• Table cell_rows data has implicit data-binding to table cell values for deletion, insertion, and change (done by diffing cell_rows value before and after change and auto-informing table of deletions [LibUI.table_model_row_deleted], insertions [LibUI.table_model_row_deleted], and changes [LibUI.table_model_row_changed]). When deleting data rows from cell_rows array, then actual rows from the table are automatically deleted. When inserting data rows into cell_rows array, then actual table rows are automatically inserted. When updating data rows in cell_rows array, then actual table rows are automatically updated.
• image instances are automatically freed from memory after window is destroyed.
• image width and height can be left off if it has one image_part only as they default to the same width and height of the image_part
• Automatically provide shifted :key characters in area_key_event provided in area key listeners on_key_event, on_key_down, and on_key_up
• scrolling_area width and height default to main window width and height if not specified.
• scrolling_area #scroll_to 3rd and 4th arguments (width and height) default to main window width and height if not specified.
• area paths are specified declaratively with shapes/figures underneath (e.g. rectangle), and area draw listener is automatically generated
• area path shapes can be added directly under area without declaring path explicitly as a convenient shorthand
• line and bezier automatically start a new figure if placed outside of figure
• Observe figure properties (e.g. rectangle width) for changes and automatically redraw containing area accordingly
• Observe path fill and stroke hashes for changes and automatically redraw containing area accordingly
• Observe text and string properties for changes and automatically redraw containing area accordingly
• All controls are protected from garbage collection until no longer needed (explicitly destroyed), so there is no need to worry about surprises.
• All resources are freed automatically once no longer needed or left to garbage collection.
• When nesting an area directly underneath window (without a layout control like vertical_box), it is automatically reparented with vertical_box in between the window and area since it would not show up on Linux otherwise.
• Colors may be passed in as a hash of :r, :g, :b, :a, or :red, :green, :blue, :alpha, or X11 color like :skyblue, or 6-char hex or 3-char hex (as Integer or String with or without 0x prefix)
• Color alpha value defaults to 1.0 when not specified.