Glimmer DSL for JFX 0.0.1

Glimmer DSL for JFX enables building desktop applications with JavaFX via JRuby.

JavaFX has been Java's next generation technology for a while for desktop application GUI development. Unfortunately, when it divorced itself from its JavaFX Script roots, it became no better than Java Swing in syntax.

Furthermore, the whole stage and scene production metaphor made everything more complicated to get into it for software engineers who encountered it for the first time. After all, desktop developers simply think of windows, not stages or scenes. The metaphor unfortunately pushes software engineers into thinking of low-level details (e.g. nodes) that are not important in developing business desktop applications.

FXML attempted to rectify the situation by making JavaFX more declarative than its Swing-like Java syntax. Unfortunately, XML, like its cousin HTML, brings all the same problems web developers suffer from day-to-day to desktop development, especially multi-language dissonance. That defeated the whole point about desktop development being much simpler and more productive than web development for simple local apps. A tool called Scene Builder attempts to simplify the design of GUI through a visual designer while generating FXML automatically. Unfortunately, it maintains the multi-language dissonance that makes developers lose half the battle before they have even started to meet business goals. And, visual designers are known among desktop development professionals as being just gimmicks that only appeal to desktop development beginners while not really scaling well for bigger apps that benefit more from visual design patterns and componentization than an unproductive mouse operated tool that slows professional desktop developers down (besides, even if such a tool was wanted, it would be better if interested developers built it to generate Glimmer GUI DSL Ruby code instead of FXML to avoid multi-language dissonance). FXML was really just a step back into the wrong direction.

Glimmer DSL for JFX aims to overcome the hurdles of JavaFX by providing a declarative hierarchical alternative to FXML in pure Ruby as one language (no multi-language mixing dissonance), thus supercharging productivity and maintainability in developing JavaFX applications similarly to Glimmer DSL for SWT via:

• Declarative DSL syntax that visually maps to the GUI control hierarchy while still allowing View logic in the same language
• Convention over configuration via smart defaults and automation of low-level details
• Requiring the least amount of syntax possible to build GUI
• Custom control support
• Bidirectional Data-Binding without the complexity of static typing to declaratively wire and automatically synchronize GUI with Business Models
• Scaffolding for new custom components, apps, and gems
• Native-Executable packaging on Mac, Windows, and Linux.

Hello, World!

window {
  title 'Hello, World!'
  
  label('Hello, World!')
}

NOTE: Glimmer DSL for JFX is currently in early alpha mode (incomplete proof-of-concept). If you want it developed faster, then open an issue report. I have completed some GitHub project features much faster before due to issue reports and pull requests. Please help make better by contributing, adopting for small or low risk projects, and providing feedback. It is still an early alpha, so the more feedback and issues you report the better.Please help make better by contributing, adopting for small or low risk projects, and providing feedback. It is still an early alpha, so 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.

• JDK 17 (find at https://www.oracle.com/java/technologies/downloads/#java17)
• RVM on Mac & Linux (not available on Windows)
• JRuby 9.3.1.0 (supporting Ruby 2.6.x syntax) (get via RVM on Mac and Linux by running rvm install jruby-9.2.19.0; On Windows, find at https://www.jruby.org/download)
• JavaFX 17 Runtime SDK (find at https://gluonhq.com/products/javafx/ choosing the right "SDK" for your platform and CPU architecture. Follow environment variable instructions at https://openjfx.io/openjfx-docs/#install-javafx . Specifically, after download, export/set PATH_TO_FX environment variable to path of lib directory in extracted "SDK" directory)

Make sure to download the right JavaFX SDK for your platform and CPU architecture from https://gluonhq.com/products/javafx/ and then set the PATH_TO_FX environment variable to the location of the lib directory in the extracted SDK directory.

Run this command to install directly:

gem install glimmer-dsl-jfx -v0.0.1

Add the following to Gemfile:

gem 'glimmer-dsl-jfx', '0.0.1'

And, then run:

bundle

Simply require the library and mixin the Glimmer module to utilize the Glimmer GUI DSL for JFX:

require 'glimmer-dsl-jfx'

include Glimmer

window {
  title 'Hello, World!'
  
  label('Hello, World!')
}

For actual application development outside of simple demos, mixin the Glimmer module into a custom Ruby application class instead:

require 'glimmer-dsl-jfx'

class SomeApplication
  include Glimmer

  def launch
    window {
      title 'Hello, World!'
      
      label('Hello, World!')
    }
  end
end

SomeApplication.new.launch

The Glimmer GUI DSL enables development of desktop graphical user interfaces in a manner similar to HTML, but in one language, Ruby, thus avoiding the multi-language separation dissonance encountered on the web, especially given that Ruby looping/conditional constructs do not need scriptlets to be added around View code. This makes desktop development extremely productive.

1 - Keywords

Always start with window, which simplifies/replaces both the Stage and Scene concepts, having both their properties. Additionally, window removes the need to extend Application and worry about receiving the primary Stage before being able to set the Scene and add controls.

Inside window, you may declare any JavaFX control with its keyword, which is the underscored version of the class name. For example, label is the keyword for javafx.scene.control.Label

Examples:

v_box
label
button

2 - Arguments

You may pass any arguments that a JavaFX control constructor accepts to its Glimmer keyword.

Example (Label and Button have a constructor signature that accepts a string representing the text property):

label('Full Name')
button('Submit Form')

The recommended style is to always wrap arguments with parentheses for control keywords.

3 - Content Block

You may pass a content block to any JavaFX control keyword, which contains properties and/or nested controls.

Example:

window {
  title 'Hello, Window!'
  width 320
  height 240

  v_box {
    label('Hello, Label!')
    button('Hello, Button!')
  }
}

The recommended style for the content block is always curly braces {} to denote as View nesting code different from looping/conditional logic, which utilizes do;end instead.

Property arguments never have parentheses.

4 - Listeners

You may declare listeners with their on_-prefixed event method name as found in the JavaFX Javadoc. For example: on_action, on_key_pressed, on_key_released, on_key_typed, on_mouse_clicked, and on_mouse_moved.

For example, Button has an onAction method. In Glimmer, you simply underscore that:

window {
  title 'Hello, Button!'

  button('Click') { |b|
    on_action do
      b.text = 'Clicked'
    end
  }
}

The recommended style for listeners is always a do; end block.

5 - Component Proxy & Methods

When utilizing the Glimmer GUI DSL, you get back proxy objects that wrap JavaFX Javadoc controls. To access the original control wrapped by the proxy object, you may call the #jfx method.

Furthermore, you may invoke any method available on the control indirectly on the proxy object, like the #text method on label.

label1 = label('Full Name')
label1.text # same as label1.jfx.text

6 - Observe Model Attributes

In Smalltalk-MVC (Model View Controller Architectural Pattern), the View is an active View that observes the Model for changes and updates itself.

This can be achieved with the Glimmer GUI DSL using the observe keyword, which takes a model (any object, including self) and attribute Symbol or String expression (e.g. :count or 'address.street').

The model is automatically enhanced as an Glimmer::DataBinding::ObservableModel / Glimmer::DataBinding::ObservableHash / Glimmer::DataBinding::ObservableArray depending on its type to support notifying observers of attribute changes (when performed using the attribute writer, which automatically calls added method notify_observers(attribute))

Note that it is usually recommended to observe external model objects (not self), but self is OK in very simple cases or presentation-related attributes only.

Example:

require 'glimmer-dsl-jfx'

class Counter
  attr_accessor :count

  def initialize
    self.count = 0
  end
end

class HelloButton
  include Glimmer
  
  def initialize
    @counter = Counter.new

    observe(@counter, :count) do |new_count|
      @button.text = "Click To Increment: #{new_count}"
    end
  end
  
  def launch
    window {
      title 'Hello, Button!'
      
      @button = button('Click To Increment: 0') {
        on_action do
          @counter.count += 1
        end
      }
    }
  end
end

HelloButton.new.launch

• window automatically builds a primary Stage object, sets Stage properties and sets a Scene in primary stage.

You can run the girb command (bin/girb if you cloned the project locally):

girb

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

Run with gem installed:

jruby -r glimmer-dsl-jfx -e "require 'samples/hello/hello_world'"

Or run from locally cloned project directory:

jruby -r ./lib/glimmer-dsl-jfx samples/hello/hello_world.rb

samples/hello/hello_world.rb:

require 'glimmer-dsl-jfx'

include Glimmer

window {
  title 'Hello, World!'
  
  label('Hello, World!')
}

Run with gem installed:

jruby -r glimmer-dsl-jfx -e "require 'samples/hello/hello_button'"

Or run from locally cloned project directory:

jruby -r ./lib/glimmer-dsl-jfx samples/hello/hello_button.rb

Version 1 (without model) - samples/hello/hello_button.rb:

require 'glimmer-dsl-jfx'

include Glimmer

window {
  title 'Hello, Button!'
  
  @button = button('Click To Increment: 0') {
    on_action do
      button_text_match = @button.text.match(/([^0-9]+)(\d+)$/)
      count = button_text_match[2].to_i + 1
      @button.text = "#{button_text_match[1]}#{count}"
    end
  }
}

Version 2 (with model) - samples/hello/hello_button2.rb:

require 'glimmer-dsl-jfx'

class Counter
  attr_accessor :count

  def initialize
    self.count = 0
  end
end

class HelloButton
  include Glimmer
  
  def initialize
    @counter = Counter.new
  end
  
  def launch
    window {
      title 'Hello, Button!'
      
      @button = button('Click To Increment: 0') {
        on_action do
          @counter.count += 1
          @button.text = "Click To Increment: #{new_count}"
        end
      }
    }
  end
end

HelloButton.new.launch

This sample is not included in the Ruby gem.

Run from locally cloned project directory:

jruby -r ./lib/glimmer-dsl-jfx samples/hello/hello_button.rb

samples/hello/hello_shapes.rb:

require 'glimmer-dsl-jfx'

include Glimmer

window {
  title 'Hello, Shapes!'
  width 400
  height 400
  
  pane {
    arc(85, 85, 45, 45, 30, 230) {
      type ArcType::OPEN
      fill Paint.value_of('#ff0000')
      stroke Paint.value_of('#0080ff')
      stroke_width 3
    }

    arc(85, 185, 45, 45, 30, 230) {
      type ArcType::CHORD
      fill Paint.value_of('#ff0000')
      stroke Paint.value_of('#0080ff')
      stroke_width 3
    }

    arc(85, 285, 45, 45, 30, 230) {
      type ArcType::ROUND
      fill Paint.value_of('#ff0000')
      stroke Paint.value_of('#0080ff')
      stroke_width 3
    }

    rectangle(140, 40, 180, 90) {
      fill Paint.value_of('#ffff00')
      stroke Paint.value_of('#ff0000')
      stroke_width 3
    }

    rectangle(140, 140, 180, 90) {
      arc_width 60
      arc_height 40
      fill Paint.value_of('#ffff00')
      stroke Paint.value_of('#ff0000')
      stroke_width 3
    }

    ellipse(230, 285, 90, 45) {
      fill Paint.value_of('#ffff00')
      stroke Paint.value_of('#ff0000')
      stroke_width 3
    }

    line(180, 60, 280, 110) {
      stroke Paint.value_of('#ff0000')
      stroke_width 3
    }

    quad_curve(170, 60, 180, 90, 220, 100) {
      fill Paint.value_of('#ffff00')
      stroke Paint.value_of('#00ff00')
      stroke_width 3
    }

    cubic_curve(190, 60, 240, 40, 220, 80, 260, 70) {
      fill Paint.value_of('#ffff00')
      stroke Paint.value_of('#0000ff')
      stroke_width 3
    }
  }
}

• OpenJFX Website: https://openjfx.io/
• OpenJFX Install Instructions: https://openjfx.io/openjfx-docs/#install-javafx
• Oracle JavaFX Javadoc: https://www.javadoc.io/doc/org.openjfx/javafx-base/17.0.1/index.html

Glimmer Process

If you encounter issues that are not reported, discover missing features that are not mentioned in TODO.md, or think up better ways to use JavaFX than what is possible with Glimmer DSL for JFX, you may submit an issue or pull request on GitHub. In the meantime while waiting for a fix, you may try older gem versions of Glimmer DSL for JFX in case you find one that does not have the issue and actually works.

If you need live help, try to

These features have been planned or suggested. You might see them in a future version of Glimmer DSL for JFX. You are welcome to contribute more feature suggestions.

TODO.md

CHANGELOG.md

• Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.
• Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.
• Fork the project.
• Start a feature/bugfix branch.
• Commit and push until you are happy with your contribution.
• Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
• Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

• Andy Maleh (Founder)

Click here to view contributor commits.

MIT

Copyright (c) 2021 Andy Maleh.

--

Built for Glimmer (DSL Framework).