Glimmer DSL for Tk 0.0.63

require 'glimmer-dsl-tk'

include Glimmer

root {
  title 'Hello, World!'
  
  label {
    text 'Hello, World!'
  }
}.open

root = TkRoot.new
root.title = 'Hello, Notebook!'

notebook = ::Tk::Tile::Notebook.new(root).grid

tab1 = ::Tk::Tile::Frame.new(notebook).grid
notebook.add tab1, text: 'English'
label1 = ::Tk::Tile::Label.new(tab1).grid
label1.text = 'Hello, World!'

tab2 = ::Tk::Tile::Frame.new(notebook).grid
notebook.add tab2, text: 'French'
label2 = ::Tk::Tile::Label.new(tab2).grid
label2.text = 'Bonjour, Univers!'

root.bind('KeyPress') do |event|
  case event.keysym
  when 'e', 'E'
    notebook.select(0)
  when 'f', 'F'
    notebook.select(1)
  end
end

root.mainloop

root {
  title 'Hello, Notebook!'
   
  @notebook = notebook {
    frame(text: 'English') {
      label {
        text 'Hello, World!'
      }
    }
     
    frame(text: 'French') {
      label {
        text 'Bonjour, Univers!'
      }
    }
  }
  
  on('KeyPress') do |event|
    case event.keysym
    when 'e', 'E'
      @notebook.select(0)
    when 'f', 'F'
      @notebook.select(1)
    end
  end
}.open

    textarea_yscrollbar = y_scrollbar {
      grid row:0, column:1
    }

    textarea = text {
      grid row:0, column:0, column_weight: 0
      wrap "word"
      yscrollbar textarea_yscrollbar
    }

    textarea_xscrollbar = x_scrollbar {
      grid row:1, column:0, column_span: 2, row_weight: 0
    }

    textarea_yscrollbar = y_scrollbar {
      grid row:0, column:1
    }

    textarea = text {
      grid row:0, column:0, column_weight: 0
      xscrollbar textarea_xscrollbar
      yscrollbar textarea_yscrollbar
    }

root {
  title 'Title'
  icon_photo 'icons/glimmer.png'
}.open

root {
  title 'Title'
  icon_photo TkPhotoImage.new(file: 'icons/glimmer.png')
}.open

Tk.tk_call("::tk::unsupported::MacWindowStyle", "style", tk_toplevel_widget, mac_class, mac_attribute_list)

        label {
          grid column: 0, row: 2, sticky: 'w'
          text 'Year of Birth: '
        }
        entry {
          grid column: 1, row: 2
          width 15
          text <=> [@contact, :year_of_birth]
        }

  label {
    text <= [person, :country]
  }

  combobox {
    readonly true # this applies to text editing only (item selection still triggers a write to model)
    text <=> [person, :country]
  }

  list {
    selectmode 'browse'
    text <=> [person, :country]
  }

  list {
    text <=> [person, :provinces]
  }

  entry {
    text <=> [person, :country]
  }

  text {
    value <=> [person, :biography]
  }

  spinbox {
    orient 'horizontal' # can be 'vertical' too
    length 200
    from 0.0
    to 100.0
    variable <=> [person, :age, on_write: ->(val) {val.to_i}]
  }

progressbar {
  orient 'horizontal' # can be vertical too
  length 200
  mode 'determinate'
  maximum 100
  value <= [worker, :progress_value]
}

  spinbox {
    from 1.0 # minimum value
    to 150.0 # maximum value
    increment 5.0 # increment on up and down
    format '%0.2f'
    text <=> [person, :country]
  }

  checkbutton {
    variable <=> [person, :adult]
  }

  radiobutton {
    text 'Male'
    variable <=> [@person, :male]
  }
  
  radiobutton {
    text 'Female'
    variable <=> [@person, :female]
  }

  button {
    text "Reset Selection"
    
    command {
      person.reset_country
    }
  }

  button {
    text "Reset Selection"
    
    on('command') do
      person.reset_country
    end
  }

require 'glimmer-dsl-tk'
require 'facets'
require 'fileutils'

class MetaSample
  include Glimmer
  
  attr_accessor :selected_sample_index
  
  def initialize
    @selected_sample_index = 0
  end
  
  def samples
    if @samples.nil?
      sample_files = Dir.glob(File.join(File.expand_path('../hello', __dir__), '**', 'hello_*.rb'))
      sample_file_names = sample_files.map { |f| File.basename(f, '.rb') }
      sample_file_names = sample_file_names.reject { |f| f == 'meta_sample' || f.match(/\d$/) }
      @samples = sample_file_names.map { |f| f.underscore.titlecase }
    end
    @samples
  end
  
  def file_path_for(sample)
    File.join(File.expand_path('../hello', __dir__), "#{sample.underscore}.rb")
  end
  
  def glimmer_dsl_tk_file
    File.expand_path('../../lib/glimmer-dsl-tk', __dir__)
  end
  
  def selected_sample
    samples[@selected_sample_index]
  end
  
  def run_sample(sample)
    Thread.new do
      command = "ruby -r #{glimmer_dsl_tk_file} #{sample} 2>&1"
      result = ''
      IO.popen(command) do |f|
        f.each_line do |line|
          result << line
          puts line
          $stdout.flush
        end
      end
      ::Tk.after(100) do
        message_box(parent: @root, title: 'Error Running Sample', message: result) if result.downcase.include?('error')
      end
    end
  end
  
  def launch
    @root = root {
      title 'Glimmer Meta-Sample'
      width 1280
      height 720
      
      frame {
        grid row: 0, column: 0, column_weight: 0, row_weight: 1
        
        samples.each_with_index do |sample, index|
          radiobutton {
            text sample
            variable <=> [self, :selected_sample_index, on_write: ->(v) {v ? index : selected_sample_index}, on_read: ->(v) {v == index}]
            
            on('command') do
              @selected_sample_index = index
              @code_text.value = File.read(file_path_for(selected_sample))
            end
          }
        end
        
        frame {
          button {
            grid row: 0, column: 0
            text 'Launch'
            
            on('command') do
              begin
                parent_dir = File.join(Dir.home, '.glimmer-dsl-tk', 'samples', 'hello')
                FileUtils.mkdir_p(parent_dir)
                sample_file = File.join(parent_dir, "#{selected_sample.underscore}.rb")
                File.write(sample_file, @code_text.value)
                FileUtils.cp_r(File.expand_path('../../icons', __dir__), File.dirname(File.dirname(parent_dir)))
                FileUtils.cp_r(File.expand_path('../hello/images', __dir__), parent_dir)
                sample_namespace_directory = File.expand_path("../hello/#{selected_sample.underscore}", __dir__)
                FileUtils.cp_r(sample_namespace_directory, parent_dir) if Dir.exist?(sample_namespace_directory)
                run_sample(sample_file)
              rescue => e
                puts e.full_message
                puts 'Unable to write code changes! Running original sample...'
                run_sample(file_path_for(selected_sample))
              end
            end
          }
          button {
            grid row: 0, column: 1
            text 'Reset'
            
            on('command') do
              @code_text.value = File.read(file_path_for(selected_sample))
            end
          }
        }
      }
      
      @code_text = text {
        grid row: 0, column: 1, column_weight: 1
        value File.read(file_path_for(selected_sample))
      }
    }
    @root.open
  end
end

MetaSample.new.launch

require 'glimmer-dsl-tk'

include Glimmer

root {
  title 'Hello, World!'
  
  label {
    text 'Hello, World!'
  }
}.open

require 'glimmer-dsl-tk'

class HelloButton
  include Glimmer
  
  attr_accessor :count
  
  def initialize
    @count = 0
  end
  
  def launch
    root {
      title 'Hello, Button!'
      
      frame {
        grid row: 0, column: 0
        
        label {
          grid pady: 15
          text 'Text Button'
        }
        
        button { |b|
          text <= [self, :count, on_read: ->(value) { "Click To Increment: #{value}  " }]
          default 'active'
          focus true
          
          on('command') do
            self.count += 1
          end
        }
      }
        
      frame {
        grid row: 0, column: 1
        
        label {
          grid pady: 15
          text 'Image Button'
        }
        
        button {
          image File.expand_path('../../icons/glimmer.png', __dir__), subsample: 5
          
          on('command') do
            message_box(title: 'Image Button', message: 'Image Button Clicked!')
          end
        }
      }
      
      frame {
        grid row: 0, column: 2
        
        label {
          grid pady: 15
          text 'Text Image Buttons'
        }
        
        ['center', 'top', 'bottom', 'left', 'right'].each do |compound_option|
          button {
            image File.expand_path('../../icons/glimmer.png', __dir__), subsample: 5
            text "#{compound_option.capitalize} Image"
            compound compound_option
            
            on('command') do
              message_box(title: 'Text Image Button', message: 'Text Image Button Clicked!', detail: "(#{compound_option})")
            end
          }
        end
      }
    }.open
  end
end

HelloButton.new.launch

require 'glimmer-dsl-tk'

class HelloCheckbutton
  class Person
    attr_accessor :skiing, :snowboarding, :snowmobiling, :snowshoeing, :snow_activities, :snow_activities_alternate
    
    def initialize
      reset_activities!
      individual_observer = Glimmer::DataBinding::Observer.proc do
        unless @updating_group
          @updating_individual = true
          if skiing && snowboarding && snowmobiling && snowshoeing
            self.snow_activities = true
            self.snow_activities_alternate = false
          elsif skiing || snowboarding || snowmobiling || snowshoeing
            self.snow_activities = true
            self.snow_activities_alternate = true
          else
            self.snow_activities = false
            self.snow_activities_alternate = false
          end
          @updating_individual = false
        end
      end
      individual_observer.observe(self, :skiing)
      individual_observer.observe(self, :snowboarding)
      individual_observer.observe(self, :snowmobiling)
      individual_observer.observe(self, :snowshoeing)
      
      group_observer = Glimmer::DataBinding::Observer.proc do
        unless @updating_individual
          @updating_group = true
          self.skiing = self.snow_activities
          self.snowboarding = self.snow_activities
          self.snowmobiling = self.snow_activities
          self.snowshoeing = self.snow_activities
          @updating_group = false
        end
      end
      group_observer.observe(self, :snow_activities)
    end
    
    def reset_activities!
      self.snow_activities = true
      self.snow_activities_alternate = true
      self.skiing = false
      self.snowboarding = true
      self.snowmobiling = false
      self.snowshoeing = false
    end
  end
  
  include Glimmer
  
  def initialize
    @person = Person.new
  end
  
  def launch
    root {
      title 'Hello, Checkbutton!'
      background '#ececec' if OS.mac?
      
      label {
        text 'Check all snow activities you are interested in:'
        font 'caption'
      }
      
      frame {
        checkbutton {
          text 'Snow Activities'
          variable <=> [@person, :snow_activities]
          alternate <=> [@person, :snow_activities_alternate] # binds half-checked state
        }
        
        frame {
          checkbutton {
            text 'Skiing'
            variable <=> [@person, :skiing]
          }
          
          checkbutton {
            text 'Snowboarding'
            variable <=> [@person, :snowboarding]
          }
          
          checkbutton {
            text 'Snowmobiling'
            variable <=> [@person, :snowmobiling]
          }
          
          checkbutton {
            text 'Snowshoeing'
            variable <=> [@person, :snowshoeing]
          }
        }
      }
      
      button {
        text 'Reset Activities'
        
        command do
          @person.reset_activities!
        end
      }
    }.open
  end
end

HelloCheckbutton.new.launch

require 'glimmer-dsl-tk'

class HelloRadiobutton
  class Person
    attr_accessor :male, :female, :child, :teen, :adult, :senior
    
    def initialize
      reset!
    end
    
    def reset!
      self.male = true
      self.female = nil
      self.child = nil
      self.teen = nil
      self.adult = true
      self.senior = nil
    end
  end
  
  include Glimmer
  
  def initialize
    @person = Person.new
  end
  
  def launch
    root {
      title 'Hello, Radio!'
      background '#ececec' if OS.mac?
      
      label {
        text 'Gender:'
        font 'caption'
      }
      
      frame {
        radiobutton {
          text 'Male'
          variable <=> [@person, :male]
        }
        
        radiobutton {
          text 'Female'
          variable <=> [@person, :female]
        }
      }
      
      label {
        text 'Age Group:'
        font 'caption'
      }
      
      frame {
        radiobutton {
          text 'Child'
          variable <=> [@person, :child]
        }

        radiobutton {
          text 'Teen'
          variable <=> [@person, :teen]
        }

        radiobutton {
          text 'Adult'
          variable <=> [@person, :adult]
        }

        radiobutton {
          text 'Senior'
          variable <=> [@person, :senior]
        }
      }
      
      button {
        text 'Reset'
        
        command do
          @person.reset!
        end
      }
    }.open
  end
end

HelloRadiobutton.new.launch

require 'glimmer-dsl-tk'

class HelloFrame
  include Glimmer
  
  def launch
    root {
      title 'Hello, Frame!'
      
      frame { # frame simply contains widgets for visual organization via a layout
        relief 'sunken'
        
        label {
          grid row: 0, column: 0, columnspan: 4, padx: 5, pady: 5
          text 'Enter Your Full Name'
          font 'caption'
          anchor 'center'
        }

        label {
          grid row: 1, column: 0, padx: 5
          text "First Name:"
        }
        
        entry {
          grid row: 1, column: 1, padx: 5
        }
        
        label {
          grid row: 2, column: 0, padx: 5
          text "Last Name:"
        }
        
        entry {
          grid row: 2, column: 1, padx: 5
        }
      }
      
      frame { # an empty frame can specify width and height
        grid padx: 7, pady: 7
        width 200
        height 100
        borderwidth 3
        relief 'sunken'
      }
    }.open
  end
end

HelloFrame.new.launch

require 'glimmer-dsl-tk'

include Glimmer

root { |r|
  title 'Hello, Root!'
  icon_photo File.expand_path('../../icons/glimmer.png', __dir__)
  width 400
  height 200
  x -150
  y 300
  resizable true # same as `resizable true, true`, meaning cannot resize horizontally and vertically
  minsize 200, 100
  maxsize 600, 400
  background 'lightgrey'
  alpha 0.85 # on the mac, you can set `transparent true` as well
  topmost true
  
  on('OPEN_WINDOW') do # custom event that runs right after Tk.mainloop
    message_box(parent: r, title: 'Hi', message: 'Hi')
  end
  
  on('DELETE_WINDOW') do |event| # alias for WM_DELETE_WINDOW protocol event
    message_box(parent: r, title: 'Bye', message: 'Bye')
    exit(0)
  end
}.open

require 'glimmer-dsl-tk'

include Glimmer

def toplevel_content
  frame {
    label {
      text "This is a fully custom toplevel, meaning you can add any widgets here!\nYou can press the ESCAPE button on the keyboard to close."
    }
    separator
    checkbutton {
      text 'This is a checkbutton'
    }
    radiobutton {
      text 'This is a radiobutton'
    }
  }
end

root { |root_window|
  title 'Hello, Toplevel!'
  
  button {
    text 'Nested Window'
    
    on('command') do
      toplevel(root_window) {
        title 'Custom Window'
        escapable true
        x 150
        y 180
        width 500
        height 200
        minsize 500, 100
        maxsize 1000, 300
          
        toplevel_content
      }
    end
  }
  
  button {
    text 'Transparent Window'
    
    on('command') do
      toplevel(root_window) {
        title 'Transparent Window'
        escapable true
        alpha 0.85
        width 250
        height 100
        resizable false, false # not resizable horizontally or vertically
          
        frame {
          label {
            text "This is a transparent window\nYou can hit ESCAPE to close."
            anchor 'center'
          }
        }
      }
    end
  }
  
  button {
    text 'Fullscreen Window'
    
    on('command') do
      toplevel(root_window) {
        title 'Fullscreen Window'
        escapable true
        fullscreen true
          
        frame {
          label {
            text "This is a fullscreen window\nYou can hit ESCAPE to close."
            anchor 'center'
          }
        }
      }
    end
  }
  
  if OS.mac?
    # Mac has special support for mac styles in Tk `toplevel`
    # `mac_style` first argument (`mac_class`) and second argument (`mac_attribute_list`) can be chosen from this page: https://wiki.tcl-lang.org/page/MacWindowStyle
    
    button {
      text 'Mac Plain (No-Button-Modeless) Window'
      
      on('command') do
        toplevel(root_window) { |t|
          title 'Mac Plain (No-Button-Modeless) Window'
          escapable true
          mac_style 'plain'
          
          toplevel_content
        }
      end
    }
    
    button {
      text 'Mac Floating (Close-Button-Modeless) Window'
      
      on('command') do
        toplevel(root_window) { |t|
          title 'Mac Floating (Close-Button-Modeless) Window'
          escapable true
          mac_style 'floating'
          
          toplevel_content
        }
      end
    }
    
    button {
      text 'Mac Document (All-Button-Modeless) Window'
      
      on('command') do
        toplevel(root_window) { |t|
          title 'Mac Document (All-Button-Modeless) Window'
          escapable true
          mac_style 'document'
          
          toplevel_content
        }
      end
    }
    
    button {
      text 'Mac Utility (Close-Button-Modal) Dialog'
      
      on('command') do
        toplevel(root_window) { |t|
          title 'Mac Utility (Close-Button-Modal) Dialog'
          escapable true
          mac_style 'utility'
          
          toplevel_content
        }
      end
    }
    
    button {
      text 'Mac Utility with Attribute List (All-Button-Modal) Dialog'
      
      on('command') do
        toplevel(root_window) { |t|
          title 'Mac Utility with Attribute List (All-Button-Modal) Dialog'
          escapable true
          mac_style 'utility', 'closeBox collapseBox resizable horizontalZoom verticalZoom sideTitlebar'
          
          toplevel_content
        }
      end
    }
  end
}.open

require 'glimmer-dsl-tk'

class HelloNotebook
  include Glimmer
  
  def launch
    root {
      title 'Hello, Notebook!'
       
      notebook {
        frame(text: 'English') {
          label {
            text 'Hello, World!'
          }
        }
         
        frame(text: 'French') {
          label {
            text 'Bonjour, Univers!'
          }
        }
      }
    }.open
  end
end

HelloNotebook.new.launch

require 'glimmer-dsl-tk'

class HelloLabel
  include Glimmer
  
  LABEL_FONTS = ['default', 'text', 'fixed', 'menu', 'heading', 'caption', 'small_caption', 'icon', 'tooltip']
  LABEL_RELIEFS = ['flat', 'raised', 'sunken', 'solid', 'ridge', 'groove']
  
  def launch
    root {
      title 'Hello, Label!'
      
      notebook {
        frame(text: 'left-aligned') {
          3.times do |n|
            label {
              text "Field #{n + 1} / default font / flat relief"
              width 60
              anchor 'w'
            }
          end
        }
        
        frame(text: 'centered') {
          9.times do |n|
            label {
              text "Field #{n + 1} / fixed font / raised relief"
              width 80
              anchor 'center'
              font 'fixed'
              relief 'raised'
            }
          end
        }
        
        frame(text: 'right-aligned') {
          9.times do |n|
            label {
              text "Field #{n + 1} / small_caption font / ridge relief"
              width 80
              anchor 'e'
              font 'small_caption'
              relief 'ridge'
            }
          end
        }
        
        frame(text: 'justified') {
          label {
            text <<~MULTI_LINE_STRING
              This is a very long paragraph that spans multiple lines. It looks better and
              is easier to read when justified. In fact, this is how to make it look like a
              new paper column. That results in professional looking text. Magazines use the
              same sort of justified text. Word processors also support justified text. In
              fact, this is how text is made for news papers and magainzes, and then published
              in paper form and digitally.
            MULTI_LINE_STRING
            width 60
            anchor 'center'
            justify 'center' # other options are: 'left' and 'right'
            font 'caption' # other options are: 'default', 'text', 'fixed', 'menu', 'heading', 'small_caption', 'icon', 'tooltip'
            foreground 'blue'
            relief 'sunken' # other options are: 'flat' (default), 'raised', 'solid', 'ridge', 'groove'
          }
        }
        
        frame(text: 'images') {
          ['denmark', 'finland', 'norway'].each do |image_name|
            label {
              image File.expand_path("images/#{image_name}.png", __dir__)
            }
          end
        }
        
        frame(text: 'background images') {
          ['italy', 'france', 'mexico'].each do |image_name|
            label {
              text image_name.capitalize
              image File.expand_path("images/#{image_name}.png", __dir__)
              compound 'center'
            }
          end
        }
      }
    }.open
  end
end

HelloLabel.new.launch

root { |r|
  title 'Hello, Message Box!'
  
  frame {
    button {
      text 'Please Click To Win a Surprise'
      
      command {
        # specifying parent ensures dialog shows up centered on top of window (instead of centered in display monitor)
        @result_label.text = message_box(parent: r, title: 'Surprise', message: "Congratulations!\n\nYou won $1,000,000!") # type: 'ok' by default
      }
    }
    
    button {
      text 'Download Software Update'
      
      command {
        @result_label.text = message_box(type: 'okcancel', title: 'Software Update', message: "We will begin to download software update.")
      }
    }
    
    button {
      text 'Format Hard Drive'
      
      command {
        @result_label.text = message_box(type: 'yesno', icon: 'question', title: 'Format', message: "Would you like to format your hard drive?")
      }
    }
    
    button {
      text 'Submit Application'
      
      command {
        @result_label.text = message_box(type: 'yesnocancel', icon: 'question', title: 'Application', message: "Would you like to review application before submitting?")
      }
    }
    
    button {
      text 'Play Video'
      
      command {
        @result_label.text = message_box(type: 'retrycancel', icon: 'error', title: 'Video Replay', message: "Video has failed to play. Would you like to retry?")
      }
    }
    
    button {
      text 'Installation Completed'
      
      command {
        @result_label.text = message_box(type: 'abortretryignore', icon: 'warning', default: 'ignore', title: 'Failed To Install Extra Utilities', message: "Installation is complete, but extra utilities have failed to install. Would you like to retry installing extra utilities?", detail: 'Encountered network error in downloading extra utilities, resulting in failure to install them')
      }
    }
  }
  
  frame {
    label {
      grid row: 0, column: 0
      text 'Result:'
    }
    
    @result_label = label {
      grid row: 0, column: 1
    }
  }
}.open

# ... more code precedes
root {
  title 'Hello, Combobox!'
  
  combobox {
    readonly true # this applies to text editing only (item selection still triggers a write to model)
    text <=> [person, :country]
  }
  
  button {
    text "Reset Selection"
    command {
      person.reset_country
    }
  }
}.open
# ... more code follows

# ... more code precedes
root {
  title 'Hello, List Single Selection!'
  
  list {
    selectmode 'browse'
    selection <=> [person, :country]
  }
  
  button {
    text "Reset Selection To Default Value"
    
    command { person.reset_country }
  }
}.open
# ... more code follows

# ... more code precedes
root {
  title 'Hello, List Multi Selection!'
  
  list {
    selection <=> [person, :provinces]
  }
  
  button {
    text "Reset Selection To Defaults"
    
    command { person.reset_provinces }
  }
}.open
# ... more code follows

require 'glimmer-dsl-tk'

class HelloEntry
  include Glimmer
  
  attr_accessor :default, :password, :telephone, :read_only
  
  def initialize
    self.default = 'default'
    self.password = 'password'
    self.telephone = '555-555-5555'
    self.read_only = 'Telephone area code is 555'
  end
  
  def launch
    root {
      title 'Hello, Entry!'
      minsize 230, 0
         
      label {
        grid sticky: 'ew'
        text 'default entry'
      }
      entry { |the_entry|
        grid sticky: 'ew'
        text <=> [self, :default]
      }
      
      label {
        grid sticky: 'ew'
        text 'password entry'
      }
      entry {
        grid sticky: 'ew'
        show '*'
        text <=> [self, :password]
      }

      @validated_entry_label = label {
        grid sticky: 'ew'
        text 'entry with event handlers'
      }
      entry { |the_entry|
        grid sticky: 'ew'
        text <=> [self, :telephone]

        # validate 'key' # default when on('validate') or on('invalid') is specified
        ## Validation happens on key change by default when validation listeners are specified
        ## (other accepted values: 'none', 'focus', 'focusin', 'focusout', 'key', or 'all')
        
        ## this event kicks in just after the user typed and before modifying the text variable
        on('validate') do |new_text_variable|
          telephone?(new_text_variable.value)
        end

        ## this event kicks in just after the text variable is validated and before it is modified
        on('invalid') do |validate_args|
          @validated_entry_label.text = "#{validate_args.value} is not a valid phone!"
          @validated_entry_label.foreground = 'red'
        end

        ## this event kicks in just after the text variable is validated and modified
        on('change') do |new_text_variable|
          self.read_only = "Telephone area code is #{new_text_variable.value.gsub(/[^0-9]/, '')[0...3]}"
          @validated_entry_label.text = 'entry with event handlers'
          @validated_entry_label.foreground = nil
        end
        
        ## this is similar to on('change') (which is Glimmer-specific), but more low level at the Tk level
        ## it is the equivalent of calling: the_entry.tk.textvariable.trace('write') { puts "..." }
        ## More at: https://tkdocs.com/tutorial/widgets.html#entry and https://tcl.tk/man/tcl8.6/TclCmd/trace.htm#M14
        on_textvariable('write') do
          puts "\"#{the_entry.text}\" has been written to entry!"
        end
      }

      label {
        grid sticky: 'ew'
        text 'read-only entry'
      }
      entry {
        grid sticky: 'ew'
        text <=> [self, :read_only]
        readonly true
      }
    }.open
  end
  
  def telephone?(text)
    !!text.match(/^\d{0,3}[-.\/]?\d{0,3}[-.\/]?\d{0,4}$/)
  end
end

HelloEntry.new.launch

require 'glimmer-dsl-tk'

class HelloText
  include Glimmer
  
  COLOR_OPTIONS = %w[black purple blue green orange yellow red white].map(&:capitalize)
  FONT_FAMILY_OPTIONS = ::TkFont.families
  FOREGROUND_PROMPT = '<foreground>'
  BACKGROUND_PROMPT = '<background>'
  FONT_FAMILY_PROMPT = '<font family>'
  FONT_SIZE_PROMPT = '<font size>'
  
  def initialize
    @foreground = FOREGROUND_PROMPT
    @background = BACKGROUND_PROMPT
    @font_family = FONT_FAMILY_PROMPT
    @font_size = FONT_SIZE_PROMPT
    @document = <<~MULTI_LINE_STRING
      According to the National Post, a heavy metal-loving high school principal in Canada will be allowed to keep her job, days after a public campaign to oust her made headlines around the globe.
      
      Parents at Eden High School in St. Catharines, Ontario launched a petition to remove principal Sharon Burns after discovering she's an IRON MAIDEN fan.
      
      The petition, titled "Eden High School Principal, Sharon Burns, Needs to Be Transferred Immediately!" read, "We are deeply disturbed that the principal assigned to the school blatantly showed Satanic symbols and her allegiance to Satanic practices on her public social media platforms where all the students can see them under @edenprincipal (not her personal account)."
      
      More than 500 people signed the petition to transfer Burns after she posted a picture of herself flashing the "devil horns" hand sign with a doll of the MAIDEN zombie mascot Eddie behind her as well as a personalized license plate reading "IRNMADEN" and a handwritten note that reads "Eddie 666" on a car's dashboard.
      
      
      The number 666 is used to represent the devil, and is featured prominently in MAIDEN's artwork by the band, whose classic third album is titled "The Number Of The Beast".
      
      The petition was later updated to state that the demand for her transfer is not because of her love for metal, but for "openly displaying her own handmade sign with the 666 clearly displayed on it".
      
      The creator of the original petition wrote: "Sharon knows full well what she did was simply inappropriate, unnecessary and not professional but has yet to publicly admit so and is willing to allow people to believe a completely different story, making very real concerns seem petty."
      
      Meanwhile, a counter-petition supporting Burns garnered over 20,000 signatures.
      
      "It is ridiculous that a couple of parents judge her role as a principal only based on an Instagram post. (About liking the band IRON MAIDEN. That's it.) Eden High School is a public school. Not a Christian school," the petition titled "We need Mrs Burns" stated. "She has made Eden a safe space for so many people. She spreads nothing but love and kindness."
      
      After the complaints were aired, the District School Board of Niagara spoke with Burns and the parents who launched the petition, and the issue is over as far as the board is concerned, Kim Sweeney, the board's chief communications officer, told the National Post. No disciplinary action or policy changes were needed.
      
      "Our belief is that taste in music is subjective and we support that both students and staff enjoy a wide variety of genres," Sweeney said.
      
      The original petition has since been removed.
    MULTI_LINE_STRING
  end
  
  attr_accessor :document, :find_text
      
  attr_accessor :foreground
  
  def foreground_options
    [FOREGROUND_PROMPT] + COLOR_OPTIONS
  end
  
  attr_accessor :background
  
  def background_options
    [BACKGROUND_PROMPT] + COLOR_OPTIONS
  end
  
  attr_accessor :font_family
  
  def font_family_options
    [FONT_FAMILY_PROMPT] + FONT_FAMILY_OPTIONS
  end
  
  attr_accessor :font_size
  
  def font_size_options
    [FONT_SIZE_PROMPT] + (9..64).to_a.map(&:to_s)
  end
  
  def find
    text_index = @text.search(/#{find_text}/i, @text.tag_ranges('sel')&.first&.last || @text.index('insert'))
    unless text_index.to_s.empty?
      @text.tag_remove('sel', '1.0', 'end')
      @text.tag_add('sel', text_index, "#{text_index} + #{find_text.size} chars")
    end
  end
  
  def launch
    @root = root {
      title 'Hello, Text!'
      width 1280
      height 800
      
      frame {
        grid row: 0, column: 0
        
        column_index = -1
        
        combobox { |cb|
          grid row: 1, column: column_index += 1, column_weight: 1
          readonly true
          text <=> [self, :font_family, after_write: ->(value) { @text.toggle_selection_font_format('family', value == FONT_FAMILY_PROMPT ? 'Courier New' : value, focus: 100) }]
        }
        
        combobox {
          grid row: 1, column: column_index += 1, column_weight: 1
          readonly true
          text <=> [self, :font_size, after_write: ->(value) { @text.toggle_selection_font_format('size', value == FONT_SIZE_PROMPT ? 13 : value, focus: 100) }]
        }
        
        combobox {
          grid row: 1, column: column_index += 1, column_weight: 1
          readonly true
          text <=> [self, :foreground, after_write: ->(value) { @text.add_selection_format('foreground', value == FOREGROUND_PROMPT ? 'black' : value, focus: 100) }]
        }
        
        combobox {
          grid row: 1, column: column_index += 1, column_weight: 1
          readonly true
          text <=> [self, :background, after_write: ->(value) { @text.add_selection_format('background', value == BACKGROUND_PROMPT ? 'white' : value, focus: 100) }]
        }
        
        separator {
          grid row: 1, column: column_index += 1, column_weight: 0
          orient 'vertical'
        }
        
        @bold_button = button {
          grid row: 1, column: column_index += 1, column_weight: 0
          text 'B'
          style font: {weight: 'bold'}
          
          on('command') do
            @text.toggle_selection_font_format('weight', 'bold')
          end
        }
        
        @italic_button = button {
          grid row: 1, column: column_index += 1, column_weight: 0
          text 'I'
          style font: {slant: 'italic'}
          
          on('command') do
            @text.toggle_selection_font_format('slant', 'italic')
          end
        }
        
        @underline_button = button {
          grid row: 1, column: column_index += 1, column_weight: 0
          text 'U'
          style font: {underline: true}
          
          on('command') do
            @text.toggle_selection_font_format('underline', true)
          end
        }

        separator {
          grid row: 1, column: column_index += 1, column_weight: 0
          orient 'vertical'
        }
        
        @justify_left_button = button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/align-left.png", __dir__), subsample: 32
          
          on('command') do
            @text.add_selection_format('justify', 'left')
          end
        }
        
        @justify_center_button = button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/align-center.png", __dir__), subsample: 32
          
          on('command') do
            @text.add_selection_format('justify', 'center')
          end
        }
        
        @justify_right_button = button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/align-right.png", __dir__), subsample: 32
          
          on('command') do
            @text.add_selection_format('justify', 'right')
          end
        }
        
        separator {
          grid row: 1, column: column_index += 1, column_weight: 0
          orient 'vertical'
        }
        
        button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/picture.png", __dir__), subsample: 32
          
          on('command') do
            @text.get_open_file_to_insert_image
          end
        }
        
        button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/search.png", __dir__), subsample: 32
          
          on('command') do
            show_find_dialog
          end
        }
        
        separator {
          grid row: 1, column: column_index += 1, column_weight: 0
          orient 'vertical'
        }
        
        button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/cut.png", __dir__), subsample: 32
          
          on('command') do
            @text.text_cut
          end
        }
        
        button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/copy.png", __dir__), subsample: 32
          
          on('command') do
            @text.text_copy
          end
        }
        
        button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/paste.png", __dir__), subsample: 32
          
          on('command') do
            @text.text_paste
          end
        }
        
        separator {
          grid row: 1, column: column_index += 1, column_weight: 0
          orient 'vertical'
        }
        
        
        button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/undo.png", __dir__), subsample: 32
          
          on('command') do
            @text.edit_undo
          end
        }
        
        button {
          grid row: 1, column: column_index += 1, column_weight: 0
          image File.expand_path("images/redo.png", __dir__), subsample: 32
          
          on('command') do
            @text.edit_redo
          end
        }
      }
      
      @text = text {
        grid row: 1, column: 0, row_weight: 1
        wrap 'word'
        undo true
        value <=> [self, :document]
        
        on('InsertMarkMoved') do
          self.font_family = @text.applied_font_format_value('family')
          self.font_size = @text.applied_font_format_value('size')
          @bold_button.default = @text.applied_font_format_value('weight') == 'bold' ? 'active' : 'normal'
          @italic_button.default = @text.applied_font_format_value('slant') == 'italic' ? 'active' : 'normal'
          @underline_button.default = @text.applied_font_format_value('underline') == true ? 'active' : 'normal'
          self.background = @text.applied_format_value('background')
          self.foreground = @text.applied_format_value('foreground')
          @justify_left_button.default = @text.applied_format_value('justify') == 'left' ? 'active' : 'normal'
          @justify_center_button.default = @text.applied_format_value('justify') == 'center' ? 'active' : 'normal'
          @justify_right_button.default = @text.applied_format_value('justify') == 'right' ? 'active' : 'normal'
        end
        
        on('KeyPress') do |event|
          show_find_dialog if (event.keysym == 'f') && ((OS.mac? && event.state == 8) || (!OS.mac? && event.state == 4))
        end
      }
    }
    @root.open
  end
  
  def show_find_dialog
    toplevel(@root) { |tl|
      title 'Find'
      
      label {
        text 'Text:'
      }
      entry { |e|
        focus true
        text <=> [
          self,
          :find_text,
          after_write: lambda do
            text_index = @text.search(/#{find_text}/i, 'insert')
            unless text_index.to_s.empty?
              @text.tag_remove('sel', '1.0', 'end')
              @text.tag_add('sel', text_index, "#{text_index} + #{find_text.size} chars")
            end
          end
        ]
                
        on('KeyPress') do |event|
          if event.keysym == 'Return'
            find
          elsif event.keysym == 'Escape'
            tl.grab_release
            tl.destroy
          end
        end
      }
      button {
        text 'Find'
        default 'active'
        
        on('command') do
          find
        end
      }
    }
  end
end

HelloText.new.launch

require 'glimmer-dsl-tk'

class HelloSpinbox
  class Person
    attr_accessor :donation
  end
  
  include Glimmer
  
  def initialize
    @person = Person.new
    @person.donation = 5.0 # in dollars
  end
  
  def launch
    root {
      title 'Hello, Spinbox!'
      
      label {
        text 'Please select the amount you would like to donate to the poor:'
      }
      
      frame {
        label {
          grid row: 0, column: 0
          text 'Amount:'
          font 'caption'
        }
        
        label {
          grid row: 0, column: 1
          text '$'
        }
        
        spinbox { |sb|
          grid row: 0, column: 2
          from 1.0 # minimum value
          to 150.0 # maximum value
          increment 5.0 # increment on up and down
          format '%0.2f'
          text <=> [@person, :donation]
        }
        
        label {
          grid row: 1, column: 0, columnspan: 3
          text <=> [@person, :donation, on_read: ->(value) { "Thank you for your donation of $#{"%.2f" % value.to_f}"}]
        }

      }
    }.open
  end
end

HelloSpinbox.new.launch

# ... more code precedes
    root {
      title 'Hello, Computed!'
      
      frame {
        grid column: 0, row: 0, padx: 5, pady: 5
        
        label {
          grid column: 0, row: 0, sticky: 'w'
          text 'First Name: '
        }
        entry {
          grid column: 1, row: 0
          width 15
          text <=> [@contact, :first_name]
        }
        
        label {
          grid column: 0, row: 1, sticky: 'w'
          text 'Last Name: '
        }
        entry {
          grid column: 1, row: 1
          width 15
          text <=> [@contact, :last_name]
        }
        
        label {
          grid column: 0, row: 2, sticky: 'w'
          text 'Year of Birth: '
        }
        entry {
          grid column: 1, row: 2
          width 15
          text <=> [@contact, :year_of_birth]
        }
        
        label {
          grid column: 0, row: 3, sticky: 'w'
          text 'Name: '
        }
        label {
          grid column: 1, row: 3, sticky: 'w'
          text <=> [@contact, :name, computed_by: [:first_name, :last_name]]
        }
        
        label {
          grid column: 0, row: 4, sticky: 'w'
          text 'Age: '
        }
        label {
          grid column: 1, row: 4, sticky: 'w'
          text <=> [@contact, :age, on_write: :to_i, computed_by: [:year_of_birth]]
        }
      }
    }.open
# ... more code follows

require 'glimmer-dsl-tk'

include Glimmer

root {
  title "Hello, Drag and Drop!"
  
  frame {
    padding 5
    
    labelframe {
      text "Drag sources"
      padding 5
      
      label {
        grid :row => 0, :column => 0
        text "Label"
      }
      label {
        grid :row => 0, :column => 1, :pady => 10, :sticky => "e"
        text "Drag label text"
        width 30
        drag_source true
      }
      
      label {
        grid :row => 1, :column => 0
        text "Entry"
      }
      entry {
        grid :row => 1, :column => 1, :pady => 5, :sticky => "e"
        text "Drag entry text"
        width 30
        
        # drag_source true
        # This is how to do `drag_source true` the manual way for use in exceptional cases
        on('drag_start') do |event|
          event.data = event.source.text
          event.source.configure(:cursor => "hand2")
          event.tooltip.content { # re-open tooltip content and add a label
            lbl { # non-tile-theme version of label
              text event.data + " "
              bg "yellow"
              bitmap "warning"
              compound "right"
            }
          }
        end
        on('drag_motion') do |event|
          if event.drop_accepted?
            event.source.configure(:cursor => "hand1")
          else
            event.source.configure(:cursor => "hand2")
          end
          event.tooltip.geometry("+#{event.x_root + 10}+#{event.y_root - 4}")
        end
      }
      
      label {
        grid :row => 2, :column => 0
        text "Combobox"
      }
      combobox {
        grid :row => 2, :column => 1, :pady => 5, :sticky => "e"
        text "Spain"
        values %w[USA Canada Mexico Columbia UK Australia Germany Italy Spain]
        width 27
        
        drag_source true
      }
      
      label {
        grid :row => 3, :column => 0
        text 'List'
      }
      list {
        grid :row => 3, :column => 1, :pady => 5, :sticky => "e"
        selectmode 'browse'
        items %w[USA Canada Mexico]
        selection 'Canada'
        height 3
        
        # drag_source true
        # This is another alternative to `drag_source true` with manual specification of transferred data only
        on('drag_start') do |event|
          event.data = event.source.selection.first
        end
      }
      
      label {
        grid :row => 4, :column => 0
        text "Button"
      }
      button {
        grid :row => 4, :column => 1, :pady => 5, :sticky => "w"
        text "Drag it"
        drag_source true
      }
    }

    labelframe {
      grid :sticky => "nsew", :pady => 15
      text "Drop targets"
      padding 5
      
      label {
        grid :row => 0, :column => 0
        text "Label"
      }
      label {
        grid :row => 0, :column => 1, :pady => 10, :sticky => "e"
        width 30
        borderwidth 2
        relief "solid"
        
        drop_target true
      }
      
      label {
        grid :row => 1, :column => 0
        text "Entry"
      }
      entry {
        grid :row => 1, :column => 1, :pady => 5, :sticky => "e"
        width 30
        
        drop_target true
      }
      
      label {
        grid :row => 2, :column => 0
        text "Combobox"
      }
      combobox {
        grid :row => 2, :column => 1, :pady => 5, :sticky => "e"
        width 27
        
        drop_target true
      }
      
      label {
        grid :row => 3, :column => 0
        text 'List'
      }
      list {
        grid :row => 3, :column => 1, :pady => 5, :sticky => "e"
        selectmode 'browse'
        height 3
        
        drop_target true
      }
      
      label {
        grid :row => 4, :column => 0
        text "Button"
      }
      button {
        grid :row => 4, :column => 1, :pady => 5, :sticky => "w"
        text "Drop here"
        
        drop_target true
      }
      
      label {
        grid :row => 5, :column => 0
        text "Checkbutton"
      }
      checkbutton {
        grid :row => 5, :column => 1, :pady => 5, :sticky => "w"
        text "Drop here to destroy a widget"

        # drop_target true
        # This is an alternative to `drop_target true` with manual consumption of transferred data
        on('drop') do |event|
          event.target.text = event.data
          # execute asynchronously after 100ms to ensure all events have been processed before destruction
          ::Tk.after(100) {event.source.destroy}
        end
      }
    }
  }
}.open

require 'glimmer-dsl-tk'

include Glimmer

root { |w|
  title 'Hello, Built-in Dialog!'
  width 400
  height 400
  x 150
  y 150
  
  frame {
    %w[get_open_file get_multiple_open_file get_save_file choose_directory choose_color].each do |dialog|
      button {
        text dialog.split('_').map(&:capitalize).join(' ')
        
        on('command') do
          result = send(dialog, parent: w)
          @result_label.text = [result].flatten.join("\n")
        end
      }
    end
    
    button {
      text 'Choose Font'
      
      on('command') do
        choose_font(family: 'Courier New', size: '30', weight: 'bold') do |chosen_font|
          @result_label.text = chosen_font
        end
      end
    }
  }
  
  frame {
    grid sticky: 'nsew', padx: 15, pady: 15
    
    label {
      grid row: 0, column: 0
      text 'Result:'
    }
    
    @result_label = label {
      grid row: 0, column: 1
    }
  }
}.open

require 'glimmer-dsl-tk'

include Glimmer

root {
  title 'Hello, Separator!'
  width 200
  height 200
  
  label {
    grid row: 0, column: 0, min_width: 100, min_height: 100, column_weight: 0, sticky: 'nsew'
    text 'Label 1'
    anchor 'center'
  }
  
  separator {
    grid row: 0, column: 1
    orient 'vertical'
  }
  
  label {
    grid row: 0, column: 2, min_width: 100, min_height: 100, sticky: 'nsew'
    text 'Label 2'
    anchor 'center'
  }
  
  separator {
    grid row: 1, column: 0, column_span: 3
    # orient 'horizontal' # default
  }
  
  label {
    grid row: 2, column: 0, min_width: 100, min_height: 100, sticky: 'nsew'
    text 'Label 3'
    anchor 'center'
  }
  
  separator {
    grid row: 2, column: 1
    orient 'vertical'
  }
  
  label {
    grid row: 2, column: 2, min_width: 100, min_height: 100, sticky: 'nsew'
    text 'Label 4'
    anchor 'center'
  }
}.open

require 'glimmer-dsl-tk'

include Glimmer

root {
  title 'Hello, Scrollbar!'
  width 400
  height 500
  
  notebook {
    grid sticky: 'nsew'
    
    frame(text: 'Scrollable List') {
      @list = list {
        grid sticky: 'nsew', row: 0, column: 0, row_weight: 1, column_weight: 1
        items 40.times.map {|n| "Item #{n + 1} of a very long list" }
      }
      
      @scrollbar = scrollbar {
        grid row: 0, column: 1
        # orient 'vertical' # default
      }
      @list.yscrollbar @scrollbar
    }
    
    frame(text: 'Scrollable Text') {
      @text = text {
        grid sticky: 'nsew', row: 0, column: 0, row_weight: 1, column_weight: 1
        value ("This is a random sample of text that will repeat over and over and over"*2 + "\n")*40
      }
      
      @yscrollbar = scrollbar {
        grid row: 0, column: 1
        # orient 'vertical' # default
      }
      @text.yscrollbar @yscrollbar
       
      @xscrollbar = scrollbar {
        grid row: 1, column: 0, column_span: 2, row_weight: 0
        orient 'horizontal'
      }
      @text.xscrollbar @xscrollbar
    }
  }
  
}.open

require 'glimmer-dsl-tk'

include Glimmer

root {
  title 'Hello, Scrollbar Frame!'
  width 400
  height 400
  
  notebook {
    grid sticky: 'nsew'
    
    frame(text: 'X/Y Scroll') {
      scrollbar_frame {
        30.times do |row|
          10.times do |column|
            button {
              grid row: row, column: column, row_weight: 0, column_weight: 0
              text "Row #{row} | Column #{column}"
            }
          end
        end
      }
    }
    
    frame(text: 'Y Scroll') {
      scrollbar_frame {
        xscrollbar false
        
        30.times do |row|
          2.times do |column|
            button {
              grid row: row, column: column, row_weight: 0, column_weight: 0
              text "Row #{row} | Column #{column}"
            }
          end
        end
      }
    }
    
    frame(text: 'X Scroll') {
      scrollbar_frame {
        yscrollbar false
        
        13.times do |row|
          10.times do |column|
            button {
              grid row: row, column: column, row_weight: 0, column_weight: 0
              text "Row #{row} | Column #{column}"
            }
          end
        end
      }
    }
  }
}.open

require 'glimmer-dsl-tk'

include Glimmer

COLORS = [:white, :red, :yellow, :green, :blue, :magenta, :gray, :black]

Tk::Tile::Style.theme_use "classic" # this enables setting background on label just for demo purposes

root { |r|
  title 'Hello, Menu Bar!'
  
  @label = label {
    grid row_weight: 1, column_weight: 1
    text 'Check Out The Menu Bar Above!'
    font size: 50
    anchor 'center'
  }
  
  menu_bar {
    # Mac-specific application menu (right next to the Apple menu)
    if OS.mac?
      menu(:application) {
        menu_item(:about, label: 'About My Application') {
          accelerator 'Command+A'
          
          on('command') do
            message_box(parent: r, title: 'About', message: 'About my application.')
          end
        }
        
        menu_item(:preferences) {
          on('command') do
            message_box(parent: r, title: 'Preferences', message: 'Preferences of my application.')
          end
        }
        
        # If not defined, application simply quits upon selecting Quit menu item
        menu_item(:quit) {
          on('command') do
            message_box(parent: r, title: 'Quit', message: 'Quitting my application...')
            exit(0)
          end
        }
      }
    end
    
    # Windows-specific system menu (to the top-left of the window frame)
    if OS.windows?
      menu(label: 'System')
    end
    
    menu(label: 'File', underline: 0) {
      menu_item(label: 'New', underline: 0) {
        accelerator OS.mac? ? 'Command+N' : 'Control+N'

        on('command') do
          message_box(parent: r, title: 'New', message: 'New file created.')
        end
      }
      
      menu_item(label: 'Open...', underline: 0) {
        accelerator OS.mac? ? 'Command+O' : 'Control+O'

        on('command') do
          message_box(parent: r, title: 'Open', message: 'Opening File...')
        end
      }
      
      menu(label: 'Open Recent', underline: 5) {
        menu_item(label: 'File 1') {
          on('command') do
            message_box(parent: r, title: 'File 1', message: 'File 1 Contents')
          end
        }
        
        menu_item(label: 'File 2') {
          on('command') do
            message_box(parent: r, title: 'File 2', message: 'File 2 Contents')
          end
        }
      }
      
      menu_item(:separator)
      
      menu_item(label: 'Exit', underline: 1) {
        on('command') do
          exit(0)
        end
      }
    }
    
    menu(label: 'Edit', underline: 0) {
      menu_item(label: 'Cut', underline: 2) {
        accelerator OS.mac? ? 'Command+X' : 'Control+X'
      }
      
      menu_item(label: 'Copy', underline: 0) {
        accelerator OS.mac? ? 'Command+C' : 'Control+C'
      }
      
      menu_item(label: 'Paste', underline: 0) {
        accelerator OS.mac? ? 'Command+V' : 'Control+V'
      }
    }
    
    menu(label: 'Options', underline: 0) {
      menu_item(:checkbutton, label: 'Enabled', underline: 0) {
        on('command') do
          @select_one_menu.children.each { |menu_item| menu_item.state = menu_item.state == 'disabled' ? 'normal' : 'disabled' }
          @select_multiple_menu.children.each { |menu_item| menu_item.state = menu_item.state == 'disabled' ? 'normal' : 'disabled' }
        end
      }
      
      @select_one_menu = menu(label: 'Select One', underline: 7) {
        menu_item(:radiobutton, label: 'Option 1') {
          state 'disabled'
        }
        menu_item(:radiobutton, label: 'Option 2') {
          state 'disabled'
        }
        menu_item(:radiobutton, label: 'Option 3') {
          state 'disabled'
        }
      }
      
      @select_multiple_menu = menu(label: 'Select Multiple', underline: 7) {
        menu_item(:checkbutton, label: 'Option 4') {
          state 'disabled'
        }
        menu_item(:checkbutton, label: 'Option 5') {
          state 'disabled'
        }
        menu_item(:checkbutton, label: 'Option 6') {
          state 'disabled'
        }
      }
    }
    
    menu(label: 'Language', underline: 3) {
      ['denmark', 'finland', 'france', 'germany', 'italy', 'mexico', 'netherlands', 'norway', 'usa'].each do |image_name|
        menu_item(:radiobutton, label: image_name.capitalize) {
          selection image_name == 'usa'
          image File.expand_path("images/#{image_name}.png", __dir__)
          
          on('command') do
            message_box(parent: r, title: 'Language Selection', message: "You selected the language of #{image_name.capitalize}!")
          end
        }
      end
    }
    
    menu(label: 'Country', underline: 0) {
      ['denmark', 'finland', 'france', 'germany', 'italy', 'mexico', 'netherlands', 'norway', 'usa'].each do |image_name|
        menu_item(:radiobutton, label: image_name.capitalize) {
          selection image_name == 'usa'
          image File.expand_path("images/#{image_name}.png", __dir__)
          compound 'left'
          
          on('command') do
            message_box(parent: r, title: 'Country Selection', message: "You selected the country of #{image_name.capitalize}!")
          end
        }
      end
    }
    
    menu(label: 'Format', underline: 0) {
      menu(label: 'Background Color', underline: 0) {
        COLORS.each { |color_style|
          menu_item(:radiobutton, label: color_style.to_s.split('_').map(&:capitalize).join(' ')) {
            on('command') do
              @label.background = color_style
            end
          }
        }
      }
      
      menu(label: 'Foreground Color', underline: 11) {
        COLORS.each { |color_style|
          menu_item(:radiobutton, label: color_style.to_s.split('_').map(&:capitalize).join(' ')) {
            on('command') do
              @label.foreground = color_style
            end
          }
        }
      }
    }
    
    menu(label: 'View', underline: 0) {
      menu_item(:radiobutton, label: 'Small', underline: 0) {
        accelerator OS.mac? ? 'Command+S' : 'Control+S'
        
        on('command') do
          @label.font = {size: 25}
        end
      }
      
      menu_item(:radiobutton, label: 'Medium', underline: 0) {
        accelerator OS.mac? ? 'Command+M' : 'Control+M'
        selection true

        on('command') do
          @label.font = {size: 50}
        end
      }
      
      menu_item(:radiobutton, label: 'Large', underline: 0) {
        accelerator OS.mac? ? 'Command+L' : 'Control+L'
        
        on('command') do
          @label.font = {size: 75}
        end
      }
    }
    
    # Mac-specific window menu (containing zooming/resizing menu items)
    menu(label: 'Window', underline: 0) if OS.mac?
    
    menu(label: 'Help', underline: 0) {
      if OS.mac?
        menu_item(:help) {
          on('command') do
            message_box(parent: r, title: 'Help', message: 'Help for my application.')
          end
        }
      end
      
      menu_item(label: 'Manual', underline: 0) {
        accelerator OS.mac? ? 'Command+Shift+M' : 'Control+U'

        on('command') do
          message_box(parent: r, title: 'Manual', message: 'Manual Contents')
        end
      }
      
      menu_item(label: 'Tutorial', underline: 0) {
        accelerator OS.mac? ? 'Command+Shift+T' : 'Control+T'

        on('command') do
          message_box(parent: r, title: 'Tutorial', message: 'Tutorial Contents')
        end
      }
      
      menu_item(:separator)
      
      menu_item(label: 'Report an Issue...', underline: 0) {
        on('command') do
          message_box(parent: r, title: 'Report an Issue', message: 'Reporting an issue...')
        end
      }
    }
  }
}.open