Class: Glimmer::SWT::DisplayProxy

Inherits:
Object
  • Object
show all
Includes:
Custom::Drawable
Defined in:
lib/glimmer/swt/display_proxy.rb

Overview

Proxy for org.eclipse.swt.widgets.Display

Maintains a singleton instance since SWT only supports a single active display at a time.

Supports SWT Display’s very useful asyncExec and syncExec methods to support proper multi-threaded manipulation of SWT UI objects

Invoking ‘#swt_display` returns the SWT Display object wrapped by this proxy

Follows the Proxy Design Pattern

Defined Under Namespace

Classes: ConcreteListener

Constant Summary collapse

OBSERVED_MENU_ITEMS = 
['about', 'preferences', 'quit']

Instance Attribute Summary collapse

Attributes included from Custom::Drawable

#image_double_buffered, #requires_shape_disposal

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Custom::Drawable

#add_shape, #clear_shapes, #deregister_shape_painting, #expanded_shapes, #image_buffered_shapes, #paint_pixel_by_pixel, #setup_shape_painting, #shape_at_location, #shapes, #swt_drawable

Constructor Details

#initialize(*args) ⇒ DisplayProxy

Returns a new instance of DisplayProxy.



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# File 'lib/glimmer/swt/display_proxy.rb', line 76

def initialize(*args)
  Display.app_name ||= 'Glimmer'
  @swt_display = Display.new(*args)
  @swt_display.set_data('proxy', self)
  @execs_in_progress = {}
  on_swt_Dispose {
    clear_shapes
  }
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object 



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# File 'lib/glimmer/swt/display_proxy.rb', line 163

def method_missing(method, *args, &block)
  if can_handle_observation_request?(method)
    handle_observation_request(method, &block)
  else
    swt_display.send(method, *args, &block)
  end
rescue => e
  Glimmer::Config.logger.debug {"Neither DisplayProxy nor #{swt_display.class.name} can handle the method ##{method}"}
  super
end

Instance Attribute Details

#swt_display ⇒ Object (readonly)

SWT Display object wrapped



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# File 'lib/glimmer/swt/display_proxy.rb', line 74

def swt_display
  @swt_display
end

Class Method Details

.instance(*args) ⇒ Object

Returns singleton instance



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# File 'lib/glimmer/swt/display_proxy.rb', line 59

def instance(*args)
  if @instance.nil? || @instance.swt_display.nil? || @instance.swt_display.isDisposed
    @thread = Thread.current
    @instance = new(*args)
  end
  @instance
end

.thread ⇒ Object 



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# File 'lib/glimmer/swt/display_proxy.rb', line 67

def thread
  instance # ensure instance
  @thread
end

Instance Method Details

#add_swt_event_filter(swt_constant, &block) ⇒ Object 



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# File 'lib/glimmer/swt/display_proxy.rb', line 213

def add_swt_event_filter(swt_constant, &block)
  event_type = SWTProxy[swt_constant]
  swt_listener = ConcreteListener.new(&block)
  @swt_display.addFilter(event_type, swt_listener)
  #WidgetListenerProxy.new(@swt_display.getListeners(event_type).last)
  WidgetListenerProxy.new(
    swt_display: @swt_display,
    event_type: event_type,
    filter: true,
    swt_listener: swt_listener,
    widget_add_listener_method: 'addFilter',
    swt_listener_class:  ConcreteListener,
    swt_listener_method: 'handleEvent'
  )
end

#async_exec(&block) ⇒ Object

asynchronously executes the block (required from threads other than first GUI thread) does not return the value produced by the block since it is async, running after the return



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# File 'lib/glimmer/swt/display_proxy.rb', line 92

def async_exec(&block)
  @swt_display.asyncExec do
    execs_in_progress << :async_exec
    begin
      result = block.call
    ensure
      execs_in_progress.pop
    end
  end
end

#async_exec_in_progress? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/display_proxy.rb', line 128

def async_exec_in_progress?
  execs_in_progress.last == :async_exec
end

#auto_exec(override_sync_exec: nil, override_async_exec: nil, &block) ⇒ Object

Invoke block with ‘sync_exec` only when necessary (running from a separate thread) Override sync_exec as `true` to force using or `false` to force avoiding Override async_exec as `true` to force using or `:unless_in_progress` to force using only if no `async_exec` is in progress Disable auto execution of `sync_exec` via `Glimmer::Config.auto_sync_exec = false` Otherwise, runs normally, thus allowing SWT to decide how to batch/optimize GUI updates



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# File 'lib/glimmer/swt/display_proxy.rb', line 145

def auto_exec(override_sync_exec: nil, override_async_exec: nil, &block)
  if override_sync_exec || override_sync_exec.nil? && !override_async_exec && sync_exec_required? && Config.auto_sync_exec? && !sync_exec_in_progress? && !async_exec_in_progress?
    sync_exec(&block)
  elsif override_async_exec || override_async_exec.to_s == 'unless_in_progress' && !async_exec_in_progress?
    async_exec(&block)
  else
    block.call
  end
end

#can_handle_observation_request?(observation_request) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/display_proxy.rb', line 180

def can_handle_observation_request?(observation_request)
  observation_request = observation_request.to_s
  if observation_request.start_with?('on_swt_')
    constant_name = observation_request.sub(/^on_swt_/, '')
    SWTProxy.has_constant?(constant_name)
  elsif observation_request.start_with?('on_')
    event_name = observation_request.sub(/^on_/, '')
    OBSERVED_MENU_ITEMS.include?(event_name)
  else
    false
  end
end

#content(&block) ⇒ Object 



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# File 'lib/glimmer/swt/display_proxy.rb', line 86

def content(&block)
  Glimmer::DSL::Engine.add_content(self, Glimmer::DSL::SWT::DisplayExpression.new, 'display', &block)
end

#disposed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/display_proxy.rb', line 159

def disposed?
  @swt_display.isDisposed
end

#execs_in_progress ⇒ Object 



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# File 'lib/glimmer/swt/display_proxy.rb', line 136

def execs_in_progress
  @execs_in_progress[Thread.current] ||= []
end

#handle_observation_request(observation_request, &block) ⇒ Object 



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# File 'lib/glimmer/swt/display_proxy.rb', line 193

def handle_observation_request(observation_request, &block)
  observation_request = observation_request.to_s
  if observation_request.start_with?('on_swt_')
    constant_name = observation_request.sub(/^on_swt_/, '')
    swt_event_reg = add_swt_event_filter(constant_name, &block)
    Glimmer::UI::CustomWidget.current_custom_widgets.last&.observer_registrations&.push(swt_event_reg)
    swt_event_reg
  elsif observation_request.start_with?('on_')
    event_name = observation_request.sub(/^on_/, '')
    if OBSERVED_MENU_ITEMS.include?(event_name) && OS.mac?
      system_menu = swt_display.getSystemMenu
      menu_item = system_menu.getItems.find {|menu_item| menu_item.getID == SWTProxy["ID_#{event_name.upcase}"]}
      listener = ConcreteListener.new(&block)
      display_mac_event_registration = menu_item.addListener(SWTProxy[:Selection], listener)
      Glimmer::UI::CustomWidget.current_custom_widgets.last&.observer_registrations&.push(display_mac_event_registration)
      display_mac_event_registration
    end
  end
end

#on_widget_disposed(&block) ⇒ Object 



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# File 'lib/glimmer/swt/display_proxy.rb', line 155

def on_widget_disposed(&block)
  on_swt_Dispose(&block)
end

#respond_to?(method, *args, &block) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/display_proxy.rb', line 174

def respond_to?(method, *args, &block)
  super ||
    can_handle_observation_request?(method) ||
    swt_display.respond_to?(method, *args, &block)
end

#sync_exec(&block) ⇒ Object

synchronously executes the block (required from threads other than first GUI thread) returns the value produced by the block



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# File 'lib/glimmer/swt/display_proxy.rb', line 105

def sync_exec(&block)
  result = nil
  @swt_display.syncExec do
    execs_in_progress << :sync_exec
    begin
      result = block.call
    ensure
      execs_in_progress.pop
    end
  end
  result
end

#sync_exec_in_progress? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/display_proxy.rb', line 132

def sync_exec_in_progress?
  execs_in_progress.include?(:sync_exec)
end

#sync_exec_required? ⇒ Boolean

Indicates whether ‘sync_exec` is required because of running in a different thread from the GUI thread `async_exec` could be used as an alternative to `sync_exec` when required.

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/display_proxy.rb', line 124

def sync_exec_required?
  Thread.current != DisplayProxy.thread
end

#timer_exec(delay_in_millis, &block) ⇒ Object 



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# File 'lib/glimmer/swt/display_proxy.rb', line 118

def timer_exec(delay_in_millis, &block)
  @swt_display.timerExec(delay_in_millis, &block)
end