Class: Glimmer::SWT::WidgetProxy

Inherits:
Object
  • Object
show all
Includes:
DataBinding::ObservableWidget, Packages
Defined in:
lib/glimmer/swt/widget_proxy.rb

Overview

Proxy for SWT Widget objects

Sets default SWT styles to widgets upon inititalizing as per DEFAULT_STYLES

Also, auto-initializes widgets as per initializer blocks in DEFAULT_INITIALIZERS (e.g. setting Composite default layout)

Follows the Proxy Design Pattern

Direct Known Subclasses

MenuProxy, ShellProxy, TabItemProxy

Constant Summary collapse

DEFAULT_STYLES = 
{
  "text"        => [:border],
  "table"       => [:border],
  "spinner"     => [:border],
  "list"        => [:border, :v_scroll],
  "button"      => [:push],
  "menu_item"   => [:push],
}
DEFAULT_INITIALIZERS = 
{
  "composite" => proc do |composite|
    composite.setLayout(GridLayout.new)
  end,
  "table" => proc do |table|
    table.setHeaderVisible(true)
    table.setLinesVisible(true)
  end,
  "table_column" => proc do |table_column|
    table_column.setWidth(80)
  end,
  "group" => proc do |group|
    group.setLayout(GridLayout.new)
  end,
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from DataBinding::ObservableWidget

#method_missing

Constructor Details

#initialize(underscored_widget_name, parent, args) ⇒ WidgetProxy

Initializes a new SWT Widget

Styles is a comma separate list of symbols representing SWT styles in lower case



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# File 'lib/glimmer/swt/widget_proxy.rb', line 54

def initialize(underscored_widget_name, parent, args)
  styles, extra_options = extract_args(underscored_widget_name, args)
  swt_widget_class = self.class.swt_widget_class_for(underscored_widget_name)
  @swt_widget = swt_widget_class.new(parent.swt_widget, style(underscored_widget_name, styles), *extra_options)
  DEFAULT_INITIALIZERS[underscored_widget_name]&.call(@swt_widget)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Glimmer::DataBinding::ObservableWidget

Instance Attribute Details

#swt_widget ⇒ Object (readonly)

Returns the value of attribute swt_widget.



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# File 'lib/glimmer/swt/widget_proxy.rb', line 49

def swt_widget
  @swt_widget
end

Class Method Details

.swt_widget_class_for(underscored_widget_name) ⇒ Object

This supports widgets in and out of basic SWT



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# File 'lib/glimmer/swt/widget_proxy.rb', line 146

def self.swt_widget_class_for(underscored_widget_name)
  swt_widget_name = underscored_widget_name.camelcase(:upper)
  swt_widget_class = eval(swt_widget_name)
  unless swt_widget_class.ancestors.include?(org.eclipse.swt.widgets.Widget)
    Glimmer.logger&.debug("Class #{swt_widget_class} matching #{underscored_widget_name} is not a subclass of org.eclipse.swt.widgets.Widget")
    return nil
  end
  swt_widget_class
rescue NameError => e
  Glimmer.logger&.debug e.message
  # Glimmer.logger&.debug("#{e.message}\n#{e.backtrace.join("\n")}")
  nil
rescue => e
  Glimmer.logger&.debug e.message
  # Glimmer.logger&.debug("#{e.message}\n#{e.backtrace.join("\n")}")
  nil
end

.widget_exists?(underscored_widget_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/widget_proxy.rb', line 141

def self.widget_exists?(underscored_widget_name)
  !!swt_widget_class_for(underscored_widget_name)
end

Instance Method Details

#add_observer(observer, property_name) ⇒ Object

Used for data-binding only. Consider renaming or improving to avoid the confusion it causes



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# File 'lib/glimmer/swt/widget_proxy.rb', line 187

def add_observer(observer, property_name)
  property_listener_installers = @swt_widget.class.ancestors.map {|ancestor| widget_property_listener_installers[ancestor]}.compact
  widget_listener_installers = property_listener_installers.map{|installer| installer[property_name.to_s.to_sym]}.compact if !property_listener_installers.empty?
  widget_listener_installers.each do |widget_listener_installer|
    widget_listener_installer.call(observer)
  end
end

#async_exec(&block) ⇒ Object 



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# File 'lib/glimmer/swt/widget_proxy.rb', line 164

def async_exec(&block)
  DisplayProxy.instance.async_exec(&block)
end

#can_add_observer?(property_name) ⇒ Boolean

TODO Consider renaming these methods as they are mainly used for data-binding

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/widget_proxy.rb', line 182

def can_add_observer?(property_name)
  @swt_widget.class.ancestors.map {|ancestor| widget_property_listener_installers[ancestor]}.compact.map(&:keys).flatten.map(&:to_s).include?(property_name.to_s)
end

#can_handle_observation_request?(observation_request) ⇒ Boolean

TODO eliminate duplication in the following methods perhaps by relying on exceptions

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/widget_proxy.rb', line 201

def can_handle_observation_request?(observation_request)
  observation_request = observation_request.to_s
  if observation_request.start_with?('on_event_')
    constant_name = observation_request.sub(/^on_event_/, '')
    SWTProxy.has_constant?(constant_name)
  elsif observation_request.start_with?('on_')
    event = observation_request.sub(/^on_/, '')
    can_add_listener?(event)
  else
    false
  end
end

#content(&block) ⇒ Object 



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# File 'lib/glimmer/swt/widget_proxy.rb', line 224

def content(&block)
  Glimmer::DSL::Engine.add_content(self, DSL::WidgetExpression.new, &block)
end

#dispose ⇒ Object 



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# File 'lib/glimmer/swt/widget_proxy.rb', line 176

def dispose
  @swt_widget.dispose
end

#extract_args(underscored_widget_name, args) ⇒ Object 



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# File 'lib/glimmer/swt/widget_proxy.rb', line 61

def extract_args(underscored_widget_name, args)
  @arg_extractor_mapping ||= {
    'menu_item' => lambda do |args|
      index = args.delete(args.last) if args.last.is_a?(Numeric)
      extra_options = [index].compact
      styles = args
      [styles, extra_options]
    end,
  }
  if @arg_extractor_mapping[underscored_widget_name]
    @arg_extractor_mapping[underscored_widget_name].call(args)
  else
    [args, []]
  end
end

#get_attribute(attribute_name) ⇒ Object 



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# File 'lib/glimmer/swt/widget_proxy.rb', line 96

def get_attribute(attribute_name)
  widget_custom_attribute = widget_custom_attribute_mapping[attribute_name.to_s]
  if widget_custom_attribute
    @swt_widget.send(widget_custom_attribute[:getter][:name])
  else
    @swt_widget.send(attribute_getter(attribute_name))
  end
end

#handle_observation_request(observation_request, &block) ⇒ Object 



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# File 'lib/glimmer/swt/widget_proxy.rb', line 214

def handle_observation_request(observation_request, &block)
  if observation_request.start_with?('on_event_')
    constant_name = observation_request.sub(/^on_event_/, '')
    add_swt_event_listener(constant_name, &block)
  elsif observation_request.start_with?('on_')
    event = observation_request.sub(/^on_/, '')
    add_listener(event, &block)
  end
end

#has_attribute?(attribute_name, *args) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/widget_proxy.rb', line 77

def has_attribute?(attribute_name, *args)
  widget_custom_attribute = widget_custom_attribute_mapping[attribute_name.to_s]
  if widget_custom_attribute
    @swt_widget.respond_to?(widget_custom_attribute[:setter][:name])
  else
    @swt_widget.respond_to?(attribute_setter(attribute_name), args)
  end
end

#has_style?(style) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/swt/widget_proxy.rb', line 172

def has_style?(style)
  (@swt_widget.style & SWTProxy[style]) == SWTProxy[style]
end

#remove_observer(observer, property_name) ⇒ Object 



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# File 'lib/glimmer/swt/widget_proxy.rb', line 195

def remove_observer(observer, property_name)
  # TODO consider implementing if remove_observer is needed (consumers can remove listener via SWT API)
end

#set_attribute(attribute_name, *args) ⇒ Object 



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

def set_attribute(attribute_name, *args)
  widget_custom_attribute = widget_custom_attribute_mapping[attribute_name.to_s]
  if widget_custom_attribute
    widget_custom_attribute[:setter][:invoker].call(@swt_widget, args)
  else
    apply_property_type_converters(attribute_name, args)
    @swt_widget.send(attribute_setter(attribute_name), *args) unless @swt_widget.send(attribute_getter(attribute_name)) == args.first
  end
end

#sync_exec(&block) ⇒ Object 



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# File 'lib/glimmer/swt/widget_proxy.rb', line 168

def sync_exec(&block)
  DisplayProxy.instance.sync_exec(&block)
end

#widget_property_listener_installers ⇒ Object 



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

def widget_property_listener_installers
  @swt_widget_property_listener_installers ||= {
    Java::OrgEclipseSwtWidgets::Control => {
      :focus => proc do |observer|
        on_focus_gained { |focus_event|
          observer.call(true)
        }
        on_focus_lost { |focus_event|
          observer.call(false)
        }
      end,
    },
    Java::OrgEclipseSwtWidgets::Text => {
      :text => proc do |observer|
        on_modify_text { |modify_event|
          observer.call(@swt_widget.getText)
        }
      end,
    },
    Java::OrgEclipseSwtWidgets::Button => {
      :selection => proc do |observer|
        on_widget_selected { |selection_event|
          observer.call(@swt_widget.getSelection)
        }
      end
    },
    Java::OrgEclipseSwtWidgets::Spinner => {
      :selection => proc do |observer|
        on_widget_selected { |selection_event|
          observer.call(@swt_widget.getSelection)
        }
      end
    }
  }
end