Module: Glimmer::Tk::DraggableAndDroppable

Included in:
WidgetProxy
Defined in:
lib/glimmer/tk/draggable_and_droppable.rb

Defined Under Namespace

Classes: DragAndDropEvent

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#on_drag_motion_block ⇒ Object

Returns the value of attribute on_drag_motion_block.



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 27

def on_drag_motion_block
  @on_drag_motion_block
end

Instance Method Details

#drag_source=(value) ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 42

def drag_source=(value)
  @drag_source = value
  if @drag_source
    make_draggable
  else
    make_non_draggable
  end
end

#drop_target=(value) ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 51

def drop_target=(value)
  @drop_target = value
  if @drop_target
    make_droppable
  else
    make_non_droppable
  end
end

#handle_listener(listener_name, &listener) ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 29

def handle_listener(listener_name, &listener)
  case listener_name.to_s.downcase
  when 'drag_start'
    self.on_drag_start_block = listener
  when 'drag_motion'
    self.on_drag_motion_block = listener
  when 'drop'
    self.on_drop_block = listener
  else
    super
  end
end

#make_draggable ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 81

def make_draggable
  drag_event = nil
  bind("<DropAcceptedEvent>", proc { |event| drag_event.drop_accepted = true })
  bind("B1-Motion", proc { |tk_event|
    if drag_event.nil?
      tooltip = WidgetProxy.new('toplevel', root_parent_proxy, [])
      tooltip.overrideredirect(1) #create tooltip window to display dragged data
      tooltip.geometry("+#{tk_event.x_root + 10}+#{tk_event.y_root - 2}")
      drag_event = DragAndDropEvent.new(self, nil, tooltip, tk_event.x_root, tk_event.y_root, nil, false)
      if @drag_source
        tk_event.widget.configure(:cursor => "hand2")
        # Default data to drag is text
        drag_event.data = if textvariable_defined?
          tk.textvariable.value
        elsif has_attribute?('text')
          tk.text
        elsif has_attribute?('selection')
          selection.first
        end
        tooltip_label = WidgetProxy.new('label', tooltip, [])
        tooltip_label.text = drag_event.data
        tooltip_label.pack # TODO look into using grid instead to be consistent with the modern Tk way
      elsif !@on_drag_start_block.nil?
        @on_drag_start_block.call(drag_event)
        if tooltip.winfo_children().length == 0
          tooltip_label = WidgetProxy.new('label', tooltip, [])
          tooltip_label.text = drag_event.data
          tooltip_label.pack # TODO look into using grid instead to be consistent with the modern Tk way
        end
      end
    else
      drag_event.x_root, drag_event.y_root = tk_event.x_root, tk_event.y_root
      drag_event.drop_accepted = false
      move_over_widget = tk_event.widget.winfo_containing(tk_event.x_root, tk_event.y_root)
      drag_event.target = move_over_widget.proxy
      move_over_widget.event_generate("<DropCheckEvent>", :data => drag_event.to_json)
      if @on_drag_motion_block.nil?
        # Default motion behavior:
        # 1.Change cursor to show whether text can be dropped.
        # 2.Move tooltip with dragged data.
        if drag_event.drop_accepted
          tk_event.widget.configure(:cursor => "hand1")
        else
          tk_event.widget.configure(:cursor => "hand2")
        end
        drag_event.tooltip.geometry("+#{tk_event.x_root + 10}+#{tk_event.y_root - 2}")
      else
        @on_drag_motion_block.call(drag_event)
      end
    end
  })
  bind("ButtonRelease-1", proc { |tk_event|
    if drag_event
      drag_event.target = tk_event.widget.winfo_containing(tk_event.x_root, tk_event.y_root).proxy
      drag_event.source.configure(:cursor => "")
      drag_event.target.event_generate("<DropEvent>", :data => drag_event.to_json)
      drag_event.tooltip.destroy
      drag_event = nil
    end
  })
end

#make_droppable ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 149

def make_droppable
  self.on_drop_block = Proc.new do |event|
    event.target.text = event.data if event.target.has_attribute?('text')
    event.target.items += [event.data] if event.target.has_attribute?('items')
    event.target.selection += [event.data] if event.target.has_attribute?('selection')
  end
end

#make_non_draggable ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 143

def make_non_draggable
  @tk.bind_remove("B1-Motion")
  @tk.bind_remove("ButtonRelease-1")
  @tk.bind_remove("<DropAcceptedEvent>")
end

#make_non_droppable ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 157

def make_non_droppable
  @tk.bind_remove('<DropEvent>')
  @tk.bind_remove('<DropCheckEvent>')
  @on_drop_block = nil
end

#on_drag_start_block=(block) ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 60

def on_drag_start_block=(block)
  @on_drag_start_block = block
  make_draggable
end

#on_drop_block=(value) ⇒ Object 



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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 65

def on_drop_block=(value)
  @on_drop_block = value
  self.tk.bind("<DropEvent>", proc { |tk_event|
    drop_event = DragAndDropEvent.json_create(JSON.parse("{" + tk_event.detail + "}"))
    @on_drop_block.call(drop_event) if self == drop_event.target
  })
  self.tk.bind("<DropCheckEvent>", proc { |tk_event|
    drop_check_event = DragAndDropEvent.json_create(JSON.parse("{" + tk_event.detail + "}"))
    drop_check_event.source.event_generate("<DropAcceptedEvent>")
  })
end

#textvariable_defined? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/glimmer/tk/draggable_and_droppable.rb', line 77

def textvariable_defined?
  tk_widget_has_attribute_setter?(:textvariable) && !tk.textvariable.nil?
end