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Philippe Lang

2006-Oct-07 12:15 UTC

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

Hi,

I have read that message handlers can return a value, either true or false,
depending on if the handler actually did something, or not. In the latter case,
the message is forwarded to the default message handler.

I have tried this, and found something strange: in this code, decommenting:

    @data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|
        puts d.code
        false
    end

... breaks the update of the textfield. The handler returns false in every case,
it should have no effect at all, no?

I''m I missing something maybe?

Philippe


----------------------------
#!/usr/bin/ruby

require ''fox16''

include Fox

class MyWindow < FXMainWindow
    
  def initialize(app)

    super(app, "Window", nil, nil, DECOR_ALL, 0, 0, 200, 100)

    # Menu bar stretched along the top of the main window
    menubar = FXMenuBar.new(self, LAYOUT_SIDE_TOP|LAYOUT_FILL_X)
  
    # File menu
    filemenu = FXMenuPane.new(self)
    FXMenuTitle.new(menubar, "&File", nil, filemenu)
    FXMenuCommand.new(filemenu, "&Quit\tCtl-Q\tQuit the
application",
        nil, app, FXApp::ID_QUIT)

    # Frames
    frame = FXMatrix.new(self, 4,
        LAYOUT_FILL_X|LAYOUT_FILL_Y|FRAME_THICK|FRAME_RAISED)

    # Data target
    @data_target = FXDataTarget.new()
    
    # Widget
    @data_widget = FXTextField.new(frame, 5, @data_target,
FXDataTarget::ID_VALUE)
    
    # We put some data into the data target
    @data_target.value = 123
    
    # We add a message handler
    #@data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|
    #    puts d.code
    #    false
    #end
    
  end

  def create
    super
    show(PLACEMENT_SCREEN)
  end

end

if __FILE__ == $0
  application = FXApp.new("Attik System", "FXRuby Test")
  MyWindow.new(application)
  application.create
  application.run
end


---------------
Philippe Lang
Attik System

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Philippe Lang

2006-Oct-07 15:26 UTC

head link

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

I wrote:
> Hi,
> 
> I have read that message handlers can return a value, either
> true or false, depending on if the handler actually did
> something, or not. In the latter case, the message is
> forwarded to the default message handler.
> 
> I have tried this, and found something strange: in this code,
> decommenting: 
> 
>     @data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|   
>         puts d.code false
>     end
> 
> ... breaks the update of the textfield. The handler returns
> false in every case, it should have no effect at all, no?
> 
> I''m I missing something maybe?
> 
> Philippe
> 
> 
> ----------------------------
> #!/usr/bin/ruby
> 
> require ''fox16''
> 
> include Fox
> 
> class MyWindow < FXMainWindow
> 
>   def initialize(app)
> 
>     super(app, "Window", nil, nil, DECOR_ALL, 0, 0, 200, 100)
> 
>     # Menu bar stretched along the top of the main window
>     menubar = FXMenuBar.new(self, LAYOUT_SIDE_TOP|LAYOUT_FILL_X)
> 
>     # File menu
>     filemenu = FXMenuPane.new(self)
>     FXMenuTitle.new(menubar, "&File", nil, filemenu)
>     FXMenuCommand.new(filemenu, "&Quit\tCtl-Q\tQuit the
application",
>         nil, app, FXApp::ID_QUIT)
> 
>     # Frames
>     frame = FXMatrix.new(self, 4,
>         LAYOUT_FILL_X|LAYOUT_FILL_Y|FRAME_THICK|FRAME_RAISED)
> 
>     # Data target
>     @data_target = FXDataTarget.new()
> 
>     # Widget
>     @data_widget = FXTextField.new(frame, 5, @data_target,
> FXDataTarget::ID_VALUE) 
> 
>     # We put some data into the data target
>     @data_target.value = 123
> 
>     # We add a message handler
>     #@data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|  
>     #    puts d.code #    false
>     #end
> 
>   end
> 
>   def create
>     super
>     show(PLACEMENT_SCREEN)
>   end
> 
> end
> 
> if __FILE__ == $0
>   application = FXApp.new("Attik System", "FXRuby
Test")
>   MyWindow.new(application) application.create
>   application.run
> end
Hi again,

I understand more or less what happens here. The link between the data target
and the widget works here:

----------------------------------------
#!/usr/bin/ruby

require ''fox16''

include Fox

class MyWindow < FXMainWindow
    
  def initialize(app)

    super(app, "Window", nil, nil, DECOR_ALL, 0, 0, 200, 100)

    # Menu bar stretched along the top of the main window
    menubar = FXMenuBar.new(self, LAYOUT_SIDE_TOP|LAYOUT_FILL_X)
  
    # File menu
    filemenu = FXMenuPane.new(self)
    FXMenuTitle.new(menubar, "&File", nil, filemenu)
    FXMenuCommand.new(filemenu, "&Quit\tCtl-Q\tQuit the
application",
        nil, app, FXApp::ID_QUIT)

    # Frames
    frame = FXMatrix.new(self, 4,
        LAYOUT_FILL_X|LAYOUT_FILL_Y|FRAME_THICK|FRAME_RAISED)

    # Data target
    @data_target = FXDataTarget.new()
    
    # Widget
    #@data_widget = FXTextField.new(frame, 5, @data_target,
FXDataTarget::ID_VALUE)
    @data_widget = FXTextField.new(frame, 5)
    
    # We put some data into the data target
    @data_target.value = 123

    # We add a message handler
    @data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|
        puts data.code
        0
    end
    
    # We connect the data target to the widget
    @data_widget.target = @data_target
    @data_widget.selector = FXDataTarget::ID_VALUE

  end

  def create
    super
    show(PLACEMENT_SCREEN)
  end

end

if __FILE__ == $0
  application = FXApp.new("Attik System", "FXRuby Test")
  MyWindow.new(application)
  application.create
  application.run
end
----------------------------------------


But here it does not:

----------------------------------------
#!/usr/bin/ruby

require ''fox16''

include Fox

class MyWindow < FXMainWindow
    
  def initialize(app)

    super(app, "Window", nil, nil, DECOR_ALL, 0, 0, 200, 100)

    # Menu bar stretched along the top of the main window
    menubar = FXMenuBar.new(self, LAYOUT_SIDE_TOP|LAYOUT_FILL_X)
  
    # File menu
    filemenu = FXMenuPane.new(self)
    FXMenuTitle.new(menubar, "&File", nil, filemenu)
    FXMenuCommand.new(filemenu, "&Quit\tCtl-Q\tQuit the
application",
        nil, app, FXApp::ID_QUIT)

    # Frames
    frame = FXMatrix.new(self, 4,
        LAYOUT_FILL_X|LAYOUT_FILL_Y|FRAME_THICK|FRAME_RAISED)

    # Data target
    @data_target = FXDataTarget.new()
    
    # Widget
    #@data_widget = FXTextField.new(frame, 5, @data_target,
FXDataTarget::ID_VALUE)
    @data_widget = FXTextField.new(frame, 5)
    
    # We put some data into the data target
    @data_target.value = 123
    
    # We connect the data target to the widget
    @data_widget.target = @data_target
    @data_widget.selector = FXDataTarget::ID_VALUE

    # We add a message handler
    @data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|
        puts data.code
        0
    end

  end

  def create
    super
    show(PLACEMENT_SCREEN)
  end

end

if __FILE__ == $0
  application = FXApp.new("Attik System", "FXRuby Test")
  MyWindow.new(application)
  application.create
  application.run
end
----------------------------------------


To say things briefly, we have to connect the data target to it''s
widget AFTER we have added our first handler. Otherwise the link between the
data target and the widget gets deleted:

The problem comes from here:

----------------------------------------
module Responder2
  #
  # Assign a "handler" for all FOX messages of type _messageType_
  # sent from this widget. When called with only one argument,
  # a block is expected, e.g.
  #
  #     aButton.connect(SEL_COMMAND) { |sender, selector, data|
  #       ... code to handle this event ...
  #     }
  #
  # The arguments passed into the block are the _sender_ of the
  # message (i.e. the widget), the _selector_ for the message, and
  # any message-specific _data_.
  #
  # When #connect is called with two arguments, the second argument
  # should be some callable object such as a Method or Proc instance, e.g.
  #
  #     aButton.connect(SEL_COMMAND, method(:onCommand))
  #
  # As with the one-argument form of #connect, the callable object
  # will be "called" with three arguments (the sender, selector and
  # message data).
  #
  def connect(messageType, callableObject=nil, &block)
    unless instance_variables.include?(''@pseudoTarget'')
      @pseudoTarget = Fox::FXPseudoTarget.new
      self.target = @pseudoTarget
    end
    @pseudoTarget.pconnect(messageType, callableObject, block)
  end
End
----------------------------------------


When calling

    @data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|
        puts data.code
        0
    end

... A pseudoTarget is being created, and the target starts pointing at it.


I don''t know how to handle that. For now, I have just added an
exception, like this:

----------------------------------------
module Responder2
  #
  # Assign a "handler" for all FOX messages of type _messageType_
  # sent from this widget. When called with only one argument,
  # a block is expected, e.g.
  #
  #     aButton.connect(SEL_COMMAND) { |sender, selector, data|
  #       ... code to handle this event ...
  #     }
  #
  # The arguments passed into the block are the _sender_ of the
  # message (i.e. the widget), the _selector_ for the message, and
  # any message-specific _data_.
  #
  # When #connect is called with two arguments, the second argument
  # should be some callable object such as a Method or Proc instance, e.g.
  #
  #     aButton.connect(SEL_COMMAND, method(:onCommand))
  #
  # As with the one-argument form of #connect, the callable object
  # will be "called" with three arguments (the sender, selector and
  # message data).
  #
  def connect(messageType, callableObject=nil, &block)
    unless instance_variables.include?(''@pseudoTarget'')
      
      # We check if another target is already registered.
      # This might be true for a widget already linked to an
      # FXDataTarget object.
      if self.target
        raise "A target is already registered for this object."
      end
      
      @pseudoTarget = Fox::FXPseudoTarget.new
      self.target = @pseudoTarget
    end
    @pseudoTarget.pconnect(messageType, callableObject, block)
  end
End
----------------------------------------



Cheers,

---------------
Philippe Lang
Attik System

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Jeroen van der Zijp

2006-Oct-10 14:59 UTC

head link

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

On Saturday 07 October 2006 07:15, Philippe Lang wrote:> Hi,
> 
> I have read that message handlers can return a value, either true or false,
depending on if the handler actually did something, or not. In the latter case,
the message is forwarded to the default message handler.
> 
> I have tried this, and found something strange: in this code, decommenting:
> 
>     @data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|
>         puts d.code
>         false
>     end
> 
> ... breaks the update of the textfield. The handler returns false in every
case, it should have no effect at all, no?
> 
> I''m I missing something maybe?
Do the same for the SEL_KEYRELEASE and it will work....


		- Jeroen

Philippe Lang

2006-Oct-10 16:17 UTC

head link

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

Jeroen van der Zijp wrote:> On Saturday 07 October 2006 07:15, Philippe Lang wrote:
>> Hi,
>> 
>> I have read that message handlers can return a value,
> either true or false, depending on if the handler actually
> did something, or not. In the latter case, the message is
> forwarded to the default message handler.
>> 
>> I have tried this, and found something strange: in this code,
>> decommenting: 
>> 
>>     @data_widget.connect(SEL_KEYPRESS) do |sender, selector, data|  
>>         puts d.code false
>>     end
>> 
>> ... breaks the update of the textfield. The handler returns
> false in every case, it should have no effect at all, no?
>> 
>> I''m I missing something maybe?
> 
> Do the same for the SEL_KEYRELEASE and it will work....
Hi,

I''m convinced it is not the problem: under FXRuby, message handling has
been implemented using "PseudoTargets", in order to simplify the way
you write message handlers. Connecting a handler to a widget changes its target
(the new target is the pseudo target!). So if you previously set the target of
widget to an FXDataTarget, the link gets lost after you connect the handler.

This makes FXDataTarget objects pretty useless under FXRuby...

---------------
Philippe Lang
Attik System

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Joel VanderWerf

2006-Oct-10 22:15 UTC

head link

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

Philippe Lang wrote:> This makes FXDataTarget objects pretty useless under FXRuby...
Have you looked at FoxTails/Observable? FoxTails subclasses some of the 
Fox/FXRuby classes and defines an initialize method that (typically) 
takes an object and an attribute name instead of the usual target 
arguments. The attribute name is used to keep that attr in sync when the 
widget is used.

FoxTails uses Fox''s #connect mechanism for this functionality 
(typically, using SEL_COMMAND, SEL_FOCUSOUT, etc) rather than data 
targets. This means you can still use connect (with other messages) for 
other purposes. You can also use the #when_foo methods to register 
blocks of code to execute when the attr changes or matches a pattern.

Here''s a simple combobox example that lets you select an object (in 
terms of its string representation using #inspect) and then changes a 
label to display the class of the object.

#!/usr/bin/env ruby

require ''foxtails''

include Fox
include FoxTails

class ComboWindow < FXMainWindow
   observable :items, :selected

   def initialize(*args)
     super

     self.items = [:foo, "Bar", String, 3, ["a",
"b"], 1.23]
     self.selected = items[3]

     FXStatusBar.new(self,
        LAYOUT_SIDE_BOTTOM|LAYOUT_FILL_X|STATUSBAR_WITH_DRAGCORNER)

     mb = FXMenuBar.new(self, LAYOUT_SIDE_TOP|LAYOUT_FILL_X)

     file_menu = FXMenuPane.new(self)
     FXMenuTitle.new(mb, "&File", nil, file_menu)

     FXMenuCommand.new(file_menu, "&Quit\tCtl-Q\tQuit the
application.").
       connect(SEL_COMMAND) { getApp().exit }

     combo = FTComboBox.new(self, 20, self, :items, :selected,
                    COMBOBOX_STATIC|FRAME_THICK)
     def combo.display(item); item.inspect; end

     label = FXLabel.new(self, "")

     when_selected CHANGES do
       label.setText("Class of item is #{selected.class}")
     end

   end

   def create
     super
     show
   end
end

class ComboApp < FTApp
   def initialize
     super("Combo", "TEST")
     FoxTails.get_standard_icons
     ComboWindow.new(self, "Combo")
   end
end

ComboApp.new.run


-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

Philippe Lang

2006-Oct-11 06:37 UTC

head link

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

fxruby-users-bounces at rubyforge.org wrote:
>> This makes FXDataTarget objects pretty useless under FXRuby...
> 
> Have you looked at FoxTails/Observable? FoxTails subclasses
> some of the Fox/FXRuby classes and defines an initialize
> method that (typically) takes an object and an attribute name
> instead of the usual target arguments. The attribute name is
> used to keep that attr in sync when the widget is used.
> 
> FoxTails uses Fox''s #connect mechanism for this functionality
> (typically, using SEL_COMMAND, SEL_FOCUSOUT, etc) rather than
> data targets. This means you can still use connect (with
> other messages) for other purposes. You can also use the
> #when_foo methods to register blocks of code to execute when
> the attr changes or matches a pattern.
> 
> Here''s a simple combobox example that lets you select an
> object (in terms of its string representation using #inspect)
> and then changes a label to display the class of the object.
> 
> #!/usr/bin/env ruby
> 
> require ''foxtails''...

Thanks Joel, I have to check your library.

Otherwise, Lyle, do you think it would be possible to implement messaging in
FXRuby differently, without the FXPseudoTarget? I''m wondering why the
content of the FXPseudoTarget class cannot be included directly, at run-time, in
the object itself, rather than in in a separate class. This would avoid
modifying the target of an object when connecting a handler to it.


  class FXPseudoTarget < FXObject

    include Responder

    @@targets_of_pending_timers = {}
    @@targets_of_pending_chores = {}
    @@targets_of_pending_signals = {}
    @@targets_of_pending_inputs = {}

    #
    # Returns an initialized FXPseudoTarget object.
    #
    def initialize
      super
      @blocks = {}
    end

    #
    # Store an association between a message of type
    # _messageType_ with a callable object or a block.
    #
    def pconnect(messageType, callableObject, block)
      if callableObject.nil?
	@blocks[messageType] = block
      else
	@blocks[messageType] = callableObject
      end
      FXMAPTYPE(messageType, :onHandleMsg)
      
      case messageType
        when SEL_TIMEOUT
	  @@targets_of_pending_timers[self] = self
        when SEL_CHORE
	  @@targets_of_pending_chores[self] = self
        when SEL_SIGNAL
	  @@targets_of_pending_signals[self] = self
        when SEL_IO_READ, SEL_IO_WRITE, SEL_IO_EXCEPT
	  @@targets_of_pending_inputs[self] = self
      end
    end

    #
    # Handle a message from _sender_, with selector _sel_ and
    # message data _ptr_.
    #
    def onHandleMsg(sender, sel, ptr)
      messageType = Fox.FXSELTYPE(sel)
      result = @blocks[messageType].call(sender, sel, ptr)
      case messageType
        when SEL_TIMEOUT
	  @@targets_of_pending_timers.delete(self)
        when SEL_CHORE
	  @@targets_of_pending_chores.delete(self)
      end
      result
    end
  end


---------------
Philippe Lang
Attik System

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Lyle Johnson

2006-Oct-11 14:51 UTC

head link

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

On Oct 10, 2006, at 11:17 AM, Philippe Lang wrote:
> I''m convinced it is not the problem: under FXRuby, message
handling
> has been implemented using "PseudoTargets", in order to simplify
> the way you write message handlers. Connecting a handler to a  
> widget changes its target (the new target is the pseudo target!).  
> So if you previously set the target of widget to an FXDataTarget,  
> the link gets lost after you connect the handler.
>
> This makes FXDataTarget objects pretty useless under FXRuby...
Unless I''m misunderstanding what it is that you''re trying to
do, this
has nothing to do with FXRuby. A FOX widget (such a FXTextField) can  
only have a single message target. That target object can be an  
FXDataTarget, or it can be some other object that responds to  
messages, but there can only be one. You can''t (directly) connect an  
FXTextField to, say, both an FXDataTarget and some other object that  
handles SEL_KEYPRESS and SEL_KEYRELEASE messages sent from the  
FXTextField.

fxruby users - Oct 2006 - Data Targets and message handlers [was: Default double-click in FXTable?]

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]

[fxruby-users] Data Targets and message handlers [was: Default double-click in FXTable?]