fxruby users - Apr 2005 - Draw on top of a widget?

Is there a way to draw an arbitrary text string "on top of" an FXRuby 
widget, in this case an FXListBox? I want to overwrite a portion of the 
text in the selection box with that same text but drawn as if 
"selected". Can this be done in FXRuby?

What am I trying to do? I''m making a version of the FXListBox widget 
with a keyboard interface. As you type characters, the first item in the 
list that matches the typed character(s) is selected. I have the key 
capturing and list matching routine down, and the correct item is 
getting displayed in the selection box. But I want to visually indicate 
what portion of that item has matched the typed text, and thus I want to 
draw just a portion of the item in the "selected" state. Since the 
selection box portion of the FXListBox widget is an FXButton under the 
skin in Fox and FXButtons don''t have any way to display partial 
selection like say an FXTextField would, I don''t see any way to do this
directly in the FXListBox itself. Thus my idea of this "draw on top"
kludge.

I know a much cleaner approach would be to make a Fox FXButton widget 
that implements and displays subselection of the caption, make a new Fox 
"MyFXListBox" that uses that altered FXButton, all in C++, and make
the
glue code that imports that new widget into FXRuby. But my C++ is really 
weak, and I don''t know thing one about SWIG. If it turns out that the 
"draw on top" kludge can''t work, I''d appreciate
seeing the source for
any  custom Fox C++ widgets that have been merged into FXRuby, or at 
least pointers for getting started with SWIG.

Thanks for your time.

David Peoples

David Peoples schrieb:
> Is there a way to draw an arbitrary text string "on top of" an
FXRuby
> widget, in this case an FXListBox? I want to overwrite a portion of 
> the text in the selection box with that same text but drawn as if 
> "selected". Can this be done in FXRuby?
>
> What am I trying to do? I''m making a version of the FXListBox
widget
> with a keyboard interface. As you type characters, the first item in 
> the list that matches the typed character(s) is selected. I have the 
> key capturing and list matching routine down, and the correct item is 
> getting displayed in the selection box. But I want to visually 
> indicate what portion of that item has matched the typed text, and 
> thus I want to draw just a portion of the item in the "selected" 
> state. Since the selection box portion of the FXListBox widget is an 
> FXButton under the skin in Fox and FXButtons don''t have any way to
> display partial selection like say an FXTextField would, I don''t
see
> any way to do this directly in the FXListBox itself. Thus my idea of 
> this "draw on top" kludge.
>
> I know a much cleaner approach would be to make a Fox FXButton widget 
> that implements and displays subselection of the caption, make a new 
> Fox "MyFXListBox" that uses that altered FXButton, all in C++,
and
> make the glue code that imports that new widget into FXRuby. But my 
> C++ is really weak, and I don''t know thing one about SWIG. If it
turns
> out that the "draw on top" kludge can''t work,
I''d appreciate seeing
> the source for any  custom Fox C++ widgets that have been merged into 
> FXRuby, or at least pointers for getting started with SWIG.
>
> Thanks for your time.
>
> David Peoples
Hi.

That''s very simple.

Subclass the widget you want to draw upon and overload onPaint(sender, 
sel, event) this way:

    def onPaint(sender, sel, event)
       super // Draws the widget
       dc = FXDCWindow.new(self, event)
       font = FXFont.new(getApp, "Verdana", 10) // whatever you like
       font.create
       dc.font = font
       dc.drawText(event.rect.x, event.rect.y, "Hello World") //
choords
have to be changed if you don''t want to draw in the upper left corner
    end

Maybe you will have to add Responder functionality to your widget:

class MyList
    include Responder

    def initialize(...)
       FXMAPFUNC(SEL_PAINT, 0, "onPaint")
    end

    ...
end
      
Is this what you wanted to do?

Regards,
Jannis