From: "Daniel P. Zepeda" <daniel@...>
Date: 2003-01-28T08:00:40+09:00
Subject: Re: [FXRuby] How to force a paint on a canvas.

On Tue, 28 Jan 2003 07:28:34 +0900
Steve Tuckner <STUCKNER@MULTITECH.COM> wrote:

> Hello all,
>  
> I am working on a simple turtle graphics demonstration program that I
> can use to give a demonstration to several classes of 1st graders. The
> problem I am having is that I can draw on the canvas widget, but I can't
> force it repaint after I draw. The canvas code looks like below:
>  
> @outputCanvas.connect(SEL_PAINT) do |sender, sel, event|
>     dc = FXDCWindow.new(@outputCanvas)
>     dc.background = FXColor::White
>     dc.foreground = FXColor::White
>     dc.fillRectangle(event.rect.x, event.rect.y, event.rect.w,
> event.rect.h)
>     dc.foreground = FXColor::Red
>     @actions.each do |action|
>       action.do(dc)
>     end
> #    dc.fillRectangle(0,0,@x,@y)
> #    @x += 10; @y += 10
>     dc.end
> end
> 
> on a paint it iterates through a list of actions which do lines and
> turns (for now). It works fine except that I have to cover and uncover
> the window to see the results.
>  
> I tried FXWindow#repaint and FXApplication#repaint to no avail.
>  
> Any ideas?

Try @outputCanvas.update, although you probably want to reorganize your code
and connect it to SEL_MOTION instead of SEL_PAINT. As you are seeing,
SEL_PAINT only gets sent when the window has been obscured and is
uncovered. Look at scribble.rb in the 'examples' directory of the distribution.

>  
> Thanks,
>  
> Steve Tuckner
>  
> 


-- 
"Daniel P. Zepeda" <daniel@z,e,p,e,d,a,-,z,o,n,e.net>
(Remove commas for address)