From: David Bailey <david.bailey@...>
Date: 2006-04-01T23:14:59+09:00
Subject: Re: Ruby/Tk (X,Y) Coordinate Question

Chris Alfeld wrote:
> Actually, what I think you are looking for is the translation from
> "real" coordinates to canvas coordinates for which you want:
> 
> canvas.canvasx and canvas.canvasy
> 
> also note that you can bind mouse clicks to Tkc objects, though be
> careful that if the fill is none then TkcRect's won't register clicks
> on the interior.
> 
> So, in summary, see TkCanvas.canvasx, TkCanvas.canvasy, and 
> TkcRectangle.bind
>  (actually part of the TkcTagAccess mixin).
> 
> Another command you may find useful is TkCanvas.find_overlapping which
> can translate a mouse click to a TkcObject.  Thus code such as:
> 
> obj_at_xy = 
> @canvas.find_overlapping(@canvas.canvasx(x),@canvas.canvasy(y),
>   @canvas.canvasx(x),@canvas.canvasy(y))
> 
> Here I believe x,y should be from %x,%y, that is, relative to the canvas 
> widget.
> 
> c.


Chris,

I'm researching these canvasx and canvasy methods now.  I'll let you 
know how I make out.  Thank you for your help.

David

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