[R] RGtk2 - retrieve ggraphics mouse coordinates during drag-and-drop event

john verzani jverzani at gmail.com
Mon Dec 28 04:17:15 CET 2009


Mark Heckmann <mark.heckmann <at> gmx.de> writes:

> 
> Hi all,
> 
> I have a gtable and a ggraphic widget.
> I want to drag an element from the table onto the graphic.
> When the drag object is released over the ggraphic widget, I want the  
> mouse coordinates inside the ggraphic to be returned.
> Right now I do not know how to get the mouse ccordinates of the  
> ggraphic widget at any given time.
> How can I access the ggraphics mouse coordinates?
> 

The handler has h$x and h$y components to do this. In your code 
(which I clipped to save space) you might
look at:


defHandlerTarget = function(h, ...){
theArgs <- list(...)
w <- theArgs[[1]]

allocation = w$GetAllocation()
## h$x, h$y give x,y coords for g
x = h$x/allocation$width
y = 1 - (allocation$height - h$y)/allocation$height
print(c(x,y))
}

If that doesn't help, let me know.

> Below you find my sample code (windows only due to ggraphics).
> 

(The ggraphics widget works with linux and mac too, although the mac can have
issues with some installations.)


> TIA,
> Mark
> 

..snip..

> –––––––––––––––––––––––––––––––––––––––
> Mark Heckmann
> Dipl. Wirt.-Ing. cand. Psych.
> Vorstraße 93 B01
> 28359 Bremen
> Blog: www.markheckmann.de
> R-Blog: http://ryouready.wordpress.com
> 
>




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