Re: Events in GnomeCanvas

[Havoc Pennington <hp redhat com>]

BTW, gnome-devel-list is probably a better place to ask questions
(more developers read it).

Loban Rahman <loban@enigma.caltech.edu> writes:
> Question 1:
> When I click a mouse button (ie. press and release), shouldn't the events
> generated by a GDK_BUTTON_PRESS and then a GDK_BUTTON_RELEASE? Instead, I'm
> getting one GDK_MOTION_NOTIFY in between them each time I clicked. This is
> happening on a GnomeCanvas.
> 

You should always get a press and a release, but there are no
guarantees about what comes in between them.

> Question 2:
> I have a GnomeCanvasPixbuf item on a GnomeCanvas. The item has transparent
> areas. Now, when using this, it seems that the transparent areas generate
> no events (in particular GDK_MOTION_NOTIFY) when the mouse is over them.
> But the non-transparent areas do generate events. However, if I press the
> mouse button on a non-transparent area, and then drag it to a transparent
> area with the button still down, the transparent areas start generating 
> GDK_MOTION_NOTIFY events. Is this inconsistency on purpose? And if so, why?
> 

There's a pointer grab in effect while the button is held down. You
should also get motion events if you drag to an entirely different
section of the screen.

There should be a way to turn this grab off, IMO, but right now there isn't.

Havoc