[Sugar-devel] tracking CTRL and ALT keys in a sugar activity

[Erik Blankinship]

On Fri, Dec 17, 2010 at 4:52 PM, Walter Bender <walter.bender at gmail.com>wrote:

> On Fri, Dec 17, 2010 at 4:48 PM, Erik Blankinship <erikb at mediamods.com>
> wrote:
> > I would like to know when CTRL or ALT are being pressed in my sugar
> > activity.  To be complete, I would need to know if they are pressed when
> the
> > activity regains focus (e.g. changing activities or if the focus was in a
> > textfield).
> >
> > I am not sure of the right way to do this. My current thinking is to keep
> a
> > dictionary with CTRL_L, CTRL_R, ALT_L, and ALT_R key states which are
> > updated on key-press and key-release events.
> >
> > But this model breaks as soon the application loses focus and the user
> > releases one of those keys -- I would never know when there is a
> mouse-up.
> > My workaround is to clear the dictionary when the application loses
> focus. I
> > can also attempt to update the dictionary when there are mouse events by
> > skimming information from these events regarding CTRL and ALT modifiers.
> >
> > Is this a good approach? Maybe I am missing something obvious?
>
> Maybe I am misunderstanding the complexity of what you are trying to
> do...


I want to change my cursor into a magicwand whenever CTRL or ALT are held
down, and when none of them are pressed, I want to change my cursor into the
system pointer.  I do not want someone to cheat by switching out of the
activity with CTRL down and return with my activity thinking CTRL is still
down.

don't you simply check the mode mask when you get a keyboard
> event to determine whether or not Alt or Ctrl is pressed?
>

Thank you!  Yes, I can do that while the activity is running.  That sure
makes things simpler while the activity has focus.

But to determine if CTRL or ALT are pressed when returning to the activity?
 I am not sure what signal to listen to that would have the correct mode
mask.
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