[fxruby-users] Handling Escape key-press in dialog window

Lyle Johnson lyle at lylejohnson.name
Fri Jan 11 12:20:02 EST 2008

On Jan 11, 2008, at 11:04 AM, Vladimir Konrad wrote:

> I am trying to do a log-in screen for an application and have a  
> problem
> with handling ESC key - when you press it, the dialog box closes and
> the application opens. What I would like is to quit the application if
> user hits ESC key while the initial log-in window is open.
> The LoginWindow class looks like:
> class LoginWindow < FXDialogBox
>   def initialize(owner)
>     super(owner, "gbrs - log in", :opts => DECOR_TITLE |
> DECOR_BORDER, :width => 300, :height => 250)
>     <paint the log-in window here>
>     # the following code should do it but it does not
>     self.accelTable.removeAccel(fxparseAccel("ESC"))
>     self.accelTable.addAccel(fxparseAccel("ESC"), getApp(), \
>   end
> end

The problem is that the FXDialogBox doesn't store that mapping for  
the "Esc" key in its accelerator table, as you're assuming here. The  
FXDialogBox is just listening for SEL_KEYPRESS and SEL_KEYRELEASE  
messages and checking to see if the key being pressed (and released)  
is the Escape key (KEY_Escape).

See what happens if you do something like this:

	self.connect(SEL_KEYPRESS) do |sender, sel, event|
		app.exit(0) if event.code == KEY_Escape

In other words, we're overriding the default handler for SEL_KEYPRESS  
to check for the KEY_Escape keypress, and exiting the application if  
we see it. If we don't, the handler returns 'false' to indicate that  
we didn't handle whatever key was pressed.

Hope this helps,


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