Re: Key presses and releases

[Lyle Underwood <lyleunderwood gmail com>]

This must be different between my computer and yours. I'm on Ubuntu
9.10, are you on a linux system?

I compiled and ran your test code, but this too is affected by key
repeat. If I hold down the space bar for just a second then I get a
whole bunch of output.

In this example I only pressed the spacebar one time, and tried to hold
it down for exactly one second:

$ ./test 
Toggled (active)
Toggled (inactive)
Toggled (active)
Toggled (inactive)
Toggled (active)
Toggled (inactive)
Toggled (active)
Toggled (inactive)
Toggled (active)
Toggled (inactive)
Toggled (active)
Toggled (inactive)

For the first quarter to half a second there was only one
active/inactive pair, and then my key repeat kicked in and I got all the
rest. Is this not what happens for you?

Thanks for taking the time, by the way.

On Wed, 2009-12-23 at 16:24 +0600, Галымжан Кожаев wrote:
> I don't know why your code doesn't work. Look at this, I've written
> and tested this code:
> 
> bool hasToggled;
> 
> bool keyPressHandler(GdkEventKey* event) {
>   if(event->type == GDK_KEY_PRESS && event->keyval == GDK_space &&
> !hasToggled) {
>     hasToggled = true;
>     cout << "Toggled (active)" << endl;
>   }
>   else if(event->type == GDK_KEY_RELEASE && event->keyval == GDK_space
> && hasToggled) {
>     hasToggled = false;
>     cout << "Toggled (inactive)" << endl;
>   }
>   return false;
> }
> 
> gint main(int argc, char *argv[]) {
>   Gtk::Main program(argc, argv);
>   Gtk::Window wnd;
>   hasToggled = false;
>   wnd.signal_key_press_event().connect(sigc::ptr_fun(&keyPressHandler), false);
>   wnd.signal_key_release_event().connect(sigc::ptr_fun(&keyPressHandler),
> false);
>   program.run(wnd);
>   return 0;
> }
> 
> Try to compile and run it. Works perfectly, I think it's exactly what
> you need. Write if you have any problems.
> 
> 2009/12/23, Lyle Underwood <lyleunderwood gmail com>:
> > That's what I'm doing now. The problem is that the signals don't seem to
> > fire in this way. I expected the same behavior you did, I thought it
> > would work like this:
> >
> > pressed event <-- // spacebar held down
> > released event <-- // spacebar let go after a couple seconds
> >
> > pressed event <-- // spacebar held down
> > released event <-- // spacebar let go after a couple seconds
> >
> > pressed event <-- // spacebar held down
> > released event <-- // spacebar let go after a couple seconds
> >
> > But it actually does this:
> >
> > pressed event // <-- spacebar held down
> > released event
> > pressed event
> > released event
> > pressed event
> > released event
> > pressed event
> > released event
> > pressed event
> > released event // <-- spacebar let go after a couple seconds
> >
> > pressed event // <-- spacebar held down
> > released event
> > pressed event
> > released event
> > pressed event
> > released event
> > pressed event
> > released event
> > pressed event
> > released event // <-- spacebar let go after a couple seconds
> >
> > This results in the keyAlreadyPressed bool flipping between true and
> > false over and over in quick succession while the space bar is
> > depressed.
> >
> > On Wed, 2009-12-23 at 12:42 +0600, Галымжан Кожаев wrote:
> >> Hi,
> >>
> >> Maybe you can do like this:
> >>
> >> void onKeyPressed(...) {
> >>   if(!keyAlreadyPressed) {
> >>      // space toggled (now active)
> >>      keyAlreadyPressed = true;
> >>      //... additional handling
> >>   }
> >> }
> >>
> >> void onKeyReleased(...) {
> >>    // space toggled (now inactive)
> >>    keyAlreadyPressed = false;
> >> }
> >>
> >> keyAlreadyPressed is a bool private member or global variable.
> >>
> >> 2009/12/23, Lyle Underwood <lyleunderwood gmail com>:
> >> > I'm so close to finishing up this application now, I'm just putting some
> >> > polish on it.
> >> >
> >> > I have a drawing area in a viewport for scrolling. I want to add the
> >> > ability to pan with the mouse, but since the user is usually drawing
> >> > onto the drawing area I wanted them to use the spacebar to pan. So, you
> >> > hold down spacebar and drag around to pan, just like in photoshop, gimp,
> >> > etc..
> >> >
> >> > I'm pretty sure I'm not going to have any problem with the actual
> >> > panning, but I can't figure out how to use the spacebar as a toggled
> >> > state. It seems the events are triggered by some kind of key repeat,
> >> > because when I hold down space I get a huge series of press events and
> >> > release events. So is there some way that I can tell if the spacebar is
> >> > held down constantly? I was looking through the GdkEventKey struct and
> >> > couldn't find a solution.
> >> >
> >> > Also, I wanted to ask, what's the easiest way to get the selected row in
> >> > a TreeView to redraw?
> >> >
> >> > Thanks.
> >> >
> >> > _______________________________________________
> >> > gtkmm-list mailing list
> >> > gtkmm-list gnome org
> >> > http://mail.gnome.org/mailman/listinfo/gtkmm-list
> >> >
> >
> >
> >