[Sugar-devel] How to make a GTK3 EventBox accept the focus?

[Daniel Narvaez]

Sigh, I hoped gtk3 had got rid of the no-window widgets mess...

I think you need to use EventBox with a window and grab_focus on
button_press events. See the attached test.

On 1 March 2013 18:32, James Simmons <nicestep at gmail.com> wrote:
> Daniel,
>
> I played with your code last night at home.  I modified it so it actually
> loads pictures in the left and right Gtk.Image.  I found that when I tabbed
> through the controls in the window that the focus_in and focus_out methods
> were invoked.  However, when I tried to change the focus by clicking on
> either image nothing happened.  Before trying this I changed View Slides to
> eliminate the event box and the Activity still doesn't work.
>
> I added code like this:
>
> self.image1.set_events(Gdk.EventMask.KEY_PRESS_MASK |
> Gdk.EventMask.BUTTON_PRESS_MASK)
>
> to your example but it had no effect.  You can tab into an Image but you
> can't make it take the focus by clicking on it.
>
> This link suggests that the event box is necessary:
>
> http://stackoverflow.com/questions/14861503/catching-button-click-on-gtk-image-python-gtk3
>
> I'm going to fool with this some more this weekend.
>
> James Simmons
>
> On Thu, Feb 28, 2013 at 10:20 AM, Daniel Narvaez <dwnarvaez at gmail.com>
> wrote:
>>
>> GtkImage only works for me:
>>
>> from gi.repository import Gtk
>>
>> def image1_focus_in_cb(a, b):
>>     print("focus in 1")
>>
>> def image1_focus_out_cb(a, b):
>>     print("focus out 1")
>>
>> def image2_focus_in_cb(a, b):
>>     print("focus in 2")
>>
>> def image2_focus_out_cb(a, b):
>>     print("focus out 2")
>>
>>
>> window = Gtk.Window()
>> box = Gtk.HBox()
>>
>> image1 = Gtk.Image.new_from_file("")
>> image1.set_can_focus(True)
>>
>> image1.connect("focus-in-event", image1_focus_in_cb)
>> image1.connect("focus-out-event", image1_focus_out_cb)
>>
>> image2 = Gtk.Image.new_from_file("")
>> image2.set_can_focus(True)
>>
>> image2.connect("focus-in-event", image2_focus_in_cb)
>> image2.connect("focus-out-event", image2_focus_out_cb)
>>
>> box.pack_start(image1, False, False, 0)
>> box.pack_start(image2, False, False, 0)
>>
>> window.add(box)
>> window.show_all()
>>
>> Gtk.main()
>>
>>
>> On 28 February 2013 17:06, Daniel Narvaez <dwnarvaez at gmail.com> wrote:
>> > Two things you could try:
>> >
>> > - set_visible_window(True) the event box and also set_can_focus
>> >
>> > - Remove the box and set_can_focus the image.
>> >
>> >
>> > On Thursday, 28 February 2013, James Simmons wrote:
>> >>
>> >> Gonzalo,
>> >>
>> >> The problem with that it I want the arrow keys to page through the
>> >> images
>> >> only when the image has the focus.  There are other places in the
>> >> Activity
>> >> where I don't want to interfere with the arrow keys.  For instance, you
>> >> can
>> >> make annotations for a specific image.
>> >>
>> >> I notice that GtkImage is a subclass of GtkWidget, so maybe that means
>> >> that I don't need the event box anymore.  Maybe the image itself can
>> >> accept
>> >> the focus and receive the events.  The problem I have with that is that
>> >> the
>> >> old GTK made Image extend Widget also, and as I remember it you
>> >> couldn't get
>> >> events from an Image.  It was years ago.  Maybe I've been doing it
>> >> wrong the
>> >> whole time.
>> >>
>> >> James Simmons
>> >>
>> >>
>> >> On Wed, Feb 27, 2013 at 6:24 PM, Gonzalo Odiard <gonzalo at laptop.org>
>> >> wrote:
>> >>>
>> >>> Can you catch the key-press-event in the activity class?
>> >>> I think other activities like Read or Terminal do this.
>> >>>
>> >>> Gonzalo
>> >>>
>> >>> On Wed, Feb 27, 2013 at 1:53 PM, James Simmons <nicestep at gmail.com>
>> >>> wrote:
>> >>>>
>> >>>> Aneesh,
>> >>>>
>> >>>> I'm trying to incorporate your GTK3 update to View Slides and release
>> >>>> the result on ASLO.  The problem I'm still having is that I cannot
>> >>>> page
>> >>>> through the images using the keyboard as I used to.  What I did in
>> >>>> the past
>> >>>> was to nest the image control in an event box and make the event box
>> >>>> able to
>> >>>> accept the focus.  Then the user clicks on the image with the mouse
>> >>>> to set
>> >>>> the focus and at that point the event box receives key press events.
>> >>>>
>> >>>> When you upgraded View Slides to use GTK3 you removed the code to
>> >>>> make
>> >>>> the event box focusable.  I have tried to replace the missing line of
>> >>>> code
>> >>>> with what seems to be the GTK3 equivalent but it isn't working.  I've
>> >>>> done a
>> >>>> lot of google searches trying to figure out the problem and I'm not
>> >>>> getting
>> >>>> anywhere.  I cannot release View Slides as it is.  It really needs to
>> >>>> be
>> >>>> able to navigate through the images with the keyboard to be usable.
>> >>>>
>> >>>> I'm hoping you might have some thoughts or maybe an idea of how to do
>> >>>> the keyboard paging a different way.
>> >>>>
>> >>>> James Simmons
>> >>>>
>> >>>>
>> >>>> On Mon, Feb 25, 2013 at 6:20 AM, Manuel Quiñones <manuq at laptop.org>
>> >>>> wrote:
>> >>>>>
>> >>>>> Hi James,
>> >>>>>
>> >>>>> 2013/2/24 James Simmons <nicestep at gmail.com>:
>> >>>>> > I was looking at the upgrade to GTK3 done for View Slides and it
>> >>>>> > seems that
>> >>>>> > it no longer responds to the keyboard.  What I had done previously
>> >>>>> > to
>> >>>>> > get it
>> >>>>> > to do that was to put the image I was displaying in an event box.
>> >>>>> > I
>> >>>>> > then
>> >>>>> > made the event box accept the focus like this:
>> >>>>> >
>> >>>>> > self.eventbox.set_events(gtk.gdk.KEY_PRESS_MASK |
>> >>>>> > gtk.gdk.BUTTON_PRESS_MASK)
>> >>>>> > self.eventbox.set_flags(gtk.CAN_FOCUS)
>> >>>>> >
>> >>>>> > The Gtk3 port changed the code to this:
>> >>>>> >
>> >>>>> > self.eventbox.set_events(Gdk.EventMask.KEY_PRESS_MASK |
>> >>>>> > Gdk.EventMask.BUTTON_PRESS_MASK)
>> >>>>> >
>> >>>>> > There was no code to make it accept the focus.  I tried adding
>> >>>>> > this:
>> >>>>> >
>> >>>>> > self.eventbox.set_can_focus(True)
>> >>>>> >
>> >>>>> > This does not prevent the Activity from running, but it doesn't
>> >>>>> > make
>> >>>>> > the
>> >>>>> > Event Box focusable either.
>> >>>>>
>> >>>>> Have you tried self.eventbox.grab_focus() ?
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>> http://developer.gnome.org/gtk3/stable/GtkWidget.html#gtk-widget-grab-focus
>> >>>>>
>> >>>>> --
>> >>>>> .. manuq ..
>> >>>>
>> >>>>
>> >>>>
>> >>>> _______________________________________________
>> >>>> Sugar-devel mailing list
>> >>>> Sugar-devel at lists.sugarlabs.org
>> >>>> http://lists.sugarlabs.org/listinfo/sugar-devel
>> >>>>
>> >>>
>> >>
>> >
>> >
>> > --
>> > Daniel Narvaez
>> >
>>
>>
>>
>> --
>> Daniel Narvaez
>
>



-- 
Daniel Narvaez
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