Gtk: some widgets do receive a GDK_CROSSING_UNGRAB leave event when tapped

[erikos]

Some widgets (e.g. Gtk.EventBox or a Gtk.TreeView) do get a GDK_CROSSING_UNGRAB leave event when tapped.

Looking at the example attached when I tap on the treeview I do get:

• a button release event

• a leave event of mode GDK_CROSSING_TOUCH_END

• a leave event of mode GDK_CROSSING_UNGRAB

When I click (mouse) on the treeview I do get:

• a button release event

Now the same for the Gtk.Button, when I tap on the button I do get:

• a leave event of mode GDK_CROSSING_TOUCH_END

When I click (mouse) on the button I do get:

• a button release event

[erikos]

test script that has a treeview and a button

[garnacho]

This is related to ticket #4132, the bogus button mask on ButtonRelease seems to trigger gdk to go again through pointer grab checks, which then emits the spurious crossing event. The patch in ​https://bugs.freedesktop.org/show_bug.cgi?id=56558#c1 fixes the issue

[erikos]

When this lands we can revert ​http://git.sugarlabs.org/sugar-toolkit-gtk3/sugar-toolkit-gtk3/blobs/master/src/sugar3/graphics/icon.py#line494 and ​http://bugs.sugarlabs.org/attachment/ticket/3921/0001-Journal-TreeView-make-sure-Palette-is-hidden-when-re.patch is obsolete.

Another case are the TrayIcons (used in the device Frame for example) ​http://git.sugarlabs.org/sugar-toolkit-gtk3/sugar-toolkit-gtk3/blobs/master/src/sugar3/graphics/tray.py#line404 which are packed in a Gtk.EventBox as well. The case where we see this is when you reveal the Palette for a Frame device icon with a tap you can not dismiss it by tapping outside the invoker. This is because of the ungrab leave event from above.

[garnacho]

Some further investigation revealed that the Xorg fix was indirectly fixing this through other broken behavior, as pointed out in ​https://bugs.freedesktop.org/show_bug.cgi?id=56558#c3 , I'm attaching a tentative GDK patch to improve the situation here, more testing is due though

[garnacho]

gdk patch, avoid double crossing events on touch end

[dnarvaez]

What remains to be done here? Was garnacho patch upstreamed?