The 0x0 dummyCursor works well when the menu pops up directly underneath
the pointer (e.g. when triggered by right-clicking the titlebar) or by
keyboard, but not when triggered by the menu button - the menu does not
point to the center of the button's bottom edge, and unless the user
keeps holding the mouse button while moving into the menu, the menu will
be dismissed immediately on button release.
Address these issues by using the button geometry to overlay the window
button with an appropriately sized actor that acts as a proper sourceActor,
to make the window menu behavior consistent with other shell menus.
https://bugzilla.gnome.org/show_bug.cgi?id=731058
Having the full geometry of the menu's source button (if any) will
allow us to address several misbehaviors of window menus, so use
that instead of show_menu().
https://bugzilla.gnome.org/show_bug.cgi?id=731058
When workspaces are disabled by the session mode, all workspace
related actions don't make sense. Worse, the "Move to Workspace ..."
actions allow sending windows into a nirvana with no means to
get them back.
https://bugzilla.gnome.org/show_bug.cgi?id=730653
The fallback app-menu in GTK+'s client side decorations obviously
uses the GTK+ theme rather than the shell one; update the style
of our own fallback app-menu to resemble that style.
https://bugzilla.gnome.org/show_bug.cgi?id=730752
We now allow "appmenu" in the button layout to make synchronizing it
with GTK+'s client-side decorations easier, but as some people tweak
their settings to get in-window app menus even when using the shell,
actually pop up the app menu when the button is activated.
https://bugzilla.gnome.org/show_bug.cgi?id=730752
