Fixes two things: 1) As GTK+ can be coerced into using the wayland IM
module despite the compositor not implementing the interface, all paths
not checking for global state before sending requests are prone to
crashes, this one fell hit this pitfall.
And 2) ensures the tap gesture only triggers TOGGLE_INPUT_PANEL if the
widget IM is focused. This is a possibility on eg. WebKit pages, where
its IM is only focused as long as a form element in the page is focused.
Tapping elsewhere shouldn't toggle the OSK.
https://gitlab.gnome.org/GNOME/gtk/issues/114Closes: #114
This IM context implementation goes through the gtk-text-input protocol,
leaving up to the compositor the actual interaction with IM engines. If
the protocol is not offered by the compositor, GTK+ will fallback to the
IMs as specified through GtkSettings.
