How to bind Modifier+MouseButton in GJS?

[fmuellner (Florian Müllner)]

@Schneegans

Bind to events of global.stage. This event is only emitted when some ui elements of Gnome-Shell are clicked on, not client windows (why?).

global.stage.connect('button-release-event', (actor, event) => {
  // do something
  return Clutter.EVENT_STOP;
});

First, events start at the reactive actor “closest” to the event, and only bubble up to the parent if the event wasn’t handled. That is, clicks on any actor that return Clutter.EVENT_STOP from their own handler will stop the event and it won’t reach the stage.

You could get around that by using captured-event::button, as that is emitted first on the stage and then bubbles down to the actor under the pointer, however that still won’t work for windows:

Mutter filters all events beore they are processed normally by Clutter, and events that are processed either by mutter itself (shortcuts, gestures, window drag operations etc.) or by clients (clicks inside windows, keyboard events while a window has key focus etc.) aren’t passed on to Clutter. And even if they were, the client would already have processed the event, which isn’t what you want anyway.

@Schneegans

Bind to events of global.display. Someone on Stackoverflow mentioned a key-press-event on the global MetaDisplay . But it seems that this does not exist (anymore?). Is there an alternative?

There never was such a signal on MetaDisplay. There is API for (un)registering keyboard shortcuts, but no equivalent for global “mouse shortcuts”.

@Schneegans

Weird combination of Main.pushModal() and Seat.create_virtual_device(). It might be possible to capture the input globally and forward the events I am not interested in with virtual devices. While this could work - I did not try this yet - it sounds veeery hacky.

Indeed, and also likely to break stuff left-and-right.

I’m afraid the best option isn’t quick and easy: Instead of trying to find a way to work around mutter’s event machinery, implement new API for “mouse shortcuts” and propose its inclusion in mutter. That would give you (and others) a clean way for building functionality on top.