[gnome-shell] windowMenu: Do actions requiring grab once ungrabbed

[Florian Müllner <fmuellner src gnome org>]

commit 2b3ab3ececd2b70023547552b1acf84cbc4fecb1
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Mon May 27 16:16:38 2019 -0500

    windowMenu: Do actions requiring grab once ungrabbed
    
    Resizing or moving a window needs starting a keyboard grab. However, if the
    action is triggered by a menu entry activation it might not work as we already
    have already an active grab on input devices to manage the menu itself.
    
    So, possibly wait maximum 100ms for the current grab operation to be completed
    before trying go start a new one.
    
    Needs https://gitlab.gnome.org/GNOME/mutter/merge_requests/596
    Fixes https://gitlab.gnome.org/GNOME/gnome-shell/issues/1326
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/557

 js/ui/windowMenu.js | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)
---
diff --git a/js/ui/windowMenu.js b/js/ui/windowMenu.js
index 18bda4057..78b307db8 100644
--- a/js/ui/windowMenu.js
+++ b/js/ui/windowMenu.js
@@ -1,6 +1,6 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*
 
-const { Meta, St } = imports.gi;
+const { GLib, Meta, St } = imports.gi;
 
 const BoxPointer = imports.ui.boxpointer;
 const Main = imports.ui.main;
@@ -42,13 +42,13 @@ var WindowMenu = class extends PopupMenu.PopupMenu {
             item.setSensitive(false);
 
         item = this.addAction(_("Move"), event => {
-            window.begin_grab_op(Meta.GrabOp.KEYBOARD_MOVING, true, event.get_time());
+            this._grabAction(window, Meta.GrabOp.KEYBOARD_MOVING, event.get_time());
         });
         if (!window.allows_move())
             item.setSensitive(false);
 
         item = this.addAction(_("Resize"), event => {
-            window.begin_grab_op(Meta.GrabOp.KEYBOARD_RESIZING_UNKNOWN, true, event.get_time());
+            this._grabAction(window, Meta.GrabOp.KEYBOARD_RESIZING_UNKNOWN, event.get_time());
         });
         if (!window.allows_resize())
             item.setSensitive(false);
@@ -169,6 +169,26 @@ var WindowMenu = class extends PopupMenu.PopupMenu {
         if (!window.can_close())
             item.setSensitive(false);
     }
+
+    _grabAction(window, grabOp, time) {
+        if (global.display.get_grab_op() == Meta.GrabOp.NONE) {
+            window.begin_grab_op(grabOp, true, time);
+            return;
+        }
+
+        let waitId = 0;
+        let id = global.display.connect('grab-op-end', (display) => {
+            display.disconnect(id);
+            GLib.source_remove(waitId);
+
+            window.begin_grab_op(grabOp, true, time);
+        });
+
+        waitId = GLib.timeout_add(GLib.PRIORITY_DEFAULT, 100, () => {
+            global.display.disconnect(id);
+            return GLib.SOURCE_REMOVE;
+        });
+    }
 };
 
 var WindowMenuManager = class {