[gnome-shell/T29763: 44/249] backgroundMenu: Release click action if actor moves from underneath us

[Matthew Leeds <mwleeds src gnome org>]

commit 2609334115db9b66830c794ab9425262d16c58ea
Author: Sam Spilsbury <sam endlessm com>
Date:   Wed Aug 23 13:27:45 2017 +0800

    backgroundMenu: Release click action if actor moves from underneath us
    
    This might happen in the case of the DesktopOverlay where
    its y-position is synchronised to that of the discovery feed, in
    that case, we should query the pointer position and release the
    long-press action if the pointer is no longer within the window,
    otherwise we'll never receive the ButtonRelease event and the
    event will be fired anyway

 js/ui/backgroundMenu.js | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)
---
diff --git a/js/ui/backgroundMenu.js b/js/ui/backgroundMenu.js
index 30abad60ba..1a3eb6e383 100644
--- a/js/ui/backgroundMenu.js
+++ b/js/ui/backgroundMenu.js
@@ -1,7 +1,7 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
 /* exported addBackgroundMenu */
 
-const { Clutter, Shell, St } = imports.gi;
+const { Clutter, Meta, Shell, St } = imports.gi;
 
 const AppActivation = imports.ui.appActivation;
 const BoxPointer = imports.ui.boxpointer;
@@ -68,6 +68,7 @@ function addBackgroundMenu(actor, layoutManager) {
     let grabOpBeginId = global.display.connect('grab-op-begin', () => {
         clickAction.release();
     });
+    let cursorTracker = Meta.CursorTracker.get_for_display(global.display);
 
     actor.connect('destroy', () => {
         actor._backgroundMenu.destroy();
@@ -75,4 +76,15 @@ function addBackgroundMenu(actor, layoutManager) {
         actor._backgroundManager = null;
         global.display.disconnect(grabOpBeginId);
     });
+
+    actor.connect('notify::allocation', () => {
+        // If the actor moves from underneath us, we should probably not
+        // fire the long press action. It may have moved outside of the
+        // range of where the cursor is, where we will never get ButtonPress
+        // events
+        let [xHot, yHot] = cursorTracker.get_hot();
+
+        if (!actor.allocation.contains(xHot, yHot))
+            clickAction.release();
+    });
 }