expo: Use unique pointer trackers for motion tracking.

This was causing issues with motion events to change window
highlighting and overview triggering. Each set of event handlers
need to be tracked separately, so hasMoved can be correct for
that set.

Author: mtwebster

js/ui/expoThumbnail.js

@@ -12,6 +12,7 @@ const Main = imports.ui.main;
 const Tweener = imports.ui.tweener;
 const ModalDialog = imports.ui.modalDialog;
 const Tooltips = imports.ui.tooltips;
+const PointerTracker = imports.misc.pointerTracker;
 const SignalManager = imports.misc.signalManager;
 const GridNavigator = imports.misc.gridNavigator;
 const WindowUtils = imports.misc.windowUtils;
@@ -72,14 +73,16 @@ ExpoWindowClone.prototype = {
             return true;
         }));
 
+        let pointerTracker = new PointerTracker.PointerTracker();
+
         this.actor.connect('motion-event', Lang.bind(this, function (actor, event) {
-            if (Main.pointerTracker.hasMoved()) {
+            if (pointerTracker.hasMoved()) {
                 this.emit('hovering', true);
             }
             return false;
         }));
         this.actor.connect('leave-event', Lang.bind(this, function (actor, event) {
-            if (Main.pointerTracker.hasMoved()) {
+            if (pointerTracker.hasMoved()) {
                 this.emit('hovering', false);
             }
             return false;
@@ -1290,8 +1293,9 @@ ExpoThumbnailsBox.prototype = {
 
             // We want to ignore spurious events caused by animations
             // (when the contents are moving and not the pointer).
+            let pointerTracker = new PointerTracker.PointerTracker();
             thumbnail.actor.connect('motion-event', Lang.bind(this, function (actor, event) {
-                if (!Main.pointerTracker.hasMoved()) {return;}
+                if (!pointerTracker.hasMoved()) {return;}
                 if (!thumbnail.hovering) {
                     thumbnail.hovering = true;
                     this.lastHovered = thumbnail; 
@@ -1307,7 +1311,7 @@ ExpoThumbnailsBox.prototype = {
             }));
 
             thumbnail.actor.connect('leave-event', Lang.bind(this, function (actor, event) {
-                if (!Main.pointerTracker.hasMoved()) {return;}
+                if (!pointerTracker.hasMoved()) {return;}
                 if (this.isShowingModalDialog()) {return;}
                 if (thumbnail.hovering && !isInternalEvent(thumbnail, actor, event)) {
                     thumbnail.hovering = false;

js/ui/main.js

@@ -168,7 +168,6 @@ var tracker = null;
 var settingsManager = null;
 var systrayManager = null;
 var wmSettings = null;
-var pointerTracker = null;
 
 var workspace_names = [];
 
@@ -398,7 +397,7 @@ function start() {
         layoutManager._prepareStartupAnimation();
     }
 
-    pointerTracker = new PointerTracker.PointerTracker();
+    let pointerTracker = new PointerTracker.PointerTracker();
     pointerTracker.setPosition(layoutManager.primaryMonitor.x + layoutManager.primaryMonitor.width/2,
         layoutManager.primaryMonitor.y + layoutManager.primaryMonitor.height/2);