ScreenShield: don't animate arrows if the user is idle

If the user is idle, it is very likely the monitor is off too, so let's
save some power by avoiding animations noone is going to see.

https://bugzilla.gnome.org/show_bug.cgi?id=690857

diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index 3c8dd6ea0e33dd229baf552d0017855c4bb0a3b9..0dfb58d8d1f152a61cdfbe8517089ccbf0c6eae1 100644 (file)
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -38,6 +38,7 @@ const ARROW_DRAG_THRESHOLD = 0.1;
 const N_ARROWS = 3;
 const ARROW_ANIMATION_TIME = 0.6;
 const ARROW_ANIMATION_PEAK_OPACITY = 0.4;
+const ARROW_IDLE_TIME = 30000; // ms
 
 const SUMMARY_ICON_SIZE = 48;
 
@@ -451,6 +452,9 @@ const ScreenShield = new Lang.Class({
         this._updateBackgrounds();
         Main.layoutManager.connect('monitors-changed', Lang.bind(this, this._updateBackgrounds));
 
+        this._arrowAnimationId = 0;
+        this._arrowWatchId = 0;
+        this._arrowActiveWatchId = 0;
         this._arrowContainer = new St.BoxLayout({ style_class: 'screen-shield-arrows',
                                                   vertical: true,
                                                   x_align: Clutter.ActorAlign.CENTER,
@@ -971,16 +975,60 @@ const ScreenShield = new Lang.Class({
             Main.sessionMode.pushMode('lock-screen');
     },
 
+    _startArrowAnimation: function() {
+        this._arrowActiveWatchId = 0;
+
+        if (!this._arrowAnimationId) {
+            this._arrowAnimationId = Mainloop.timeout_add(6000, Lang.bind(this, this._animateArrows));
+            this._animateArrows();
+        }
+
+        if (!this._arrowWatchId)
+            this._arrowWatchId = this.idleMonitor.add_idle_watch(ARROW_IDLE_TIME,
+                                                                 Lang.bind(this, this._pauseArrowAnimation));
+    },
+
+    _pauseArrowAnimation: function() {
+        if (this._arrowAnimationId) {
+            Mainloop.source_remove(this._arrowAnimationId);
+            this._arrowAnimationId = 0;
+        }
+
+        if (!this._arrowActiveWatchId)
+            this._arrowActiveWatchId = this.idleMonitor.add_user_active_watch(Lang.bind(this, this._startArrowAnimation));
+    },
+
+    _stopArrowAnimation: function() {
+        if (this._arrowAnimationId) {
+            Mainloop.source_remove(this._arrowAnimationId);
+            this._arrowAnimationId = 0;
+        }
+        if (this._arrowActiveWatchId) {
+            this.idleMonitor.remove_watch(this._arrowActiveWatchId);
+            this._arrowActiveWatchId = 0;
+        }
+        if (this._arrowWatchId) {
+            this.idleMonitor.remove_watch(this._arrowWatchId);
+            this._arrowWatchId = 0;
+        }
+    },
+
+    _checkArrowAnimation: function() {
+        let idleTime = this.idleMonitor.get_idletime();
+
+        if (idleTime < ARROW_IDLE_TIME)
+            this._startArrowAnimation();
+        else
+            this._pauseArrowAnimation();
+    },
+
     _lockScreenShown: function() {
         if (this._dialog && !this._isGreeter) {
             this._dialog.destroy();
             this._dialog = null;
         }
 
-        if (this._arrowAnimationId)
-            Mainloop.source_remove(this._arrowAnimationId);
-        this._arrowAnimationId = Mainloop.timeout_add(6000, Lang.bind(this, this._animateArrows));
-        this._animateArrows();
+        this._checkArrowAnimation();
 
         let motionId = global.stage.connect('captured-event', function(stage, event) {
             if (event.type() == Clutter.EventType.MOTION) {
@@ -1043,12 +1091,9 @@ const ScreenShield = new Lang.Class({
             this._notificationsBox = null;
         }
 
-        this._lockScreenContentsBox.destroy();
+        this._stopArrowAnimation();
 
-        if (this._arrowAnimationId) {
-            Mainloop.source_remove(this._arrowAnimationId);
-            this._arrowAnimationId = 0;
-        }
+        this._lockScreenContentsBox.destroy();
 
         this._hasLockScreen = false;
     },