From a9815ae1e9844ac8ae06496981a9ddd23a4a30eb Mon Sep 17 00:00:00 2001
From: Giovanni Campagna <gcampagna@src.gnome.org>
Date: Sat, 29 Dec 2012 15:24:03 +0100
Subject: [PATCH] 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
---
 js/ui/screenShield.js | 63 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 54 insertions(+), 9 deletions(-)

diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index 3c8dd6ea0..0dfb58d8d 100644
--- 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;
     },