Fix issue with animation behaviour when sending the app to the backgr…

…ound For living animation objects (usually retained animation objects) which are not running, the resume mechanism was leading to the animation still being played
jeffreywugz · Dec 21, 2012 · f282241 · f282241
1 parent 2943087
commit f282241
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Showing 2 changed files with 28 additions and 18 deletions.
diff --git a/CoconutKit/Sources/Animation/HLSAnimation.h b/CoconutKit/Sources/Animation/HLSAnimation.h
@@ -71,6 +71,7 @@
     NSUInteger m_currentRepeatCount;
     NSTimeInterval m_remainingTimeBeforeStart;                      // the time remaining before the start time is reached
     NSTimeInterval m_elapsedTime;                                   // the currently elapsed time (does not include pauses)
+    BOOL m_runningBeforeEnteringBackground;                         // was the animation running before the application entered background?
     BOOL m_pausedBeforeEnteringBackground;                          // was the animation paused before the application entered background?
     BOOL m_running;
     BOOL m_playing;

diff --git a/CoconutKit/Sources/Animation/HLSAnimation.m b/CoconutKit/Sources/Animation/HLSAnimation.m
@@ -582,28 +582,37 @@ - (id)copyWithZone:(NSZone *)zone
 
 - (void)applicationDidEnterBackground:(NSNotification *)notification
 {
-    // Core Animations are removed and added back again automatically when the application enters / leaves background. This makes
-    // it very hard to resume running animations after the application wakes up, since we have no real control over this process.
-    // But since HLSAnimations can be given a start time, we can apply the following strategy to solve those issues:
-    //   1) Remember how much time has elapsed and cancel the animation when the application enters background. The remaining
-    //      delegate events are not received
-    //   2) Rewind the animation at the beginning, without a delegate
-    //   3) Play the animation from where it was cancelled when the application enters foreground
-    m_elapsedTime += [self.currentAnimationStep elapsedTime];
-    m_pausedBeforeEnteringBackground = self.paused;
-
-    [self cancel];
-
-    HLSAnimation *reverseAnimation = [self reverseAnimation];
-    reverseAnimation.delegate = nil;
-    [reverseAnimation playAnimated:NO];
+    m_runningBeforeEnteringBackground = self.running;
+
+    if (m_runningBeforeEnteringBackground) {
+        // Core Animations are removed and added back again automatically when the application enters / leaves background. This makes
+        // it very hard to resume running animations after the application wakes up, since we have no real control over this process.
+        // But since HLSAnimations can be given a start time, we can apply the following strategy to solve those issues:
+        //   1) Remember how much time has elapsed and cancel the animation when the application enters background. The remaining
+        //      delegate events are not received
+        //   2) Rewind the animation at the beginning, without a delegate
+        //   3) Play the animation from where it was cancelled when the application enters foreground
+        m_elapsedTime += [self.currentAnimationStep elapsedTime];
+        m_pausedBeforeEnteringBackground = self.paused;
+
+        [self cancel];
+
+        HLSAnimation *reverseAnimation = [self reverseAnimation];
+        reverseAnimation.delegate = nil;
+        [reverseAnimation playAnimated:NO];
+    }
 }
 
 - (void)applicationWillEnterForeground:(NSNotification *)notification
 {
-    [self playWithStartTime:m_elapsedTime repeatCount:m_repeatCount];
-    if (m_pausedBeforeEnteringBackground) {
-        [self pause];
+    if (m_runningBeforeEnteringBackground) {
+        [self playWithStartTime:m_elapsedTime repeatCount:m_repeatCount];
+        if (m_pausedBeforeEnteringBackground) {
+            [self pause];
+        }
+
+        m_runningBeforeEnteringBackground = NO;
+        m_pausedBeforeEnteringBackground = NO;
     }
 }