Merge pull request #4202 from vishalduggal/timob-12988-31X

[TIMOB-12988] (3_1_X) Delay setContentOffset if scrollRectToVisible called

iphone/Classes/TiUIScrollView.h

@@ -12,6 +12,11 @@
 @private
     TiUIView * touchHandler;
     UIView * touchedContentView;
+    //TIMOB-12988 Additions
+    BOOL delay;
+    BOOL ignore;
+    BOOL offsetAnimated;
+    CGPoint offsetPoint;
 }
 -(void)setTouchHandler:(TiUIView*)handler;
 @end

iphone/Classes/TiUIScrollView.m

@@ -12,6 +12,43 @@
 
 @implementation TiUIScrollViewImpl
 
+//TIMOB-12988 Additions BEGIN.
+/*
+ * If you log the scrollRectToVisible and setContentOffset calls, you can see
+ * IOS is passing values we do not want. This is a hack to workaround 
+ * bad contentoffset call. We calculate it correctly in our own code
+ * and that call follows soon after.
+ * Happens on IOS 5.1, 5.0 and 4.3. Not on iOS 6. Although values passed in are identical. Timing?
+ * Delete this block when we drop support for older versions of IOS.
+ */
+-(void) delayContentOffset
+{
+    if(!ignore){
+        [self setContentOffset:offsetPoint animated:offsetAnimated];
+    }
+}
+
+- (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated
+{
+    if (delay && ![TiUtils isIOS6OrGreater]) {
+        delay = NO;
+        ignore = NO;
+        offsetPoint = contentOffset;
+        offsetAnimated = animated;
+        [self performSelector:@selector(delayContentOffset) withObject:nil afterDelay:0.2];
+        return;
+    }
+    ignore = YES;
+    [super setContentOffset:contentOffset animated:animated];
+}
+
+- (void)scrollRectToVisible:(CGRect)rect animated:(BOOL)animated
+{
+    delay = YES;
+    [super scrollRectToVisible:rect animated:animated];
+}
+//TIMOB-12988 Additions END.
+
 -(void)setTouchHandler:(TiUIView*)handler
 {
     //Assign only. No retain