Cancel previous new tab "submarine" animations when starting the animation fo...

chrome/browser/cocoa/tab_strip_controller.mm

Index: chrome/browser/cocoa/tab_strip_controller.mm
===================================================================
--- chrome/browser/cocoa/tab_strip_controller.mm	(revision 28808)
+++ chrome/browser/cocoa/tab_strip_controller.mm	(working copy)
@@ -360,6 +360,9 @@
 // tabs would cause an overflow.
 - (void)layoutTabsWithAnimation:(BOOL)animate
              regenerateSubviews:(BOOL)doUpdate {
+  // A very short duration used to cancel in-progress animations by making the
+  // new animation happen "instantly".
+  const float kInstantly = 0.000001;

[Mark Mentovai, 2009/10/13 17:30:23]

Can you #include <limits> and use the std::numeric_limits<NSTimeInterval>::min()
trick that I used in status_bubble_mac.mm?  Also, this should be an
NSTimeInterval, not a float.

   const float kTabOverlap = 20.0;
   const float kNewTabButtonOffset = 8.0;
   const float kMaxTabWidth = [TabController maxTabWidth];
@@ -417,7 +420,7 @@
       // Move the current tab to the correct location instantly.
       // We need a duration or else it doesn't cancel an inflight animation.
       [NSAnimationContext beginGrouping];
-      [[NSAnimationContext currentContext] setDuration:0.000001];
+      [[NSAnimationContext currentContext] setDuration:kInstantly];

[Mark Mentovai, 2009/10/13 17:30:23]

Seems kind of funny to say "set duration to instantly" - since the only thing we
use the constant for is "set duration," we might as well make it grammatically
correct.

       tabFrame.origin.x = placeholderFrame_.origin.x;
       // TODO(alcor): reenable this
       //tabFrame.size.height += 10.0 * placeholderStretchiness_;
@@ -440,19 +443,19 @@
         tabFrame.origin.x = offset;
       }
 
-      // Animate the tab in by putting it below the horizon, but don't bother
+      // Set the width. Selected tabs are slightly wider when things get
+      // really small and thus we enforce a different minimum width.
+      tabFrame.size.width =
+          [tab selected] ? MAX(baseTabWidth, kMinSelectedTabWidth) :
+                           baseTabWidth;
+
+      // Animate a new tab in by putting it below the horizon, but don't bother
       // if we only have 1 tab.
       BOOL shouldAnimate = animate && [tabContentsArray_ count] > 1;
       if (newTab && visible && shouldAnimate) {
         [[tab view] setFrame:NSOffsetRect(tabFrame, 0, -NSHeight(tabFrame))];
       }
 
-      // Set the width. Selected tabs are slightly wider when things get
-      // really small and thus we enforce a different minimum width.
-      tabFrame.size.width =
-          [tab selected] ? MAX(baseTabWidth, kMinSelectedTabWidth) :
-                           baseTabWidth;
-
       // Check the frame by identifier to avoid redundant calls to animator.
       id frameTarget = visible && animate ? [[tab view] animator] : [tab view];
       NSValue* identifier = [NSValue valueWithPointer:[tab view]];
@@ -463,6 +466,7 @@
         [targetFrames_ setObject:[NSValue valueWithRect:tabFrame]
                           forKey:identifier];
       }
+
       enclosingRect = NSUnionRect(tabFrame, enclosingRect);
     }
 
@@ -489,9 +493,19 @@
       [newTabButton_ setHidden:NO];
 
     if (!NSEqualRects(newTabTargetFrame_, newTabNewFrame)) {
-      [newTabButton_ setFrame:newTabNewFrame];
+      // Move the new tab button into place. We want to animate the new tab
+      // button if it's moving to the left (closing a tab), but not when it's
+      // moving to the right (inserting a new tab). If moving right, we need
+      // to use a very small duration to make sure we cancel any in-flight
+      // animation to the left.
+      BOOL movingLeft = NSMinX(newTabNewFrame) < NSMinX(newTabTargetFrame_);
+      id target = animate ? [newTabButton_ animator] : newTabButton_;
+      [NSAnimationContext beginGrouping];

[Mark Mentovai, 2009/10/13 17:30:23]

Adding this is what fixed the bug I was seeing earlier with the disappearing new
tab button.

+      if (!movingLeft)
+        [[NSAnimationContext currentContext] setDuration:kInstantly];
+      [target setFrame:newTabNewFrame];
+      [NSAnimationContext endGrouping];
       newTabTargetFrame_ = newTabNewFrame;
-      // Move the new tab button into place.
     }
   }