Implement 3-stage minimize animation for Panels on OSX.

Fast close to titlebar only -> pause on titlebar-only -> slow minimize.

Also, moved close button 1 px lower so it doesn't show up when panel is minimized.

BUG=104645

Review URL: http://codereview.chromium.org/8773030

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@112746 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/panels/panel_titlebar_view_cocoa.mm

@@ -212,7 +212,6 @@ static NSEvent* MakeMouseEvent(NSEventType type,
   [[settingsButton_ cell] setHighlightsBy:NSNoCellMask];
   [self checkMouseAndUpdateSettingsButtonVisibility];
 
-  // Update layout of controls in the titlebar.
   [self updateCloseButtonLayout];
 
   // Set autoresizing behavior: glued to edges on left, top and right.
@@ -264,19 +263,20 @@ static NSEvent* MakeMouseEvent(NSEventType type,
   NSRect bounds = [self bounds];
 
   buttonFrame.origin.x = kButtonPadding;
-  buttonFrame.origin.y = (NSHeight(bounds) - NSHeight(buttonFrame)) / 2;
+  // Lower Close Button's frame 1 px to avoid it 'peeking' in MINIMIZED mode.
+  buttonFrame.origin.y = (NSHeight(bounds) - NSHeight(buttonFrame)) / 2 - 1;
   [closeButton_ setFrame:buttonFrame];
-
-  DCHECK(!closeButtonTrackingArea_.get());
+  if (!closeButtonTrackingArea_.get()) {
     closeButtonTrackingArea_.reset(
-      [[CrTrackingArea alloc] initWithRect:buttonFrame
+        [[CrTrackingArea alloc] initWithRect:[closeButton_ bounds]
                                      options:(NSTrackingMouseEnteredAndExited |
                                               NSTrackingActiveAlways)
                                 proxiedOwner:self
                                     userInfo:nil]);
     NSWindow* panelWindow = [self window];
     [closeButtonTrackingArea_.get() clearOwnerWhenWindowWillClose:panelWindow];
-  [self addTrackingArea:closeButtonTrackingArea_.get()];
+    [closeButton_ addTrackingArea:closeButtonTrackingArea_.get()];
+  }
 }
 
 - (void)updateIconAndTitleLayout {

chrome/browser/ui/panels/panel_window_controller_cocoa.h

@@ -52,6 +52,8 @@ class PanelBrowserWindowCocoa;
   BOOL animateOnBoundsChange_;
   ScopedCrTrackingArea windowTrackingArea_;
   BOOL throbberShouldSpin_;
+  BOOL playingMinimizeAnimation_;
+  float animationStopToShowTitlebarOnly_;
 }
 
 // Load the browser window nib and do any Cocoa-specific initialization.

chrome/browser/ui/panels/panel_window_controller_cocoa.mm

@@ -429,20 +429,19 @@ enum {
   // Will be enabled back in animationDidEnd callback.
   [self disableTabContentsViewAutosizing];
 
+  // Terminate previous animation, if it is still playing.
+  [self terminateBoundsAnimation];
+
   NSDictionary *windowResize = [NSDictionary dictionaryWithObjectsAndKeys:
       [self window], NSViewAnimationTargetKey,
       [NSValue valueWithRect:frame], NSViewAnimationEndFrameKey, nil];
 
   NSArray *animations = [NSArray arrayWithObjects:windowResize, nil];
 
-  // Terminate previous animation, if it is still playing.
-  [self terminateBoundsAnimation];
   boundsAnimation_ =
       [[NSViewAnimation alloc] initWithViewAnimations:animations];
   [boundsAnimation_ setDelegate:self];
 
-  [boundsAnimation_ setAnimationBlockingMode: NSAnimationNonblocking];
-
   NSRect currentFrame = [[self window] frame];
   // Compute duration. We use constant speed of animation, however if the change
   // is too large, we clip the duration (effectively increasing speed) to
@@ -455,11 +454,55 @@ enum {
   double distance = std::max(distanceX, distanceY);
   double duration = std::min(distance / kBoundsAnimationSpeedPixelsPerSecond,
                              kBoundsAnimationMaxDurationSeconds);
+  // Detect animation that happens when expansion state is set to MINIMIZED
+  // and there is relatively big portion of the panel to hide from view.
+  // Initialize animation differently in this case, using fast-pause-slow
+  // method, see below for more details.
+  if (windowShim_->panel()->expansion_state() == Panel::MINIMIZED) {
+    animationStopToShowTitlebarOnly_ =
+        1.0 - (windowShim_->TitleOnlyHeight() - NSHeight(frame)) / distanceY;
+    if (animationStopToShowTitlebarOnly_ > 0.7) {  // Relatively big movement.
+      playingMinimizeAnimation_ = YES;
+      duration = 1.5;
+    }
+  }
   [boundsAnimation_ setDuration: duration];
+  [boundsAnimation_ setFrameRate:0.0];
+  [boundsAnimation_ setAnimationBlockingMode: NSAnimationNonblocking];
   [boundsAnimation_ startAnimation];
 }
 
+- (float)animation:(NSAnimation*)animation
+  valueForProgress:(NSAnimationProgress)progress {
+  if (!playingMinimizeAnimation_) {
+    // Cubic easing out.
+    float value = 1.0 - progress;
+    return 1.0 - value * value * value;
+  }
+
+  // Minimize animation:
+  // 1. Quickly (0 -> 0.15) make only titlebar visible.
+  // 2. Stay a little bit (0.15->0.6) in place, just showing titlebar.
+  // 3. Slowly minimize to thin strip (0.6->1.0)
+  const float kAnimationStopAfterQuickDecrease = 0.15;
+  const float kAnimationStopAfterShowingTitlebar = 0.6;
+  float value;
+  if (progress <= kAnimationStopAfterQuickDecrease) {
+      value = progress * animationStopToShowTitlebarOnly_ /
+              kAnimationStopAfterQuickDecrease;
+  } else if (progress <= kAnimationStopAfterShowingTitlebar) {
+      value = animationStopToShowTitlebarOnly_;
+  } else {
+      value = animationStopToShowTitlebarOnly_ +
+          (progress - kAnimationStopAfterShowingTitlebar) *
+          (1.0 - animationStopToShowTitlebarOnly_) /
+          (1.0 - kAnimationStopAfterShowingTitlebar);
+  }
+  return value;
+}
+
 - (void)animationDidEnd:(NSAnimation*)animation {
+  playingMinimizeAnimation_ = NO;
   if (windowShim_->panel()->expansion_state() == Panel::EXPANDED)
     [self enableTabContentsViewAutosizing];