Implemented fullscreen exit animation with AppKit

chrome/browser/ui/cocoa/browser_window_fullscreen_transition.mm

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "chrome/browser/ui/cocoa/browser_window_enter_fullscreen_transition.h"
+#import "chrome/browser/ui/cocoa/browser_window_fullscreen_transition.h"
 
 #include <QuartzCore/QuartzCore.h>
 
-#include "base/mac/scoped_cftyperef.h"
-#include "base/mac/scoped_nsobject.h"
-#include "base/mac/sdk_forward_declarations.h"
+#include "base/mac/bind_objc_block.h"
+#include "base/mac/foundation_util.h"
+#include "base/mac/mac_util.h"
+#import "base/mac/sdk_forward_declarations.h"
+#include "base/memory/scoped_ptr.h"
+#import "chrome/browser/ui/cocoa/framed_browser_window.h"
 
 namespace {
 
 NSString* const kPrimaryWindowAnimationID = @"PrimaryWindowAnimationID";
 NSString* const kSnapshotWindowAnimationID = @"SnapshotWindowAnimationID";
 NSString* const kAnimationIDKey = @"AnimationIDKey";
 
 // This class has two simultaneous animations to resize and reposition layers.
 // These animations must use the same timing function, otherwise there will be
 // visual discordance.
 NSString* TransformAnimationTimingFunction() {
   return kCAMediaTimingFunctionEaseInEaseOut;
 }
 
+// This class locks and unlocks the FrameBrowserWindow. Its destructor ensures
+// that the lock gets released.
+class FrameAndStyleLock {
+ public:
+  explicit FrameAndStyleLock(FramedBrowserWindow* window) : window_(window) {}
+
+  ~FrameAndStyleLock() { set_lock(NO); }
+
+  void set_lock(bool lock) { [window_ setFrameAndStyleMaskLock:lock]; }
+
+ private:
+  FramedBrowserWindow* window_;  // weak
+
+  DISALLOW_COPY_AND_ASSIGN(FrameAndStyleLock);
+};
+
 }  // namespace
 
-@interface BrowserWindowEnterFullscreenTransition () {
+@interface BrowserWindowFullscreenTransition () {
+  // Flag to keep track of whether we are entering or exiting fullscreen.
+  BOOL isEnteringFullscreen_;
+
   // The window which is undergoing the fullscreen transition.
-  base::scoped_nsobject<NSWindow> primaryWindow_;
+  base::scoped_nsobject<FramedBrowserWindow> primaryWindow_;
 
   // A layer that holds a snapshot of the original state of |primaryWindow_|.
   base::scoped_nsobject<CALayer> snapshotLayer_;
 
   // A temporary window that holds |snapshotLayer_|.
   base::scoped_nsobject<NSWindow> snapshotWindow_;
 
-  // The frame of the |primaryWindow_| before the transition began.
-  NSRect primaryWindowInitialFrame_;
-
   // The background color of |primaryWindow_| before the transition began.
   base::scoped_nsobject<NSColor> primaryWindowInitialBackgroundColor_;
 
   // Whether |primaryWindow_| was opaque before the transition began.
   BOOL primaryWindowInitialOpaque_;
 
   // Whether the instance is in the process of changing the size of
   // |primaryWindow_|.
   BOOL changingPrimaryWindowSize_;
 
+  // The frame of the |primaryWindow_| before it starts the transition.
+  NSRect initialFrame_;
+
+  // The root layer's frame at the beginning of the exit transition. This ivar
+  // holds the value of the expected frame at the end of transition, which is
+  // relative to the current screen's coordinate system. At the beginning of
+  // the exit fullscreen animation, the root layer of the window is immediately
+  // moved and resized to match this frame.
+  NSRect exitLayerFrame_;
+
   // The frame that |primaryWindow_| is expected to have after the transition
   // is finished.
-  NSRect primaryWindowFinalFrame_;
+  NSRect finalFrame_;
+
+  // Locks and unlocks the FullSizeContentWindow.
+  scoped_ptr<FrameAndStyleLock> lock_;
 }
 
 // Takes a snapshot of |primaryWindow_| and puts it in |snapshotLayer_|.
 - (void)takeSnapshot;
 
 // Creates |snapshotWindow_| and adds |snapshotLayer_| to it.
 - (void)makeAndPrepareSnapshotWindow;
 
 // This method has several effects on |primaryWindow_|:
 //  - Saves current state.
 //  - Makes window transparent, with clear background.
-//  - Adds NSFullScreenWindowMask style mask.
-//  - Sets the size to the screen's size.
+//  - If we are entering fullscreen, it will also:
+//    - Add NSFullScreenWindowMask style mask.
+//    - Set the size to the screen's size.
 - (void)preparePrimaryWindowForAnimation;
 
 // Applies the fullscreen animation to |snapshotLayer_|.
 - (void)animateSnapshotWindowWithDuration:(CGFloat)duration;
 
-// Applies the fullscreen animation to the root layer of |primaryWindow_|.
-- (void)animatePrimaryWindowWithDuration:(CGFloat)duration;
+// Sets |primaryWindow_|'s frame to the expected frame.
+- (void)changePrimaryWindowToFinalFrame;
 
 // Override of CAAnimation delegate method.
 - (void)animationDidStop:(CAAnimation*)theAnimation finished:(BOOL)flag;
 
 // Returns the layer of the root view of |window|.
 - (CALayer*)rootLayerOfWindow:(NSWindow*)window;
 
 @end
 
-@implementation BrowserWindowEnterFullscreenTransition
+@implementation BrowserWindowFullscreenTransition
 
 // -------------------------Public Methods----------------------------
 
-- (instancetype)initWithWindow:(NSWindow*)window {
+- (instancetype)initEnterWithWindow:(FramedBrowserWindow*)window {
   DCHECK(window);
   DCHECK([self rootLayerOfWindow:window]);
   if ((self = [super init])) {
     primaryWindow_.reset([window retain]);
+
+    isEnteringFullscreen_ = YES;
+    initialFrame_ = [primaryWindow_ frame];
+    finalFrame_ = [[primaryWindow_ screen] frame];
   }
   return self;
 }
 
-- (NSArray*)customWindowsToEnterFullScreen {
+- (instancetype)initExitWithWindow:(FramedBrowserWindow*)window
+                             frame:(NSRect)frame {
+  DCHECK(window);
+  DCHECK([self rootLayerOfWindow:window]);
+  if ((self = [super init])) {
+    primaryWindow_.reset([window retain]);
+
+    isEnteringFullscreen_ = NO;
+    finalFrame_ = frame;
+    initialFrame_ = [[primaryWindow_ screen] frame];
+
+    // Calculate the coordinates of the finalFrame, relative to the current
+    // screen it's on.
+    CGFloat screenOriginX = finalFrame_.origin.x - initialFrame_.origin.x;
+    CGFloat screenOriginY = finalFrame_.origin.y - initialFrame_.origin.y;
+    exitLayerFrame_ =
+        NSMakeRect(screenOriginX, screenOriginY, finalFrame_.size.width,
+                   finalFrame_.size.height);
+
+    lock_.reset(new FrameAndStyleLock(window));
+  }
+  return self;
+}
+
+- (NSArray*)customWindowsForFullScreenTransition {
   [self takeSnapshot];
   [self makeAndPrepareSnapshotWindow];
-  [self preparePrimaryWindowForAnimation];
   return @[ primaryWindow_.get(), snapshotWindow_.get() ];
 }
 
-- (void)startCustomAnimationToEnterFullScreenWithDuration:
-    (NSTimeInterval)duration {
+- (void)startCustomFullScreenAnimationWithDuration:(NSTimeInterval)duration {
+  [self preparePrimaryWindowForAnimation];
+  [self animatePrimaryWindowWithDuration:duration];
   [self animateSnapshotWindowWithDuration:duration];
-  [self animatePrimaryWindowWithDuration:duration];
 }
 
 - (BOOL)shouldWindowBeUnconstrained {
   return changingPrimaryWindowSize_;
 }
 
+- (NSSize)desiredWindowLayoutSize {
+  return isEnteringFullscreen_ ? [primaryWindow_ frame].size
+                               : [[primaryWindow_ contentView] bounds].size;
+}
+
 // -------------------------Private Methods----------------------------
 
 - (void)takeSnapshot {
   base::ScopedCFTypeRef<CGImageRef> windowSnapshot(CGWindowListCreateImage(
       CGRectNull, kCGWindowListOptionIncludingWindow,
       [primaryWindow_ windowNumber], kCGWindowImageBoundsIgnoreFraming));
   snapshotLayer_.reset([[CALayer alloc] init]);
   [snapshotLayer_ setFrame:NSRectToCGRect([primaryWindow_ frame])];
   [snapshotLayer_ setContents:static_cast<id>(windowSnapshot.get())];
   [snapshotLayer_ setAnchorPoint:CGPointMake(0, 0)];
   CGColorRef colorRef = CGColorCreateGenericRGB(0, 0, 0, 0);
   [snapshotLayer_ setBackgroundColor:colorRef];
   CGColorRelease(colorRef);
 }
 
 - (void)makeAndPrepareSnapshotWindow {
   DCHECK(snapshotLayer_);
 
-  snapshotWindow_.reset(
-      [[NSWindow alloc] initWithContentRect:[[primaryWindow_ screen] frame]
-                                  styleMask:0
-                                    backing:NSBackingStoreBuffered
-                                      defer:NO]);
+  snapshotWindow_.reset([[NSWindow alloc]
+      initWithContentRect:[[primaryWindow_ screen] frame]
+                styleMask:0
+                  backing:NSBackingStoreBuffered
+                    defer:NO]);
   [[snapshotWindow_ contentView] setWantsLayer:YES];
   [snapshotWindow_ setOpaque:NO];
   [snapshotWindow_ setBackgroundColor:[NSColor clearColor]];
   [snapshotWindow_ setAnimationBehavior:NSWindowAnimationBehaviorNone];
 
-  [snapshotWindow_ orderFront:nil];
   [[[snapshotWindow_ contentView] layer] addSublayer:snapshotLayer_];
 
   // Compute the frame of the snapshot layer such that the snapshot is
   // positioned exactly on top of the original position of |primaryWindow_|.
   NSRect snapshotLayerFrame =
       [snapshotWindow_ convertRectFromScreen:[primaryWindow_ frame]];
   [snapshotLayer_ setFrame:snapshotLayerFrame];
 }
 
 - (void)preparePrimaryWindowForAnimation {
-  // Save initial state of |primaryWindow_|.
-  primaryWindowInitialFrame_ = [primaryWindow_ frame];
+  // Save the initial state of the primary window.
   primaryWindowInitialBackgroundColor_.reset(
       [[primaryWindow_ backgroundColor] copy]);
   primaryWindowInitialOpaque_ = [primaryWindow_ isOpaque];
 
-  primaryWindowFinalFrame_ = [[primaryWindow_ screen] frame];
-
   // Make |primaryWindow_| invisible. This must happen before the window is
   // resized, since resizing the window will call drawRect: and cause content
   // to flash over the entire screen.
   [primaryWindow_ setOpaque:NO];
-  [primaryWindow_ setBackgroundColor:[NSColor clearColor]];
-  CALayer* rootLayer = [self rootLayerOfWindow:primaryWindow_];
-  rootLayer.opacity = 0;
+  CALayer* root = [self rootLayerOfWindow:primaryWindow_];
+  root.opacity = 0;
 
-  // As soon as the style mask includes the flag NSFullScreenWindowMask, the
-  // window is expected to receive fullscreen layout. This must be set before
-  // the window is resized, as that causes a relayout.
-  [primaryWindow_
-      setStyleMask:[primaryWindow_ styleMask] | NSFullScreenWindowMask];
-
-  // Resize |primaryWindow_|.
-  changingPrimaryWindowSize_ = YES;
-  [primaryWindow_ setFrame:primaryWindowFinalFrame_ display:YES];
-  changingPrimaryWindowSize_ = NO;
+  if (isEnteringFullscreen_) {
+    // As soon as the style mask includes the flag NSFullScreenWindowMask, the
+    // window is expected to receive fullscreen layout. This must be set before
+    // the window is resized, as that causes a relayout.
+    [primaryWindow_
+        setStyleMask:[primaryWindow_ styleMask] | NSFullScreenWindowMask];
+    [self changePrimaryWindowToFinalFrame];
+  } else {
+    // Right before the animation begins, change the contentView size to the
+    // expected size at the end of the animation. Afterwards, lock the
+    // |primaryWindow_| so that AppKit will not be able to make unwanted
+    // changes to it during the animation.
+    root.frame = exitLayerFrame_;
+    [primaryWindow_ forceContentViewSize:finalFrame_.size];
+    lock_->set_lock(YES);
+  }
 }
 
 - (void)animateSnapshotWindowWithDuration:(CGFloat)duration {
-  // Move the snapshot layer until it's bottom-left corner is at the
-  // bottom-left corner of the screen.
+  [snapshotWindow_ orderFront:nil];
+
+  // Calculate the frame so that it's relative to the screen.
+  NSRect finalFrameRelativeToScreen =
+      [snapshotWindow_ convertRectFromScreen:finalFrame_];
+
+  // Move the snapshot layer until it's bottom-left corner is at the the
+  // bottom-left corner of the expected frame.
   CABasicAnimation* positionAnimation =
       [CABasicAnimation animationWithKeyPath:@"position"];
-  positionAnimation.toValue = [NSValue valueWithPoint:NSZeroPoint];
+  positionAnimation.toValue =
+      [NSValue valueWithPoint:finalFrameRelativeToScreen.origin];
   positionAnimation.timingFunction = [CAMediaTimingFunction
       functionWithName:TransformAnimationTimingFunction()];
 
-  // Expand the bounds until it covers the screen.
-  NSRect finalBounds = NSMakeRect(0, 0, NSWidth(primaryWindowFinalFrame_),
-                                  NSHeight(primaryWindowFinalFrame_));
+  // Resize the bounds until it reaches the expected size at the end of the
+  // animation.
+  NSRect finalBounds =
+      NSMakeRect(0, 0, NSWidth(finalFrame_), NSHeight(finalFrame_));
   CABasicAnimation* boundsAnimation =
       [CABasicAnimation animationWithKeyPath:@"bounds"];
   boundsAnimation.toValue = [NSValue valueWithRect:finalBounds];
   boundsAnimation.timingFunction = [CAMediaTimingFunction
       functionWithName:TransformAnimationTimingFunction()];
 
   // Fade out the snapshot layer.
   CABasicAnimation* opacityAnimation =
       [CABasicAnimation animationWithKeyPath:@"opacity"];
   opacityAnimation.toValue = @(0.0);
@@ skipping 18 matching lines @@
   // set back to 1. There are a couple of ways to do this. The easiest is to
   // just have a dummy animation as part of the same animation group.
   CABasicAnimation* opacityAnimation =
       [CABasicAnimation animationWithKeyPath:@"opacity"];
   opacityAnimation.fromValue = @(1.0);
   opacityAnimation.toValue = @(1.0);
 
   // The root layer's size should start scaled down to the initial size of
   // |primaryWindow_|. The animation increases the size until the root layer
   // fills the screen.
-  NSRect initialFrame = primaryWindowInitialFrame_;
-  NSRect endFrame = primaryWindowFinalFrame_;
+  NSRect initialFrame = initialFrame_;
+  NSRect endFrame = finalFrame_;
   CGFloat xScale = NSWidth(initialFrame) / NSWidth(endFrame);
   CGFloat yScale = NSHeight(initialFrame) / NSHeight(endFrame);
   CATransform3D initial = CATransform3DMakeScale(xScale, yScale, 1);
   CABasicAnimation* transformAnimation =
       [CABasicAnimation animationWithKeyPath:@"transform"];
   transformAnimation.fromValue = [NSValue valueWithCATransform3D:initial];
 
-  CALayer* root = [self rootLayerOfWindow:primaryWindow_];
-
   // Calculate the initial position of the root layer. This calculation is
   // agnostic of the anchorPoint.
+  CALayer* root = [self rootLayerOfWindow:primaryWindow_];
   CGFloat layerStartPositionDeltaX = NSMidX(initialFrame) - NSMidX(endFrame);
   CGFloat layerStartPositionDeltaY = NSMidY(initialFrame) - NSMidY(endFrame);
   NSPoint layerStartPosition =
       NSMakePoint(root.position.x + layerStartPositionDeltaX,
                   root.position.y + layerStartPositionDeltaY);
 
   // Animate the primary window from its initial position.
   CABasicAnimation* positionAnimation =
       [CABasicAnimation animationWithKeyPath:@"position"];
   positionAnimation.fromValue = [NSValue valueWithPoint:layerStartPosition];
 
   CAAnimationGroup* group = [CAAnimationGroup animation];
   group.removedOnCompletion = NO;
   group.fillMode = kCAFillModeForwards;
   group.animations =
-      @[ transformAnimation, opacityAnimation, positionAnimation ];
+      @[ opacityAnimation, positionAnimation, transformAnimation ];
   group.timingFunction = [CAMediaTimingFunction
       functionWithName:TransformAnimationTimingFunction()];
   group.duration = duration;
   [group setValue:kPrimaryWindowAnimationID forKey:kAnimationIDKey];
   group.delegate = self;
 
   [root addAnimation:group forKey:kPrimaryWindowAnimationID];
 }
 
+- (void)changePrimaryWindowToFinalFrame {
+  changingPrimaryWindowSize_ = YES;
+  [primaryWindow_ setFrame:finalFrame_ display:NO];
+  changingPrimaryWindowSize_ = NO;
+}
+
 - (void)animationDidStop:(CAAnimation*)theAnimation finished:(BOOL)flag {
   NSString* animationID = [theAnimation valueForKey:kAnimationIDKey];
+
+  // Remove the snapshot window.
   if ([animationID isEqual:kSnapshotWindowAnimationID]) {
     [snapshotWindow_ orderOut:nil];
     snapshotWindow_.reset();
     snapshotLayer_.reset();
     return;
   }
 
   if ([animationID isEqual:kPrimaryWindowAnimationID]) {
-    [primaryWindow_ setOpaque:YES];
+    // If we're exiting full screen, we want to set the |primaryWindow_|'s frame
+    // to the expected frame at the end of the animation. The window's lock
+    // must also be released.
+    if (!isEnteringFullscreen_) {
+      lock_->set_lock(NO);
+      [primaryWindow_
+          setStyleMask:[primaryWindow_ styleMask] & ~NSFullScreenWindowMask];
+      [self changePrimaryWindowToFinalFrame];
+    }
+
+    // Checks if the contentView size is correct.
+    NSSize expectedSize = finalFrame_.size;
+    NSView* content = [primaryWindow_ contentView];
+    DCHECK_EQ(NSHeight(content.frame), expectedSize.height);
+    DCHECK_EQ(NSWidth(content.frame), expectedSize.width);
+
+    // Restore the state of the primary window and make it visible again.
+    [primaryWindow_ setOpaque:primaryWindowInitialOpaque_];
     [primaryWindow_ setBackgroundColor:primaryWindowInitialBackgroundColor_];
+
     CALayer* root = [self rootLayerOfWindow:primaryWindow_];
+    [root removeAnimationForKey:kPrimaryWindowAnimationID];
     root.opacity = 1;
-    [root removeAnimationForKey:kPrimaryWindowAnimationID];
   }
 }
 
 - (CALayer*)rootLayerOfWindow:(NSWindow*)window {
   return [[[window contentView] superview] layer];
 }
 
 @end