Implemented fullscreen exit animation with AppKit

chrome/browser/ui/cocoa/browser_window_fullscreen_transition.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_COCOA_BROWSER_WINDOW_FULLSCREEN_TRANSITION_H_
 #define CHROME_BROWSER_UI_COCOA_BROWSER_WINDOW_FULLSCREEN_TRANSITION_H_
 
 #import <Cocoa/Cocoa.h>
 
+#import "chrome/browser/ui/cocoa/framed_browser_window.h"

[erikchen, 2015/08/11 22:42:54]

You can just a forward declaration instead. @class FramedBrowserWindow;

[spqchan1, 2015/08/12 19:34:41]

Done.

+
 // This class is responsible for managing the custom transition of a
-// BrowserWindow from its normal state into an AppKit Fullscreen state.
+// BrowserWindow from its normal state into an AppKit Fullscreen state
+// and vice versa.
 //
 // By default, when AppKit Fullscreens a window, it creates a new virtual
 // desktop and slides it in from the right of the screen. At the same time, the
 // old virtual desktop slides off to the left. This animation takes one second,
 // and the time is not customizable without elevated privileges or a
 // self-modifying binary
 // (https://code.google.com/p/chromium/issues/detail?id=414527). During that
 // second, no user interaction is possible.
 //
 // The default implementation of the AppKit transition smoothly animates a
 // window from its original size to the full size of the screen. At the
 // beginning of the animation, it takes a snapshot of the window's current
 // state. Then it resizes the window, calls drawRect: (theorized, not tested),
 // and takes a snapshot of the window's final state. The animation is a simple
 // crossfade between the two snapshots. This has a flaw. Frequently, the
 // renderer has not yet drawn content for the resized window by the time
 // drawRect: is called. As a result, the animation is effectively a no-op. When
 // the animation is finished, the new web content flashes in.
 //
-// The window's delegate can override two methods to customize the transition.
+// The window's delegate can override four methods to customize the transition.
 //  -customWindowsToEnterFullScreenForWindow:
 //    The return of this method is an array of NSWindows. Each window that is
 //    returned will be added to the new virtual desktop after the animation is
 //    finished, but will not be a part of the animation itself.
 //  -window:startCustomAnimationToEnterFullScreenWithDuration:
 //    In this method, the window's delegate adds animations to the windows
 //    returned in the above method.
+//  -customWindowsToExitFullScreenForWindow:
+//    This method is similar to customWindowsToEnterFullScreenForWindow,
+//    but is used for the animation is exiting full screen

[erikchen, 2015/08/11 22:42:54]

grammar check.

[spqchan1, 2015/08/12 19:34:41]

Done.

+//  -window:startCustomAnimationToExitFullScreenWithDuration:
+//    In this method, the window's delegate adds animations to the windows
+//    returned in the above method.
 //
 // The goal of this class is to mimic the default animation, but instead of
 // taking a snapshot of the final web content, it uses the live web content
 // during the animation.
 //
 // See https://code.google.com/p/chromium/issues/detail?id=414527#c22 and its
 // preceding comments for a more detailed description of the implementation,
 // and the reasoning behind the decisions made.
 //
 // Recommended usage:
@@ skipping 16 matching lines @@
 //    self.transition = nil;
 //  }
 //
 //  (Override method on NSWindow)
 //  - (NSRect)constrainFrameRect:(NSRect)frame toScreen:(NSScreen*)screen {
 //    if (self.transition && ![self.transition shouldWindowBeConstrained])
 //      return frame;
 //    return [super constrainFrameRect:frame toScreen:screen];
 //  }
 
-@interface BrowserWindowEnterFullscreenTransition : NSObject
+@interface BrowserWindowFullscreenTransition : NSObject
 
 // Designated initializer. |window| is the NSWindow that is going to be moved
 // into a fullscreen Space (virtual desktop), and resized to have the same size
 // as the screen. |window|'s root view must be layer backed.
-- (instancetype)initWithWindow:(NSWindow*)window;
+- (instancetype)initEnterWithWindow:(FramedBrowserWindow*)window;

[erikchen, 2015/08/11 22:42:54]

Please add a comment indicating when each of these two initializers should be
used.

[spqchan1, 2015/08/12 19:34:41]

Done.

 
-// Returns the windows to be used in the custom transition.
-//   - Takes a snapshot of the current window.
-//   - Makes a new snapshot window which shows the snapshot in the same
-//   location as the current window.
-//   - Adds the style mask NSFullScreenWindowMask to the current window.
-//   - Makes the current window transparent, and resizes the current window to
-//   be the same size as the screen.
-- (NSArray*)customWindowsToEnterFullScreen;
+- (instancetype)initExitWithWindow:(FramedBrowserWindow*)window
+                             frame:(NSRect)frame;
 
-// Begins the animations used for the custom fullscreen transition.
-//   - Animates the snapshot to the full size of the screen while fading it out.
+// Returns the windows to be used in the custom fullscreen transition.
+- (NSArray*)customWindowsForFullScreenTransition;
+
+// These two methods begins animation for exit and enter fullscreen transitions

[erikchen, 2015/08/11 22:42:54]

which two methods?

[spqchan1, 2015/08/12 19:34:41]

Done.

+// In both methods, the following happens:
+//   - Animates the snapshot to the expected final size of the window while
+//   fading it out.
 //   - Animates the current window from it's original location to its final
 //   location, while fading it in.
+// In startCustomExitFullScreenAnimationWithDuration, the content view gets

[erikchen, 2015/08/11 22:42:54]

Can you be more precise? Are you referring to the exit or enter animation? How
does it get resized? Does it become bigger or smaller?

[spqchan1, 2015/08/12 19:34:41]

Done.

+// resized in order

[erikchen, 2015/08/11 22:42:55]

remove newline.

[spqchan1, 2015/08/12 19:34:41]

Done.

+// to avoid clipping from the window

[erikchen, 2015/08/11 22:42:55]

missing period at end.

[spqchan1, 2015/08/12 19:34:41]

Done.

+
 // Note: The two animations are added to different layers in different windows.
 // There is no explicit logic to keep the two animations in sync. If this
 // proves to be a problem, the relevant layers should attempt to sync up their
 // time offsets with CACurrentMediaTime().
-- (void)startCustomAnimationToEnterFullScreenWithDuration:
-    (NSTimeInterval)duration;
+- (void)startCustomFullScreenAnimationWithDuration:(NSTimeInterval)duration;
 
 // When this method returns true, the NSWindow method
 // -constrainFrameRect:toScreen: must return the frame rect without
 // constraining it. The owner of the instance of this class is responsible for
 // hooking up this logic.
 - (BOOL)shouldWindowBeUnconstrained;
 
+// Returns the size of the window we expect the BrowserWindowLayout to have.
+// During exit fullscreen transition, the content size shrinks while the

[erikchen, 2015/08/11 22:42:54]

During /the/ exit fullscreen...

[spqchan1, 2015/08/12 19:34:41]

Done.

+// window frame stays the same. When that happens, we want to set the

[erikchen, 2015/08/11 22:42:54]

Precision of language: We are not setting BrowserWindowLayout to the content
size, we are passing it a size. Also, your use of the word "window" in the first
line conflicts with your use of the word |window| in the last line. 

Your later sentence is correct - this method is not returning the size of the
window, which your first sentence contradicts.

[spqchan1, 2015/08/12 19:34:41]

Fixed the comments so that it's more precise

+// BrowserWindowLayout to the content size instead of the window's size.
+- (NSSize)getDesiredWindowLayoutSize;
+
 @end
 
 #endif  // CHROME_BROWSER_UI_COCOA_BROWSER_WINDOW_FULLSCREEN_TRANSITION_H_