chrome/browser/ui/cocoa/presentation_mode_controller.mm - platform/external/chromium_org - Git at Google

 // Copyright (c) 2012 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/presentation_mode_controller.h"

 #include <algorithm>

 #include "base/command_line.h"
 #import "base/mac/mac_util.h"
 #include "chrome/browser/fullscreen.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #include "chrome/common/chrome_switches.h"
 #import "third_party/GTM/AppKit/GTMNSAnimation+Duration.h"

 NSString* const kWillEnterFullscreenNotification =
     @"WillEnterFullscreenNotification";
 NSString* const kWillLeaveFullscreenNotification =
     @"WillLeaveFullscreenNotification";

 namespace {
 // The activation zone for the main menu is 4 pixels high; if we make it any
 // smaller, then the menu can be made to appear without the bar sliding down.
 const CGFloat kDropdownActivationZoneHeight = 4;
 const NSTimeInterval kDropdownAnimationDuration = 0.12;
 const NSTimeInterval kMouseExitCheckDelay = 0.1;
 // This show delay attempts to match the delay for the main menu.
 const NSTimeInterval kDropdownShowDelay = 0.3;
 const NSTimeInterval kDropdownHideDelay = 0.2;

 // The amount by which the floating bar is offset downwards (to avoid the menu)
 // in presentation mode. (We can't use |-[NSMenu menuBarHeight]| since it
 // returns 0 when the menu bar is hidden.)
 const CGFloat kFloatingBarVerticalOffset = 22;

 }  // end namespace


 // Helper class to manage animations for the dropdown bar.  Calls
 // [PresentationModeController changeFloatingBarShownFraction] once per
 // animation step.
 @interface DropdownAnimation : NSAnimation {
  @private
   PresentationModeController* controller_;
   CGFloat startFraction_;
   CGFloat endFraction_;
 }

 @property(readonly, nonatomic) CGFloat startFraction;
 @property(readonly, nonatomic) CGFloat endFraction;

 // Designated initializer.  Asks |controller| for the current shown fraction, so
 // if the bar is already partially shown or partially hidden, the animation
 // duration may be less than |fullDuration|.
 - (id)initWithFraction:(CGFloat)fromFraction
           fullDuration:(CGFloat)fullDuration
         animationCurve:(NSAnimationCurve)animationCurve
             controller:(PresentationModeController*)controller;

 @end

 @implementation DropdownAnimation

 @synthesize startFraction = startFraction_;
 @synthesize endFraction = endFraction_;

 - (id)initWithFraction:(CGFloat)toFraction
           fullDuration:(CGFloat)fullDuration
         animationCurve:(NSAnimationCurve)animationCurve
             controller:(PresentationModeController*)controller {
   // Calculate the effective duration, based on the current shown fraction.
   DCHECK(controller);
   CGFloat fromFraction = [controller floatingBarShownFraction];
   CGFloat effectiveDuration = fabs(fullDuration * (fromFraction - toFraction));

   if ((self = [super gtm_initWithDuration:effectiveDuration
                                 eventMask:NSLeftMouseDownMask
                            animationCurve:animationCurve])) {
     startFraction_ = fromFraction;
     endFraction_ = toFraction;
     controller_ = controller;
   }
   return self;
 }

 // Called once per animation step.  Overridden to change the floating bar's
 // position based on the animation's progress.
 - (void)setCurrentProgress:(NSAnimationProgress)progress {
   CGFloat fraction =
       startFraction_ + (progress * (endFraction_ - startFraction_));
   [controller_ changeFloatingBarShownFraction:fraction];
 }

 @end


 @interface PresentationModeController (PrivateMethods)

 // Returns YES if the window is on the primary screen.
 - (BOOL)isWindowOnPrimaryScreen;

 // Returns YES if it is ok to show and hide the menu bar in response to the
 // overlay opening and closing.  Will return NO if the window is not main or not
 // on the primary monitor.
 - (BOOL)shouldToggleMenuBar;

 // Returns |kFullScreenModeHideAll| when the overlay is hidden and
 // |kFullScreenModeHideDock| when the overlay is shown.
 - (base::mac::FullScreenMode)desiredSystemFullscreenMode;

 // Change the overlay to the given fraction, with or without animation. Only
 // guaranteed to work properly with |fraction == 0| or |fraction == 1|. This
 // performs the show/hide (animation) immediately. It does not touch the timers.
 - (void)changeOverlayToFraction:(CGFloat)fraction
                   withAnimation:(BOOL)animate;

 // Schedule the floating bar to be shown/hidden because of mouse position.
 - (void)scheduleShowForMouse;
 - (void)scheduleHideForMouse;

 // Set up the tracking area used to activate the sliding bar or keep it active
 // using with the rectangle in |trackingAreaBounds_|, or remove the tracking
 // area if one was previously set up.
 - (void)setupTrackingArea;
 - (void)removeTrackingAreaIfNecessary;

 // Returns YES if the mouse is currently in any current tracking rectangle, NO
 // otherwise.
 - (BOOL)mouseInsideTrackingRect;

 // The tracking area can "falsely" report exits when the menu slides down over
 // it. In that case, we have to monitor for a "real" mouse exit on a timer.
 // |-setupMouseExitCheck| schedules a check; |-cancelMouseExitCheck| cancels any
 // scheduled check.
 - (void)setupMouseExitCheck;
 - (void)cancelMouseExitCheck;

 // Called (after a delay) by |-setupMouseExitCheck|, to check whether the mouse
 // has exited or not; if it hasn't, it will schedule another check.
 - (void)checkForMouseExit;

 // Start timers for showing/hiding the floating bar.
 - (void)startShowTimer;
 - (void)startHideTimer;
 - (void)cancelShowTimer;
 - (void)cancelHideTimer;
 - (void)cancelAllTimers;

 // Methods called when the show/hide timers fire. Do not call directly.
 - (void)showTimerFire:(NSTimer*)timer;
 - (void)hideTimerFire:(NSTimer*)timer;

 // Stops any running animations, removes tracking areas, etc.
 - (void)cleanup;

 // Shows and hides the UI associated with this window being active (having main
 // status).  This includes hiding the menu bar.  These functions are called when
 // the window gains or loses main status as well as in |-cleanup|.
 - (void)showActiveWindowUI;
 - (void)hideActiveWindowUI;

 @end


 @implementation PresentationModeController

 @synthesize inPresentationMode = inPresentationMode_;

 - (id)initWithBrowserController:(BrowserWindowController*)controller {
   if ((self = [super init])) {
     browserController_ = controller;
     systemFullscreenMode_ = base::mac::kFullScreenModeNormal;
   }

   // Let the world know what we're up to.
   [[NSNotificationCenter defaultCenter]
     postNotificationName:kWillEnterFullscreenNotification
                   object:nil];

   return self;
 }

 - (void)dealloc {
   DCHECK(!inPresentationMode_);
   DCHECK(!trackingArea_);
   [super dealloc];
 }

 - (void)enterPresentationModeForContentView:(NSView*)contentView
                                showDropdown:(BOOL)showDropdown {
   DCHECK(!inPresentationMode_);
   enteringPresentationMode_ = YES;
   inPresentationMode_ = YES;
   contentView_ = contentView;
   [self changeFloatingBarShownFraction:(showDropdown ? 1 : 0)];

   // Register for notifications.  Self is removed as an observer in |-cleanup|.
   NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
   NSWindow* window = [browserController_ window];

   // Disable these notifications on Lion as they cause crashes.
   // TODO(rohitrao): Figure out what happens if a fullscreen window changes
   // monitors on Lion.
   if (base::mac::IsOSSnowLeopard()) {
     [nc addObserver:self
            selector:@selector(windowDidChangeScreen:)
                name:NSWindowDidChangeScreenNotification
              object:window];

     [nc addObserver:self
            selector:@selector(windowDidMove:)
                name:NSWindowDidMoveNotification
              object:window];
   }

   [nc addObserver:self
          selector:@selector(windowDidBecomeMain:)
              name:NSWindowDidBecomeMainNotification
            object:window];

   [nc addObserver:self
          selector:@selector(windowDidResignMain:)
              name:NSWindowDidResignMainNotification
            object:window];

   enteringPresentationMode_ = NO;
 }

 - (void)exitPresentationMode {
   [[NSNotificationCenter defaultCenter]
     postNotificationName:kWillLeaveFullscreenNotification
                   object:nil];
   DCHECK(inPresentationMode_);
   inPresentationMode_ = NO;
   [self cleanup];
 }

 - (void)windowDidChangeScreen:(NSNotification*)notification {
   [browserController_ resizeFullscreenWindow];
 }

 - (void)windowDidMove:(NSNotification*)notification {
   [browserController_ resizeFullscreenWindow];
 }

 - (void)windowDidBecomeMain:(NSNotification*)notification {
   [self showActiveWindowUI];
 }

 - (void)windowDidResignMain:(NSNotification*)notification {
   [self hideActiveWindowUI];
 }

 - (CGFloat)floatingBarVerticalOffset {
   return [self isWindowOnPrimaryScreen] ? kFloatingBarVerticalOffset : 0;
 }

 - (void)overlayFrameChanged:(NSRect)frame {
   if (!inPresentationMode_)
     return;

   // Make sure |trackingAreaBounds_| always reflects either the tracking area or
   // the desired tracking area.
   trackingAreaBounds_ = frame;
   // The tracking area should always be at least the height of activation zone.
   NSRect contentBounds = [contentView_ bounds];
   trackingAreaBounds_.origin.y =
       std::min(trackingAreaBounds_.origin.y,
                NSMaxY(contentBounds) - kDropdownActivationZoneHeight);
   trackingAreaBounds_.size.height =
       NSMaxY(contentBounds) - trackingAreaBounds_.origin.y + 1;

   // If an animation is currently running, do not set up a tracking area now.
   // Instead, leave it to be created it in |-animationDidEnd:|.
   if (currentAnimation_)
     return;

   // If this is part of the initial setup, lock bar visibility if the mouse is
   // within the tracking area bounds.
   if (enteringPresentationMode_ && [self mouseInsideTrackingRect])
     [browserController_ lockBarVisibilityForOwner:self
                                     withAnimation:NO
                                             delay:NO];
   [self setupTrackingArea];
 }

 - (void)ensureOverlayShownWithAnimation:(BOOL)animate delay:(BOOL)delay {
   if (!inPresentationMode_)
     return;

   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kKioskMode))
     return;

   if (animate) {
     if (delay) {
       [self startShowTimer];
     } else {
       [self cancelAllTimers];
       [self changeOverlayToFraction:1 withAnimation:YES];
     }
   } else {
     DCHECK(!delay);
     [self cancelAllTimers];
     [self changeOverlayToFraction:1 withAnimation:NO];
   }
 }

 - (void)ensureOverlayHiddenWithAnimation:(BOOL)animate delay:(BOOL)delay {
   if (!inPresentationMode_)
     return;

   if (animate) {
     if (delay) {
       [self startHideTimer];
     } else {
       [self cancelAllTimers];
       [self changeOverlayToFraction:0 withAnimation:YES];
     }
   } else {
     DCHECK(!delay);
     [self cancelAllTimers];
     [self changeOverlayToFraction:0 withAnimation:NO];
   }
 }

 - (void)cancelAnimationAndTimers {
   [self cancelAllTimers];
   [currentAnimation_ stopAnimation];
   currentAnimation_.reset();
 }

 - (CGFloat)floatingBarShownFraction {
   return [browserController_ floatingBarShownFraction];
 }

 - (void)changeFloatingBarShownFraction:(CGFloat)fraction {
   [browserController_ setFloatingBarShownFraction:fraction];

   base::mac::FullScreenMode desiredMode = [self desiredSystemFullscreenMode];
   if (desiredMode != systemFullscreenMode_ && [self shouldToggleMenuBar]) {
     if (systemFullscreenMode_ == base::mac::kFullScreenModeNormal)
       base::mac::RequestFullScreen(desiredMode);
     else
       base::mac::SwitchFullScreenModes(systemFullscreenMode_, desiredMode);
     systemFullscreenMode_ = desiredMode;
   }
 }

 // Used to activate the floating bar in presentation mode.
 - (void)mouseEntered:(NSEvent*)event {
   DCHECK(inPresentationMode_);

   // Having gotten a mouse entered, we no longer need to do exit checks.
   [self cancelMouseExitCheck];

   NSTrackingArea* trackingArea = [event trackingArea];
   if (trackingArea == trackingArea_) {
     // The tracking area shouldn't be active during animation.
     DCHECK(!currentAnimation_);
     [self scheduleShowForMouse];
   }
 }

 // Used to deactivate the floating bar in presentation mode.
 - (void)mouseExited:(NSEvent*)event {
   DCHECK(inPresentationMode_);

   NSTrackingArea* trackingArea = [event trackingArea];
   if (trackingArea == trackingArea_) {
     // The tracking area shouldn't be active during animation.
     DCHECK(!currentAnimation_);

     // We can get a false mouse exit when the menu slides down, so if the mouse
     // is still actually over the tracking area, we ignore the mouse exit, but
     // we set up to check the mouse position again after a delay.
     if ([self mouseInsideTrackingRect]) {
       [self setupMouseExitCheck];
       return;
     }

     [self scheduleHideForMouse];
   }
 }

 - (void)animationDidStop:(NSAnimation*)animation {
   // Reset the |currentAnimation_| pointer now that the animation is over.
   currentAnimation_.reset();

   // Invariant says that the tracking area is not installed while animations are
   // in progress. Ensure this is true.
   DCHECK(!trackingArea_);
   [self removeTrackingAreaIfNecessary];  // For paranoia.

   // Don't automatically set up a new tracking area. When explicitly stopped,
   // either another animation is going to start immediately or the state will be
   // changed immediately.
 }

 - (void)animationDidEnd:(NSAnimation*)animation {
   [self animationDidStop:animation];

   // |trackingAreaBounds_| contains the correct tracking area bounds, including
   // |any updates that may have come while the animation was running. Install a
   // new tracking area with these bounds.
   [self setupTrackingArea];

   // TODO(viettrungluu): Better would be to check during the animation; doing it
   // here means that the timing is slightly off.
   if (![self mouseInsideTrackingRect])
     [self scheduleHideForMouse];
 }

 @end


 @implementation PresentationModeController (PrivateMethods)

 - (BOOL)isWindowOnPrimaryScreen {
   NSScreen* screen = [[browserController_ window] screen];
   NSScreen* primaryScreen = [[NSScreen screens] objectAtIndex:0];
   return (screen == primaryScreen);
 }

 - (BOOL)shouldToggleMenuBar {
   return !chrome::mac::SupportsSystemFullscreen() &&
          [self isWindowOnPrimaryScreen] &&
          [[browserController_ window] isMainWindow];
 }

 - (base::mac::FullScreenMode)desiredSystemFullscreenMode {
   if ([browserController_ floatingBarShownFraction] >= 1.0)
     return base::mac::kFullScreenModeHideDock;
   return base::mac::kFullScreenModeHideAll;
 }

 - (void)changeOverlayToFraction:(CGFloat)fraction
                   withAnimation:(BOOL)animate {
   // The non-animated case is really simple, so do it and return.
   if (!animate) {
     [currentAnimation_ stopAnimation];
     [self changeFloatingBarShownFraction:fraction];
     return;
   }

   // If we're already animating to the given fraction, then there's nothing more
   // to do.
   if (currentAnimation_ && [currentAnimation_ endFraction] == fraction)
     return;

   // In all other cases, we want to cancel any running animation (which may be
   // to show or to hide).
   [currentAnimation_ stopAnimation];

   // Now, if it happens to already be in the right state, there's nothing more
   // to do.
   if ([browserController_ floatingBarShownFraction] == fraction)
     return;

   // Create the animation and set it up.
   currentAnimation_.reset(
       [[DropdownAnimation alloc] initWithFraction:fraction
                                      fullDuration:kDropdownAnimationDuration
                                    animationCurve:NSAnimationEaseOut
                                        controller:self]);
   DCHECK(currentAnimation_);
   [currentAnimation_ setAnimationBlockingMode:NSAnimationNonblocking];
   [currentAnimation_ setDelegate:self];

   // If there is an existing tracking area, remove it. We do not track mouse
   // movements during animations (see class comment in the header file).
   [self removeTrackingAreaIfNecessary];

   [currentAnimation_ startAnimation];
 }

 - (void)scheduleShowForMouse {
   [browserController_ lockBarVisibilityForOwner:self
                                   withAnimation:YES
                                           delay:YES];
 }

 - (void)scheduleHideForMouse {
   [browserController_ releaseBarVisibilityForOwner:self
                                      withAnimation:YES
                                              delay:YES];
 }

 - (void)setupTrackingArea {
   if (trackingArea_) {
     // If the tracking rectangle is already |trackingAreaBounds_|, quit early.
     NSRect oldRect = [trackingArea_ rect];
     if (NSEqualRects(trackingAreaBounds_, oldRect))
       return;

     // Otherwise, remove it.
     [self removeTrackingAreaIfNecessary];
   }

   // Create and add a new tracking area for |frame|.
   trackingArea_.reset(
       [[NSTrackingArea alloc] initWithRect:trackingAreaBounds_
                                    options:NSTrackingMouseEnteredAndExited |
                                            NSTrackingActiveInKeyWindow
                                      owner:self
                                   userInfo:nil]);
   DCHECK(contentView_);
   [contentView_ addTrackingArea:trackingArea_];
 }

 - (void)removeTrackingAreaIfNecessary {
   if (trackingArea_) {
     DCHECK(contentView_);  // |contentView_| better be valid.
     [contentView_ removeTrackingArea:trackingArea_];
     trackingArea_.reset();
   }
 }

 - (BOOL)mouseInsideTrackingRect {
   NSWindow* window = [browserController_ window];
   NSPoint mouseLoc = [window mouseLocationOutsideOfEventStream];
   NSPoint mousePos = [contentView_ convertPoint:mouseLoc fromView:nil];
   return NSMouseInRect(mousePos, trackingAreaBounds_, [contentView_ isFlipped]);
 }

 - (void)setupMouseExitCheck {
   [self performSelector:@selector(checkForMouseExit)
              withObject:nil
              afterDelay:kMouseExitCheckDelay];
 }

 - (void)cancelMouseExitCheck {
   [NSObject cancelPreviousPerformRequestsWithTarget:self
       selector:@selector(checkForMouseExit) object:nil];
 }

 - (void)checkForMouseExit {
   if ([self mouseInsideTrackingRect])
     [self setupMouseExitCheck];
   else
     [self scheduleHideForMouse];
 }

 - (void)startShowTimer {
   // If there's already a show timer going, just keep it.
   if (showTimer_) {
     DCHECK([showTimer_ isValid]);
     DCHECK(!hideTimer_);
     return;
   }

   // Cancel the hide timer (if necessary) and set up the new show timer.
   [self cancelHideTimer];
   showTimer_.reset(
       [[NSTimer scheduledTimerWithTimeInterval:kDropdownShowDelay
                                         target:self
                                       selector:@selector(showTimerFire:)
                                       userInfo:nil
                                        repeats:NO] retain]);
   DCHECK([showTimer_ isValid]);  // This also checks that |showTimer_ != nil|.
 }

 - (void)startHideTimer {
   // If there's already a hide timer going, just keep it.
   if (hideTimer_) {
     DCHECK([hideTimer_ isValid]);
     DCHECK(!showTimer_);
     return;
   }

   // Cancel the show timer (if necessary) and set up the new hide timer.
   [self cancelShowTimer];
   hideTimer_.reset(
       [[NSTimer scheduledTimerWithTimeInterval:kDropdownHideDelay
                                         target:self
                                       selector:@selector(hideTimerFire:)
                                       userInfo:nil
                                        repeats:NO] retain]);
   DCHECK([hideTimer_ isValid]);  // This also checks that |hideTimer_ != nil|.
 }

 - (void)cancelShowTimer {
   [showTimer_ invalidate];
   showTimer_.reset();
 }

 - (void)cancelHideTimer {
   [hideTimer_ invalidate];
   hideTimer_.reset();
 }

 - (void)cancelAllTimers {
   [self cancelShowTimer];
   [self cancelHideTimer];
 }

 - (void)showTimerFire:(NSTimer*)timer {
   DCHECK_EQ(showTimer_, timer);  // This better be our show timer.
   [showTimer_ invalidate];       // Make sure it doesn't repeat.
   showTimer_.reset();            // And get rid of it.
   [self changeOverlayToFraction:1 withAnimation:YES];
 }

 - (void)hideTimerFire:(NSTimer*)timer {
   DCHECK_EQ(hideTimer_, timer);  // This better be our hide timer.
   [hideTimer_ invalidate];       // Make sure it doesn't repeat.
   hideTimer_.reset();            // And get rid of it.
   [self changeOverlayToFraction:0 withAnimation:YES];
 }

 - (void)cleanup {
   [self cancelMouseExitCheck];
   [self cancelAnimationAndTimers];
   [[NSNotificationCenter defaultCenter] removeObserver:self];

   [self removeTrackingAreaIfNecessary];
   contentView_ = nil;

   // This isn't tracked when not in presentation mode.
   [browserController_ releaseBarVisibilityForOwner:self
                                      withAnimation:NO
                                              delay:NO];

   // Call the main status resignation code to perform the associated cleanup,
   // since we will no longer be receiving actual status resignation
   // notifications.
   [self hideActiveWindowUI];

   // No more calls back up to the BWC.
   browserController_ = nil;
 }

 - (void)showActiveWindowUI {
   DCHECK_EQ(systemFullscreenMode_, base::mac::kFullScreenModeNormal);
   if (systemFullscreenMode_ != base::mac::kFullScreenModeNormal)
     return;

   if ([self shouldToggleMenuBar]) {
     base::mac::FullScreenMode desiredMode = [self desiredSystemFullscreenMode];
     base::mac::RequestFullScreen(desiredMode);
     systemFullscreenMode_ = desiredMode;
   }

   // TODO(rohitrao): Insert the Exit Fullscreen button.  http://crbug.com/35956
 }

 - (void)hideActiveWindowUI {
   if (systemFullscreenMode_ != base::mac::kFullScreenModeNormal) {
     base::mac::ReleaseFullScreen(systemFullscreenMode_);
     systemFullscreenMode_ = base::mac::kFullScreenModeNormal;
   }

   // TODO(rohitrao): Remove the Exit Fullscreen button.  http://crbug.com/35956
 }

 @end
	// Copyright (c) 2012 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/presentation_mode_controller.h"

	#include <algorithm>

	#include "base/command_line.h"
	#import "base/mac/mac_util.h"
	#include "chrome/browser/fullscreen.h"
	#import "chrome/browser/ui/cocoa/browser_window_controller.h"
	#include "chrome/common/chrome_switches.h"
	#import "third_party/GTM/AppKit/GTMNSAnimation+Duration.h"

	NSString* const kWillEnterFullscreenNotification =
	@"WillEnterFullscreenNotification";
	NSString* const kWillLeaveFullscreenNotification =
	@"WillLeaveFullscreenNotification";

	namespace {
	// The activation zone for the main menu is 4 pixels high; if we make it any
	// smaller, then the menu can be made to appear without the bar sliding down.
	const CGFloat kDropdownActivationZoneHeight = 4;
	const NSTimeInterval kDropdownAnimationDuration = 0.12;
	const NSTimeInterval kMouseExitCheckDelay = 0.1;
	// This show delay attempts to match the delay for the main menu.
	const NSTimeInterval kDropdownShowDelay = 0.3;
	const NSTimeInterval kDropdownHideDelay = 0.2;

	// The amount by which the floating bar is offset downwards (to avoid the menu)
	// in presentation mode. (We can't use \|-[NSMenu menuBarHeight]\| since it
	// returns 0 when the menu bar is hidden.)
	const CGFloat kFloatingBarVerticalOffset = 22;

	} // end namespace


	// Helper class to manage animations for the dropdown bar. Calls
	// [PresentationModeController changeFloatingBarShownFraction] once per
	// animation step.
	@interface DropdownAnimation : NSAnimation {
	@private
	PresentationModeController* controller_;
	CGFloat startFraction_;
	CGFloat endFraction_;
	}

	@property(readonly, nonatomic) CGFloat startFraction;
	@property(readonly, nonatomic) CGFloat endFraction;

	// Designated initializer. Asks \|controller\| for the current shown fraction, so
	// if the bar is already partially shown or partially hidden, the animation
	// duration may be less than \|fullDuration\|.
	- (id)initWithFraction:(CGFloat)fromFraction
	fullDuration:(CGFloat)fullDuration
	animationCurve:(NSAnimationCurve)animationCurve
	controller:(PresentationModeController*)controller;

	@end

	@implementation DropdownAnimation

	@synthesize startFraction = startFraction_;
	@synthesize endFraction = endFraction_;

	- (id)initWithFraction:(CGFloat)toFraction
	fullDuration:(CGFloat)fullDuration
	animationCurve:(NSAnimationCurve)animationCurve
	controller:(PresentationModeController*)controller {
	// Calculate the effective duration, based on the current shown fraction.
	DCHECK(controller);
	CGFloat fromFraction = [controller floatingBarShownFraction];
	CGFloat effectiveDuration = fabs(fullDuration * (fromFraction - toFraction));

	if ((self = [super gtm_initWithDuration:effectiveDuration
	eventMask:NSLeftMouseDownMask
	animationCurve:animationCurve])) {
	startFraction_ = fromFraction;
	endFraction_ = toFraction;
	controller_ = controller;
	}
	return self;
	}

	// Called once per animation step. Overridden to change the floating bar's
	// position based on the animation's progress.
	- (void)setCurrentProgress:(NSAnimationProgress)progress {
	CGFloat fraction =
	startFraction_ + (progress * (endFraction_ - startFraction_));
	[controller_ changeFloatingBarShownFraction:fraction];
	}

	@end


	@interface PresentationModeController (PrivateMethods)

	// Returns YES if the window is on the primary screen.
	- (BOOL)isWindowOnPrimaryScreen;

	// Returns YES if it is ok to show and hide the menu bar in response to the
	// overlay opening and closing. Will return NO if the window is not main or not
	// on the primary monitor.
	- (BOOL)shouldToggleMenuBar;

	// Returns \|kFullScreenModeHideAll\| when the overlay is hidden and
	// \|kFullScreenModeHideDock\| when the overlay is shown.
	- (base::mac::FullScreenMode)desiredSystemFullscreenMode;

	// Change the overlay to the given fraction, with or without animation. Only
	// guaranteed to work properly with \|fraction == 0\| or \|fraction == 1\|. This
	// performs the show/hide (animation) immediately. It does not touch the timers.
	- (void)changeOverlayToFraction:(CGFloat)fraction
	withAnimation:(BOOL)animate;

	// Schedule the floating bar to be shown/hidden because of mouse position.
	- (void)scheduleShowForMouse;
	- (void)scheduleHideForMouse;

	// Set up the tracking area used to activate the sliding bar or keep it active
	// using with the rectangle in \|trackingAreaBounds_\|, or remove the tracking
	// area if one was previously set up.
	- (void)setupTrackingArea;
	- (void)removeTrackingAreaIfNecessary;

	// Returns YES if the mouse is currently in any current tracking rectangle, NO
	// otherwise.
	- (BOOL)mouseInsideTrackingRect;

	// The tracking area can "falsely" report exits when the menu slides down over
	// it. In that case, we have to monitor for a "real" mouse exit on a timer.
	// \|-setupMouseExitCheck\| schedules a check; \|-cancelMouseExitCheck\| cancels any
	// scheduled check.
	- (void)setupMouseExitCheck;
	- (void)cancelMouseExitCheck;

	// Called (after a delay) by \|-setupMouseExitCheck\|, to check whether the mouse
	// has exited or not; if it hasn't, it will schedule another check.
	- (void)checkForMouseExit;

	// Start timers for showing/hiding the floating bar.
	- (void)startShowTimer;
	- (void)startHideTimer;
	- (void)cancelShowTimer;
	- (void)cancelHideTimer;
	- (void)cancelAllTimers;

	// Methods called when the show/hide timers fire. Do not call directly.
	- (void)showTimerFire:(NSTimer*)timer;
	- (void)hideTimerFire:(NSTimer*)timer;

	// Stops any running animations, removes tracking areas, etc.
	- (void)cleanup;

	// Shows and hides the UI associated with this window being active (having main
	// status). This includes hiding the menu bar. These functions are called when
	// the window gains or loses main status as well as in \|-cleanup\|.
	- (void)showActiveWindowUI;
	- (void)hideActiveWindowUI;

	@end


	@implementation PresentationModeController

	@synthesize inPresentationMode = inPresentationMode_;

	- (id)initWithBrowserController:(BrowserWindowController*)controller {
	if ((self = [super init])) {
	browserController_ = controller;
	systemFullscreenMode_ = base::mac::kFullScreenModeNormal;
	}

	// Let the world know what we're up to.
	[[NSNotificationCenter defaultCenter]
	postNotificationName:kWillEnterFullscreenNotification
	object:nil];

	return self;
	}

	- (void)dealloc {
	DCHECK(!inPresentationMode_);
	DCHECK(!trackingArea_);
	[super dealloc];
	}

	- (void)enterPresentationModeForContentView:(NSView*)contentView
	showDropdown:(BOOL)showDropdown {
	DCHECK(!inPresentationMode_);
	enteringPresentationMode_ = YES;
	inPresentationMode_ = YES;
	contentView_ = contentView;
	[self changeFloatingBarShownFraction:(showDropdown ? 1 : 0)];

	// Register for notifications. Self is removed as an observer in \|-cleanup\|.
	NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
	NSWindow* window = [browserController_ window];

	// Disable these notifications on Lion as they cause crashes.
	// TODO(rohitrao): Figure out what happens if a fullscreen window changes
	// monitors on Lion.
	if (base::mac::IsOSSnowLeopard()) {
	[nc addObserver:self
	selector:@selector(windowDidChangeScreen:)
	name:NSWindowDidChangeScreenNotification
	object:window];

	[nc addObserver:self
	selector:@selector(windowDidMove:)
	name:NSWindowDidMoveNotification
	object:window];
	}

	[nc addObserver:self
	selector:@selector(windowDidBecomeMain:)
	name:NSWindowDidBecomeMainNotification
	object:window];

	[nc addObserver:self
	selector:@selector(windowDidResignMain:)
	name:NSWindowDidResignMainNotification
	object:window];

	enteringPresentationMode_ = NO;
	}

	- (void)exitPresentationMode {
	[[NSNotificationCenter defaultCenter]
	postNotificationName:kWillLeaveFullscreenNotification
	object:nil];
	DCHECK(inPresentationMode_);
	inPresentationMode_ = NO;
	[self cleanup];
	}

	- (void)windowDidChangeScreen:(NSNotification*)notification {
	[browserController_ resizeFullscreenWindow];
	}

	- (void)windowDidMove:(NSNotification*)notification {
	[browserController_ resizeFullscreenWindow];
	}

	- (void)windowDidBecomeMain:(NSNotification*)notification {
	[self showActiveWindowUI];
	}

	- (void)windowDidResignMain:(NSNotification*)notification {
	[self hideActiveWindowUI];
	}

	- (CGFloat)floatingBarVerticalOffset {
	return [self isWindowOnPrimaryScreen] ? kFloatingBarVerticalOffset : 0;
	}

	- (void)overlayFrameChanged:(NSRect)frame {
	if (!inPresentationMode_)
	return;

	// Make sure \|trackingAreaBounds_\| always reflects either the tracking area or
	// the desired tracking area.
	trackingAreaBounds_ = frame;
	// The tracking area should always be at least the height of activation zone.
	NSRect contentBounds = [contentView_ bounds];
	trackingAreaBounds_.origin.y =
	std::min(trackingAreaBounds_.origin.y,
	NSMaxY(contentBounds) - kDropdownActivationZoneHeight);
	trackingAreaBounds_.size.height =
	NSMaxY(contentBounds) - trackingAreaBounds_.origin.y + 1;

	// If an animation is currently running, do not set up a tracking area now.
	// Instead, leave it to be created it in \|-animationDidEnd:\|.
	if (currentAnimation_)
	return;

	// If this is part of the initial setup, lock bar visibility if the mouse is
	// within the tracking area bounds.
	if (enteringPresentationMode_ && [self mouseInsideTrackingRect])
	[browserController_ lockBarVisibilityForOwner:self
	withAnimation:NO
	delay:NO];
	[self setupTrackingArea];
	}

	- (void)ensureOverlayShownWithAnimation:(BOOL)animate delay:(BOOL)delay {
	if (!inPresentationMode_)
	return;

	if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kKioskMode))
	return;

	if (animate) {
	if (delay) {
	[self startShowTimer];
	} else {
	[self cancelAllTimers];
	[self changeOverlayToFraction:1 withAnimation:YES];
	}
	} else {
	DCHECK(!delay);
	[self cancelAllTimers];
	[self changeOverlayToFraction:1 withAnimation:NO];
	}
	}

	- (void)ensureOverlayHiddenWithAnimation:(BOOL)animate delay:(BOOL)delay {
	if (!inPresentationMode_)
	return;

	if (animate) {
	if (delay) {
	[self startHideTimer];
	} else {
	[self cancelAllTimers];
	[self changeOverlayToFraction:0 withAnimation:YES];
	}
	} else {
	DCHECK(!delay);
	[self cancelAllTimers];
	[self changeOverlayToFraction:0 withAnimation:NO];
	}
	}

	- (void)cancelAnimationAndTimers {
	[self cancelAllTimers];
	[currentAnimation_ stopAnimation];
	currentAnimation_.reset();
	}

	- (CGFloat)floatingBarShownFraction {
	return [browserController_ floatingBarShownFraction];
	}

	- (void)changeFloatingBarShownFraction:(CGFloat)fraction {
	[browserController_ setFloatingBarShownFraction:fraction];

	base::mac::FullScreenMode desiredMode = [self desiredSystemFullscreenMode];
	if (desiredMode != systemFullscreenMode_ && [self shouldToggleMenuBar]) {
	if (systemFullscreenMode_ == base::mac::kFullScreenModeNormal)
	base::mac::RequestFullScreen(desiredMode);
	else
	base::mac::SwitchFullScreenModes(systemFullscreenMode_, desiredMode);
	systemFullscreenMode_ = desiredMode;
	}
	}

	// Used to activate the floating bar in presentation mode.
	- (void)mouseEntered:(NSEvent*)event {
	DCHECK(inPresentationMode_);

	// Having gotten a mouse entered, we no longer need to do exit checks.
	[self cancelMouseExitCheck];

	NSTrackingArea* trackingArea = [event trackingArea];
	if (trackingArea == trackingArea_) {
	// The tracking area shouldn't be active during animation.
	DCHECK(!currentAnimation_);
	[self scheduleShowForMouse];
	}
	}

	// Used to deactivate the floating bar in presentation mode.
	- (void)mouseExited:(NSEvent*)event {
	DCHECK(inPresentationMode_);

	NSTrackingArea* trackingArea = [event trackingArea];
	if (trackingArea == trackingArea_) {
	// The tracking area shouldn't be active during animation.
	DCHECK(!currentAnimation_);

	// We can get a false mouse exit when the menu slides down, so if the mouse
	// is still actually over the tracking area, we ignore the mouse exit, but
	// we set up to check the mouse position again after a delay.
	if ([self mouseInsideTrackingRect]) {
	[self setupMouseExitCheck];
	return;
	}

	[self scheduleHideForMouse];
	}
	}

	- (void)animationDidStop:(NSAnimation*)animation {
	// Reset the \|currentAnimation_\| pointer now that the animation is over.
	currentAnimation_.reset();

	// Invariant says that the tracking area is not installed while animations are
	// in progress. Ensure this is true.
	DCHECK(!trackingArea_);
	[self removeTrackingAreaIfNecessary]; // For paranoia.

	// Don't automatically set up a new tracking area. When explicitly stopped,
	// either another animation is going to start immediately or the state will be
	// changed immediately.
	}

	- (void)animationDidEnd:(NSAnimation*)animation {
	[self animationDidStop:animation];

	// \|trackingAreaBounds_\| contains the correct tracking area bounds, including
	// \|any updates that may have come while the animation was running. Install a
	// new tracking area with these bounds.
	[self setupTrackingArea];

	// TODO(viettrungluu): Better would be to check during the animation; doing it
	// here means that the timing is slightly off.
	if (![self mouseInsideTrackingRect])
	[self scheduleHideForMouse];
	}

	@end


	@implementation PresentationModeController (PrivateMethods)

	- (BOOL)isWindowOnPrimaryScreen {
	NSScreen* screen = [[browserController_ window] screen];
	NSScreen* primaryScreen = [[NSScreen screens] objectAtIndex:0];
	return (screen == primaryScreen);
	}

	- (BOOL)shouldToggleMenuBar {
	return !chrome::mac::SupportsSystemFullscreen() &&
	[self isWindowOnPrimaryScreen] &&
	[[browserController_ window] isMainWindow];
	}

	- (base::mac::FullScreenMode)desiredSystemFullscreenMode {
	if ([browserController_ floatingBarShownFraction] >= 1.0)
	return base::mac::kFullScreenModeHideDock;
	return base::mac::kFullScreenModeHideAll;
	}

	- (void)changeOverlayToFraction:(CGFloat)fraction
	withAnimation:(BOOL)animate {
	// The non-animated case is really simple, so do it and return.
	if (!animate) {
	[currentAnimation_ stopAnimation];
	[self changeFloatingBarShownFraction:fraction];
	return;
	}

	// If we're already animating to the given fraction, then there's nothing more
	// to do.
	if (currentAnimation_ && [currentAnimation_ endFraction] == fraction)
	return;

	// In all other cases, we want to cancel any running animation (which may be
	// to show or to hide).
	[currentAnimation_ stopAnimation];

	// Now, if it happens to already be in the right state, there's nothing more
	// to do.
	if ([browserController_ floatingBarShownFraction] == fraction)
	return;

	// Create the animation and set it up.
	currentAnimation_.reset(
	[[DropdownAnimation alloc] initWithFraction:fraction
	fullDuration:kDropdownAnimationDuration
	animationCurve:NSAnimationEaseOut
	controller:self]);
	DCHECK(currentAnimation_);
	[currentAnimation_ setAnimationBlockingMode:NSAnimationNonblocking];
	[currentAnimation_ setDelegate:self];

	// If there is an existing tracking area, remove it. We do not track mouse
	// movements during animations (see class comment in the header file).
	[self removeTrackingAreaIfNecessary];

	[currentAnimation_ startAnimation];
	}

	- (void)scheduleShowForMouse {
	[browserController_ lockBarVisibilityForOwner:self
	withAnimation:YES
	delay:YES];
	}

	- (void)scheduleHideForMouse {
	[browserController_ releaseBarVisibilityForOwner:self
	withAnimation:YES
	delay:YES];
	}

	- (void)setupTrackingArea {
	if (trackingArea_) {
	// If the tracking rectangle is already \|trackingAreaBounds_\|, quit early.
	NSRect oldRect = [trackingArea_ rect];
	if (NSEqualRects(trackingAreaBounds_, oldRect))
	return;

	// Otherwise, remove it.
	[self removeTrackingAreaIfNecessary];
	}

	// Create and add a new tracking area for \|frame\|.
	trackingArea_.reset(
	[[NSTrackingArea alloc] initWithRect:trackingAreaBounds_
	options:NSTrackingMouseEnteredAndExited \|
	NSTrackingActiveInKeyWindow
	owner:self
	userInfo:nil]);
	DCHECK(contentView_);
	[contentView_ addTrackingArea:trackingArea_];
	}

	- (void)removeTrackingAreaIfNecessary {
	if (trackingArea_) {
	DCHECK(contentView_); // \|contentView_\| better be valid.
	[contentView_ removeTrackingArea:trackingArea_];
	trackingArea_.reset();
	}
	}

	- (BOOL)mouseInsideTrackingRect {
	NSWindow* window = [browserController_ window];
	NSPoint mouseLoc = [window mouseLocationOutsideOfEventStream];
	NSPoint mousePos = [contentView_ convertPoint:mouseLoc fromView:nil];
	return NSMouseInRect(mousePos, trackingAreaBounds_, [contentView_ isFlipped]);
	}

	- (void)setupMouseExitCheck {
	[self performSelector:@selector(checkForMouseExit)
	withObject:nil
	afterDelay:kMouseExitCheckDelay];
	}

	- (void)cancelMouseExitCheck {
	[NSObject cancelPreviousPerformRequestsWithTarget:self
	selector:@selector(checkForMouseExit) object:nil];
	}

	- (void)checkForMouseExit {
	if ([self mouseInsideTrackingRect])
	[self setupMouseExitCheck];
	else
	[self scheduleHideForMouse];
	}

	- (void)startShowTimer {
	// If there's already a show timer going, just keep it.
	if (showTimer_) {
	DCHECK([showTimer_ isValid]);
	DCHECK(!hideTimer_);
	return;
	}

	// Cancel the hide timer (if necessary) and set up the new show timer.
	[self cancelHideTimer];
	showTimer_.reset(
	[[NSTimer scheduledTimerWithTimeInterval:kDropdownShowDelay
	target:self
	selector:@selector(showTimerFire:)
	userInfo:nil
	repeats:NO] retain]);
	DCHECK([showTimer_ isValid]); // This also checks that \|showTimer_ != nil\|.
	}

	- (void)startHideTimer {
	// If there's already a hide timer going, just keep it.
	if (hideTimer_) {
	DCHECK([hideTimer_ isValid]);
	DCHECK(!showTimer_);
	return;
	}

	// Cancel the show timer (if necessary) and set up the new hide timer.
	[self cancelShowTimer];
	hideTimer_.reset(
	[[NSTimer scheduledTimerWithTimeInterval:kDropdownHideDelay
	target:self
	selector:@selector(hideTimerFire:)
	userInfo:nil
	repeats:NO] retain]);
	DCHECK([hideTimer_ isValid]); // This also checks that \|hideTimer_ != nil\|.
	}

	- (void)cancelShowTimer {
	[showTimer_ invalidate];
	showTimer_.reset();
	}

	- (void)cancelHideTimer {
	[hideTimer_ invalidate];
	hideTimer_.reset();
	}

	- (void)cancelAllTimers {
	[self cancelShowTimer];
	[self cancelHideTimer];
	}

	- (void)showTimerFire:(NSTimer*)timer {
	DCHECK_EQ(showTimer_, timer); // This better be our show timer.
	[showTimer_ invalidate]; // Make sure it doesn't repeat.
	showTimer_.reset(); // And get rid of it.
	[self changeOverlayToFraction:1 withAnimation:YES];
	}

	- (void)hideTimerFire:(NSTimer*)timer {
	DCHECK_EQ(hideTimer_, timer); // This better be our hide timer.
	[hideTimer_ invalidate]; // Make sure it doesn't repeat.
	hideTimer_.reset(); // And get rid of it.
	[self changeOverlayToFraction:0 withAnimation:YES];
	}

	- (void)cleanup {
	[self cancelMouseExitCheck];
	[self cancelAnimationAndTimers];
	[[NSNotificationCenter defaultCenter] removeObserver:self];

	[self removeTrackingAreaIfNecessary];
	contentView_ = nil;

	// This isn't tracked when not in presentation mode.
	[browserController_ releaseBarVisibilityForOwner:self
	withAnimation:NO
	delay:NO];

	// Call the main status resignation code to perform the associated cleanup,
	// since we will no longer be receiving actual status resignation
	// notifications.
	[self hideActiveWindowUI];

	// No more calls back up to the BWC.
	browserController_ = nil;
	}

	- (void)showActiveWindowUI {
	DCHECK_EQ(systemFullscreenMode_, base::mac::kFullScreenModeNormal);
	if (systemFullscreenMode_ != base::mac::kFullScreenModeNormal)
	return;

	if ([self shouldToggleMenuBar]) {
	base::mac::FullScreenMode desiredMode = [self desiredSystemFullscreenMode];
	base::mac::RequestFullScreen(desiredMode);
	systemFullscreenMode_ = desiredMode;
	}

	// TODO(rohitrao): Insert the Exit Fullscreen button. http://crbug.com/35956
	}

	- (void)hideActiveWindowUI {
	if (systemFullscreenMode_ != base::mac::kFullScreenModeNormal) {
	base::mac::ReleaseFullScreen(systemFullscreenMode_);
	systemFullscreenMode_ = base::mac::kFullScreenModeNormal;
	}

	// TODO(rohitrao): Remove the Exit Fullscreen button. http://crbug.com/35956
	}

	@end