content/browser/web_contents/web_contents_view_mac.mm

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #import <Carbon/Carbon.h>
   6
   7 #import "content/browser/web_contents/web_contents_view_mac.h"
   8
   9 #include <string>
  10
  11 #import "base/mac/mac_util.h"
  12 #import "base/mac/scoped_sending_event.h"
  13 #include "base/mac/sdk_forward_declarations.h"
  14 #include "base/message_loop/message_loop.h"
  15 #import "base/message_loop/message_pump_mac.h"
  16 #include "content/browser/frame_host/popup_menu_helper_mac.h"
  17 #include "content/browser/renderer_host/render_view_host_factory.h"
  18 #include "content/browser/renderer_host/render_view_host_impl.h"
  19 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
  20 #include "content/browser/web_contents/web_contents_impl.h"
  21 #import "content/browser/web_contents/web_drag_dest_mac.h"
  22 #import "content/browser/web_contents/web_drag_source_mac.h"
  23 #include "content/common/view_messages.h"
  24 #include "content/public/browser/web_contents_delegate.h"
  25 #include "content/public/browser/web_contents_view_delegate.h"
  26 #include "skia/ext/skia_utils_mac.h"
  27 #import "third_party/mozilla/NSPasteboard+Utils.h"
  28 #include "ui/base/clipboard/custom_data_helper.h"
  29 #import "ui/base/cocoa/focus_tracker.h"
  30 #include "ui/base/dragdrop/cocoa_dnd_util.h"
  31 #include "ui/gfx/image/image_skia_util_mac.h"
  32
  33 using blink::WebDragOperation;
  34 using blink::WebDragOperationsMask;
  35 using content::DropData;
  36 using content::PopupMenuHelper;
  37 using content::RenderViewHostFactory;
  38 using content::RenderWidgetHostView;
  39 using content::RenderWidgetHostViewMac;
  40 using content::WebContents;
  41 using content::WebContentsImpl;
  42 using content::WebContentsViewMac;
  43
  44 // Ensure that the blink::WebDragOperation enum values stay in sync with
  45 // NSDragOperation constants, since the code below static_casts between 'em.
  46 #define STATIC_ASSERT_MATCHING_ENUM(name) \
  47   static_assert(int(NS##name) == int(blink::Web##name), "enum mismatch: " #name)
  48 STATIC_ASSERT_MATCHING_ENUM(DragOperationNone);
  49 STATIC_ASSERT_MATCHING_ENUM(DragOperationCopy);
  50 STATIC_ASSERT_MATCHING_ENUM(DragOperationLink);
  51 STATIC_ASSERT_MATCHING_ENUM(DragOperationGeneric);
  52 STATIC_ASSERT_MATCHING_ENUM(DragOperationPrivate);
  53 STATIC_ASSERT_MATCHING_ENUM(DragOperationMove);
  54 STATIC_ASSERT_MATCHING_ENUM(DragOperationDelete);
  55 STATIC_ASSERT_MATCHING_ENUM(DragOperationEvery);
  56
  57 @interface WebContentsViewCocoa (Private)
  58 - (id)initWithWebContentsViewMac:(WebContentsViewMac*)w;
  59 - (void)registerDragTypes;
  60 - (void)setCurrentDragOperation:(NSDragOperation)operation;
  61 - (DropData*)dropData;
  62 - (void)startDragWithDropData:(const DropData&)dropData
  63             dragOperationMask:(NSDragOperation)operationMask
  64                         image:(NSImage*)image
  65                        offset:(NSPoint)offset;
  66 - (void)cancelDeferredClose;
  67 - (void)clearWebContentsView;
  68 - (void)closeTabAfterEvent;
  69 - (void)viewDidBecomeFirstResponder:(NSNotification*)notification;
  70 @end
  71
  72 namespace content {
  73
  74 WebContentsView* CreateWebContentsView(
  75     WebContentsImpl* web_contents,
  76     WebContentsViewDelegate* delegate,
  77     RenderViewHostDelegateView** render_view_host_delegate_view) {
  78   WebContentsViewMac* rv = new WebContentsViewMac(web_contents, delegate);
  79   *render_view_host_delegate_view = rv;
  80   return rv;
  81 }
  82
  83 WebContentsViewMac::WebContentsViewMac(WebContentsImpl* web_contents,
  84                                        WebContentsViewDelegate* delegate)
  85     : web_contents_(web_contents),
  86       delegate_(delegate),
  87       allow_other_views_(false) {
  88 }
  89
  90 WebContentsViewMac::~WebContentsViewMac() {
  91   // This handles the case where a renderer close call was deferred
  92   // while the user was operating a UI control which resulted in a
  93   // close.  In that case, the Cocoa view outlives the
  94   // WebContentsViewMac instance due to Cocoa retain count.
  95   [cocoa_view_ cancelDeferredClose];
  96   [cocoa_view_ clearWebContentsView];
  97 }
  98
  99 gfx::NativeView WebContentsViewMac::GetNativeView() const {
 100   return cocoa_view_.get();
 101 }
 102
 103 gfx::NativeView WebContentsViewMac::GetContentNativeView() const {
 104   RenderWidgetHostView* rwhv = web_contents_->GetRenderWidgetHostView();
 105   if (!rwhv)
 106     return NULL;
 107   return rwhv->GetNativeView();
 108 }
 109
 110 gfx::NativeWindow WebContentsViewMac::GetTopLevelNativeWindow() const {
 111   NSWindow* window = [cocoa_view_.get() window];
 112   return window ? window : delegate_->GetNativeWindow();
 113 }
 114
 115 void WebContentsViewMac::GetContainerBounds(gfx::Rect* out) const {
 116   // Convert bounds to window coordinate space.
 117   NSRect bounds =
 118       [cocoa_view_.get() convertRect:[cocoa_view_.get() bounds] toView:nil];
 119
 120   // Convert bounds to screen coordinate space.
 121   NSWindow* window = [cocoa_view_.get() window];
 122   bounds.origin = [window convertBaseToScreen:bounds.origin];
 123
 124   // Flip y to account for screen flip.
 125   NSScreen* screen = [[NSScreen screens] objectAtIndex:0];
 126   bounds.origin.y = [screen frame].size.height - bounds.origin.y
 127       - bounds.size.height;
 128   *out = gfx::Rect(NSRectToCGRect(bounds));
 129 }
 130
 131 void WebContentsViewMac::StartDragging(
 132     const DropData& drop_data,
 133     WebDragOperationsMask allowed_operations,
 134     const gfx::ImageSkia& image,
 135     const gfx::Vector2d& image_offset,
 136     const DragEventSourceInfo& event_info) {
 137   // By allowing nested tasks, the code below also allows Close(),
 138   // which would deallocate |this|.  The same problem can occur while
 139   // processing -sendEvent:, so Close() is deferred in that case.
 140   // Drags from web content do not come via -sendEvent:, this sets the
 141   // same flag -sendEvent: would.
 142   base::mac::ScopedSendingEvent sending_event_scoper;
 143
 144   // The drag invokes a nested event loop, arrange to continue
 145   // processing events.
 146   base::MessageLoop::ScopedNestableTaskAllower allow(
 147       base::MessageLoop::current());
 148   NSDragOperation mask = static_cast<NSDragOperation>(allowed_operations);
 149   NSPoint offset = NSPointFromCGPoint(
 150       gfx::PointAtOffsetFromOrigin(image_offset).ToCGPoint());
 151   [cocoa_view_ startDragWithDropData:drop_data
 152                    dragOperationMask:mask
 153                                image:gfx::NSImageFromImageSkia(image)
 154                               offset:offset];
 155 }
 156
 157 void WebContentsViewMac::SizeContents(const gfx::Size& size) {
 158   // TODO(brettw | japhet) This is a hack and should be removed.
 159   // See web_contents_view.h.
 160   // Note(erikchen): This method has /never/ worked correctly. I've removed the
 161   // previous implementation.
 162 }
 163
 164 gfx::NativeView WebContentsViewMac::GetNativeViewForFocus() const {
 165   RenderWidgetHostView* rwhv =
 166       web_contents_->GetFullscreenRenderWidgetHostView();
 167   if (!rwhv)
 168     rwhv = web_contents_->GetRenderWidgetHostView();
 169   return rwhv ? rwhv->GetNativeView() : nil;
 170 }
 171
 172 void WebContentsViewMac::Focus() {
 173   gfx::NativeView native_view = GetNativeViewForFocus();
 174   NSWindow* window = [native_view window];
 175   [window makeFirstResponder:native_view];
 176   if (![window isVisible])
 177     return;
 178   [window makeKeyAndOrderFront:nil];
 179 }
 180
 181 void WebContentsViewMac::SetInitialFocus() {
 182   if (web_contents_->FocusLocationBarByDefault())
 183     web_contents_->SetFocusToLocationBar(false);
 184   else
 185     Focus();
 186 }
 187
 188 void WebContentsViewMac::StoreFocus() {
 189   gfx::NativeView native_view = GetNativeViewForFocus();
 190   // We're explicitly being asked to store focus, so don't worry if there's
 191   // already a view saved.
 192   focus_tracker_.reset(
 193       [[FocusTracker alloc] initWithWindow:[native_view window]]);
 194 }
 195
 196 void WebContentsViewMac::RestoreFocus() {
 197   gfx::NativeView native_view = GetNativeViewForFocus();
 198   // TODO(avi): Could we be restoring a view that's no longer in the key view
 199   // chain?
 200   if (!(focus_tracker_.get() &&
 201         [focus_tracker_ restoreFocusInWindow:[native_view window]])) {
 202     // Fall back to the default focus behavior if we could not restore focus.
 203     // TODO(shess): If location-bar gets focus by default, this will
 204     // select-all in the field.  If there was a specific selection in
 205     // the field when we navigated away from it, we should restore
 206     // that selection.
 207     SetInitialFocus();
 208   }
 209
 210   focus_tracker_.reset(nil);
 211 }
 212
 213 DropData* WebContentsViewMac::GetDropData() const {
 214   return [cocoa_view_ dropData];
 215 }
 216
 217 void WebContentsViewMac::UpdateDragCursor(WebDragOperation operation) {
 218   [cocoa_view_ setCurrentDragOperation: operation];
 219 }
 220
 221 void WebContentsViewMac::GotFocus() {
 222   // This is only used in the views FocusManager stuff but it bleeds through
 223   // all subclasses. http://crbug.com/21875
 224 }
 225
 226 // This is called when the renderer asks us to take focus back (i.e., it has
 227 // iterated past the last focusable element on the page).
 228 void WebContentsViewMac::TakeFocus(bool reverse) {
 229   if (reverse) {
 230     [[cocoa_view_ window] selectPreviousKeyView:cocoa_view_.get()];
 231   } else {
 232     [[cocoa_view_ window] selectNextKeyView:cocoa_view_.get()];
 233   }
 234 }
 235
 236 void WebContentsViewMac::ShowContextMenu(
 237     RenderFrameHost* render_frame_host,
 238     const ContextMenuParams& params) {
 239   // Allow delegates to handle the context menu operation first.
 240   if (web_contents_->GetDelegate() &&
 241       web_contents_->GetDelegate()->HandleContextMenu(params)) {
 242     return;
 243   }
 244
 245   if (delegate())
 246     delegate()->ShowContextMenu(render_frame_host, params);
 247   else
 248     DLOG(ERROR) << "Cannot show context menus without a delegate.";
 249 }
 250
 251 void WebContentsViewMac::ShowPopupMenu(
 252     RenderFrameHost* render_frame_host,
 253     const gfx::Rect& bounds,
 254     int item_height,
 255     double item_font_size,
 256     int selected_item,
 257     const std::vector<MenuItem>& items,
 258     bool right_aligned,
 259     bool allow_multiple_selection) {
 260   popup_menu_helper_.reset(new PopupMenuHelper(render_frame_host));
 261   popup_menu_helper_->ShowPopupMenu(bounds, item_height, item_font_size,
 262                                     selected_item, items, right_aligned,
 263                                     allow_multiple_selection);
 264   popup_menu_helper_.reset();
 265 }
 266
 267 void WebContentsViewMac::HidePopupMenu() {
 268   if (popup_menu_helper_)
 269     popup_menu_helper_->Hide();
 270 }
 271
 272 gfx::Rect WebContentsViewMac::GetViewBounds() const {
 273   // This method is not currently used on mac.
 274   NOTIMPLEMENTED();
 275   return gfx::Rect();
 276 }
 277
 278 void WebContentsViewMac::SetAllowOtherViews(bool allow) {
 279   if (allow_other_views_ == allow)
 280     return;
 281
 282   allow_other_views_ = allow;
 283   RenderWidgetHostViewMac* view = static_cast<RenderWidgetHostViewMac*>(
 284       web_contents_->GetRenderWidgetHostView());
 285   if (view)
 286     view->SetAllowPauseForResizeOrRepaint(!allow_other_views_);
 287 }
 288
 289 bool WebContentsViewMac::GetAllowOtherViews() const {
 290   return allow_other_views_;
 291 }
 292
 293 void WebContentsViewMac::CreateView(
 294     const gfx::Size& initial_size, gfx::NativeView context) {
 295   WebContentsViewCocoa* view =
 296       [[WebContentsViewCocoa alloc] initWithWebContentsViewMac:this];
 297   cocoa_view_.reset(view);
 298 }
 299
 300 RenderWidgetHostViewBase* WebContentsViewMac::CreateViewForWidget(
 301     RenderWidgetHost* render_widget_host, bool is_guest_view_hack) {
 302   if (render_widget_host->GetView()) {
 303     // During testing, the view will already be set up in most cases to the
 304     // test view, so we don't want to clobber it with a real one. To verify that
 305     // this actually is happening (and somebody isn't accidentally creating the
 306     // view twice), we check for the RVH Factory, which will be set when we're
 307     // making special ones (which go along with the special views).
 308     DCHECK(RenderViewHostFactory::has_factory());
 309     return static_cast<RenderWidgetHostViewBase*>(
 310         render_widget_host->GetView());
 311   }
 312
 313   RenderWidgetHostViewMac* view = new RenderWidgetHostViewMac(
 314       render_widget_host, is_guest_view_hack);
 315   if (delegate()) {
 316     base::scoped_nsobject<NSObject<RenderWidgetHostViewMacDelegate> >
 317         rw_delegate(
 318             delegate()->CreateRenderWidgetHostViewDelegate(render_widget_host));
 319
 320     view->SetDelegate(rw_delegate.get());
 321   }
 322   view->SetAllowPauseForResizeOrRepaint(!allow_other_views_);
 323
 324   // Fancy layout comes later; for now just make it our size and resize it
 325   // with us. In case there are other siblings of the content area, we want
 326   // to make sure the content area is on the bottom so other things draw over
 327   // it.
 328   NSView* view_view = view->GetNativeView();
 329   [view_view setFrame:[cocoa_view_.get() bounds]];
 330   [view_view setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
 331   // Add the new view below all other views; this also keeps it below any
 332   // overlay view installed.
 333   [cocoa_view_.get() addSubview:view_view
 334                      positioned:NSWindowBelow
 335                      relativeTo:nil];
 336   // For some reason known only to Cocoa, the autorecalculation of the key view
 337   // loop set on the window doesn't set the next key view when the subview is
 338   // added. On 10.6 things magically work fine; on 10.5 they fail
 339   // <http://crbug.com/61493>. Digging into Cocoa key view loop code yielded
 340   // madness; TODO(avi,rohit): look at this again and figure out what's really
 341   // going on.
 342   [cocoa_view_.get() setNextKeyView:view_view];
 343   return view;
 344 }
 345
 346 RenderWidgetHostViewBase* WebContentsViewMac::CreateViewForPopupWidget(
 347     RenderWidgetHost* render_widget_host) {
 348   return new RenderWidgetHostViewMac(render_widget_host, false);
 349 }
 350
 351 void WebContentsViewMac::SetPageTitle(const base::string16& title) {
 352   // Meaningless on the Mac; widgets don't have a "title" attribute
 353 }
 354
 355
 356 void WebContentsViewMac::RenderViewCreated(RenderViewHost* host) {
 357   // We want updates whenever the intrinsic width of the webpage changes.
 358   // Put the RenderView into that mode. The preferred width is used for example
 359   // when the "zoom" button in the browser window is clicked.
 360   host->EnablePreferredSizeMode();
 361 }
 362
 363 void WebContentsViewMac::RenderViewSwappedIn(RenderViewHost* host) {
 364 }
 365
 366 void WebContentsViewMac::SetOverscrollControllerEnabled(bool enabled) {
 367 }
 368
 369 bool WebContentsViewMac::IsEventTracking() const {
 370   return base::MessagePumpMac::IsHandlingSendEvent();
 371 }
 372
 373 // Arrange to call CloseTab() after we're back to the main event loop.
 374 // The obvious way to do this would be PostNonNestableTask(), but that
 375 // will fire when the event-tracking loop polls for events.  So we
 376 // need to bounce the message via Cocoa, instead.
 377 void WebContentsViewMac::CloseTabAfterEventTracking() {
 378   [cocoa_view_ cancelDeferredClose];
 379   [cocoa_view_ performSelector:@selector(closeTabAfterEvent)
 380                     withObject:nil
 381                     afterDelay:0.0];
 382 }
 383
 384 void WebContentsViewMac::CloseTab() {
 385   web_contents_->Close(web_contents_->GetRenderViewHost());
 386 }
 387
 388 }  // namespace content
 389
 390 @implementation WebContentsViewCocoa
 391
 392 - (id)initWithWebContentsViewMac:(WebContentsViewMac*)w {
 393   self = [super initWithFrame:NSZeroRect];
 394   if (self != nil) {
 395     webContentsView_ = w;
 396     dragDest_.reset(
 397         [[WebDragDest alloc] initWithWebContentsImpl:[self webContents]]);
 398     [self registerDragTypes];
 399
 400     [[NSNotificationCenter defaultCenter]
 401          addObserver:self
 402             selector:@selector(viewDidBecomeFirstResponder:)
 403                 name:kViewDidBecomeFirstResponder
 404               object:nil];
 405
 406     if (webContentsView_->delegate()) {
 407       [dragDest_ setDragDelegate:webContentsView_->delegate()->
 408           GetDragDestDelegate()];
 409     }
 410   }
 411   return self;
 412 }
 413
 414 - (void)dealloc {
 415   // Cancel any deferred tab closes, just in case.
 416   [self cancelDeferredClose];
 417
 418   // This probably isn't strictly necessary, but can't hurt.
 419   [self unregisterDraggedTypes];
 420
 421   [[NSNotificationCenter defaultCenter] removeObserver:self];
 422
 423   [super dealloc];
 424 }
 425
 426 - (BOOL)allowsVibrancy {
 427   // Returning YES will allow rendering this view with vibrancy effect if it is
 428   // incorporated into a view hierarchy that uses vibrancy, it will have no
 429   // effect otherwise.
 430   // For details see Apple documentation on NSView and NSVisualEffectView.
 431   return YES;
 432 }
 433
 434 // Registers for the view for the appropriate drag types.
 435 - (void)registerDragTypes {
 436   NSArray* types = [NSArray arrayWithObjects:
 437       ui::kChromeDragDummyPboardType,
 438       kWebURLsWithTitlesPboardType,
 439       NSURLPboardType,
 440       NSStringPboardType,
 441       NSHTMLPboardType,
 442       NSRTFPboardType,
 443       NSFilenamesPboardType,
 444       ui::kWebCustomDataPboardType,
 445       nil];
 446   [self registerForDraggedTypes:types];
 447 }
 448
 449 - (void)setCurrentDragOperation:(NSDragOperation)operation {
 450   [dragDest_ setCurrentOperation:operation];
 451 }
 452
 453 - (DropData*)dropData {
 454   return [dragDest_ currentDropData];
 455 }
 456
 457 - (WebContentsImpl*)webContents {
 458   if (webContentsView_ == NULL)
 459     return NULL;
 460   return webContentsView_->web_contents();
 461 }
 462
 463 - (void)mouseEvent:(NSEvent*)theEvent {
 464   WebContentsImpl* webContents = [self webContents];
 465   if (webContents && webContents->GetDelegate()) {
 466     NSPoint location = [NSEvent mouseLocation];
 467     if ([theEvent type] == NSMouseMoved)
 468       webContents->GetDelegate()->ContentsMouseEvent(
 469           webContents, gfx::Point(location.x, location.y), true);
 470     if ([theEvent type] == NSMouseExited)
 471       webContents->GetDelegate()->ContentsMouseEvent(
 472           webContents, gfx::Point(location.x, location.y), false);
 473   }
 474 }
 475
 476 - (void)setMouseDownCanMoveWindow:(BOOL)canMove {
 477   mouseDownCanMoveWindow_ = canMove;
 478 }
 479
 480 - (BOOL)mouseDownCanMoveWindow {
 481   // This is needed to prevent mouseDowns from moving the window
 482   // around.  The default implementation returns YES only for opaque
 483   // views.  WebContentsViewCocoa does not draw itself in any way, but
 484   // its subviews do paint their entire frames.  Returning NO here
 485   // saves us the effort of overriding this method in every possible
 486   // subview.
 487   return mouseDownCanMoveWindow_;
 488 }
 489
 490 - (void)setOpaque:(BOOL)opaque {
 491   RenderWidgetHostViewMac* view = static_cast<RenderWidgetHostViewMac*>(
 492       webContentsView_->web_contents()->GetRenderWidgetHostView());
 493   DCHECK(view);
 494   [view->cocoa_view() setOpaque:opaque];
 495 }
 496
 497 - (void)pasteboard:(NSPasteboard*)sender provideDataForType:(NSString*)type {
 498   [dragSource_ lazyWriteToPasteboard:sender
 499                              forType:type];
 500 }
 501
 502 - (void)startDragWithDropData:(const DropData&)dropData
 503             dragOperationMask:(NSDragOperation)operationMask
 504                         image:(NSImage*)image
 505                        offset:(NSPoint)offset {
 506   dragSource_.reset([[WebDragSource alloc]
 507       initWithContents:[self webContents]
 508                   view:self
 509               dropData:&dropData
 510                  image:image
 511                 offset:offset
 512             pasteboard:[NSPasteboard pasteboardWithName:NSDragPboard]
 513      dragOperationMask:operationMask]);
 514   [dragSource_ startDrag];
 515 }
 516
 517 // NSDraggingSource methods
 518
 519 // Returns what kind of drag operations are available. This is a required
 520 // method for NSDraggingSource.
 521 - (NSDragOperation)draggingSourceOperationMaskForLocal:(BOOL)isLocal {
 522   if (dragSource_)
 523     return [dragSource_ draggingSourceOperationMaskForLocal:isLocal];
 524   // No web drag source - this is the case for dragging a file from the
 525   // downloads manager. Default to copy operation. Note: It is desirable to
 526   // allow the user to either move or copy, but this requires additional
 527   // plumbing to update the download item's path once its moved.
 528   return NSDragOperationCopy;
 529 }
 530
 531 // Called when a drag initiated in our view ends.
 532 - (void)draggedImage:(NSImage*)anImage
 533              endedAt:(NSPoint)screenPoint
 534            operation:(NSDragOperation)operation {
 535   [dragSource_ endDragAt:screenPoint operation:operation];
 536
 537   // Might as well throw out this object now.
 538   dragSource_.reset();
 539 }
 540
 541 // Called when a drag initiated in our view moves.
 542 - (void)draggedImage:(NSImage*)draggedImage movedTo:(NSPoint)screenPoint {
 543 }
 544
 545 // Called when a file drag is dropped and the promised files need to be written.
 546 - (NSArray*)namesOfPromisedFilesDroppedAtDestination:(NSURL*)dropDest {
 547   if (![dropDest isFileURL])
 548     return nil;
 549
 550   NSString* fileName = [dragSource_ dragPromisedFileTo:[dropDest path]];
 551   if (!fileName)
 552     return nil;
 553
 554   return @[ fileName ];
 555 }
 556
 557 // NSDraggingDestination methods
 558
 559 - (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
 560   return [dragDest_ draggingEntered:sender view:self];
 561 }
 562
 563 - (void)draggingExited:(id<NSDraggingInfo>)sender {
 564   [dragDest_ draggingExited:sender];
 565 }
 566
 567 - (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender {
 568   return [dragDest_ draggingUpdated:sender view:self];
 569 }
 570
 571 - (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
 572   return [dragDest_ performDragOperation:sender view:self];
 573 }
 574
 575 - (void)cancelDeferredClose {
 576   SEL aSel = @selector(closeTabAfterEvent);
 577   [NSObject cancelPreviousPerformRequestsWithTarget:self
 578                                            selector:aSel
 579                                              object:nil];
 580 }
 581
 582 - (void)clearWebContentsView {
 583   webContentsView_ = NULL;
 584   [dragSource_ clearWebContentsView];
 585 }
 586
 587 - (void)closeTabAfterEvent {
 588   webContentsView_->CloseTab();
 589 }
 590
 591 - (void)viewDidBecomeFirstResponder:(NSNotification*)notification {
 592   NSView* view = [notification object];
 593   if (![[self subviews] containsObject:view])
 594     return;
 595
 596   NSSelectionDirection direction =
 597       [[[notification userInfo] objectForKey:kSelectionDirection]
 598         unsignedIntegerValue];
 599   if (direction == NSDirectSelection)
 600     return;
 601
 602   [self webContents]->
 603       FocusThroughTabTraversal(direction == NSSelectingPrevious);
 604 }
 605
 606 // When the subviews require a layout, their size should be reset to the size
 607 // of this view. (It is possible for the size to get out of sync as an
 608 // optimization in preparation for an upcoming WebContentsView resize.
 609 // http://crbug.com/264207)
 610 - (void)resizeSubviewsWithOldSize:(NSSize)oldBoundsSize {
 611   for (NSView* subview in self.subviews)
 612     [subview setFrame:self.bounds];
 613 }
 614
 615 - (void)viewWillMoveToWindow:(NSWindow*)newWindow {
 616   NSWindow* oldWindow = [self window];
 617
 618   NSNotificationCenter* notificationCenter =
 619       [NSNotificationCenter defaultCenter];
 620
 621   // Occlusion notification APIs are new in Mavericks.
 622   bool supportsOcclusionAPIs = base::mac::IsOSMavericksOrLater();
 623
 624   if (supportsOcclusionAPIs) {
 625     if (oldWindow) {
 626       [notificationCenter
 627           removeObserver:self
 628                     name:NSWindowDidChangeOcclusionStateNotification
 629                   object:oldWindow];
 630     }
 631     if (newWindow) {
 632       [notificationCenter
 633           addObserver:self
 634              selector:@selector(windowChangedOcclusionState:)
 635                  name:NSWindowDidChangeOcclusionStateNotification
 636                object:newWindow];
 637     }
 638   }
 639 }
 640
 641 - (void)windowChangedOcclusionState:(NSNotification*)notification {
 642   DCHECK(base::mac::IsOSMavericksOrLater());
 643   NSWindow* window = [notification object];
 644   WebContentsImpl* webContents = [self webContents];
 645   if (window && webContents && !webContents->IsBeingDestroyed()) {
 646     if ([window occlusionState] & NSWindowOcclusionStateVisible) {
 647       webContents->WasUnOccluded();
 648     } else {
 649       webContents->WasOccluded();
 650     }
 651   }
 652 }
 653
 654 @end