Handle resize corner layout entirely in the platform BrowserWindow*/BrowserView* code...

chrome/browser/cocoa/tab_contents_controller.mm

Index: chrome/browser/cocoa/tab_contents_controller.mm
===================================================================
--- chrome/browser/cocoa/tab_contents_controller.mm	(revision 66034)
+++ chrome/browser/cocoa/tab_contents_controller.mm	(working copy)
@@ -8,15 +8,105 @@
 #include "base/scoped_nsobject.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/renderer_host/render_widget_host_view.h"
+#include "chrome/browser/tab_contents/navigation_controller.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/common/notification_details.h"
+#include "chrome/common/notification_observer.h"
+#include "chrome/common/notification_registrar.h"
+#include "chrome/common/notification_source.h"
+#include "chrome/common/notification_type.h"
 
 
+@interface TabContentsController(Private)
+// Forwards frame update to |delegate_| (ResizeNotificationView calls it).
+- (void)tabContentsViewFrameWillChange:(NSRect)frameRect;
+// Notification from TabContents (forwarded by TabContentsNotificationBridge).
+- (void)tabContentsRenderViewHostChanged:(RenderViewHost*)oldHost
+                                 newHost:(RenderViewHost*)newHost;
+@end
+
+
+// A supporting C++ bridge object to register for TabContents notifications.
+
+class TabContentsNotificationBridge : public NotificationObserver {
+ public:
+  explicit TabContentsNotificationBridge(TabContentsController* controller);
+
+  // Overriden from NotificationObserver.
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+  // Register for |contents|'s notifications, remove all prior registrations.
+  void ChangeTabContents(TabContents* contents);
+ private:
+  NotificationRegistrar registrar_;
+  TabContentsController* controller_;  // weak, owns us
+};
+
+TabContentsNotificationBridge::TabContentsNotificationBridge(
+    TabContentsController* controller)
+    : controller_(controller) {
+}
+
+void TabContentsNotificationBridge::Observe(
+    NotificationType type,
+    const NotificationSource& source,
+    const NotificationDetails& details) {
+  if (type == NotificationType::RENDER_VIEW_HOST_CHANGED) {
+    RenderViewHostSwitchedDetails* switched_details =
+        Details<RenderViewHostSwitchedDetails>(details).ptr();
+    [controller_ tabContentsRenderViewHostChanged:switched_details->old_host
+                                          newHost:switched_details->new_host];
+  } else {
+    NOTREACHED();
+  }
+}
+
+void TabContentsNotificationBridge::ChangeTabContents(TabContents* contents) {
+  registrar_.RemoveAll();
+  if (contents) {
+    registrar_.Add(this,
+                   NotificationType::RENDER_VIEW_HOST_CHANGED,
+                   Source<NavigationController>(&contents->controller()));
+  }
+}
+
+
+// A custom view that notifies |controller| that view's frame is changing.
+
+@interface ResizeNotificationView : NSView {
+  TabContentsController* controller_;
+}
+- (id)initWithController:(TabContentsController*)controller;
+@end
+
+@implementation ResizeNotificationView
+
+- (id)initWithController:(TabContentsController*)controller {
+  if ((self = [super initWithFrame:NSZeroRect])) {
+    controller_ = controller;
+  }
+  return self;
+}
+
+- (void)setFrame:(NSRect)frameRect {
+  [controller_ tabContentsViewFrameWillChange:frameRect];
+  [super setFrame:frameRect];
+}
+
+@end
+
+
 @implementation TabContentsController
 @synthesize tabContents = contents_;
 
-- (id)initWithContents:(TabContents*)contents {
+- (id)initWithContents:(TabContents*)contents
+              delegate:(id<TabContentsControllerDelegate>)delegate {
   if ((self = [super initWithNibName:nil bundle:nil])) {
     contents_ = contents;
+    delegate_ = delegate;
+    tabContentsBridge_.reset(new TabContentsNotificationBridge(self));
+    tabContentsBridge_->ChangeTabContents(contents);
   }
   return self;
 }
@@ -28,47 +118,76 @@
 }
 
 - (void)loadView {
-  scoped_nsobject<NSView> view([[NSView alloc] initWithFrame:NSZeroRect]);
+  scoped_nsobject<ResizeNotificationView> view(
+      [[ResizeNotificationView alloc] initWithController:self]);
   [view setAutoresizingMask:NSViewHeightSizable|NSViewWidthSizable];
   [self setView:view];
 }
 
 - (void)ensureContentsSizeDoesNotChange {
-  NSView* contentsContainer = [self view];
-  NSArray* subviews = [contentsContainer subviews];
-  if ([subviews count] > 0)
-    [contents_->GetNativeView() setAutoresizingMask:NSViewNotSizable];
+  if (contents_) {
+    NSView* contentsContainer = [self view];
+    NSArray* subviews = [contentsContainer subviews];
+    if ([subviews count] > 0)
+      [contents_->GetNativeView() setAutoresizingMask:NSViewNotSizable];
+  }
 }
 
 // Call when the tab view is properly sized and the render widget host view
 // should be put into the view hierarchy.
 - (void)ensureContentsVisible {
+  if (!contents_)
+    return;
   NSView* contentsContainer = [self view];
   NSArray* subviews = [contentsContainer subviews];
   NSView* contentsNativeView = contents_->GetNativeView();
-  [contentsNativeView setFrame:[contentsContainer frame]];
+
+  NSRect contentsNativeViewFrame = [contentsContainer frame];
+  contentsNativeViewFrame.origin = NSZeroPoint;
+
+  [delegate_ tabContentsViewFrameWillChange:self
+                                  frameRect:contentsNativeViewFrame];
+
+  // Native view is resized to the actual size before it becomes visible
+  // to avoid flickering.
+  [contentsNativeView setFrame:contentsNativeViewFrame];
   if ([subviews count] == 0) {
     [contentsContainer addSubview:contentsNativeView];
   } else if ([subviews objectAtIndex:0] != contentsNativeView) {
     [contentsContainer replaceSubview:[subviews objectAtIndex:0]
                                  with:contentsNativeView];
   }
+  // Restore autoresizing properties possibly stripped by
+  // ensureContentsSizeDoesNotChange call.
   [contentsNativeView setAutoresizingMask:NSViewWidthSizable|
                                           NSViewHeightSizable];
 }
 
-// Returns YES if the tab represented by this controller is the front-most.
-- (BOOL)isCurrentTab {
-  // We're the current tab if we're in the view hierarchy, otherwise some other
-  // tab is.
-  return [[self view] superview] ? YES : NO;
+- (void)changeTabContents:(TabContents*)newContents {
+  contents_ = newContents;
+  tabContentsBridge_->ChangeTabContents(contents_);
 }
 
+- (void)tabContentsViewFrameWillChange:(NSRect)frameRect {
+  [delegate_ tabContentsViewFrameWillChange:self frameRect:frameRect];
+}
+
+- (void)tabContentsRenderViewHostChanged:(RenderViewHost*)oldHost
+                                 newHost:(RenderViewHost*)newHost {
+  if (oldHost && newHost && oldHost->view() && newHost->view()) {
+    newHost->view()->set_reserved_contents_rect(
+        oldHost->view()->reserved_contents_rect());
+  } else {
+    [delegate_ tabContentsViewFrameWillChange:self
+                                    frameRect:[[self view] frame]];
+  }
+}
+
 - (void)willBecomeUnselectedTab {
   // The RWHV is ripped out of the view hierarchy on tab switches, so it never
   // formally resigns first responder status.  Handle this by explicitly sending
   // a Blur() message to the renderer, but only if the RWHV currently has focus.
-  RenderViewHost* rvh = contents_->render_view_host();
+  RenderViewHost* rvh = [self tabContents]->render_view_host();
   if (rvh && rvh->view() && rvh->view()->HasFocus())
     rvh->Blur();
 }
@@ -83,9 +202,10 @@
   // Calling setContentView: here removes any first responder status
   // the view may have, so avoid changing the view hierarchy unless
   // the view is different.
-  if (contents_ != updatedContents) {
-    contents_ = updatedContents;
-    [self ensureContentsVisible];
+  if ([self tabContents] != updatedContents) {
+    [self changeTabContents:updatedContents];
+    if ([self tabContents])
+      [self ensureContentsVisible];
   }
 }