Implement back/forward toolbar menus on Mac....

chrome/browser/cocoa/back_forward_menu_controller.mm

+// Copyright (c) 2009 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/cocoa/back_forward_menu_controller.h"
+
+#include "base/logging.h"
+#include "base/scoped_ptr.h"
+#include "base/sys_string_conversions.h"
+#include "chrome/browser/back_forward_menu_model.h"
+#import "chrome/browser/cocoa/delayedmenu_button.h"
+#include "skia/ext/skia_utils_mac.h"
+
+using base::SysUTF16ToNSString;
+using gfx::SkBitmapToNSImage;
+
+@implementation BackForwardMenuController
+
+// Accessors and mutators:
+
+@synthesize type = type_;
+
+// Own methods:
+
+- (id)initWithBrowser:(Browser*)browser
+            modelType:(BackForwardMenuType)type
+               button:(DelayedMenuButton*)button {
+  if ((self = [super init])) {
+    type_ = type;
+    button_ = button;
+    model_.reset(new BackForwardMenuModel(browser, type_));
+    DCHECK(model_.get());
+    menu_.reset([[NSMenu alloc] initWithTitle:@""]);
+    DCHECK(menu_.get());
+    [menu_ setDelegate:self];
+
+    [button_ setMenu:menu_];
+    [button_ setMenuEnabled:YES];
+  }
+  return self;
+}
+
+// Methods as delegate:
+
+// Called by menu_ just before tracking begins.
+//TODO(viettrungluu@gmail.com): do anything for chapter stops (see model)?
+- (void)menuNeedsUpdate:(NSMenu*)menu {
+  DCHECK(menu == menu_);
+
+  // Remove old menu items (backwards order is as good as any).
+  for (NSInteger i = [menu_ numberOfItems]; i > 0; i--)
+    [menu_ removeItemAtIndex:(i-1)];
+
+  // 0-th item must be blank. (This is because we use a pulldown list, for which
+  // Cocoa uses the 0-th item as "title" in the button.)
+  [menu_ insertItemWithTitle:@""
+                      action:nil
+               keyEquivalent:@""
+                     atIndex:0];
+  for (int menuID = 1; menuID <= model_->GetTotalItemCount(); menuID++) {
+    if (model_->IsSeparator(menuID)) {
+      [menu_ insertItem:[NSMenuItem separatorItem]
+                atIndex:menuID];
+    } else {
+      // Create a menu item with the right label.
+      NSMenuItem* menuItem = [[NSMenuItem alloc]
+              initWithTitle:SysUTF16ToNSString(model_->GetItemLabel(menuID))
+                     action:nil
+              keyEquivalent:@""];
+      [menuItem autorelease];
+
+      // Only enable it if it's supposed to do something.
+      [menuItem setEnabled:(model_->ItemHasCommand(menuID) ? YES : NO)];
+
+      // Icon (if it has one).
+      if (model_->ItemHasIcon(menuID))
+        [menuItem setImage:SkBitmapToNSImage(model_->GetItemIcon(menuID))];
+
+      // This will make it call our |-executeMenuItem:| method. We store the
+      // |menuID| (or |menu_id|) in the tag.
+      [menuItem setTag:menuID];
+      [menuItem setTarget:self];
+      [menuItem setAction:@selector(executeMenuItem:)];
+
+      // Put it in the menu!
+      [menu_ insertItem:menuItem
+                atIndex:menuID];
+    }
+  }
+}
+
+// Action methods:
+
+- (void)executeMenuItem:(id)sender {
+  DCHECK([sender isKindOfClass:[NSMenuItem class]]);
+  int menuID = [sender tag];
+  model_->ExecuteCommandById(menuID);
+}
+
+@end  // @implementation BackForwardMenuController