OLD | NEW |
(Empty) | |
| 1 // Copyright (c) 2011 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 #ifndef CHROME_BROWSER_TAB_CONTENTS_RENDER_VIEW_CONTEXT_MENU_OBSERVER_H_ |
| 6 #define CHROME_BROWSER_TAB_CONTENTS_RENDER_VIEW_CONTEXT_MENU_OBSERVER_H_ |
| 7 #pragma once |
| 8 |
| 9 struct ContextMenuParams; |
| 10 |
| 11 // The interface used for implementing context-menu items. The following |
| 12 // instruction describe how to implement a context-menu item with this |
| 13 // interface. |
| 14 // |
| 15 // 1. Add command IDs for the context-menu items to 'chrome_command_ids.h'. |
| 16 // |
| 17 // #define IDC_MY_COMMAND 99999 |
| 18 // |
| 19 // 2. Add strings for the context-menu items to 'generated_sources.grd'. |
| 20 // |
| 21 // <message name="IDS_MY_COMMAND" desc="..."> |
| 22 // My command |
| 23 // </message> |
| 24 // |
| 25 // 3. Create a class that implements this interface. (It is a good idea to use |
| 26 // the RenderViewContextMenuDelegate interface to avoid accessing the |
| 27 // RenderViewContextMenu class directly.) |
| 28 // |
| 29 // class MyMenuObserver : public RenderViewContextMenuObserver { |
| 30 // public: |
| 31 // MyMenuObserver(RenderViewContextMenuDelegate* d); |
| 32 // ~MyMenuObserver(); |
| 33 // |
| 34 // virtual void InitMenu(const ContextMenuParams& params) OVERRIDE; |
| 35 // virtual bool IsCommandIdSupported(int command_id) OVERRIDE; |
| 36 // virtual bool IsCommandIdEnabled(int command_id) OVERRIDE; |
| 37 // virtual void ExecuteCommand(int command_id) OVERRIDE; |
| 38 // |
| 39 // private: |
| 40 // RenderViewContextMenuDelgate* delegate_; |
| 41 // } |
| 42 // |
| 43 // void MyMenuObserver::InitMenu(const ContextMenuParams& params) { |
| 44 // delegate_->AddMenuItem(IDC_MY_COMMAND,...); |
| 45 // } |
| 46 // |
| 47 // bool MyMenuObserver::IsCommandIdSupported(int command_id) { |
| 48 // return command_id == IDC_MY_COMMAND; |
| 49 // } |
| 50 // |
| 51 // bool MyMenuObserver::IsCommandIdEnabled(int command_id) { |
| 52 // DCHECK(command_id == IDC_MY_COMMAND); |
| 53 // return true; |
| 54 // } |
| 55 // |
| 56 // void MyMenuObserver::ExecuteCommand(int command_id) { |
| 57 // DCHECK(command_id == IDC_MY_COMMAND); |
| 58 // } |
| 59 // |
| 60 // 4. Add this observer class to the RenderViewContextMenu class. (It is good |
| 61 // to use scoped_ptr<> so Chrome can create its instances only when it needs.) |
| 62 // |
| 63 // class RenderViewContextMenu { |
| 64 // ... |
| 65 // private: |
| 66 // scoped_ptr<MyMenuObserver> my_menu_observer_; |
| 67 // }; |
| 68 // |
| 69 // 5. Create its instance in InitMenu() and add it to the observer list of the |
| 70 // RenderViewContextMenu class. |
| 71 // |
| 72 // void RenderViewContextMenu::InitMenu() { |
| 73 // ... |
| 74 // my_menu_observer_.reset(new MyMenuObserver(this)); |
| 75 // observers_.AddObserver(my_menu_observer_.get()); |
| 76 // } |
| 77 // |
| 78 // |
| 79 class RenderViewContextMenuObserver { |
| 80 public: |
| 81 virtual ~RenderViewContextMenuObserver() {} |
| 82 |
| 83 // Called when the RenderViewContextMenu class initializes a context menu. We |
| 84 // usually call RenderViewContextMenuDelegate::AddMenuItem() to add menu items |
| 85 // in this function. |
| 86 virtual void InitMenu(const ContextMenuParams& params); |
| 87 |
| 88 // Called when the RenderViewContextMenu class asks whether an observer |
| 89 // listens for the specified command ID. If this function returns true, the |
| 90 // RenderViewContextMenu class calls IsCommandIdEnabled() or ExecuteCommand(). |
| 91 virtual bool IsCommandIdSupported(int command_id); |
| 92 |
| 93 // Called when the RenderViewContextMenu class sets the initial status of the |
| 94 // specified context-menu item. If we need to enable or disable a context-menu |
| 95 // item while showing, use RenderViewContextMenuDelegate::UpdateMenuItem(). |
| 96 virtual bool IsCommandIdEnabled(int command_id); |
| 97 |
| 98 // Called when a user selects the specified context-menu item. |
| 99 virtual void ExecuteCommand(int command_id); |
| 100 }; |
| 101 |
| 102 #endif // CHROME_BROWSER_TAB_CONTENTS_RENDER_VIEW_CONTEXT_MENU_OBSERVER_H_ |
OLD | NEW |