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 8 namespace content { 9 struct ContextMenuParams; 10 } 11 12 // The interface used for implementing context-menu items. The following 13 // instruction describe how to implement a context-menu item with this 14 // interface. 15 // 16 // 1. Add command IDs for the context-menu items to 'chrome_command_ids.h'. 17 // 18 // #define IDC_MY_COMMAND 99999 19 // 20 // 2. Add strings for the context-menu items to 'generated_sources.grd'. 21 // 22 // <message name="IDS_MY_COMMAND" desc="..."> 23 // My command 24 // </message> 25 // 26 // 3. Create a class that implements this interface. (It is a good idea to use 27 // the RenderViewContextMenuDelegate interface to avoid accessing the 28 // RenderViewContextMenu class directly.) 29 // 30 // class MyMenuObserver : public RenderViewContextMenuObserver { 31 // public: 32 // MyMenuObserver(RenderViewContextMenuDelegate* d); 33 // ~MyMenuObserver(); 34 // 35 // virtual void InitMenu(const content::ContextMenuParams& params) OVERRIDE; 36 // virtual bool IsCommandIdSupported(int command_id) OVERRIDE; 37 // virtual bool IsCommandIdEnabled(int command_id) OVERRIDE; 38 // virtual void ExecuteCommand(int command_id) OVERRIDE; 39 // 40 // private: 41 // RenderViewContextMenuDelgate* delegate_; 42 // } 43 // 44 // void MyMenuObserver::InitMenu(const content::ContextMenuParams& params) { 45 // delegate_->AddMenuItem(IDC_MY_COMMAND,...); 46 // } 47 // 48 // bool MyMenuObserver::IsCommandIdSupported(int command_id) { 49 // return command_id == IDC_MY_COMMAND; 50 // } 51 // 52 // bool MyMenuObserver::IsCommandIdEnabled(int command_id) { 53 // DCHECK(command_id == IDC_MY_COMMAND); 54 // return true; 55 // } 56 // 57 // void MyMenuObserver::ExecuteCommand(int command_id) { 58 // DCHECK(command_id == IDC_MY_COMMAND); 59 // } 60 // 61 // 4. Add this observer class to the RenderViewContextMenu class. (It is good 62 // to use scoped_ptr<> so Chrome can create its instances only when it needs.) 63 // 64 // class RenderViewContextMenu { 65 // ... 66 // private: 67 // scoped_ptr<MyMenuObserver> my_menu_observer_; 68 // }; 69 // 70 // 5. Create its instance in InitMenu() and add it to the observer list of the 71 // RenderViewContextMenu class. 72 // 73 // void RenderViewContextMenu::InitMenu() { 74 // ... 75 // my_menu_observer_.reset(new MyMenuObserver(this)); 76 // observers_.AddObserver(my_menu_observer_.get()); 77 // } 78 // 79 // 80 class RenderViewContextMenuObserver { 81 public: 82 virtual ~RenderViewContextMenuObserver() {} 83 84 // Called when the RenderViewContextMenu class initializes a context menu. We 85 // usually call RenderViewContextMenuDelegate::AddMenuItem() to add menu items 86 // in this function. 87 virtual void InitMenu(const content::ContextMenuParams& params); 88 89 // Called when the RenderViewContextMenu class asks whether an observer 90 // listens for the specified command ID. If this function returns true, the 91 // RenderViewContextMenu class calls IsCommandIdEnabled() or ExecuteCommand(). 92 virtual bool IsCommandIdSupported(int command_id); 93 94 // Called when the RenderViewContextMenu class sets the initial status of the 95 // specified context-menu item. If we need to enable or disable a context-menu 96 // item while showing, use RenderViewContextMenuDelegate::UpdateMenuItem(). 97 virtual bool IsCommandIdChecked(int command_id); 98 virtual bool IsCommandIdEnabled(int command_id); 99 100 // Called when a user selects the specified context-menu item. 101 virtual void ExecuteCommand(int command_id); 102 103 // Called when a user closes the context menu without selecting any items. 104 virtual void OnMenuCancel(); 105 }; 106 107 #endif // CHROME_BROWSER_TAB_CONTENTS_RENDER_VIEW_CONTEXT_MENU_OBSERVER_H_ 108
