Add a context menu to the gtk task manager.

chrome/browser/gtk/task_manager_gtk.h

 // 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.
 
 #ifndef CHROME_BROWSER_GTK_TASK_MANAGER_GTK_H_
 #define CHROME_BROWSER_GTK_TASK_MANAGER_GTK_H_
 
 #include <gtk/gtk.h>
 
 #include <string>
 
 #include "chrome/browser/task_manager.h"
 
 class TaskManagerGtk : public TaskManagerModelObserver {
  public:
   TaskManagerGtk();
   virtual ~TaskManagerGtk();
 
   // TaskManagerModelObserver
   virtual void OnModelChanged();
   virtual void OnItemsChanged(int start, int length);
   virtual void OnItemsAdded(int start, int length);
   virtual void OnItemsRemoved(int start, int length);
 
   // Creates the task manager if it doesn't exist; otherwise, it activates the
   // existing task manager window.
   static void Show();
 
  private:
+  class ContextMenuController;
+  friend class ContextMenuController;
+
   // Initializes the task manager dialog.
   void Init();
 
   // Sets up the treeview widget.
   void CreateTaskManagerTreeview();
 
   // Returns the model data for a given |row| and |col_id|.
   std::string GetModelText(int row, int col_id);
 
   // Retrieves the resource icon from the model for |row|.
   GdkPixbuf* GetModelIcon(int row);
 
   // Sets the treeview row data.  |row| is an index into the model and |iter|
   // is the current position in the treeview.
   void SetRowDataFromModel(int row, GtkTreeIter* iter);
 
   // Queries the treeview for the selected rows, and kills those processes.
   void KillSelectedProcesses();
 
+  // Opens the context menu used to select the task manager columns.
+  void ShowContextMenu();
+
   // response signal handler that notifies us of dialog responses.
   static void OnResponse(GtkDialog* dialog, gint response_id,
                          TaskManagerGtk* task_manager);
 
   // changed signal handler that is sent when the treeview selection changes.
   static void OnSelectionChanged(GtkTreeSelection* selection,
                                  TaskManagerGtk* task_manager);
 
+  // button-release-event handler that opens the right-click context menu.
+  static gboolean OnButtonReleaseEvent(GtkWidget* widget, GdkEventButton* event,
+                                       TaskManagerGtk* task_manager);
+
   // The task manager.
   TaskManager* task_manager_;
 
   // Our model.
   TaskManagerModel* model_;
 
   // The task manager dialog window.
   GtkWidget* dialog_;
 
   // The treeview that contains the process list.
   GtkWidget* treeview_;
 
   // The list of processes.
   GtkListStore* process_list_;
 
   // The number of processes in |process_list_|.
   int process_count_;
 
+  // The context menu controller.
+  scoped_ptr<ContextMenuController> menu_controller_;
+
   // An open task manager window. There can only be one open at a time. This
   // is reset to NULL when the window is closed.
   static TaskManagerGtk* instance_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskManagerGtk);
 };
 
 #endif  // CHROME_BROWSER_GTK_TASK_MANAGER_GTK_H_