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git.saurik.com Git - wxWidgets.git/blob - interface/cmdproc.h
1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: interface of wxCommandProcessor and wxCommand
4 // Author: wxWidgets team
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
13 wxCommand is a base class for modelling an application command, which is an
14 action usually performed by selecting a menu item, pressing a toolbar
15 button or any other means provided by the application to change the data or
21 @see @ref overview_docview_wxcommand
23 class wxCommand
: public wxObject
27 Constructor. wxCommand is an abstract class, so you will need to derive
28 a new class and call this constructor from your own constructor.
31 Tells the command processor whether this command is undo-able. You
32 can achieve the same functionality by overriding the CanUndo()
33 member function (if for example the criteria for undoability is
36 Must be supplied for the command processor to display the command
37 name in the application's edit menu.
39 wxCommand(bool canUndo
= false, const wxString
& name
= NULL
);
47 Returns @true if the command can be undone, @false otherwise.
52 Override this member function to execute the appropriate action when
55 @returns @true to indicate that the action has taken place, @false
56 otherwise. Returning @false will indicate to the command
57 processor that the action is not undoable and should not be
58 added to the command history.
63 Returns the command name.
68 Override this member function to un-execute a previous Do.
70 How you implement this command is totally application dependent, but
71 typical strategies include:
73 - Perform an inverse operation on the last modified piece of data in
74 the document. When redone, a copy of data stored in command is pasted
75 back or some operation reapplied. This relies on the fact that you
76 know the ordering of Undos; the user can never Undo at an arbitrary
77 position in the command history.
78 - Restore the entire document state (perhaps using document
79 transactioning). Potentially very inefficient, but possibly easier to
80 code if the user interface and data are complex, and an "inverse
81 execute" operation is hard to write. The docview sample uses the
82 first method, to remove or restore segments in the drawing.
84 @returns @true to indicate that the action has taken place, @false
85 otherwise. Returning @false will indicate to the command
86 processor that the action is not redoable and no change should
87 be made to the command history.
95 @class wxCommandProcessor
98 wxCommandProcessor is a class that maintains a history of wxCommands, with
99 undo/redo functionality built-in. Derive a new class from this if you want
105 @see @ref overview_docview_wxcommandproc, wxCommand
107 class wxCommandProcessor
: public wxObject
114 May be set to a positive integer to limit the number of commands
115 stored to it, otherwise (and by default) the list of commands can
118 wxCommandProcessor(int maxCommands
= -1);
123 ~wxCommandProcessor();
126 Returns @true if the currently-active command can be undone, @false
129 virtual bool CanUndo();
132 Deletes all commands in the list and sets the current command pointer
135 virtual void ClearCommands();
138 Returns the list of commands.
140 wxList
& GetCommands() const;
143 Returns the edit menu associated with the command processor.
145 wxMenu
* GetEditMenu() const;
148 Returns the maximum number of commands that the command processor
151 int GetMaxCommands() const;
154 Returns the string that will be appended to the Redo menu item.
156 const wxString
& GetRedoAccelerator() const;
159 Returns the string that will be shown for the redo menu item.
161 wxString
GetRedoMenuLabel() const;
164 Returns the string that will be appended to the Undo menu item.
166 const wxString
& GetUndoAccelerator() const;
169 Returns the string that will be shown for the undo menu item.
171 wxString
GetUndoMenuLabel() const;
174 Initializes the command processor, setting the current command to the
175 last in the list (if any), and updating the edit menu (if one has been
178 virtual void Initialize();
181 Returns a boolean value that indicates if changes have been made since
182 the last save operation. This only works if MarkAsSaved() is called
183 whenever the project is saved.
185 virtual bool IsDirty();
188 You must call this method whenever the project is saved if you plan to
191 virtual void MarkAsSaved();
194 Executes (redoes) the current command (the command that has just been
200 Tells the command processor to update the Undo and Redo items on this
201 menu as appropriate. Set this to @NULL if the menu is about to be
202 destroyed and command operations may still be performed, or the command
203 processor may try to access an invalid pointer.
205 void SetEditMenu(wxMenu
* menu
);
208 Sets the menu labels according to the currently set menu and the
209 current command state.
211 void SetMenuStrings();
214 Sets the string that will be appended to the Redo menu item.
216 void SetRedoAccelerator(const wxString
& accel
);
219 Sets the string that will be appended to the Undo menu item.
221 void SetUndoAccelerator(const wxString
& accel
);
224 Submits a new command to the command processor. The command processor
225 calls wxCommand::Do() to execute the command; if it succeeds, the
226 command is stored in the history list, and the associated edit menu (if
227 any) updated appropriately. If it fails, the command is deleted
228 immediately. Once Submit() has been called, the passed command should
229 not be deleted directly by the application.
232 Indicates whether the successful command should be stored in the
235 virtual bool Submit(wxCommand
* command
, bool storeIt
= true);
238 Undoes the last command executed.