| -rw-r--r-- | kaddressbook/undo.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/kaddressbook/undo.h b/kaddressbook/undo.h new file mode 100644 index 0000000..843bc26 --- a/dev/null +++ b/kaddressbook/undo.h @@ -0,0 +1,95 @@ +/* + This file is part of KAddressBook. + Copyright (C) 1999 Don Sanders <sanders@kde.org> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + + As a special exception, permission is given to link this program + with any edition of Qt, and distribute the resulting executable, + without including the source code for Qt in the source distribution. +*/ + +#ifndef UNDO_H +#define UNDO_H + +#include <qobject.h> +#include <qptrstack.h> +#include <qstring.h> + +class Command +{ +public: + Command() {} + virtual ~Command() {}; + virtual QString name() = 0; + virtual void redo() = 0; // egcs requires these methods to have + virtual void undo() = 0; // implementations (Seems like a bug) + // pure virtual may not work +}; + +/** The Undo and Redo stacks now no longer inherit directly from a stack. +* They now contain a stack internally and inherit from StackBase, which +* has a signal for when the stack is modified. This is need to keep +* the edit menu and toolbar up to date. +* +* Really this is a simple observable stack. +*/ +class StackBase : public QObject +{ + Q_OBJECT + + public: + StackBase() : QObject() {} + + void push(Command *c); + bool isEmpty(); + Command *top(); + void clear(); + + signals: + void changed(); + + protected: + /** Protect the pop method so users must call undo/redo to properly + * use the stack, however the subclasses need it to modify the stack. + */ + Command *pop(); + + QPtrStack<Command> mCommandStack; +}; + +class UndoStack : public StackBase +{ +public: + static UndoStack *instance(); + void undo(); + +protected: + UndoStack(); + static UndoStack* instance_; +}; + +class RedoStack : public StackBase +{ +public: + static RedoStack *instance(); + void redo(); + +protected: + RedoStack(); + static RedoStack* instance_; +}; + +#endif |