comparison base/CommandHistory.h @ 17:2fb933f88604

* Update some copyright notice dates
* Add commands for basic editing operations in time-instants and time-value layers

+/* -*- c-basic-offset: 4 -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    A waveform viewer and audio annotation editor.
+    Chris Cannam, Queen Mary University of London, 2005-2006
+    
+    This is experimental software.  Not for distribution.
+*/
+
+/*
+   This is a modified version of a source file from the Rosegarden
+   MIDI and audio sequencer and notation editor, copyright 2000-2006
+   Chris Cannam, distributed under the GNU General Public License.
+
+   This file contains traces of the KCommandHistory class from the KDE
+   project, copyright 2000 Werner Trobin and David Faure and
+   distributed under the GNU Lesser General Public License.
+*/
+
+#ifndef _MULTI_VIEW_COMMAND_HISTORY_H_
+#define _MULTI_VIEW_COMMAND_HISTORY_H_
+
+#include <QObject>
+#include <QString>
+
+#include <stack>
+#include <set>
+#include <map>
+
+class Command;
+class QAction;
+class QMenu;
+class QToolBar;
+
+/**
+ * The CommandHistory class stores a list of executed commands and
+ * maintains Undo and Redo actions synchronised with those commands.
+ *
+ * CommandHistory allows you to associate more than one Undo and Redo
+ * menu or toolbar with the same command history, and it keeps them
+ * all up-to-date at once.  This makes it effective in systems where
+ * multiple views may be editing the same data.
+ */
+
+class CommandHistory : public QObject
+{
+    Q_OBJECT
+
+public:
+    virtual ~CommandHistory();
+
+    static CommandHistory *getInstance();
+
+    void clear();
+    
+    void registerMenu(QMenu *menu);
+    void registerToolbar(QToolBar *toolbar);
+
+    void addCommand(Command *command, bool execute = true);
+    
+    /// Return the maximum number of items in the undo history.
+    int undoLimit() { return m_undoLimit; }
+
+    /// Set the maximum number of items in the undo history.
+    void setUndoLimit(int limit);
+
+    /// Return the maximum number of items in the redo history.
+    int redoLimit() { return m_redoLimit; }
+
+    /// Set the maximum number of items in the redo history.
+    void setRedoLimit(int limit);
+    
+public slots:
+    /**
+     * Checkpoint function that should be called when the document is
+     * saved.  If the undo/redo stack later returns to the point at
+     * which the document was saved, the documentRestored signal will
+     * be emitted.
+     */
+    virtual void documentSaved();
+
+    /**
+     * Add a command to the history that has already been executed,
+     * without executing it again.  Equivalent to addCommand(command, false).
+     */
+    void addExecutedCommand(Command *);
+
+    /**
+     * Add a command to the history and also execute it.  Equivalent
+     * to addCommand(command, true).
+     */
+    void addCommandAndExecute(Command *);
+
+protected slots:
+    void undo();
+    void redo();
+    void undoActivated(QAction *);
+    void redoActivated(QAction *);
+
+signals:
+    /**
+     * Emitted whenever a command has just been executed or
+     * unexecuted, whether by addCommand, undo, or redo.
+     */
+    void commandExecuted();
+
+    /**
+     * Emitted whenever a command has just been executed, whether by
+     * addCommand or redo.
+     */
+    void commandExecuted(Command *);
+
+    /**
+     * Emitted whenever a command has just been unexecuted, whether by
+     * addCommand or undo.
+     */
+    void commandUnexecuted(Command *);
+
+    /**
+     * Emitted when the undo/redo stack has reached the same state at
+     * which the documentSaved slot was last called.
+     */
+    void documentRestored();
+
+protected:
+    CommandHistory();
+    static CommandHistory *m_instance;
+
+    QAction *m_undoAction;
+    QAction *m_redoAction;
+    QAction *m_undoMenuAction;
+    QAction *m_redoMenuAction;
+    QMenu *m_undoMenu;
+    QMenu *m_redoMenu;
+
+    std::map<QAction *, int> m_actionCounts;
+
+    typedef std::stack<Command *> CommandStack;
+    CommandStack m_undoStack;
+    CommandStack m_redoStack;
+
+    int m_undoLimit;
+    int m_redoLimit;
+    int m_savedAt;
+
+    void updateActions();
+
+    void clipCommands();
+
+    void clipStack(CommandStack &stack, int limit);
+    void clearStack(CommandStack &stack);
+};
+
+
+#endif