comparison widgets/CommandHistory.h @ 376:e1a9e478b7f2

* juggle some files around in order to free audioio, base, and system libraries
  from dependency on QtGui

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    
+    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.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+/*
+   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 MacroCommand;
+class QAction;
+class QMenu;
+class QToolBar;
+class QTimer;
+
+/**
+ * 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);
+
+    /**
+     * Add a command to the command history.
+     * 
+     * The command will normally be executed before being added; but
+     * if a compound operation is in use (see startCompoundOperation
+     * below), the execute status of the compound operation will
+     * determine whether the command is executed or not.
+     */
+    void addCommand(Command *command);
+    
+    /**
+     * Add a command to the command history.
+     *
+     * If execute is true, the command will be executed before being
+     * added.  Otherwise it will be assumed to have been already
+     * executed -- a command should not be added to the history unless
+     * its work has actually been done somehow!
+     *
+     * If a compound operation is in use (see startCompoundOperation
+     * below), the execute value passed to this method will override
+     * the execute status of the compound operation.  In this way it's
+     * possible to have a compound operation mixing both to-execute
+     * and pre-executed commands.
+     *
+     * If bundle is true, the command will be a candidate for bundling
+     * with any adjacent bundleable commands that have the same name,
+     * into a single compound command.  This is useful for small
+     * commands that may be executed repeatedly altering the same data
+     * (e.g. type text, set a parameter) whose number and extent is
+     * not known in advance.  The bundle parameter will be ignored if
+     * a compound operation is already in use.
+     */
+    void addCommand(Command *command, bool execute, bool bundle = false);
+    
+    /// Return the maximum number of items in the undo history.
+    int getUndoLimit() const { 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 getRedoLimit() const { return m_redoLimit; }
+
+    /// Set the maximum number of items in the redo history.
+    void setRedoLimit(int limit);
+    
+    /// Return the maximum number of items visible in undo and redo menus.
+    int getMenuLimit() const { return m_menuLimit; }
+
+    /// Set the maximum number of items in the menus.
+    void setMenuLimit(int limit);
+
+    /// Return the time after which a bundle will be closed if nothing is added.
+    int getBundleTimeout() const { return m_bundleTimeout; }
+
+    /// Set the time after which a bundle will be closed if nothing is added.
+    void setBundleTimeout(int msec);
+
+    /// Start recording commands to batch up into a single compound command.
+    void startCompoundOperation(QString name, bool execute);
+
+    /// Finish recording commands and store the compound command.
+    void endCompoundOperation();
+
+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 *);
+
+    void undo();
+    void redo();
+
+protected slots:
+    void undoActivated(QAction *);
+    void redoActivated(QAction *);
+    void bundleTimerTimeout();
+    
+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_menuLimit;
+    int m_savedAt;
+
+    MacroCommand *m_currentCompound;
+    bool m_executeCompound;
+    void addToCompound(Command *command, bool execute);
+
+    MacroCommand *m_currentBundle;
+    QString m_currentBundleName;
+    QTimer *m_bundleTimer;
+    int m_bundleTimeout;
+    void addToBundle(Command *command, bool execute);
+    void closeBundle();
+    
+    void updateActions();
+
+    void clipCommands();
+
+    void clipStack(CommandStack &stack, int limit);
+    void clearStack(CommandStack &stack);
+};
+
+
+#endif