Subversion Repositories Scribus

Rev

Rev 1287 | Rev 1293 | Go to most recent revision | Blame | Compare with Previous | Last modification | View Log | RSS feed

/***************************************************************************
 *   Copyright (C) 2005 by Riku Leino                                      *
 *   tsoots@gmail.com                                                      *
 *                                                                         *
 *   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.             *
 ***************************************************************************/


#ifndef UNDOMANAGER_H
#define UNDOMANAGER_H

#include <vector>
#include <utility>
#include <qobject.h>
#include <qpixmap.h>
#include <qstring.h>
#include "undostate.h"
#include "undoobject.h"

class UndoGui;
class PrefsContext;

typedef std::pair<UndoObject*, UndoState*> ActionPair;
typedef std::vector<ActionPair> ActionList;
typedef std::pair<ActionList::iterator, ActionList> StackPair;
typedef QMap<QString, StackPair> StackMap;

/**
 * @brief UndoManager handles the undo stack.
 *
 * UndoManager is the engine of the undo/redo handling. When ever an undoable
 * action happens an UndoState object will be sent to the UndoManager which then
 * stores the state in the undo stack. When an undo is requested the state is
 * send back to it's creator which is then responsible for doing the actual undo or
 * redo.
 *
 * UndoManager also handles the UndoGuis by linking them together and reporting
 * all undo/redo actions to the guis for them to update the visual representation.
 * For this to work all UndoGuis need to be registered to the UndoManager with the
 * registerGui() method.
 *
 * @author Riku Leino tsoots@gmail.com
 * @date December 2004
 */

class UndoManager : public QObject
{
        Q_OBJECT

private:

/*** UndoManager::TransactionState ***************************************************/

        /**
         * @brief TransactionState provides a container where multiple actions can be stored
         * @brief as a single action which then appears in the attached <code>UndoGui</code>s.
         * @author Riku Leino tsoots@gmail.com
         * @date January 2005
         */

        class TransactionState : public UndoState
        {
        private:
                /** @brief Number of undo states stored in this transaction */
                uint _size;
                /** @brief vector to keep the states in */
                std::vector<ActionPair*> states;
        public:
                /** @brief Creates a new TransactionState instance */
                TransactionState();
                /** @brief Destroys the TransactionState instance */
                ~TransactionState();
                /**
                 * @brief Add a new <code>UndoState</code> object to the transaction.
                 * @param state state to be added to the transaction
                 */

                void pushBack(UndoObject *target, UndoState *state);
                /**
                 * @brief Returns the count of the <code>UndoState</code> objects in this transaction.
                 * @return count of the <code>UndoState</code> objects in this transaction
                 */

                uint sizet();
                /** @brief Use the name from last action added to this <code>TransactionState</code> */
                void useActionName();
                /**
                 * @brief Returns an <code>UndoState</code> object at <code>index</code>.
                 * @param index index from where an <code>UndoState</code> object is returned.
                 * If <code>index</code> is out of scope <code>NULL</code> will be rerturned.
                 * @return <code>UndoState</code> object from <code>index</code> or <code>NULL</code>
                 * if <code>index</code> is out of scope.
                 */

                ActionPair* at(int index);
                /**
                 * @brief Replace object with id uid with new UndoObject newUndoObject.
                 * @param uid id of the object that is wanted to be replaced
                 * @param newUndoObject object that is used for replacing
                 */

                void replace(ulong uid, UndoObject *newUndoObject);
        };

/*** UndoManager::TransactionObject ***************************************************/

        /**
         * @brief Dummy subclass of <code>UndoObject</code> which is used for holding the name
         * @brief for the transaction's target object(group) (f.e "Selection", "Group", "Script"...).
         * @author Riku Leino tsoots@gmail.com
         * @date January 2005
         */

        class TransactionObject : public UndoObject
        {
        public:
                TransactionObject() {};
                virtual ~TransactionObject() {};
                void restore(UndoState*, bool) {};
        };

/**************************************************************************************/

        /**
         * @brief The only instance of UndoManager available.
         *
         * UndoManager is singleton and the instance can be queried with the method
         * instance().
         */

        static UndoManager* _instance;

        /** @brief Should undo states be stored or ignored */
        static bool _undoEnabled;

        PrefsContext *prefs;

        /** @brief Doc to which the currently active stack belongs */
        QString currentDoc;

        /**
         * @brief Id number of the object for what the object specific undo is shown
         * @brief or -1 if global undo is used.
         */

        int currentUndoObjectId;

        /**
         * @brief Stores the transactions which are currently started but not
         * @brief canceled or commited.
         */

        std::vector<std::pair<TransactionObject*, TransactionState*> > transactions;

        /**
         * @brief If in transaction mode this is the container for incoming <code>UndoState</code>
         * @brief objects.
         *
         * It is also used to detect if we are in the transaction mode. When it is <code>NULL</code>
         * normal mode is on.
         */

        TransactionState *transaction;

        /** @brief Dummy object for storing transaction target's name */
        TransactionObject *transactionTarget;

        /**
         * @brief UndoGuis attached to this UndoManager
         * @sa UndoGui
         * @sa UndoWidget
         * @sa UndoPalette
         */

        std::vector<UndoGui*> undoGuis;

        /** @brief Undo stacks for all open documents */
        StackMap stacks;

        /** @brief Maximum length of the undo stack. 0 marks for infinite length. */
        int historyLength;

        /**
         * @brief Initializes the UndoGui.
         * @param gui UndoGui to be initialized
         * @param uid UndoObject's id if in object specific mode or -1 to tell
         * that global undo is used.
         */

        void setState(UndoGui* gui, int uid = -1);

        /**
         * @brief Disconnect all attached UndoGui instances from signals provided by this
         * @brief class and other UndoGui objects.
         */

        void connectGuis();
        /**
         * @brief Connect all attached UndoGui instances to signals provided by this
         * @brief class and other UndoGui objects.
         */

        void disconnectGuis();
        /**
         * @brief Load icons needed for Action History window.
         */

        void initIcons();
        /**
         * @brief Checks the stack length against historyLength variable and removes
         * @brief actions until it is of right length.
         *
         * This method is used when a user alters the history length option in preferences
         * and whenever a new action is added to the stack.
         */

        void checkStackLength();
        /**
         * @brief Extracts actions from TransactionState object and undos them.
         * @param tstate TransactionState object from where the actions are going to be extracted.
         */

        void doTransactionUndo(TransactionState *tstate);
        /**
         * @brief Extracts actions from TransactionState object and redos them.
         * @param tstate TransactionState object from where the actions are going to be extracted.
         */

        void doTransactionRedo(TransactionState *tstate);

public:
        /**
         * @brief Returns a pointer to the UndoManager instance
         * @return A pointer to the UndoManager instance
         */

        static UndoManager* instance();

        /**
         * @brief Deletes the UndoManager Instance
         *
         * Must be called when UndoManager is no more needed.
         */

        static void deleteInstance();

        /**
         * @brief Sets the undo action tracking enabled or disabled.
         * @param isEnabled If true undo stack is updated with the states sent
         * to the UndoManager else undo stack is not updated and attached UndoGuis
         * are not informed of the actions.
         */

        void setUndoEnabled(bool isEnabled);

        /**
         * @brief Returns true if undo actions are stored, if not will return false.
         * @return true if undo actions are stored, if not will return false
         */

        static bool undoEnabled();

        /**
         * @brief Start a transaction.
         *
         * After this method has been invoked <code>UndoManager</code> will switch to the
     * transaction (silent) mode where it does not report actions to the attached
         * <UndoGui> widgets but stores all incoming <code>UndoState</code> objects into
         * the transaction container which after call to the method commit() will be sent
         * to the guis as a single undo action. Transaction can be named when starting it or
         * naming can be done when commiting it.
         * @param targetName name for the target of this transaction (f.e. "Selection")
         * @param targetPixmap Icon for the target on which this transaction works.
         * this icon will be drawn first when the action is presented in Action History
         * window and icon for the action will be drawn over this one.
         * @param name name for the transaction (f.e. "Move" would make with the above
         * "Move Selection")
         * @param description description for the transaction
         * @param actionPixmap icon for the action performed by the transaction
         * @sa commit()
         */

        void beginTransaction(const QString &targetName = "",
                          QPixmap *targetPixmap = 0,
                          const QString &actionName = "",
                          const QString &description = "",
                          QPixmap *actionPixmap = 0);

        /**
         * @brief Cancels the current transaction and deletes groupped <code>UndoState</code>s.
         * @brief Nothing from canceled transaction will be sent to the undo gui widgets.
         */

        void cancelTransaction();

        /**
         * @brief Commit the current transaction.
         *
         * Current transaction will be commited and <code>UndoManager</code> will be switched
         * to the normal mode. Commited transaction will be sent to the attached undo gui
         * widgets and it will show up there as a single undo action. Details used as a parameter
         * will be details shown in the gui widgets.
         * @param targetName name for the target of this transaction (f.e. "Selection")
         * @param targetPixmap Icon for the target on which this transaction works.
         * this icon will be drawn first when the action is presented in Action History
         * window and icon for the action will be drawn over this one.
         * @param name name for the action
         * @param description description for the action
         * @param actionPixmap icon for the action performed by the transaction
         * @sa beginTransaction()
         */

        void commit(const QString &targetName = "",
                QPixmap *targetPixmap = 0,
                const QString &name = "",
                const QString &description = "",
                QPixmap *actionPixmap = 0);

        /**
         * @brief Returns true if in transaction mode if not will return false.
         * @return true if in transaction mode if not will return false
         */

        bool isTransactionMode();

        /**
         * @brief Register an UndoGui to the UndoManager.
         *
         * After registering a gui to the manager the gui will be updated with the
         * undo action information received by the UndoManager. Actions done with the
         * UndoGui to be registered are also handled after registering.
         * @param gui A pointer to the UndoGui that is wanted to be registered.
         */

        void registerGui(UndoGui* gui);

        /**
         * @brief Removes an UndoGui from UndoManager.
         * @param gui UndoGui to be removed from the UndoManager.
         */

        void removeGui(UndoGui* gui);

        /**
         * @brief Changes the active undo stack.
         *
         * Sets the stack connected to the name <code>stackName</code> active. Calling
         * this method will send clear() signal to the attached <code>UndoGui</code>s and
         * will update their undo stack representations.
         * @param stackName Name of the stack to be used
         */

        void switchStack(const QString& stackName);

        /**
         * @brief Rename the current stack
         * @param newName New name for the current stack.
         */

        void renameStack(const QString& newName);

        /**
         * @brief Remove the stack with the name <code>stackName</code>
         * @param stackName Name of the stack that is wanted to be removed
         */

        void removeStack(const QString& stackName);

        /**
         * @brief Returns true if there are actions that can be undone otherwise returns false.
         *
         * This is useful when undo/redo actions are handled with a gui that is not attached to
         * the UndoManager (f.e. menu items) and when those gui items are wanted to set enabled
         * or disabled depending on the status of the undo stack.
         * @return true if there are actions that can be undone otherwise returns false
         */

        bool hasUndoActions();

        /**
         * @brief Returns true if there are actions that can be redone otherwise returns false.
         * @return true if there are actions that can be redone otherwise returns false
         * @sa UndoManager::hasUndoActions()
         */

        bool hasRedoActions();

        /**
         * @brief Switches the state of UndoManager (global/object specific undo).
         *
         * If parameter uid is less than 0 global undo is used else the undo state
         * is object specific using the object whose uid is given as a parameter.
         * @param uid UndoObject's id for what the object specific undo is wanted or
         * -1 if global undo is wanted.
         */

        void showObject(int uid);

        /**
         * @brief Replace an UndoObject with the id uid with a new UndoObject new.
         * @param uid Id for the UndoObject that is wanted to be replaced.
         * @param newUndoObject UndoObject which will replace an old UndoObject in the stack.
         */

        void replaceObject(ulong uid, UndoObject *newUndoObject);

        /**
         * @brief Returns the maximum length of the undostack.
         * @return the maximum length of the undostack
         */

        int getHistoryLength();

        /**
        * @name Action strings
        * Strings describing undo actions
        */

        /*@{*/
        static const QString AddVGuide;
        static const QString AddHGuide;
        static const QString DelVGuide;
        static const QString DelHGuide;
        static const QString MoveVGuide;
        static const QString MoveHGuide;
        static const QString LockGuides;
        static const QString UnlockGuides;
        static const QString Move;
        static const QString Resize;
        static const QString Rotate;
        static const QString MoveFromTo;
        static const QString ResizeFromTo;
        static const QString RotateFromTo;
        static const QString Selection;
        static const QString Group;
        static const QString Create;
        static const QString CreateTo;
        static const QString AlignDistribute;
        static const QString ItemsInvolved;
        static const QString Cancel;
        static const QString SetFill;
        static const QString ColorFromTo;
        static const QString SetShade;
        static const QString ShadeFromTo;
        static const QString SetLineColor;
        static const QString SetLineShade;
        static const QString FlipH;
        static const QString FlipV;
        static const QString Lock;
        static const QString UnLock;
        static const QString SizeLock;
        static const QString SizeUnLock;
        /*@}*/

        /**
         * @name Action icons
         * Icons for undo actions
         */

        /*@{*/
/*** Icons for UndoObjects *******************************************/
        static QPixmap *IImageFrame;
        static QPixmap *ITextFrame;
        static QPixmap *ILine;
        static QPixmap *IPolygon;
        static QPixmap *IPolyline;
        static QPixmap *IPathText;
        static QPixmap *IGroup;
/*** Icons for actions ***********************************************/
        static QPixmap *IMove;
        static QPixmap *IResize;
        static QPixmap *IRotate;
        static QPixmap *IGuides;
        static QPixmap *ILockGuides;
        static QPixmap *IAlignDistribute;
        static QPixmap *IFill;
        static QPixmap *IShade;
        static QPixmap *IFlipH;
        static QPixmap *IFlipV;
        static QPixmap *ILock;
        static QPixmap *IUnLock;
        /*@}*/

protected:
        /** @brief Creates a new UndoManager instance */
        UndoManager();

        /** @brief Destroys the UndoManager instance */
        ~UndoManager();

private slots:
        /**
         * @brief Take undo steps the given amount
         *
         * When an UndoGui is registered to the UndoManager gui's undo() signal
         * is connected to this slot. Emitting an undo() signal will make the
         * UndoManager perform undo actions the given number of steps.
         * @param steps Number of undo actions to make
         */

        void doUndo(int steps);

        /**
         * @brief Take redo steps the given amount
         * @param steps Number of redo actions to make
         * @sa UndoManager::doUndo(int steps)
         */

        void doRedo(int steps);

public slots:
        /**
         * @brief Adds a new action to the undo stack.
         *
         * If _unodEnabled is true the action will be stored otherwise it will
         * be just ignored. When a new action is added redo items from the stack
         * will be removed and the current action will be set to the one which was
         * added.
         * @param target Source of the action. When undoing/redoing this action
         * restore() method of this UndoObject will be called.
         * @param state UndoSate describing the state (action).
         */

        void action(UndoObject* target, UndoState* state);

        /**
         * @brief Informs UndoManager to perform undo
         *
         * If an undo is wanted and the caller is not registered UndoGui this method
         * can be used. Useful for example with the menu entry for undo.
         * @param steps Number of undo steps to take
         */

        void undo(int steps);

        /**
         * @brief Informs UndoManager to perform redo
         * @param steps Number of redo steps to take
         * @sa UndoManager::undo(int steps)
         */

        void redo(int steps);

        /**
         * @brief Sets the length of the undo stack.
         *
         * Tells how many UndoStates are stored.
         * @param steps number of UndoStates to store in the undo stack
         */

        void setHistoryLength(int steps);

signals:
        /**
         * @brief Emitted when a new undo action is stored to the undo stack.
         *
         * This signal is connected to the registered UndoGuis for them to update the
         * visual representation of the undo stack.
         * @param target Source of the action
         * @param state UndoState describing the action
         */

        void newAction(UndoObject* target, UndoState* state);

        /**
         * @brief Emitted when an undo action has been done.
         *
         * It is connected to attached guis to inform them to update the visual
         * representation of the undo stack. This signal will be also sent to the
         * <code>UndoGui</code> where it came from.
         * @param steps Number of steps to take
         */

        void undoSignal(int steps);

        /**
         * @brief Emitted when a redo action has been done.
         * @param steps Number of steps to take
         * @sa UndoManager::undoSignal(int steps)
         */

        void redoSignal(int steps);

        /**
         * @brief This signal is used to notify registered UndoGui instances that
         * @brief history limit is reached and the last item from the stack
         * @brief representation should be removed.
         */

        void popBack();

        /**
         * @brief This signal is emitted when all requested undo/redo actions have been done.
         *
         * It could be used in the application as a signal when the view can be rendered
         * again after undo/redo.
         */

        void undoRedoDone();

};

typedef UndoManager Um;

#endif