kalarm/src/undo.h

0001 /*
0002  *  undo.h  -  undo/redo facility
0003  *  Program:  kalarm
0004  *  SPDX-FileCopyrightText: 2005-2022 David Jarvie <djarvie@kde.org>
0005  *
0006  *  SPDX-License-Identifier: GPL-2.0-or-later
0007  */
0008
0009 #pragma once
0010
0011 /**  @file undo.h - undo/redo facility */
0012
0013 #include "resources/resource.h"
0014 #include "lib/autodeletelist.h"
0015 #include "kalarmcalendar/kaevent.h"
0016
0017 #include <QStringList>
0018
0019 class UndoItem;
0020 using namespace KAlarmCal;
0021
0022
0023 class Undo : public QObject
0024 {
0025     Q_OBJECT
0026 public:
0027     enum Type { NONE, UNDO, REDO };
0028     // N.B. The Event structure must be constructed before the action for
0029     // which the undo is being created is carried out, since the
0030     // don't-show-errors status is not contained within the KAEvent itself.
0031     struct Event
0032     {
0033         Event() = default;
0034         Event(const KAEvent&, const Resource&);
0035         KAEvent          event;
0036         mutable Resource resource;
0037         QStringList      dontShowErrors;
0038     };
0039     class EventList : public QList<Event>
0040     {
0041     public:
0042         void append(const KAEvent& e, const Resource& res)  { QList<Event>::append(Event(e, res)); }
0043     };
0044
0045     static Undo*       instance();
0046     static void        saveAdd(const KAEvent&, const Resource&, const QString& name = QString());
0047     static void        saveAdds(const EventList&, const QString& name = QString());
0048     static void        saveEdit(const Event& oldEvent, const KAEvent& newEvent);
0049     static void        saveDelete(const Event&, const QString& name = QString());
0050     static void        saveDeletes(const EventList&, const QString& name = QString());
0051     static void        saveReactivate(const KAEvent&, const Resource&, const QString& name = QString());
0052     static void        saveReactivates(const EventList&, const QString& name = QString());
0053     static bool        undo(QWidget* parent, const QString& action)
0054                                           { return undo(0, UNDO, parent, action); }
0055     static bool        undo(int id, QWidget* parent, const QString& action)
0056                                           { return undo(findItem(id, UNDO), UNDO, parent, action); }
0057     static bool        redo(QWidget* parent, const QString& action)
0058                                           { return undo(0, REDO, parent, action); }
0059     static bool        redo(int id, QWidget* parent, const QString& action)
0060                                           { return undo(findItem(id, REDO), REDO, parent, action); }
0061     static void        clear();
0062     static bool        haveUndo()         { return !mUndoList.isEmpty(); }
0063     static bool        haveRedo()         { return !mRedoList.isEmpty(); }
0064     static QString     actionText(Type);
0065     static QString     actionText(Type, int id);
0066     static QString     description(Type, int id);
0067     static QList<int>  ids(Type);
0068     static void        emitChanged();
0069     static void        dumpDebug(Type, int count);
0070
0071     // Types for use by UndoItem class and its descendants
0072     using List = AutoDeleteList<UndoItem>;
0073
0074 Q_SIGNALS:
0075     void               changed(const QString& undo, const QString& redo);
0076
0077 protected:
0078     // Methods for use by UndoItem class
0079     static void        add(UndoItem*, bool undo);
0080     static void        remove(UndoItem*, bool undo);
0081     static void        replace(UndoItem* old, UndoItem* New);
0082
0083 private:
0084     explicit Undo(QObject* parent)  : QObject(parent) {}
0085     static void        removeRedos(const QString& eventID);
0086     static bool        undo(int index, Type, QWidget* parent, const QString& action);
0087     static UndoItem*   getItem(int id, Type);
0088     static int         findItem(int id, Type);
0089     void               emitChanged(const QString& undo, const QString& redo)
0090                                        { Q_EMIT changed(undo, redo); }
0091
0092     static Undo*       mInstance;     // the one and only Undo instance
0093     static List        mUndoList;     // edit history for undo, latest undo first
0094     static List        mRedoList;     // edit history for redo, latest redo first
0095
0096 friend class UndoItem;
0097 };
0098
0099 // vim: et sw=4: