mirror of https://github.com/JakubMelka/PDF4QT.git
105 lines
3.3 KiB
C++
105 lines
3.3 KiB
C++
// Copyright (C) 2020-2021 Jakub Melka
|
|
//
|
|
// This file is part of PDF4QT.
|
|
//
|
|
// PDF4QT is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// with the written consent of the copyright owner, any later version.
|
|
//
|
|
// PDF4QT 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 Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with PDF4QT. If not, see <https://www.gnu.org/licenses/>.
|
|
|
|
#ifndef PDFUNDOREDOMANAGER_H
|
|
#define PDFUNDOREDOMANAGER_H
|
|
|
|
#include "pdfdocument.h"
|
|
|
|
#include <QObject>
|
|
|
|
namespace pdfviewer
|
|
{
|
|
|
|
/// Undo/Redo document manager, it is managing undo and redo steps,
|
|
/// when document is modified.
|
|
class PDFUndoRedoManager : public QObject
|
|
{
|
|
Q_OBJECT
|
|
|
|
private:
|
|
using BaseClass = QObject;
|
|
|
|
public:
|
|
explicit PDFUndoRedoManager(QObject* parent);
|
|
virtual ~PDFUndoRedoManager() override;
|
|
|
|
bool canUndo() const { return !m_undoSteps.empty(); }
|
|
bool canRedo() const { return !m_redoSteps.empty(); }
|
|
|
|
/// Performs single undo step. If Undo action can't be performed,
|
|
/// then nothing happens.
|
|
void doUndo();
|
|
|
|
/// Performs single redo step. If Redo action can't be performed,
|
|
/// then nothing happens.
|
|
void doRedo();
|
|
|
|
/// Clears all undo/redo steps
|
|
void clear();
|
|
|
|
/// Create undo action (after document modification)
|
|
/// \param document Document created by modification
|
|
/// \param oldDocument Old document
|
|
void createUndo(pdf::PDFModifiedDocument document, pdf::PDFDocumentPointer oldDocument);
|
|
|
|
/// Sets maximum steps for undo/redo
|
|
/// \param undoLimit Maximum undo steps
|
|
/// \param redoLimit Maximum redo steps
|
|
void setMaximumSteps(size_t undoLimit, size_t redoLimit);
|
|
|
|
signals:
|
|
/// This signals are emitted, when undo/redo action availability has
|
|
/// been changed (for example, user pressed undo/redo action)
|
|
void undoRedoStateChanged();
|
|
|
|
/// This signal is being emitted, when user performs undo/redo action.
|
|
/// Before signal is emitted, this object is in corrected state, as action
|
|
/// is performed.
|
|
/// \param document Document
|
|
void documentChangeRequest(pdf::PDFModifiedDocument document);
|
|
|
|
private:
|
|
/// Clamps undo/redo steps so they fit the limits
|
|
void clampUndoRedoSteps();
|
|
|
|
struct UndoRedoItem
|
|
{
|
|
explicit inline UndoRedoItem() = default;
|
|
explicit inline UndoRedoItem(pdf::PDFDocumentPointer oldDocument, pdf::PDFDocumentPointer newDocument, pdf::PDFModifiedDocument::ModificationFlags flags) :
|
|
oldDocument(qMove(oldDocument)),
|
|
newDocument(qMove(newDocument)),
|
|
flags(flags)
|
|
{
|
|
|
|
}
|
|
|
|
pdf::PDFDocumentPointer oldDocument;
|
|
pdf::PDFDocumentPointer newDocument;
|
|
pdf::PDFModifiedDocument::ModificationFlags flags = pdf::PDFModifiedDocument::None;
|
|
};
|
|
|
|
size_t m_undoLimit = 0;
|
|
size_t m_redoLimit = 0;
|
|
std::vector<UndoRedoItem> m_undoSteps;
|
|
std::vector<UndoRedoItem> m_redoSteps;
|
|
};
|
|
|
|
} // namespace pdfviewer
|
|
|
|
#endif // PDFUNDOREDOMANAGER_H
|