UndoManager.cpp Example File

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    #include "UndoManager.hpp"

    #include "MoveCommand.hpp"

    #include <QUndoStack>

    UndoManager::UndoManager(QObject *parent)
        : QObject(parent)
        , m_undoStack(new QUndoStack(this))
    {
        // We connect the signals from the QUndoStack directly to our own signals ...
        connect(m_undoStack, SIGNAL(canRedoChanged(bool)), this, SIGNAL(canRedoChanged()));
        connect(m_undoStack, SIGNAL(canUndoChanged(bool)), this, SIGNAL(canUndoChanged()));
        connect(m_undoStack, SIGNAL(redoTextChanged(QString)), this, SIGNAL(redoTextChanged()));
        connect(m_undoStack, SIGNAL(undoTextChanged(QString)), this, SIGNAL(undoTextChanged()));
    }

    bool UndoManager::canRedo() const
    {
        // ... and also just forward the getter methods to the QUndoStack
        return m_undoStack->canRedo();
    }

    bool UndoManager::canUndo() const
    {
        return m_undoStack->canUndo();
    }

    QString UndoManager::redoText() const
    {
        return m_undoStack->redoText();
    }

    QString UndoManager::undoText() const
    {
        return m_undoStack->undoText();
    }

    void UndoManager::redo()
    {
        m_undoStack->redo();
    }

    void UndoManager::undo()
    {
        m_undoStack->undo();
    }

    void UndoManager::createMoveCommand(bb::cascades::Control *control, int sourceX, int sourceY, int targetX, int targetY)
    {
        /**
         * We simply create a new instance of a MoveCommand, pass all needed data to its constructor and push
         * it on the QUndoStack.
         * The stack will take ownership of the command object, and will delete it when it's no longer used.
         */
        m_undoStack->push(new MoveCommand(control, QPoint(sourceX, sourceY), QPoint(targetX, targetY)));
    }