/****************************************************************************
**
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt 3D Studio.
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** $QT_BEGIN_LICENSE:GPL-EXCEPT$
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** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
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#ifndef MOUSEHELPER_H
#define MOUSEHELPER_H

#include <QtCore/qobject.h>
#include <QtCore/qpoint.h>
#include <QtCore/qtimer.h>

QT_FORWARD_DECLARE_CLASS(QWidget)
QT_FORWARD_DECLARE_CLASS(QWindow)

class MouseHelper : public QObject
{
    Q_OBJECT

public:
    explicit MouseHelper(QObject *parent = nullptr);
    ~MouseHelper() {};

    Q_INVOKABLE void startUnboundedDrag();
    Q_INVOKABLE void endUnboundedDrag();
    Q_INVOKABLE QPoint delta();

    void setWidget(QWidget *widget);

private Q_SLOTS:
    void resetCursor();

protected:
    bool eventFilter(QObject *obj, QEvent *event) override;

private:
    QPoint m_startPos;
    QPoint m_referencePoint;
    QPoint m_previousPoint;
    QTimer m_cursorResetTimer;

    enum DragState {
        StateNotDragging,
        StateDragging,
        StateEndingDrag,
        StateFinalCursorReset
    };
    DragState m_dragState;
    QWidget *m_widget = nullptr; // Not owned
    QWindow *m_window = nullptr; // Not owned
    QPoint m_maxDelta;
};

#endif // MOUSEHELPER_H