/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Virtual Keyboard module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
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****************************************************************************/

#ifndef DESKTOPINPUTSELECTIONCONTROL_H
#define DESKTOPINPUTSELECTIONCONTROL_H

#include <QtCore/qpointer.h>
#include <QtCore/qobject.h>
#include <QtGui/qimage.h>

QT_BEGIN_NAMESPACE
class QMouseEvent;
QT_END_NAMESPACE

namespace QtVirtualKeyboard {
class InputContext;
class InputSelectionHandle;

class DesktopInputSelectionControl : public QObject
{
    Q_OBJECT

public:
    DesktopInputSelectionControl(QObject *parent, InputContext *inputContext);
    ~DesktopInputSelectionControl() {}

    void createHandles();
    void destroyHandles();
    void setEnabled(bool enable);
    QImage *handleImage();

public Q_SLOTS:
    void updateAnchorHandlePosition();
    void updateCursorHandlePosition();
    void updateVisibility();
    void reloadGraphics();
protected:
    bool eventFilter(QObject *object, QEvent *event);

private:
    QRect anchorHandleRect() const;
    QRect cursorHandleRect() const;
    QRect handleRectForCursorRect(const QRectF &cursorRect) const;

private:
    InputContext *m_inputContext;
    QSharedPointer<InputSelectionHandle> m_anchorSelectionHandle;
    QSharedPointer<InputSelectionHandle> m_cursorSelectionHandle;
    QImage m_handleImage;

    enum {
        HandleIsReleased = 0,
        HandleIsHeld = 1,
        HandleIsMoving = 2
    };
    enum HandleType {
        AnchorHandle = 0,
        CursorHandle = 1
    };

    unsigned m_handleState : 2;
    unsigned m_currentDragHandle : 1;
    unsigned m_enabled : 1;
    unsigned m_anchorHandleVisible : 1;
    unsigned m_cursorHandleVisible : 1;
    unsigned m_eventFilterEnabled : 1;
    QPoint m_otherSelectionPoint;
    QVector <QMouseEvent*> m_eventQueue;
    QPoint m_distanceBetweenMouseAndCursor;
    QPoint m_handleDragStartedPosition;
    QSize m_handleWindowSize;
};
} // namespace QtVirtualKeyboard

#endif // DESKTOPINPUTSELECTIONCONTROL_H