/****************************************************************************

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** This file is part of the Qt Designer of the Qt Toolkit.

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** GNU Lesser General Public License Usage

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** General Public License version 2.1 as published by the Free Software

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//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists for the convenience

// of Qt Designer.  This header

// file may change from version to version without notice, or even be removed.

//

// We mean it.

//

#ifndef ZOOMWIDGET_H

#define ZOOMWIDGET_H

#include "shared_global_p.h"

#include <QtGui/QGraphicsView>

#include <QtGui/QGraphicsProxyWidget>

#include <QtCore/QList>

QT_BEGIN_NAMESPACE

class QGraphicsScene;

class QMenu;

class QAction;

class QActionGroup;

namespace qdesigner_internal {

// A checkable zoom menu action group. Operates in percent.

class QDESIGNER_SHARED_EXPORT ZoomMenu : public QObject {

    Q_OBJECT

    Q_DISABLE_COPY(ZoomMenu)

public:

    ZoomMenu(QObject *parent = 0);

    void addActions(QMenu *m);

    int zoom() const;

    // Return a list of available zoom values.

    static QList<int> zoomValues();

public slots:

    void setZoom(int percent);

signals:

    void zoomChanged(int);

private slots:

    void slotZoomMenu(QAction *);

private:

    static int zoomOf(const QAction *a);

    QActionGroup *m_menuActions;

};

/* Zoom view: A QGraphicsView with a zoom menu */

class QDESIGNER_SHARED_EXPORT ZoomView : public QGraphicsView

{

    Q_PROPERTY(int zoom READ zoom WRITE setZoom DESIGNABLE true SCRIPTABLE true)

    Q_PROPERTY(bool zoomContextMenuEnabled READ isZoomContextMenuEnabled WRITE setZoomContextMenuEnabled DESIGNABLE true SCRIPTABLE true)

    Q_OBJECT

    Q_DISABLE_COPY(ZoomView)

public:

    ZoomView(QWidget *parent = 0);

    /*  Zoom in percent (for easily implementing menus) and qreal zoomFactor

     * in sync */

    int zoom() const; // in percent

    qreal zoomFactor() const;

    // Zoom Menu on QGraphicsView.

    bool isZoomContextMenuEnabled() const;

    void setZoomContextMenuEnabled(bool e);

    QGraphicsScene &scene() { return *m_scene; }

    const QGraphicsScene &scene() const { return *m_scene; }

    // Helpers for menu

    ZoomMenu *zoomMenu();

    QPoint scrollPosition() const;

    void setScrollPosition(const QPoint& pos);

    void scrollToOrigin();

public slots:

    void setZoom(int percent);

    void showContextMenu(const QPoint &globalPos);

protected:

    void contextMenuEvent(QContextMenuEvent *event);

    // Overwrite for implementing additional behaviour when doing setZoom();

    virtual void applyZoom();

private:

    QGraphicsScene *m_scene;

    int m_zoom;

    qreal m_zoomFactor;

    bool m_zoomContextMenuEnabled;    

    bool m_resizeBlocked;

    ZoomMenu *m_zoomMenu;

};

/* The proxy widget used in  ZoomWidget. It  refuses to move away from 0,0,

 * This behaviour is required for Windows only. */

class  QDESIGNER_SHARED_EXPORT ZoomProxyWidget : public QGraphicsProxyWidget {

    Q_DISABLE_COPY(ZoomProxyWidget)

public:

    explicit ZoomProxyWidget(QGraphicsItem *parent = 0, Qt::WindowFlags wFlags = 0);

protected:

    virtual QVariant itemChange(GraphicsItemChange change, const QVariant &value);

};

/* Zoom widget: A QGraphicsView-based container for a widget that allows for

 * zooming it. Communicates changes in size in the following ways:

 * 1) Embedded widget wants to resize: Listen for its resize in event filter

 *    and resize

 * 2) Zoom is changed: resize to fully display the embedded widget

 * 3) Outer widget changes (by manually resizing the window:

 *    Pass the scaled change on to the embedded widget.

 * Provides helper functions for a zoom context menu on the widget. */

class QDESIGNER_SHARED_EXPORT ZoomWidget : public ZoomView

{

    Q_PROPERTY(bool widgetZoomContextMenuEnabled READ isWidgetZoomContextMenuEnabled WRITE setWidgetZoomContextMenuEnabled DESIGNABLE true SCRIPTABLE true)

    Q_PROPERTY(bool itemAcceptDrops READ itemAcceptDrops WRITE setItemAcceptDrops DESIGNABLE true SCRIPTABLE true)

    Q_OBJECT

    Q_DISABLE_COPY(ZoomWidget)

public:

    ZoomWidget(QWidget *parent = 0);

    void setWidget(QWidget *w, Qt::WindowFlags wFlags = 0);

    const QGraphicsProxyWidget *proxy() const { return m_proxy; }

    QGraphicsProxyWidget *proxy() { return m_proxy; }

    /* Enable the zoom Menu on the Widget (as opposed ZoomView's menu which

     * is on the canvas). */

    bool isWidgetZoomContextMenuEnabled() const;

    void setWidgetZoomContextMenuEnabled(bool e);

    void setItemAcceptDrops(bool);

    bool itemAcceptDrops() const;

    virtual QSize minimumSizeHint() const;

    virtual QSize sizeHint() const;

    bool zoomedEventFilter(QObject *watched, QEvent *event);

public slots:

    // debug state

    void dump() const;

protected:

    void resizeEvent(QResizeEvent * event);

    // Overwritten from ZoomView

    virtual void applyZoom();

    // Overwrite to actually perform a resize. This is required if we are in a layout. Default does resize().

    virtual void doResize(const QSize &s);

private:

    // Factory function for QGraphicsProxyWidgets which can be overwritten. Default creates a ZoomProxyWidget

    virtual QGraphicsProxyWidget *createProxyWidget(QGraphicsItem *parent = 0, Qt::WindowFlags wFlags = 0) const;

    QSize widgetSizeToViewSize(const QSize &s, bool *ptrToValid = 0) const;

    void resizeToWidgetSize();

    QSize viewPortMargin() const;

    QSize widgetSize() const;

    QSizeF widgetDecorationSizeF() const;

    QGraphicsProxyWidget *m_proxy;

    bool m_viewResizeBlocked;

    bool m_widgetResizeBlocked;

    bool m_widgetZoomContextMenuEnabled;

};

} // namespace qdesigner_internal

QT_END_NAMESPACE

#endif