composition.h Example File
^{demos/composition/composition.h}

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     ** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.
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     ** This file is part of the documentation of the Qt Toolkit.
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    #ifndef COMPOSITION_H
    #define COMPOSITION_H

    #include "arthurwidgets.h"

    #include <QPainter>
    #include <QEvent>

    class QPushButton;
    class QRadioButton;

    class CompositionWidget : public QWidget
    {
        Q_OBJECT

    public:
        CompositionWidget(QWidget *parent);

    public slots:
    void nextMode();

    private:
        bool m_cycle_enabled;

        QRadioButton *rbClear;
        QRadioButton *rbSource;
        QRadioButton *rbDest;
        QRadioButton *rbSourceOver;
        QRadioButton *rbDestOver;
        QRadioButton *rbSourceIn;
        QRadioButton *rbDestIn;
        QRadioButton *rbSourceOut;
        QRadioButton *rbDestOut;
        QRadioButton *rbSourceAtop;
        QRadioButton *rbDestAtop;
        QRadioButton *rbXor;
    };

    class CompositionRenderer : public ArthurFrame
    {
        Q_OBJECT

        enum ObjectType { NoObject, Circle, Rectangle, Image };

        Q_PROPERTY(int circleColor READ circleColor WRITE setCircleColor)
        Q_PROPERTY(int circleAlpha READ circleAlpha WRITE setCircleAlpha)
        Q_PROPERTY(bool animation READ animationEnabled WRITE setAnimationEnabled)

    public:
        CompositionRenderer(QWidget *parent);

        void paint(QPainter *);

        void mousePressEvent(QMouseEvent *);
        void mouseMoveEvent(QMouseEvent *);
        void mouseReleaseEvent(QMouseEvent *);

        void setCirclePos(const QPointF &pos) { m_circle_pos = pos; update(); }

        QSize sizeHint() const { return QSize(500, 400); }

        bool animationEnabled() const { return m_animation_enabled; }
        int circleColor() const { return m_circle_hue; }
        int circleAlpha() const { return m_circle_alpha; }

    public slots:
    void setClearMode() { m_composition_mode = QPainter::CompositionMode_Clear; update(); }
        void setSourceMode() { m_composition_mode = QPainter::CompositionMode_Source; update(); }
        void setDestMode() { m_composition_mode = QPainter::CompositionMode_Destination; update(); }
        void setSourceOverMode() { m_composition_mode = QPainter::CompositionMode_SourceOver; update(); }
        void setDestOverMode() { m_composition_mode = QPainter::CompositionMode_DestinationOver; update(); }
        void setSourceInMode() { m_composition_mode = QPainter::CompositionMode_SourceIn; update(); }
        void setDestInMode() { m_composition_mode = QPainter::CompositionMode_DestinationIn; update(); }
        void setSourceOutMode() { m_composition_mode = QPainter::CompositionMode_SourceOut; update(); }
        void setDestOutMode() { m_composition_mode = QPainter::CompositionMode_DestinationOut; update(); }
        void setSourceAtopMode() { m_composition_mode = QPainter::CompositionMode_SourceAtop; update(); }
        void setDestAtopMode() { m_composition_mode = QPainter::CompositionMode_DestinationAtop; update(); }
        void setXorMode() { m_composition_mode = QPainter::CompositionMode_Xor; update(); }

        void setCircleAlpha(int alpha) { m_circle_alpha = alpha; update(); }
        void setCircleColor(int hue) { m_circle_hue = hue; update(); }
        void setAnimationEnabled(bool enabled) { m_animation_enabled = enabled; update(); }

    private:
        void updateCirclePos();
        QPainter::CompositionMode m_composition_mode;

        QImage m_image;
        QImage m_buffer;
        QImage m_base_buffer;

        int m_circle_alpha;
        int m_circle_hue;

        QPointF m_circle_pos;
        QPointF m_offset;

        ObjectType m_current_object;
        bool m_animation_enabled;
    };

    #endif // COMPOSITION_H