context2d.h Example File

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#ifndef CONTEXT2D_H #define CONTEXT2D_H #include "domimage.h" #include <QPainter> #include <QPainterPath> #include <QString> #include <QStack> #include <QMetaType> #include <QTimerEvent> // [3] class CanvasGradient { public: CanvasGradient(const QGradient &v) : value(v) {} CanvasGradient() {} QGradient value; }; // [3] Q_DECLARE_METATYPE(CanvasGradient) Q_DECLARE_METATYPE(CanvasGradient*) class ImageData { }; class QContext2DCanvas; class Context2D : public QObject { Q_OBJECT // compositing Q_PROPERTY(qreal globalAlpha READ globalAlpha WRITE setGlobalAlpha) Q_PROPERTY(QString globalCompositeOperation READ globalCompositeOperation WRITE setGlobalCompositeOperation) Q_PROPERTY(QVariant strokeStyle READ strokeStyle WRITE setStrokeStyle) Q_PROPERTY(QVariant fillStyle READ fillStyle WRITE setFillStyle) // line caps/joins Q_PROPERTY(qreal lineWidth READ lineWidth WRITE setLineWidth) Q_PROPERTY(QString lineCap READ lineCap WRITE setLineCap) Q_PROPERTY(QString lineJoin READ lineJoin WRITE setLineJoin) Q_PROPERTY(qreal miterLimit READ miterLimit WRITE setMiterLimit) // shadows Q_PROPERTY(qreal shadowOffsetX READ shadowOffsetX WRITE setShadowOffsetX) Q_PROPERTY(qreal shadowOffsetY READ shadowOffsetY WRITE setShadowOffsetY) Q_PROPERTY(qreal shadowBlur READ shadowBlur WRITE setShadowBlur) Q_PROPERTY(QString shadowColor READ shadowColor WRITE setShadowColor) public: Context2D(QObject *parent = 0); void setSize(int width, int height); void setSize(const QSize &size); QSize size() const; void clear(); void reset(); // compositing qreal globalAlpha() const; // (default 1.0) QString globalCompositeOperation() const; // (default over) QVariant strokeStyle() const; // (default black) QVariant fillStyle() const; // (default black) void setGlobalAlpha(qreal alpha); void setGlobalCompositeOperation(const QString &op); void setStrokeStyle(const QVariant &style); void setFillStyle(const QVariant &style); // line caps/joins qreal lineWidth() const; // (default 1) QString lineCap() const; // "butt", "round", "square" (default "butt") QString lineJoin() const; // "round", "bevel", "miter" (default "miter") qreal miterLimit() const; // (default 10) void setLineWidth(qreal w); void setLineCap(const QString &s); void setLineJoin(const QString &s); void setMiterLimit(qreal m); // shadows qreal shadowOffsetX() const; // (default 0) qreal shadowOffsetY() const; // (default 0) qreal shadowBlur() const; // (default 0) QString shadowColor() const; // (default black) void setShadowOffsetX(qreal x); void setShadowOffsetY(qreal y); void setShadowBlur(qreal b); void setShadowColor(const QString &str); public slots: void save(); // push state on state stack void restore(); // pop state stack and restore state void scale(qreal x, qreal y); void rotate(qreal angle); void translate(qreal x, qreal y); void transform(qreal m11, qreal m12, qreal m21, qreal m22, qreal dx, qreal dy); void setTransform(qreal m11, qreal m12, qreal m21, qreal m22, qreal dx, qreal dy); CanvasGradient createLinearGradient(qreal x0, qreal y0, qreal x1, qreal y1); CanvasGradient createRadialGradient(qreal x0, qreal y0, qreal r0, qreal x1, qreal y1, qreal r1); // rects void clearRect(qreal x, qreal y, qreal w, qreal h); void fillRect(qreal x, qreal y, qreal w, qreal h); void strokeRect(qreal x, qreal y, qreal w, qreal h); // path API void beginPath(); void closePath(); void moveTo(qreal x, qreal y); void lineTo(qreal x, qreal y); void quadraticCurveTo(qreal cpx, qreal cpy, qreal x, qreal y); void bezierCurveTo(qreal cp1x, qreal cp1y, qreal cp2x, qreal cp2y, qreal x, qreal y); void arcTo(qreal x1, qreal y1, qreal x2, qreal y2, qreal radius); void rect(qreal x, qreal y, qreal w, qreal h); void arc(qreal x, qreal y, qreal radius, qreal startAngle, qreal endAngle, bool anticlockwise); void fill(); void stroke(); void clip(); bool isPointInPath(qreal x, qreal y) const; // drawing images void drawImage(DomImage *image, qreal dx, qreal dy); void drawImage(DomImage *image, qreal dx, qreal dy, qreal dw, qreal dh); void drawImage(DomImage *image, qreal sx, qreal sy, qreal sw, qreal sh, qreal dx, qreal dy, qreal dw, qreal dh); // pixel manipulation ImageData getImageData(qreal sx, qreal sy, qreal sw, qreal sh); void putImageData(ImageData image, qreal dx, qreal dy); signals: void changed(const QImage &image); protected: void timerEvent(QTimerEvent *e); private: void beginPainting(); const QImage &endPainting(); void scheduleChange(); int m_changeTimerId; QImage m_image; QPainter m_painter; QPainterPath m_path; enum DirtyFlag { DirtyTransformationMatrix = 0x00001, DirtyClippingRegion = 0x00002, DirtyStrokeStyle = 0x00004, DirtyFillStyle = 0x00008, DirtyGlobalAlpha = 0x00010, DirtyLineWidth = 0x00020, DirtyLineCap = 0x00040, DirtyLineJoin = 0x00080, DirtyMiterLimit = 0x00100, MDirtyPen = DirtyStrokeStyle | DirtyLineWidth | DirtyLineCap | DirtyLineJoin | DirtyMiterLimit, DirtyShadowOffsetX = 0x00200, DirtyShadowOffsetY = 0x00400, DirtyShadowBlur = 0x00800, DirtyShadowColor = 0x01000, DirtyGlobalCompositeOperation = 0x2000, DirtyFont = 0x04000, DirtyTextAlign = 0x08000, DirtyTextBaseline = 0x10000, AllIsFullOfDirt = 0xfffff }; struct State { State() : flags(0) {} QMatrix matrix; QPainterPath clipPath; QBrush strokeStyle; QBrush fillStyle; qreal globalAlpha; qreal lineWidth; Qt::PenCapStyle lineCap; Qt::PenJoinStyle lineJoin; qreal miterLimit; qreal shadowOffsetX; qreal shadowOffsetY; qreal shadowBlur; QColor shadowColor; QPainter::CompositionMode globalCompositeOperation; QFont font; int textAlign; int textBaseline; int flags; }; State m_state; QStack<State> m_stateStack; }; #endif

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