context2d.h Example File

/**************************************************************************** ** ** Copyright (C) 2017 The Qt Company Ltd. ** Contact: ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** 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 ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see For further ** information use the contact form at ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/
#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

© 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.