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# qcontext2dcanvas.cpp Example File

script/context2d/qcontext2dcanvas.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** 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.
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     **     contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
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     **
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     ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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     #include "qcontext2dcanvas.h"

     #include "context2d.h"
     #include "environment.h"
     #include "domimage.h"

     #include <QPainter>
     #include <QPaintEvent>

     QContext2DCanvas::QContext2DCanvas(Context2D *context, Environment *env, QWidget *parent)
         : QWidget(parent), m_context(context), m_env(env)
     {
         QObject::connect(context, SIGNAL(changed(QImage)), this, SLOT(contentsChanged(QImage)));
         setMouseTracking(true);
     }

     QContext2DCanvas::~QContext2DCanvas()
     {
     }

     Context2D *QContext2DCanvas::context() const
     {
         return m_context;
     }

     QScriptValue QContext2DCanvas::getContext(const QString &str)
     {
         if (str != "2d")
             return QScriptValue();
         return m_env->toWrapper(m_context);
     }

     void QContext2DCanvas::contentsChanged(const QImage &image)
     {
         m_image = image;
         update();
     }

     void QContext2DCanvas::paintEvent(QPaintEvent *e)
     {
         QPainter p(this);
     #ifdef Q_OS_SYMBIAN
         // Draw white rect first since in with some themes the js-file content will produce black-on-black.
         QBrush whiteBgBrush(Qt::white);
         p.fillRect(e->rect(), whiteBgBrush);
     #endif
         p.setClipRect(e->rect());
         p.drawImage(0, 0, m_image);
     }

     void QContext2DCanvas::mouseMoveEvent(QMouseEvent *e)
     {
         m_env->handleEvent(this, e);
     }

     void QContext2DCanvas::mousePressEvent(QMouseEvent *e)
     {
         m_env->handleEvent(this, e);
     }

     void QContext2DCanvas::mouseReleaseEvent(QMouseEvent *e)
     {
         m_env->handleEvent(this, e);
     }

     void QContext2DCanvas::keyPressEvent(QKeyEvent *e)
     {
         m_env->handleEvent(this, e);
     }

     void QContext2DCanvas::keyReleaseEvent(QKeyEvent *e)
     {
         m_env->handleEvent(this, e);
     }

     void QContext2DCanvas::resizeEvent(QResizeEvent *e)
     {
         m_context->setSize(e->size().width(), e->size().height());
     }

     void QContext2DCanvas::resize(int width, int height)
     {
         QWidget::resize(width, height);
     }

     void QContext2DCanvas::reset()
     {
         m_context->reset();
     }

     void QContext2DCanvas::addEventListener(const QString &type, const QScriptValue &listener,
                                             bool useCapture)
     {
         Q_UNUSED(useCapture);
         if (listener.isFunction()) {
             QScriptValue self = m_env->toWrapper(this);
             self.setProperty("on" + type, listener);
         }
     }