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# environment.cpp Example File

script/context2d/environment.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
     ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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     ****************************************************************************/

     #include "environment.h"
     #include "qcontext2dcanvas.h"
     #include "context2d.h"
     #include <QScriptValueIterator>
     #include <QDateTime>

     struct FakeDomEvent
     {
         enum KeyCodes  {
             DOM_VK_UNDEFINED            = 0x0,
             DOM_VK_RIGHT_ALT            = 0x12,
             DOM_VK_LEFT_ALT             = 0x12,
             DOM_VK_LEFT_CONTROL         = 0x11,
             DOM_VK_RIGHT_CONTROL        = 0x11,
             DOM_VK_LEFT_SHIFT           = 0x10,
             DOM_VK_RIGHT_SHIFT          = 0x10,
             DOM_VK_META                 = 0x9D,
             DOM_VK_BACK_SPACE           = 0x08,
             DOM_VK_CAPS_LOCK            = 0x14,
             DOM_VK_DELETE               = 0x7F,
             DOM_VK_END                  = 0x23,
             DOM_VK_ENTER                = 0x0D,
             DOM_VK_ESCAPE               = 0x1B,
             DOM_VK_HOME                 = 0x24,
             DOM_VK_NUM_LOCK             = 0x90,
             DOM_VK_PAUSE                = 0x13,
             DOM_VK_PRINTSCREEN          = 0x9A,
             DOM_VK_SCROLL_LOCK          = 0x91,
             DOM_VK_SPACE                = 0x20,
             DOM_VK_TAB                  = 0x09,
             DOM_VK_LEFT                 = 0x25,
             DOM_VK_RIGHT                = 0x27,
             DOM_VK_UP                   = 0x26,
             DOM_VK_DOWN                 = 0x28,
             DOM_VK_PAGE_DOWN            = 0x22,
             DOM_VK_PAGE_UP              = 0x21,
             DOM_VK_F1                   = 0x70,
             DOM_VK_F2                   = 0x71,
             DOM_VK_F3                   = 0x72,
             DOM_VK_F4                   = 0x73,
             DOM_VK_F5                   = 0x74,
             DOM_VK_F6                   = 0x75,
             DOM_VK_F7                   = 0x76,
             DOM_VK_F8                   = 0x77,
             DOM_VK_F9                   = 0x78,
             DOM_VK_F10                  = 0x79,
             DOM_VK_F11                  = 0x7A,
             DOM_VK_F12                  = 0x7B,
             DOM_VK_F13                  = 0xF000,
             DOM_VK_F14                  = 0xF001,
             DOM_VK_F15                  = 0xF002,
             DOM_VK_F16                  = 0xF003,
             DOM_VK_F17                  = 0xF004,
             DOM_VK_F18                  = 0xF005,
             DOM_VK_F19                  = 0xF006,
             DOM_VK_F20                  = 0xF007,
             DOM_VK_F21                  = 0xF008,
             DOM_VK_F22                  = 0xF009,
             DOM_VK_F23                  = 0xF00A,
             DOM_VK_F24                  = 0xF00B
         };

         static int qtToDomKey(int keyCode);
     };

     int FakeDomEvent::qtToDomKey(int keyCode)
     {
         switch (keyCode) {
         case Qt::Key_Backspace:
             return  DOM_VK_BACK_SPACE;
         case Qt::Key_Enter:
             return  DOM_VK_ENTER;
         case Qt::Key_Return:
             return  DOM_VK_ENTER;
         case Qt::Key_NumLock:
             return  DOM_VK_NUM_LOCK;
         case Qt::Key_Alt:
             return  DOM_VK_RIGHT_ALT;
         case Qt::Key_Control:
             return  DOM_VK_LEFT_CONTROL;
         case Qt::Key_Shift:
             return  DOM_VK_LEFT_SHIFT;
         case Qt::Key_Meta:
             return  DOM_VK_META;
         case Qt::Key_CapsLock:
             return  DOM_VK_CAPS_LOCK;
         case Qt::Key_Delete:
             return  DOM_VK_DELETE;
         case Qt::Key_End:
             return  DOM_VK_END;
         case Qt::Key_Escape:
             return  DOM_VK_ESCAPE;
         case Qt::Key_Home:
             return  DOM_VK_HOME;
         case Qt::Key_Pause:
             return  DOM_VK_PAUSE;
         case Qt::Key_Print:
             return  DOM_VK_PRINTSCREEN;
         case Qt::Key_ScrollLock:
             return  DOM_VK_SCROLL_LOCK;
         case Qt::Key_Left:
             return  DOM_VK_LEFT;
         case Qt::Key_Right:
             return  DOM_VK_RIGHT;
         case Qt::Key_Up:
             return  DOM_VK_UP;
         case Qt::Key_Down:
             return  DOM_VK_DOWN;
         case Qt::Key_PageDown:
             return  DOM_VK_PAGE_DOWN;
         case Qt::Key_PageUp:
             return  DOM_VK_PAGE_UP;
         case Qt::Key_F1:
             return  DOM_VK_F1;
         case Qt::Key_F2:
             return  DOM_VK_F2;
         case Qt::Key_F3:
             return  DOM_VK_F3;
         case Qt::Key_F4:
             return  DOM_VK_F4;
         case Qt::Key_F5:
             return  DOM_VK_F5;
         case Qt::Key_F6:
             return  DOM_VK_F6;
         case Qt::Key_F7:
             return  DOM_VK_F7;
         case Qt::Key_F8:
             return  DOM_VK_F8;
         case Qt::Key_F9:
             return  DOM_VK_F9;
         case Qt::Key_F10:
             return  DOM_VK_F10;
         case Qt::Key_F11:
             return  DOM_VK_F11;
         case Qt::Key_F12:
             return  DOM_VK_F12;
         case Qt::Key_F13:
             return  DOM_VK_F13;
         case Qt::Key_F14:
             return  DOM_VK_F14;
         case Qt::Key_F15:
             return  DOM_VK_F15;
         case Qt::Key_F16:
             return  DOM_VK_F16;
         case Qt::Key_F17:
             return  DOM_VK_F17;
         case Qt::Key_F18:
             return  DOM_VK_F18;
         case Qt::Key_F19:
             return  DOM_VK_F19;
         case Qt::Key_F20:
             return  DOM_VK_F20;
         case Qt::Key_F21:
             return  DOM_VK_F21;
         case Qt::Key_F22:
             return  DOM_VK_F22;
         case Qt::Key_F23:
             return  DOM_VK_F23;
         case Qt::Key_F24:
             return  DOM_VK_F24;
         }
         return keyCode;
     }

     Environment::Environment(QObject *parent)
         : QObject(parent)
     {
         m_engine = new QScriptEngine(this);

         m_document = m_engine->newQObject(
             new Document(this), QScriptEngine::QtOwnership,
             QScriptEngine::ExcludeSuperClassContents);

         CanvasGradientPrototype::setup(m_engine);

         m_originalGlobalObject = m_engine->globalObject();
         reset();
     }

     Environment::~Environment()
     {
     }

     QScriptEngine *Environment::engine() const
     {
         return m_engine;
     }

     QScriptValue Environment::document() const
     {
         return m_document;
     }

     int Environment::setTimeout(const QScriptValue &expression, int delay)
     {
         if (expression.isString() || expression.isFunction()) {
             int timerId = startTimer(delay);
             m_timeoutHash.insert(timerId, expression);
             return timerId;
         }
         return -1;
     }

     void Environment::clearTimeout(int timerId)
     {
         killTimer(timerId);
         m_timeoutHash.remove(timerId);
     }

     int Environment::setInterval(const QScriptValue &expression, int delay)
     {
         if (expression.isString() || expression.isFunction()) {
             int timerId = startTimer(delay);
             m_intervalHash.insert(timerId, expression);
             return timerId;
         }
         return -1;
     }

     void Environment::clearInterval(int timerId)
     {
         killTimer(timerId);
         m_intervalHash.remove(timerId);
     }

     void Environment::timerEvent(QTimerEvent *event)
     {
         int id = event->timerId();
         QScriptValue expression = m_intervalHash.value(id);
         if (!expression.isValid()) {
             expression = m_timeoutHash.value(id);
             if (expression.isValid())
                 killTimer(id);
         }
         if (expression.isString()) {
             evaluate(expression.toString());
         } else if (expression.isFunction()) {
             expression.call();
         }
         maybeEmitScriptError();
     }

     void Environment::addCanvas(QContext2DCanvas *canvas)
     {
         m_canvases.append(canvas);
     }

     QContext2DCanvas *Environment::canvasByName(const QString &name) const
     {
         for (int i = 0; i < m_canvases.size(); ++i) {
             QContext2DCanvas *canvas = m_canvases.at(i);
             if (canvas->objectName() == name)
                 return canvas;
         }
         return 0;
     }

     QList<QContext2DCanvas*> Environment::canvases() const
     {
         return m_canvases;
     }

     void Environment::reset()
     {
         if (m_engine->isEvaluating())
             m_engine->abortEvaluation();

         {
             QHash<int, QScriptValue>::const_iterator it;
             for (it = m_intervalHash.constBegin(); it != m_intervalHash.constEnd(); ++it)
                 killTimer(it.key());
             m_intervalHash.clear();
             for (it = m_timeoutHash.constBegin(); it != m_timeoutHash.constEnd(); ++it)
                 killTimer(it.key());
             m_timeoutHash.clear();
         }

         for (int i = 0; i < m_canvases.size(); ++i)
             m_canvases.at(i)->reset();

         QScriptValue self = m_engine->newQObject(
             this, QScriptEngine::QtOwnership,
             QScriptEngine::ExcludeSuperClassContents);

         {
             QScriptValueIterator it(m_originalGlobalObject);
             while (it.hasNext()) {
                 it.next();
                 self.setProperty(it.scriptName(), it.value(), it.flags());
             }
         }

         self.setProperty("self", self);
         self.setProperty("window", self);

         QScriptValue navigator = m_engine->newObject();
         navigator.setProperty("appCodeName", "context2d");
         navigator.setProperty("appMinorVersion", 1);
         navigator.setProperty("appVersion", 1);
         navigator.setProperty("browserLanguage", "en_US");
         navigator.setProperty("cookieEnabled", false);
         navigator.setProperty("cpuClass", "i686");
         navigator.setProperty("onLine", false);
         navigator.setProperty("platform", "bogus OS");
         navigator.setProperty("systemLanguage", "en_US");
         navigator.setProperty("userAgent", "Context2D/1.1");
         navigator.setProperty("userLanguage", "en_US");
         self.setProperty("navigator", navigator);

         m_engine->setGlobalObject(self);

         m_engine->collectGarbage();
     }

     QScriptValue Environment::evaluate(const QString &code, const QString &fileName)
     {
         return m_engine->evaluate(code, fileName);
     }

     bool Environment::hasIntervalTimers() const
     {
         return !m_intervalHash.isEmpty();
     }

     // This is used by the Context2D QtScript benchmark.
     void Environment::triggerTimers()
     {
         for (int x = 0; x < 2; ++x) {
             QList<int> timerIds = x ? m_intervalHash.keys() : m_timeoutHash.keys();
             for (int i = 0; i < timerIds.size(); ++i) {
                 QTimerEvent fakeEvent(timerIds.at(i));
                 timerEvent(&fakeEvent);
             }
         }
     }

     QScriptValue Environment::toWrapper(QObject *object)
     {
         return m_engine->newQObject(object, QScriptEngine::QtOwnership,
                                     QScriptEngine::PreferExistingWrapperObject
                                     | QScriptEngine::ExcludeSuperClassContents);
     }

     void Environment::handleEvent(QContext2DCanvas *canvas, QMouseEvent *e)
     {
         QString type;
         switch (e->type()) {
         case QEvent::MouseButtonPress:
             type = "mousedown"; break;
         case QEvent::MouseButtonRelease:
             type = "mouseup"; break;
         case QEvent::MouseMove:
             type = "mousemove"; break;
         default: break;
         }
         if (type.isEmpty())
             return;

         QScriptValue handlerObject;
         QScriptValue handler = eventHandler(canvas, type, &handlerObject);
         if (!handler.isFunction())
             return;

         QScriptValue scriptEvent = newFakeDomEvent(type, toWrapper(canvas));
         // MouseEvent
         scriptEvent.setProperty("screenX", e->globalX(), QScriptValue::ReadOnly);
         scriptEvent.setProperty("screenY", e->globalY(), QScriptValue::ReadOnly);
         scriptEvent.setProperty("clientX", e->x(), QScriptValue::ReadOnly);
         scriptEvent.setProperty("clientY", e->y(), QScriptValue::ReadOnly);
         scriptEvent.setProperty("layerX", e->x(), QScriptValue::ReadOnly);
         scriptEvent.setProperty("layerY", e->y(), QScriptValue::ReadOnly);
         scriptEvent.setProperty("pageX", e->x(), QScriptValue::ReadOnly);
         scriptEvent.setProperty("pageY", e->y(), QScriptValue::ReadOnly);
         scriptEvent.setProperty("altKey", (e->modifiers() & Qt::AltModifier) != 0,
                                 QScriptValue::ReadOnly);
         scriptEvent.setProperty("ctrlKey", (e->modifiers() & Qt::ControlModifier) != 0,
                                 QScriptValue::ReadOnly);
         scriptEvent.setProperty("metaKey", (e->modifiers() & Qt::MetaModifier) != 0,
                                 QScriptValue::ReadOnly);
         scriptEvent.setProperty("shiftKey", (e->modifiers() & Qt::ShiftModifier) != 0,
                                 QScriptValue::ReadOnly);
         int button = 0;
         if (e->button() == Qt::RightButton)
             button = 2;
         else if (e->button() == Qt::MidButton)
             button = 1;
         scriptEvent.setProperty("button", button);
         scriptEvent.setProperty("relatedTarget", m_engine->nullValue(),
                                 QScriptValue::ReadOnly);
         handler.call(handlerObject, QScriptValueList() << scriptEvent);
         maybeEmitScriptError();
     }

     void Environment::handleEvent(QContext2DCanvas *canvas, QKeyEvent *e)
     {
         QString type;
         switch (e->type()) {
         case QEvent::KeyPress:
             type = "keydown"; break;
         case QEvent::KeyRelease:
             type = "keyup"; break;
         default: break;
         }
         if (type.isEmpty())
             return;

         QScriptValue handlerObject;
         QScriptValue handler = eventHandler(canvas, type, &handlerObject);
         if (!handler.isFunction())
             return;

         QScriptValue scriptEvent = newFakeDomEvent(type, toWrapper(canvas));
         // KeyEvent
         scriptEvent.setProperty("isChar", !e->text().isEmpty());
         scriptEvent.setProperty("charCode", e->text());
         scriptEvent.setProperty("keyCode", FakeDomEvent::qtToDomKey(e->key()));
         scriptEvent.setProperty("which", e->key());

         handler.call(handlerObject, QScriptValueList() << scriptEvent);
         maybeEmitScriptError();
     }

     QScriptValue Environment::eventHandler(QContext2DCanvas *canvas, const QString &type,
                                            QScriptValue *who)
     {
         QString handlerName = "on" + type;
         QScriptValue obj = toWrapper(canvas);
         QScriptValue handler = obj.property(handlerName);
         if (!handler.isValid()) {
             obj = m_document;
             handler = obj.property(handlerName);
         }
         if (who && handler.isFunction())
             *who = obj;
         return handler;
     }

     QScriptValue Environment::newFakeDomEvent(const QString &type, const QScriptValue &target)
     {
         QScriptValue e = m_engine->newObject();
         // Event
         e.setProperty("type", type, QScriptValue::ReadOnly);
         e.setProperty("bubbles", true, QScriptValue::ReadOnly);
         e.setProperty("cancelable", false, QScriptValue::ReadOnly);
         e.setProperty("target", target, QScriptValue::ReadOnly);
         e.setProperty("currentTarget", target, QScriptValue::ReadOnly);
         e.setProperty("eventPhase", 3); // bubbling
         e.setProperty("timeStamp", QDateTime::currentDateTime().toTime_t());
         // UIEvent
         e.setProperty("detail", 0, QScriptValue::ReadOnly);
         e.setProperty("view", m_engine->globalObject(), QScriptValue::ReadOnly);
         return e;
     }

     void Environment::maybeEmitScriptError()
     {
         if (m_engine->hasUncaughtException())
             emit scriptError(m_engine->uncaughtException());
     }

     Document::Document(Environment *env)
         : QObject(env)
     {
     }

     Document::~Document()
     {
     }

     QScriptValue Document::getElementById(const QString &id) const
     {
         Environment *env = qobject_cast<Environment*>(parent());
         QContext2DCanvas *canvas = env->canvasByName(id);
         if (!canvas)
             return QScriptValue();
         return env->toWrapper(canvas);
     }

     QScriptValue Document::getElementsByTagName(const QString &name) const
     {
         if (name != "canvas")
             return QScriptValue();
         Environment *env = qobject_cast<Environment*>(parent());
         QList<QContext2DCanvas*> list = env->canvases();
         QScriptValue result = env->engine()->newArray(list.size());
         for (int i = 0; i < list.size(); ++i)
             result.setProperty(i, env->toWrapper(list.at(i)));
         return result;
     }

     void Document::addEventListener(const QString &type, const QScriptValue &listener,
                                     bool useCapture)
     {
         Q_UNUSED(useCapture);
         if (listener.isFunction()) {
             Environment *env = qobject_cast<Environment*>(parent());
             QScriptValue self = env->toWrapper(this);
             self.setProperty("on" + type, listener);
         }
     }

     QColor colorFromString(const QString &name);

     CanvasGradientPrototype::CanvasGradientPrototype(QObject *parent)
         : QObject(parent)
     {
     }

     void CanvasGradientPrototype::addColorStop(qreal offset, const QString &color)
     {
         CanvasGradient *self = qscriptvalue_cast<CanvasGradient*>(thisObject());
         if (!self || (self->value.type() == QGradient::NoGradient))
             return;
         self->value.setColorAt(offset, colorFromString(color));
     }

     void CanvasGradientPrototype::setup(QScriptEngine *engine)
     {
         CanvasGradientPrototype *proto = new CanvasGradientPrototype();
         engine->setDefaultPrototype(qMetaTypeId<CanvasGradient>(),
             engine->newQObject(proto, QScriptEngine::ScriptOwnership,
                                QScriptEngine::ExcludeSuperClassContents));
     }