qt-everywhere-src-5.15.1/qtbase/examples/widgets/scroller/graphicsview/main.cpp - orbit - Git at Google

 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** 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 https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** 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."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtCore>
 #include <QtWidgets>

 #define NUM_ITEMS 100
 #define NUM_LISTS 10

 /*!
     \class RectObject
     Note that it needs to be a QGraphicsObject or else the gestures will not work correctly.
 */
 class RectObject : public QGraphicsObject
 {
     Q_OBJECT

 public:

     RectObject(const QString &text, qreal x, qreal y, qreal width, qreal height, QBrush brush, QGraphicsItem *parent = nullptr)
         : QGraphicsObject(parent)
         , m_text(text)
         , m_rect(x, y, width, height)
         , m_pen(brush.color().lighter(), 3.0)
         , m_brush(brush)
     {
         setFlag(QGraphicsItem::ItemClipsToShape, true);
     }

     QRectF boundingRect() const override
     {
         // here we only want the size of the children and not the size of the children of the children...
         qreal halfpw = m_pen.widthF() / 2;
         QRectF rect = m_rect;
         if (halfpw > 0.0)
             rect.adjust(-halfpw, -halfpw, halfpw, halfpw);

         return rect;
     }

     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override
     {
         Q_UNUSED(option);
         Q_UNUSED(widget);
         painter->setPen(m_pen);
         painter->setBrush(m_brush);
         painter->drawRect(m_rect);

         painter->setPen(Qt::black);
         QFont f;
         f.setPixelSize(m_rect.height());
         painter->setFont(f);
         painter->drawText(m_rect, Qt::AlignCenter, m_text);
     }

     QString m_text;
     QRectF m_rect;
     QPen m_pen;
     QBrush m_brush;
 };

 class ViewObject : public QGraphicsObject
 {
     Q_OBJECT
 public:
     ViewObject(QGraphicsObject *parent)
         : QGraphicsObject(parent)
     { }

     QRectF boundingRect() const override
     {
         QRectF rect;
         const auto items = childItems();
         for (const QGraphicsItem *item : items)
             rect |= item->boundingRect().translated(item->pos());
         return rect;
     }

     void paint(QPainter *, const QStyleOptionGraphicsItem *, QWidget *) override
     { }
 };

 class ListObject : public QGraphicsObject
 {
     Q_OBJECT

 public:
     ListObject(const QSizeF &size, bool useTouch)
     {
         m_size = size;
         setFlag(QGraphicsItem::ItemClipsChildrenToShape, true);
         // grab gesture via Touch or Mouse events
         QScroller::grabGesture(this, useTouch ? QScroller::TouchGesture : QScroller::LeftMouseButtonGesture);

         // this needs to be QGraphicsOBJECT - otherwise gesture recognition
         // will not work for the parent of the viewport (in this case the
         // list)
         m_viewport = new ViewObject(this);

     }

     QGraphicsObject *viewport() const
     {
         return m_viewport;
     }

     bool event(QEvent *e) override
     {
         switch (e->type()) {
 // ![2]
         case QEvent::ScrollPrepare: {
             QScrollPrepareEvent *se = static_cast<QScrollPrepareEvent *>(e);
             se->setViewportSize(m_size);
             QRectF br = m_viewport->boundingRect();
             se->setContentPosRange(QRectF(0, 0,
                                           qMax(qreal(0), br.width() - m_size.width()),
                                           qMax(qreal(0), br.height() - m_size.height())));
             se->setContentPos(-m_viewport->pos());
             se->accept();
             return true;
         }
 // ![1]
 // ![2]
         case QEvent::Scroll: {
             QScrollEvent *se = static_cast<QScrollEvent *>(e);
             m_viewport->setPos(-se->contentPos() - se->overshootDistance());
             return true;
         }
 // ![2]
         default:
             break;
         }
         return QGraphicsObject::event(e);
     }

     bool sceneEvent(QEvent *e) override
     {
         switch (e->type()) {
         case QEvent::TouchBegin: {
             // We need to return true for the TouchBegin here in the
             // top-most graphics object - otherwise gestures in our parent
             // objects will NOT work at all (the accept() flag is already
             // set due to our setAcceptTouchEvents(true) call in the c'tor
             return true;

         }
         case QEvent::GraphicsSceneMousePress: {
             // We need to return true for the MousePress here in the
             // top-most graphics object - otherwise gestures in our parent
             // objects will NOT work at all (the accept() flag is already
             // set to true by Qt)
             return true;

         }
         default:
             break;
         }
         return QGraphicsObject::sceneEvent(e);
     }

     QRectF boundingRect() const override
     {
         return QRectF(0, 0, m_size.width() + 3, m_size.height());
     }

     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override
     {
         Q_UNUSED(option);
         Q_UNUSED(widget);
         painter->setPen(QPen(QColor(100, 100, 100), 3.0));
         painter->drawRect(QRectF(1.5, 1.5, m_size.width() - 3, m_size.height() - 3));
     }

     QSizeF m_size;
     ViewObject *m_viewport;
 };

 class MainWindow : public QMainWindow
 {
     Q_OBJECT

 public:
     MainWindow(bool useTouch)
     {
         m_scene = new QGraphicsScene();

         // -- make the main list
         ListObject *mainList = new ListObject(QSizeF(780, 400), useTouch);
         mainList->setObjectName(QLatin1String("MainList"));
         m_scene->addItem(mainList);
 // ![3]
         for (int i=0; i<NUM_LISTS; i++) {
             ListObject *childList = new ListObject(QSizeF(mainList->m_size.width()/3, mainList->m_size.height()), useTouch);
             childList->setObjectName(QString("ChildList %1").arg(i));
             fillList(childList);
             childList->setParentItem(mainList->viewport());
             childList->setPos(i*mainList->m_size.width()/3, 0);
         }
         mainList->viewport()->setPos(0, 0);


         /*
         list1->setTransformOriginPoint(200, 200);
         list1->setRotation(135);
         list1->setPos(20 + 200 * .41, 20 + 200 * .41);
         */
 // ![3]

         m_view = new QGraphicsView(m_scene);
         setCentralWidget(m_view);
         setWindowTitle(tr("Gesture example"));
         m_scene->setSceneRect(0, 0, m_view->viewport()->width(), m_view->viewport()->height());
     }

     /**
      *  Fills the list object \a list with RectObjects.
      */
     void fillList(ListObject *list)
     {
         qreal h = list->m_size.height() / 10;
         for (int i=0; i<NUM_ITEMS; i++) {
             QColor color =  QColor(255*i/NUM_ITEMS, 255*(NUM_ITEMS-i)/NUM_ITEMS, 127*(i%2)+64*(i/2%2));
             QString text = QLatin1String("Item #") + QString::number(i);
             QGraphicsItem *rect = new RectObject(text, 0, 0, list->m_size.width() - 6, h - 3, QBrush(color), list->viewport());
             rect->setPos(3, h*i+3);
         }
         list->viewport()->setPos(0, 0);
     }


 protected:
     void resizeEvent(QResizeEvent *e) override
     {
         // resize the scene according to our own size to prevent scrolling
         m_scene->setSceneRect(0, 0, m_view->viewport()->width(), m_view->viewport()->height());
         QMainWindow::resizeEvent(e);
     }

     QGraphicsScene *m_scene;
     QGraphicsView *m_view;
 };

 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
     bool touch = (a.arguments().contains(QLatin1String("--touch")));
     MainWindow mw(touch);
     mw.show();
 #ifdef Q_OS_MAC
     mw.raise();
 #endif
     return a.exec();
 }

 #include "main.moc"
	/****************************************************************************
	**
	** Copyright (C) 2016 The Qt Company Ltd.
	** Contact: https://www.qt.io/licensing/
	**
	** 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 https://www.qt.io/terms-conditions. For further
	** information use the contact form at https://www.qt.io/contact-us.
	**
	** 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."
	**
	** $QT_END_LICENSE$
	**
	****************************************************************************/

	#include <QtCore>
	#include <QtWidgets>

	#define NUM_ITEMS 100
	#define NUM_LISTS 10

	/*!
	\class RectObject
	Note that it needs to be a QGraphicsObject or else the gestures will not work correctly.
	*/
	class RectObject : public QGraphicsObject
	{
	Q_OBJECT

	public:

	RectObject(const QString &text, qreal x, qreal y, qreal width, qreal height, QBrush brush, QGraphicsItem *parent = nullptr)
	: QGraphicsObject(parent)
	, m_text(text)
	, m_rect(x, y, width, height)
	, m_pen(brush.color().lighter(), 3.0)
	, m_brush(brush)
	{
	setFlag(QGraphicsItem::ItemClipsToShape, true);
	}

	QRectF boundingRect() const override
	{
	// here we only want the size of the children and not the size of the children of the children...
	qreal halfpw = m_pen.widthF() / 2;
	QRectF rect = m_rect;
	if (halfpw > 0.0)
	rect.adjust(-halfpw, -halfpw, halfpw, halfpw);

	return rect;
	}

	void paint(QPainter painter, const QStyleOptionGraphicsItem option, QWidget *widget) override
	{
	Q_UNUSED(option);
	Q_UNUSED(widget);
	painter->setPen(m_pen);
	painter->setBrush(m_brush);
	painter->drawRect(m_rect);

	painter->setPen(Qt::black);
	QFont f;
	f.setPixelSize(m_rect.height());
	painter->setFont(f);
	painter->drawText(m_rect, Qt::AlignCenter, m_text);
	}

	QString m_text;
	QRectF m_rect;
	QPen m_pen;
	QBrush m_brush;
	};

	class ViewObject : public QGraphicsObject
	{
	Q_OBJECT
	public:
	ViewObject(QGraphicsObject *parent)
	: QGraphicsObject(parent)
	{ }

	QRectF boundingRect() const override
	{
	QRectF rect;
	const auto items = childItems();
	for (const QGraphicsItem *item : items)
	rect \|= item->boundingRect().translated(item->pos());
	return rect;
	}

	void paint(QPainter , const QStyleOptionGraphicsItem , QWidget *) override
	{ }
	};

	class ListObject : public QGraphicsObject
	{
	Q_OBJECT

	public:
	ListObject(const QSizeF &size, bool useTouch)
	{
	m_size = size;
	setFlag(QGraphicsItem::ItemClipsChildrenToShape, true);
	// grab gesture via Touch or Mouse events
	QScroller::grabGesture(this, useTouch ? QScroller::TouchGesture : QScroller::LeftMouseButtonGesture);

	// this needs to be QGraphicsOBJECT - otherwise gesture recognition
	// will not work for the parent of the viewport (in this case the
	// list)
	m_viewport = new ViewObject(this);

	}

	QGraphicsObject *viewport() const
	{
	return m_viewport;
	}

	bool event(QEvent *e) override
	{
	switch (e->type()) {
	// ![2]
	case QEvent::ScrollPrepare: {
	QScrollPrepareEvent se = static_cast<QScrollPrepareEvent >(e);
	se->setViewportSize(m_size);
	QRectF br = m_viewport->boundingRect();
	se->setContentPosRange(QRectF(0, 0,
	qMax(qreal(0), br.width() - m_size.width()),
	qMax(qreal(0), br.height() - m_size.height())));
	se->setContentPos(-m_viewport->pos());
	se->accept();
	return true;
	}
	// ![1]
	// ![2]
	case QEvent::Scroll: {
	QScrollEvent se = static_cast<QScrollEvent >(e);
	m_viewport->setPos(-se->contentPos() - se->overshootDistance());
	return true;
	}
	// ![2]
	default:
	break;
	}
	return QGraphicsObject::event(e);
	}

	bool sceneEvent(QEvent *e) override
	{
	switch (e->type()) {
	case QEvent::TouchBegin: {
	// We need to return true for the TouchBegin here in the
	// top-most graphics object - otherwise gestures in our parent
	// objects will NOT work at all (the accept() flag is already
	// set due to our setAcceptTouchEvents(true) call in the c'tor
	return true;

	}
	case QEvent::GraphicsSceneMousePress: {
	// We need to return true for the MousePress here in the
	// top-most graphics object - otherwise gestures in our parent
	// objects will NOT work at all (the accept() flag is already
	// set to true by Qt)
	return true;

	}
	default:
	break;
	}
	return QGraphicsObject::sceneEvent(e);
	}

	QRectF boundingRect() const override
	{
	return QRectF(0, 0, m_size.width() + 3, m_size.height());
	}

	void paint(QPainter painter, const QStyleOptionGraphicsItem option, QWidget *widget) override
	{
	Q_UNUSED(option);
	Q_UNUSED(widget);
	painter->setPen(QPen(QColor(100, 100, 100), 3.0));
	painter->drawRect(QRectF(1.5, 1.5, m_size.width() - 3, m_size.height() - 3));
	}

	QSizeF m_size;
	ViewObject *m_viewport;
	};

	class MainWindow : public QMainWindow
	{
	Q_OBJECT

	public:
	MainWindow(bool useTouch)
	{
	m_scene = new QGraphicsScene();

	// -- make the main list
	ListObject *mainList = new ListObject(QSizeF(780, 400), useTouch);
	mainList->setObjectName(QLatin1String("MainList"));
	m_scene->addItem(mainList);
	// ![3]
	for (int i=0; i<NUM_LISTS; i++) {
	ListObject *childList = new ListObject(QSizeF(mainList->m_size.width()/3, mainList->m_size.height()), useTouch);
	childList->setObjectName(QString("ChildList %1").arg(i));
	fillList(childList);
	childList->setParentItem(mainList->viewport());
	childList->setPos(i*mainList->m_size.width()/3, 0);
	}
	mainList->viewport()->setPos(0, 0);


	/*
	list1->setTransformOriginPoint(200, 200);
	list1->setRotation(135);
	list1->setPos(20 + 200 * .41, 20 + 200 * .41);
	*/
	// ![3]

	m_view = new QGraphicsView(m_scene);
	setCentralWidget(m_view);
	setWindowTitle(tr("Gesture example"));
	m_scene->setSceneRect(0, 0, m_view->viewport()->width(), m_view->viewport()->height());
	}

	/**
	* Fills the list object \a list with RectObjects.
	*/
	void fillList(ListObject *list)
	{
	qreal h = list->m_size.height() / 10;
	for (int i=0; i<NUM_ITEMS; i++) {
	QColor color = QColor(255i/NUM_ITEMS, 255(NUM_ITEMS-i)/NUM_ITEMS, 127(i%2)+64(i/2%2));
	QString text = QLatin1String("Item #") + QString::number(i);
	QGraphicsItem *rect = new RectObject(text, 0, 0, list->m_size.width() - 6, h - 3, QBrush(color), list->viewport());
	rect->setPos(3, h*i+3);
	}
	list->viewport()->setPos(0, 0);
	}


	protected:
	void resizeEvent(QResizeEvent *e) override
	{
	// resize the scene according to our own size to prevent scrolling
	m_scene->setSceneRect(0, 0, m_view->viewport()->width(), m_view->viewport()->height());
	QMainWindow::resizeEvent(e);
	}

	QGraphicsScene *m_scene;
	QGraphicsView *m_view;
	};

	int main(int argc, char *argv[])
	{
	QApplication a(argc, argv);
	bool touch = (a.arguments().contains(QLatin1String("--touch")));
	MainWindow mw(touch);
	mw.show();
	#ifdef Q_OS_MAC
	mw.raise();
	#endif
	return a.exec();
	}

	#include "main.moc"