qt-everywhere-src-5.14.1/qtbase/examples/widgets/graphicsview/elasticnodes/graphwidget.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 "graphwidget.h"
 #include "edge.h"
 #include "node.h"

 #include <math.h>

 #include <QKeyEvent>
 #include <QRandomGenerator>

 //! [0]
 GraphWidget::GraphWidget(QWidget *parent)
     : QGraphicsView(parent)
 {
     QGraphicsScene *scene = new QGraphicsScene(this);
     scene->setItemIndexMethod(QGraphicsScene::NoIndex);
     scene->setSceneRect(-200, -200, 400, 400);
     setScene(scene);
     setCacheMode(CacheBackground);
     setViewportUpdateMode(BoundingRectViewportUpdate);
     setRenderHint(QPainter::Antialiasing);
     setTransformationAnchor(AnchorUnderMouse);
     scale(qreal(0.8), qreal(0.8));
     setMinimumSize(400, 400);
     setWindowTitle(tr("Elastic Nodes"));
 //! [0]

 //! [1]
     Node *node1 = new Node(this);
     Node *node2 = new Node(this);
     Node *node3 = new Node(this);
     Node *node4 = new Node(this);
     centerNode = new Node(this);
     Node *node6 = new Node(this);
     Node *node7 = new Node(this);
     Node *node8 = new Node(this);
     Node *node9 = new Node(this);
     scene->addItem(node1);
     scene->addItem(node2);
     scene->addItem(node3);
     scene->addItem(node4);
     scene->addItem(centerNode);
     scene->addItem(node6);
     scene->addItem(node7);
     scene->addItem(node8);
     scene->addItem(node9);
     scene->addItem(new Edge(node1, node2));
     scene->addItem(new Edge(node2, node3));
     scene->addItem(new Edge(node2, centerNode));
     scene->addItem(new Edge(node3, node6));
     scene->addItem(new Edge(node4, node1));
     scene->addItem(new Edge(node4, centerNode));
     scene->addItem(new Edge(centerNode, node6));
     scene->addItem(new Edge(centerNode, node8));
     scene->addItem(new Edge(node6, node9));
     scene->addItem(new Edge(node7, node4));
     scene->addItem(new Edge(node8, node7));
     scene->addItem(new Edge(node9, node8));

     node1->setPos(-50, -50);
     node2->setPos(0, -50);
     node3->setPos(50, -50);
     node4->setPos(-50, 0);
     centerNode->setPos(0, 0);
     node6->setPos(50, 0);
     node7->setPos(-50, 50);
     node8->setPos(0, 50);
     node9->setPos(50, 50);
 }
 //! [1]

 //! [2]
 void GraphWidget::itemMoved()
 {
     if (!timerId)
         timerId = startTimer(1000 / 25);
 }
 //! [2]

 //! [3]
 void GraphWidget::keyPressEvent(QKeyEvent *event)
 {
     switch (event->key()) {
     case Qt::Key_Up:
         centerNode->moveBy(0, -20);
         break;
     case Qt::Key_Down:
         centerNode->moveBy(0, 20);
         break;
     case Qt::Key_Left:
         centerNode->moveBy(-20, 0);
         break;
     case Qt::Key_Right:
         centerNode->moveBy(20, 0);
         break;
     case Qt::Key_Plus:
         zoomIn();
         break;
     case Qt::Key_Minus:
         zoomOut();
         break;
     case Qt::Key_Space:
     case Qt::Key_Enter:
         shuffle();
         break;
     default:
         QGraphicsView::keyPressEvent(event);
     }
 }
 //! [3]

 //! [4]
 void GraphWidget::timerEvent(QTimerEvent *event)
 {
     Q_UNUSED(event);

     QVector<Node *> nodes;
     const QList<QGraphicsItem *> items = scene()->items();
     for (QGraphicsItem *item : items) {
         if (Node *node = qgraphicsitem_cast<Node *>(item))
             nodes << node;
     }

     for (Node *node : qAsConst(nodes))
         node->calculateForces();

     bool itemsMoved = false;
     for (Node *node : qAsConst(nodes)) {
         if (node->advancePosition())
             itemsMoved = true;
     }

     if (!itemsMoved) {
         killTimer(timerId);
         timerId = 0;
     }
 }
 //! [4]

 #if QT_CONFIG(wheelevent)
 //! [5]
 void GraphWidget::wheelEvent(QWheelEvent *event)
 {
     scaleView(pow(2., -event->angleDelta().y() / 240.0));
 }
 //! [5]
 #endif

 //! [6]
 void GraphWidget::drawBackground(QPainter *painter, const QRectF &rect)
 {
     Q_UNUSED(rect);

     // Shadow
     QRectF sceneRect = this->sceneRect();
     QRectF rightShadow(sceneRect.right(), sceneRect.top() + 5, 5, sceneRect.height());
     QRectF bottomShadow(sceneRect.left() + 5, sceneRect.bottom(), sceneRect.width(), 5);
     if (rightShadow.intersects(rect) || rightShadow.contains(rect))
         painter->fillRect(rightShadow, Qt::darkGray);
     if (bottomShadow.intersects(rect) || bottomShadow.contains(rect))
         painter->fillRect(bottomShadow, Qt::darkGray);

     // Fill
     QLinearGradient gradient(sceneRect.topLeft(), sceneRect.bottomRight());
     gradient.setColorAt(0, Qt::white);
     gradient.setColorAt(1, Qt::lightGray);
     painter->fillRect(rect.intersected(sceneRect), gradient);
     painter->setBrush(Qt::NoBrush);
     painter->drawRect(sceneRect);

     // Text
     QRectF textRect(sceneRect.left() + 4, sceneRect.top() + 4,
                     sceneRect.width() - 4, sceneRect.height() - 4);
     QString message(tr("Click and drag the nodes around, and zoom with the mouse "
                        "wheel or the '+' and '-' keys"));

     QFont font = painter->font();
     font.setBold(true);
     font.setPointSize(14);
     painter->setFont(font);
     painter->setPen(Qt::lightGray);
     painter->drawText(textRect.translated(2, 2), message);
     painter->setPen(Qt::black);
     painter->drawText(textRect, message);
 }
 //! [6]

 //! [7]
 void GraphWidget::scaleView(qreal scaleFactor)
 {
     qreal factor = transform().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
     if (factor < 0.07 || factor > 100)
         return;

     scale(scaleFactor, scaleFactor);
 }
 //! [7]

 void GraphWidget::shuffle()
 {
     const QList<QGraphicsItem *> items = scene()->items();
     for (QGraphicsItem *item : items) {
         if (qgraphicsitem_cast<Node *>(item))
             item->setPos(-150 + QRandomGenerator::global()->bounded(300), -150 + QRandomGenerator::global()->bounded(300));
     }
 }

 void GraphWidget::zoomIn()
 {
     scaleView(qreal(1.2));
 }

 void GraphWidget::zoomOut()
 {
     scaleView(1 / qreal(1.2));
 }
	/****************************************************************************
	**
	** 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 "graphwidget.h"
	#include "edge.h"
	#include "node.h"

	#include <math.h>

	#include <QKeyEvent>
	#include <QRandomGenerator>

	//! [0]
	GraphWidget::GraphWidget(QWidget *parent)
	: QGraphicsView(parent)
	{
	QGraphicsScene *scene = new QGraphicsScene(this);
	scene->setItemIndexMethod(QGraphicsScene::NoIndex);
	scene->setSceneRect(-200, -200, 400, 400);
	setScene(scene);
	setCacheMode(CacheBackground);
	setViewportUpdateMode(BoundingRectViewportUpdate);
	setRenderHint(QPainter::Antialiasing);
	setTransformationAnchor(AnchorUnderMouse);
	scale(qreal(0.8), qreal(0.8));
	setMinimumSize(400, 400);
	setWindowTitle(tr("Elastic Nodes"));
	//! [0]

	//! [1]
	Node *node1 = new Node(this);
	Node *node2 = new Node(this);
	Node *node3 = new Node(this);
	Node *node4 = new Node(this);
	centerNode = new Node(this);
	Node *node6 = new Node(this);
	Node *node7 = new Node(this);
	Node *node8 = new Node(this);
	Node *node9 = new Node(this);
	scene->addItem(node1);
	scene->addItem(node2);
	scene->addItem(node3);
	scene->addItem(node4);
	scene->addItem(centerNode);
	scene->addItem(node6);
	scene->addItem(node7);
	scene->addItem(node8);
	scene->addItem(node9);
	scene->addItem(new Edge(node1, node2));
	scene->addItem(new Edge(node2, node3));
	scene->addItem(new Edge(node2, centerNode));
	scene->addItem(new Edge(node3, node6));
	scene->addItem(new Edge(node4, node1));
	scene->addItem(new Edge(node4, centerNode));
	scene->addItem(new Edge(centerNode, node6));
	scene->addItem(new Edge(centerNode, node8));
	scene->addItem(new Edge(node6, node9));
	scene->addItem(new Edge(node7, node4));
	scene->addItem(new Edge(node8, node7));
	scene->addItem(new Edge(node9, node8));

	node1->setPos(-50, -50);
	node2->setPos(0, -50);
	node3->setPos(50, -50);
	node4->setPos(-50, 0);
	centerNode->setPos(0, 0);
	node6->setPos(50, 0);
	node7->setPos(-50, 50);
	node8->setPos(0, 50);
	node9->setPos(50, 50);
	}
	//! [1]

	//! [2]
	void GraphWidget::itemMoved()
	{
	if (!timerId)
	timerId = startTimer(1000 / 25);
	}
	//! [2]

	//! [3]
	void GraphWidget::keyPressEvent(QKeyEvent *event)
	{
	switch (event->key()) {
	case Qt::Key_Up:
	centerNode->moveBy(0, -20);
	break;
	case Qt::Key_Down:
	centerNode->moveBy(0, 20);
	break;
	case Qt::Key_Left:
	centerNode->moveBy(-20, 0);
	break;
	case Qt::Key_Right:
	centerNode->moveBy(20, 0);
	break;
	case Qt::Key_Plus:
	zoomIn();
	break;
	case Qt::Key_Minus:
	zoomOut();
	break;
	case Qt::Key_Space:
	case Qt::Key_Enter:
	shuffle();
	break;
	default:
	QGraphicsView::keyPressEvent(event);
	}
	}
	//! [3]

	//! [4]
	void GraphWidget::timerEvent(QTimerEvent *event)
	{
	Q_UNUSED(event);

	QVector<Node *> nodes;
	const QList<QGraphicsItem *> items = scene()->items();
	for (QGraphicsItem *item : items) {
	if (Node node = qgraphicsitem_cast<Node >(item))
	nodes << node;
	}

	for (Node *node : qAsConst(nodes))
	node->calculateForces();

	bool itemsMoved = false;
	for (Node *node : qAsConst(nodes)) {
	if (node->advancePosition())
	itemsMoved = true;
	}

	if (!itemsMoved) {
	killTimer(timerId);
	timerId = 0;
	}
	}
	//! [4]

	#if QT_CONFIG(wheelevent)
	//! [5]
	void GraphWidget::wheelEvent(QWheelEvent *event)
	{
	scaleView(pow(2., -event->angleDelta().y() / 240.0));
	}
	//! [5]
	#endif

	//! [6]
	void GraphWidget::drawBackground(QPainter *painter, const QRectF &rect)
	{
	Q_UNUSED(rect);

	// Shadow
	QRectF sceneRect = this->sceneRect();
	QRectF rightShadow(sceneRect.right(), sceneRect.top() + 5, 5, sceneRect.height());
	QRectF bottomShadow(sceneRect.left() + 5, sceneRect.bottom(), sceneRect.width(), 5);
	if (rightShadow.intersects(rect) \|\| rightShadow.contains(rect))
	painter->fillRect(rightShadow, Qt::darkGray);
	if (bottomShadow.intersects(rect) \|\| bottomShadow.contains(rect))
	painter->fillRect(bottomShadow, Qt::darkGray);

	// Fill
	QLinearGradient gradient(sceneRect.topLeft(), sceneRect.bottomRight());
	gradient.setColorAt(0, Qt::white);
	gradient.setColorAt(1, Qt::lightGray);
	painter->fillRect(rect.intersected(sceneRect), gradient);
	painter->setBrush(Qt::NoBrush);
	painter->drawRect(sceneRect);

	// Text
	QRectF textRect(sceneRect.left() + 4, sceneRect.top() + 4,
	sceneRect.width() - 4, sceneRect.height() - 4);
	QString message(tr("Click and drag the nodes around, and zoom with the mouse "
	"wheel or the '+' and '-' keys"));

	QFont font = painter->font();
	font.setBold(true);
	font.setPointSize(14);
	painter->setFont(font);
	painter->setPen(Qt::lightGray);
	painter->drawText(textRect.translated(2, 2), message);
	painter->setPen(Qt::black);
	painter->drawText(textRect, message);
	}
	//! [6]

	//! [7]
	void GraphWidget::scaleView(qreal scaleFactor)
	{
	qreal factor = transform().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
	if (factor < 0.07 \|\| factor > 100)
	return;

	scale(scaleFactor, scaleFactor);
	}
	//! [7]

	void GraphWidget::shuffle()
	{
	const QList<QGraphicsItem *> items = scene()->items();
	for (QGraphicsItem *item : items) {
	if (qgraphicsitem_cast<Node *>(item))
	item->setPos(-150 + QRandomGenerator::global()->bounded(300), -150 + QRandomGenerator::global()->bounded(300));
	}
	}

	void GraphWidget::zoomIn()
	{
	scaleView(qreal(1.2));
	}

	void GraphWidget::zoomOut()
	{
	scaleView(1 / qreal(1.2));
	}