view.cpp Example File

graphicsview/chip/view.cpp
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
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** This file is part of the demonstration applications of the Qt Toolkit.
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** $QT_BEGIN_LICENSE:LGPL21$
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** GNU Lesser General Public License Usage
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#include "view.h"

#ifndef QT_NO_PRINTER
#include <QPrinter>
#include <QPrintDialog>
#endif
#ifndef QT_NO_OPENGL
#include <QtOpenGL>
#else
#include <QtWidgets>
#endif
#include <qmath.h>

#ifndef QT_NO_WHEELEVENT
void GraphicsView::wheelEvent(QWheelEvent *e)
{
    if (e->modifiers() & Qt::ControlModifier) {
        if (e->delta() > 0)
            view->zoomIn(6);
        else
            view->zoomOut(6);
        e->accept();
    } else {
        QGraphicsView::wheelEvent(e);
    }
}
#endif

View::View(const QString &name, QWidget *parent)
    : QFrame(parent)
{
    setFrameStyle(Sunken | StyledPanel);
    graphicsView = new GraphicsView(this);
    graphicsView->setRenderHint(QPainter::Antialiasing, false);
    graphicsView->setDragMode(QGraphicsView::RubberBandDrag);
    graphicsView->setOptimizationFlags(QGraphicsView::DontSavePainterState);
    graphicsView->setViewportUpdateMode(QGraphicsView::SmartViewportUpdate);
    graphicsView->setTransformationAnchor(QGraphicsView::AnchorUnderMouse);

    int size = style()->pixelMetric(QStyle::PM_ToolBarIconSize);
    QSize iconSize(size, size);

    QToolButton *zoomInIcon = new QToolButton;
    zoomInIcon->setAutoRepeat(true);
    zoomInIcon->setAutoRepeatInterval(33);
    zoomInIcon->setAutoRepeatDelay(0);
    zoomInIcon->setIcon(QPixmap(":/zoomin.png"));
    zoomInIcon->setIconSize(iconSize);
    QToolButton *zoomOutIcon = new QToolButton;
    zoomOutIcon->setAutoRepeat(true);
    zoomOutIcon->setAutoRepeatInterval(33);
    zoomOutIcon->setAutoRepeatDelay(0);
    zoomOutIcon->setIcon(QPixmap(":/zoomout.png"));
    zoomOutIcon->setIconSize(iconSize);
    zoomSlider = new QSlider;
    zoomSlider->setMinimum(0);
    zoomSlider->setMaximum(500);
    zoomSlider->setValue(250);
    zoomSlider->setTickPosition(QSlider::TicksRight);

    // Zoom slider layout
    QVBoxLayout *zoomSliderLayout = new QVBoxLayout;
    zoomSliderLayout->addWidget(zoomInIcon);
    zoomSliderLayout->addWidget(zoomSlider);
    zoomSliderLayout->addWidget(zoomOutIcon);

    QToolButton *rotateLeftIcon = new QToolButton;
    rotateLeftIcon->setIcon(QPixmap(":/rotateleft.png"));
    rotateLeftIcon->setIconSize(iconSize);
    QToolButton *rotateRightIcon = new QToolButton;
    rotateRightIcon->setIcon(QPixmap(":/rotateright.png"));
    rotateRightIcon->setIconSize(iconSize);
    rotateSlider = new QSlider;
    rotateSlider->setOrientation(Qt::Horizontal);
    rotateSlider->setMinimum(-360);
    rotateSlider->setMaximum(360);
    rotateSlider->setValue(0);
    rotateSlider->setTickPosition(QSlider::TicksBelow);

    // Rotate slider layout
    QHBoxLayout *rotateSliderLayout = new QHBoxLayout;
    rotateSliderLayout->addWidget(rotateLeftIcon);
    rotateSliderLayout->addWidget(rotateSlider);
    rotateSliderLayout->addWidget(rotateRightIcon);

    resetButton = new QToolButton;
    resetButton->setText(tr("0"));
    resetButton->setEnabled(false);

    // Label layout
    QHBoxLayout *labelLayout = new QHBoxLayout;
    label = new QLabel(name);
    label2 = new QLabel(tr("Pointer Mode"));
    selectModeButton = new QToolButton;
    selectModeButton->setText(tr("Select"));
    selectModeButton->setCheckable(true);
    selectModeButton->setChecked(true);
    dragModeButton = new QToolButton;
    dragModeButton->setText(tr("Drag"));
    dragModeButton->setCheckable(true);
    dragModeButton->setChecked(false);
    antialiasButton = new QToolButton;
    antialiasButton->setText(tr("Antialiasing"));
    antialiasButton->setCheckable(true);
    antialiasButton->setChecked(false);
    openGlButton = new QToolButton;
    openGlButton->setText(tr("OpenGL"));
    openGlButton->setCheckable(true);
#ifndef QT_NO_OPENGL
    openGlButton->setEnabled(QGLFormat::hasOpenGL());
#else
    openGlButton->setEnabled(false);
#endif
    printButton = new QToolButton;
    printButton->setIcon(QIcon(QPixmap(":/fileprint.png")));

    QButtonGroup *pointerModeGroup = new QButtonGroup;
    pointerModeGroup->setExclusive(true);
    pointerModeGroup->addButton(selectModeButton);
    pointerModeGroup->addButton(dragModeButton);

    labelLayout->addWidget(label);
    labelLayout->addStretch();
    labelLayout->addWidget(label2);
    labelLayout->addWidget(selectModeButton);
    labelLayout->addWidget(dragModeButton);
    labelLayout->addStretch();
    labelLayout->addWidget(antialiasButton);
    labelLayout->addWidget(openGlButton);
    labelLayout->addWidget(printButton);

    QGridLayout *topLayout = new QGridLayout;
    topLayout->addLayout(labelLayout, 0, 0);
    topLayout->addWidget(graphicsView, 1, 0);
    topLayout->addLayout(zoomSliderLayout, 1, 1);
    topLayout->addLayout(rotateSliderLayout, 2, 0);
    topLayout->addWidget(resetButton, 2, 1);
    setLayout(topLayout);

    connect(resetButton, SIGNAL(clicked()), this, SLOT(resetView()));
    connect(zoomSlider, SIGNAL(valueChanged(int)), this, SLOT(setupMatrix()));
    connect(rotateSlider, SIGNAL(valueChanged(int)), this, SLOT(setupMatrix()));
    connect(graphicsView->verticalScrollBar(), SIGNAL(valueChanged(int)),
            this, SLOT(setResetButtonEnabled()));
    connect(graphicsView->horizontalScrollBar(), SIGNAL(valueChanged(int)),
            this, SLOT(setResetButtonEnabled()));
    connect(selectModeButton, SIGNAL(toggled(bool)), this, SLOT(togglePointerMode()));
    connect(dragModeButton, SIGNAL(toggled(bool)), this, SLOT(togglePointerMode()));
    connect(antialiasButton, SIGNAL(toggled(bool)), this, SLOT(toggleAntialiasing()));
    connect(openGlButton, SIGNAL(toggled(bool)), this, SLOT(toggleOpenGL()));
    connect(rotateLeftIcon, SIGNAL(clicked()), this, SLOT(rotateLeft()));
    connect(rotateRightIcon, SIGNAL(clicked()), this, SLOT(rotateRight()));
    connect(zoomInIcon, SIGNAL(clicked()), this, SLOT(zoomIn()));
    connect(zoomOutIcon, SIGNAL(clicked()), this, SLOT(zoomOut()));
    connect(printButton, SIGNAL(clicked()), this, SLOT(print()));

    setupMatrix();
}

QGraphicsView *View::view() const
{
    return static_cast<QGraphicsView *>(graphicsView);
}

void View::resetView()
{
    zoomSlider->setValue(250);
    rotateSlider->setValue(0);
    setupMatrix();
    graphicsView->ensureVisible(QRectF(0, 0, 0, 0));

    resetButton->setEnabled(false);
}

void View::setResetButtonEnabled()
{
    resetButton->setEnabled(true);
}

void View::setupMatrix()
{
    qreal scale = qPow(qreal(2), (zoomSlider->value() - 250) / qreal(50));

    QMatrix matrix;
    matrix.scale(scale, scale);
    matrix.rotate(rotateSlider->value());

    graphicsView->setMatrix(matrix);
    setResetButtonEnabled();
}

void View::togglePointerMode()
{
    graphicsView->setDragMode(selectModeButton->isChecked()
                              ? QGraphicsView::RubberBandDrag
                              : QGraphicsView::ScrollHandDrag);
    graphicsView->setInteractive(selectModeButton->isChecked());
}

void View::toggleOpenGL()
{
#ifndef QT_NO_OPENGL
    graphicsView->setViewport(openGlButton->isChecked() ? new QGLWidget(QGLFormat(QGL::SampleBuffers)) : new QWidget);
#endif
}

void View::toggleAntialiasing()
{
    graphicsView->setRenderHint(QPainter::Antialiasing, antialiasButton->isChecked());
}

void View::print()
{
#if !defined(QT_NO_PRINTER) && !defined(QT_NO_PRINTDIALOG)
    QPrinter printer;
    QPrintDialog dialog(&printer, this);
    if (dialog.exec() == QDialog::Accepted) {
        QPainter painter(&printer);
        graphicsView->render(&painter);
    }
#endif
}

void View::zoomIn(int level)
{
    zoomSlider->setValue(zoomSlider->value() + level);
}

void View::zoomOut(int level)
{
    zoomSlider->setValue(zoomSlider->value() - level);
}

void View::rotateLeft()
{
    rotateSlider->setValue(rotateSlider->value() - 10);
}

void View::rotateRight()
{
    rotateSlider->setValue(rotateSlider->value() + 10);
}

© 2016 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.