Qt 5.6 | Qt Widgets | 40000 Chips | view.cpp Example File

Qt 5.6.2 Reference Documentation

# view.cpp Example File

graphicsview/chip/view.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2015 The Qt Company Ltd.
      ** Contact: http://www.qt.io/licensing/
      **
      ** This file is part of the demonstration applications of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:LGPL21$
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      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
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      ** GNU Lesser General Public License Usage
      ** Alternatively, this file may be used under the terms of the GNU Lesser
      ** General Public License version 2.1 or version 3 as published by the Free
      ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
      ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
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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);
      }