Qt 5.11 | Qt Widgets | Basic Drawing Example | window.cpp Example File

Qt 5.11.3 Reference Documentation

# window.cpp Example File

painting/basicdrawing/window.cpp

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      #include "renderarea.h"
      #include "window.h"

      #include <QtWidgets>

      const int IdRole = Qt::UserRole;

      Window::Window()
      {
          renderArea = new RenderArea;

          shapeComboBox = new QComboBox;
          shapeComboBox->addItem(tr("Polygon"), RenderArea::Polygon);
          shapeComboBox->addItem(tr("Rectangle"), RenderArea::Rect);
          shapeComboBox->addItem(tr("Rounded Rectangle"), RenderArea::RoundedRect);
          shapeComboBox->addItem(tr("Ellipse"), RenderArea::Ellipse);
          shapeComboBox->addItem(tr("Pie"), RenderArea::Pie);
          shapeComboBox->addItem(tr("Chord"), RenderArea::Chord);
          shapeComboBox->addItem(tr("Path"), RenderArea::Path);
          shapeComboBox->addItem(tr("Line"), RenderArea::Line);
          shapeComboBox->addItem(tr("Polyline"), RenderArea::Polyline);
          shapeComboBox->addItem(tr("Arc"), RenderArea::Arc);
          shapeComboBox->addItem(tr("Points"), RenderArea::Points);
          shapeComboBox->addItem(tr("Text"), RenderArea::Text);
          shapeComboBox->addItem(tr("Pixmap"), RenderArea::Pixmap);

          shapeLabel = new QLabel(tr("&Shape:"));
          shapeLabel->setBuddy(shapeComboBox);

          penWidthSpinBox = new QSpinBox;
          penWidthSpinBox->setRange(0, 20);
          penWidthSpinBox->setSpecialValueText(tr("0 (cosmetic pen)"));

          penWidthLabel = new QLabel(tr("Pen &Width:"));
          penWidthLabel->setBuddy(penWidthSpinBox);

          penStyleComboBox = new QComboBox;
          penStyleComboBox->addItem(tr("Solid"), static_cast<int>(Qt::SolidLine));
          penStyleComboBox->addItem(tr("Dash"), static_cast<int>(Qt::DashLine));
          penStyleComboBox->addItem(tr("Dot"), static_cast<int>(Qt::DotLine));
          penStyleComboBox->addItem(tr("Dash Dot"), static_cast<int>(Qt::DashDotLine));
          penStyleComboBox->addItem(tr("Dash Dot Dot"), static_cast<int>(Qt::DashDotDotLine));
          penStyleComboBox->addItem(tr("None"), static_cast<int>(Qt::NoPen));

          penStyleLabel = new QLabel(tr("&Pen Style:"));
          penStyleLabel->setBuddy(penStyleComboBox);

          penCapComboBox = new QComboBox;
          penCapComboBox->addItem(tr("Flat"), Qt::FlatCap);
          penCapComboBox->addItem(tr("Square"), Qt::SquareCap);
          penCapComboBox->addItem(tr("Round"), Qt::RoundCap);

          penCapLabel = new QLabel(tr("Pen &Cap:"));
          penCapLabel->setBuddy(penCapComboBox);

          penJoinComboBox = new QComboBox;
          penJoinComboBox->addItem(tr("Miter"), Qt::MiterJoin);
          penJoinComboBox->addItem(tr("Bevel"), Qt::BevelJoin);
          penJoinComboBox->addItem(tr("Round"), Qt::RoundJoin);

          penJoinLabel = new QLabel(tr("Pen &Join:"));
          penJoinLabel->setBuddy(penJoinComboBox);

          brushStyleComboBox = new QComboBox;
          brushStyleComboBox->addItem(tr("Linear Gradient"),
                  static_cast<int>(Qt::LinearGradientPattern));
          brushStyleComboBox->addItem(tr("Radial Gradient"),
                  static_cast<int>(Qt::RadialGradientPattern));
          brushStyleComboBox->addItem(tr("Conical Gradient"),
                  static_cast<int>(Qt::ConicalGradientPattern));
          brushStyleComboBox->addItem(tr("Texture"), static_cast<int>(Qt::TexturePattern));
          brushStyleComboBox->addItem(tr("Solid"), static_cast<int>(Qt::SolidPattern));
          brushStyleComboBox->addItem(tr("Horizontal"), static_cast<int>(Qt::HorPattern));
          brushStyleComboBox->addItem(tr("Vertical"), static_cast<int>(Qt::VerPattern));
          brushStyleComboBox->addItem(tr("Cross"), static_cast<int>(Qt::CrossPattern));
          brushStyleComboBox->addItem(tr("Backward Diagonal"), static_cast<int>(Qt::BDiagPattern));
          brushStyleComboBox->addItem(tr("Forward Diagonal"), static_cast<int>(Qt::FDiagPattern));
          brushStyleComboBox->addItem(tr("Diagonal Cross"), static_cast<int>(Qt::DiagCrossPattern));
          brushStyleComboBox->addItem(tr("Dense 1"), static_cast<int>(Qt::Dense1Pattern));
          brushStyleComboBox->addItem(tr("Dense 2"), static_cast<int>(Qt::Dense2Pattern));
          brushStyleComboBox->addItem(tr("Dense 3"), static_cast<int>(Qt::Dense3Pattern));
          brushStyleComboBox->addItem(tr("Dense 4"), static_cast<int>(Qt::Dense4Pattern));
          brushStyleComboBox->addItem(tr("Dense 5"), static_cast<int>(Qt::Dense5Pattern));
          brushStyleComboBox->addItem(tr("Dense 6"), static_cast<int>(Qt::Dense6Pattern));
          brushStyleComboBox->addItem(tr("Dense 7"), static_cast<int>(Qt::Dense7Pattern));
          brushStyleComboBox->addItem(tr("None"), static_cast<int>(Qt::NoBrush));

          brushStyleLabel = new QLabel(tr("&Brush:"));
          brushStyleLabel->setBuddy(brushStyleComboBox);

          otherOptionsLabel = new QLabel(tr("Options:"));
          antialiasingCheckBox = new QCheckBox(tr("&Antialiasing"));
          transformationsCheckBox = new QCheckBox(tr("&Transformations"));

          connect(shapeComboBox, SIGNAL(activated(int)),
                  this, SLOT(shapeChanged()));
          connect(penWidthSpinBox, SIGNAL(valueChanged(int)),
                  this, SLOT(penChanged()));
          connect(penStyleComboBox, SIGNAL(activated(int)),
                  this, SLOT(penChanged()));
          connect(penCapComboBox, SIGNAL(activated(int)),
                  this, SLOT(penChanged()));
          connect(penJoinComboBox, SIGNAL(activated(int)),
                  this, SLOT(penChanged()));
          connect(brushStyleComboBox, SIGNAL(activated(int)),
                  this, SLOT(brushChanged()));
          connect(antialiasingCheckBox, SIGNAL(toggled(bool)),
                  renderArea, SLOT(setAntialiased(bool)));
          connect(transformationsCheckBox, SIGNAL(toggled(bool)),
                  renderArea, SLOT(setTransformed(bool)));

          QGridLayout *mainLayout = new QGridLayout;
          mainLayout->setColumnStretch(0, 1);
          mainLayout->setColumnStretch(3, 1);
          mainLayout->addWidget(renderArea, 0, 0, 1, 4);
          mainLayout->addWidget(shapeLabel, 2, 0, Qt::AlignRight);
          mainLayout->addWidget(shapeComboBox, 2, 1);
          mainLayout->addWidget(penWidthLabel, 3, 0, Qt::AlignRight);
          mainLayout->addWidget(penWidthSpinBox, 3, 1);
          mainLayout->addWidget(penStyleLabel, 4, 0, Qt::AlignRight);
          mainLayout->addWidget(penStyleComboBox, 4, 1);
          mainLayout->addWidget(penCapLabel, 3, 2, Qt::AlignRight);
          mainLayout->addWidget(penCapComboBox, 3, 3);
          mainLayout->addWidget(penJoinLabel, 2, 2, Qt::AlignRight);
          mainLayout->addWidget(penJoinComboBox, 2, 3);
          mainLayout->addWidget(brushStyleLabel, 4, 2, Qt::AlignRight);
          mainLayout->addWidget(brushStyleComboBox, 4, 3);
          mainLayout->addWidget(otherOptionsLabel, 5, 0, Qt::AlignRight);
          mainLayout->addWidget(antialiasingCheckBox, 5, 1, 1, 1, Qt::AlignRight);
          mainLayout->addWidget(transformationsCheckBox, 5, 2, 1, 2, Qt::AlignRight);
          setLayout(mainLayout);

          shapeChanged();
          penChanged();
          brushChanged();
          antialiasingCheckBox->setChecked(true);

          setWindowTitle(tr("Basic Drawing"));
      }

      void Window::shapeChanged()
      {
          RenderArea::Shape shape = RenderArea::Shape(shapeComboBox->itemData(
                  shapeComboBox->currentIndex(), IdRole).toInt());
          renderArea->setShape(shape);
      }

      void Window::penChanged()
      {
          int width = penWidthSpinBox->value();
          Qt::PenStyle style = Qt::PenStyle(penStyleComboBox->itemData(
                  penStyleComboBox->currentIndex(), IdRole).toInt());
          Qt::PenCapStyle cap = Qt::PenCapStyle(penCapComboBox->itemData(
                  penCapComboBox->currentIndex(), IdRole).toInt());
          Qt::PenJoinStyle join = Qt::PenJoinStyle(penJoinComboBox->itemData(
                  penJoinComboBox->currentIndex(), IdRole).toInt());

          renderArea->setPen(QPen(Qt::blue, width, style, cap, join));
      }

      void Window::brushChanged()
      {
          Qt::BrushStyle style = Qt::BrushStyle(brushStyleComboBox->itemData(
                  brushStyleComboBox->currentIndex(), IdRole).toInt());

          if (style == Qt::LinearGradientPattern) {
              QLinearGradient linearGradient(0, 0, 100, 100);
              linearGradient.setColorAt(0.0, Qt::white);
              linearGradient.setColorAt(0.2, Qt::green);
              linearGradient.setColorAt(1.0, Qt::black);
              renderArea->setBrush(linearGradient);
          } else if (style == Qt::RadialGradientPattern) {
              QRadialGradient radialGradient(50, 50, 50, 70, 70);
              radialGradient.setColorAt(0.0, Qt::white);
              radialGradient.setColorAt(0.2, Qt::green);
              radialGradient.setColorAt(1.0, Qt::black);
              renderArea->setBrush(radialGradient);
          } else if (style == Qt::ConicalGradientPattern) {
              QConicalGradient conicalGradient(50, 50, 150);
              conicalGradient.setColorAt(0.0, Qt::white);
              conicalGradient.setColorAt(0.2, Qt::green);
              conicalGradient.setColorAt(1.0, Qt::black);
              renderArea->setBrush(conicalGradient);
          } else if (style == Qt::TexturePattern) {
              renderArea->setBrush(QBrush(QPixmap(":/images/brick.png")));
          } else {
              renderArea->setBrush(QBrush(Qt::green, style));
          }
      }