Qt 5.11 | Qt Widgets | Diagram Scene Example | mainwindow.cpp Example File

Qt 5.11.3 Reference Documentation

# mainwindow.cpp Example File

graphicsview/diagramscene/mainwindow.cpp

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      #include "arrow.h"
      #include "diagramitem.h"
      #include "diagramscene.h"
      #include "diagramtextitem.h"
      #include "mainwindow.h"

      #include <QtWidgets>

      const int InsertTextButton = 10;

      MainWindow::MainWindow()
      {
          createActions();
          createToolBox();
          createMenus();

          scene = new DiagramScene(itemMenu, this);
          scene->setSceneRect(QRectF(0, 0, 5000, 5000));
          connect(scene, SIGNAL(itemInserted(DiagramItem*)),
                  this, SLOT(itemInserted(DiagramItem*)));
          connect(scene, SIGNAL(textInserted(QGraphicsTextItem*)),
                  this, SLOT(textInserted(QGraphicsTextItem*)));
          connect(scene, SIGNAL(itemSelected(QGraphicsItem*)),
                  this, SLOT(itemSelected(QGraphicsItem*)));
          createToolbars();

          QHBoxLayout *layout = new QHBoxLayout;
          layout->addWidget(toolBox);
          view = new QGraphicsView(scene);
          layout->addWidget(view);

          QWidget *widget = new QWidget;
          widget->setLayout(layout);

          setCentralWidget(widget);
          setWindowTitle(tr("Diagramscene"));
          setUnifiedTitleAndToolBarOnMac(true);
      }

      void MainWindow::backgroundButtonGroupClicked(QAbstractButton *button)
      {
          QList<QAbstractButton *> buttons = backgroundButtonGroup->buttons();
          foreach (QAbstractButton *myButton, buttons) {
              if (myButton != button)
                  button->setChecked(false);
          }
          QString text = button->text();
          if (text == tr("Blue Grid"))
              scene->setBackgroundBrush(QPixmap(":/images/background1.png"));
          else if (text == tr("White Grid"))
              scene->setBackgroundBrush(QPixmap(":/images/background2.png"));
          else if (text == tr("Gray Grid"))
              scene->setBackgroundBrush(QPixmap(":/images/background3.png"));
          else
              scene->setBackgroundBrush(QPixmap(":/images/background4.png"));

          scene->update();
          view->update();
      }

      void MainWindow::buttonGroupClicked(int id)
      {
          QList<QAbstractButton *> buttons = buttonGroup->buttons();
          foreach (QAbstractButton *button, buttons) {
              if (buttonGroup->button(id) != button)
                  button->setChecked(false);
          }
          if (id == InsertTextButton) {
              scene->setMode(DiagramScene::InsertText);
          } else {
              scene->setItemType(DiagramItem::DiagramType(id));
              scene->setMode(DiagramScene::InsertItem);
          }
      }

      void MainWindow::deleteItem()
      {
          foreach (QGraphicsItem *item, scene->selectedItems()) {
              if (item->type() == Arrow::Type) {
                  scene->removeItem(item);
                  Arrow *arrow = qgraphicsitem_cast<Arrow *>(item);
                  arrow->startItem()->removeArrow(arrow);
                  arrow->endItem()->removeArrow(arrow);
                  delete item;
              }
          }

          foreach (QGraphicsItem *item, scene->selectedItems()) {
               if (item->type() == DiagramItem::Type)
                   qgraphicsitem_cast<DiagramItem *>(item)->removeArrows();
               scene->removeItem(item);
               delete item;
           }
      }

      void MainWindow::pointerGroupClicked(int)
      {
          scene->setMode(DiagramScene::Mode(pointerTypeGroup->checkedId()));
      }

      void MainWindow::bringToFront()
      {
          if (scene->selectedItems().isEmpty())
              return;

          QGraphicsItem *selectedItem = scene->selectedItems().first();
          QList<QGraphicsItem *> overlapItems = selectedItem->collidingItems();

          qreal zValue = 0;
          foreach (QGraphicsItem *item, overlapItems) {
              if (item->zValue() >= zValue && item->type() == DiagramItem::Type)
                  zValue = item->zValue() + 0.1;
          }
          selectedItem->setZValue(zValue);
      }

      void MainWindow::sendToBack()
      {
          if (scene->selectedItems().isEmpty())
              return;

          QGraphicsItem *selectedItem = scene->selectedItems().first();
          QList<QGraphicsItem *> overlapItems = selectedItem->collidingItems();

          qreal zValue = 0;
          foreach (QGraphicsItem *item, overlapItems) {
              if (item->zValue() <= zValue && item->type() == DiagramItem::Type)
                  zValue = item->zValue() - 0.1;
          }
          selectedItem->setZValue(zValue);
      }

      void MainWindow::itemInserted(DiagramItem *item)
      {
          pointerTypeGroup->button(int(DiagramScene::MoveItem))->setChecked(true);
          scene->setMode(DiagramScene::Mode(pointerTypeGroup->checkedId()));
          buttonGroup->button(int(item->diagramType()))->setChecked(false);
      }

      void MainWindow::textInserted(QGraphicsTextItem *)
      {
          buttonGroup->button(InsertTextButton)->setChecked(false);
          scene->setMode(DiagramScene::Mode(pointerTypeGroup->checkedId()));
      }

      void MainWindow::currentFontChanged(const QFont &)
      {
          handleFontChange();
      }

      void MainWindow::fontSizeChanged(const QString &)
      {
          handleFontChange();
      }

      void MainWindow::sceneScaleChanged(const QString &scale)
      {
          double newScale = scale.left(scale.indexOf(tr("%"))).toDouble() / 100.0;
          QMatrix oldMatrix = view->matrix();
          view->resetMatrix();
          view->translate(oldMatrix.dx(), oldMatrix.dy());
          view->scale(newScale, newScale);
      }

      void MainWindow::textColorChanged()
      {
          textAction = qobject_cast<QAction *>(sender());
          fontColorToolButton->setIcon(createColorToolButtonIcon(
                                           ":/images/textpointer.png",
                                           qvariant_cast<QColor>(textAction->data())));
          textButtonTriggered();
      }

      void MainWindow::itemColorChanged()
      {
          fillAction = qobject_cast<QAction *>(sender());
          fillColorToolButton->setIcon(createColorToolButtonIcon(
                                           ":/images/floodfill.png",
                                           qvariant_cast<QColor>(fillAction->data())));
          fillButtonTriggered();
      }

      void MainWindow::lineColorChanged()
      {
          lineAction = qobject_cast<QAction *>(sender());
          lineColorToolButton->setIcon(createColorToolButtonIcon(
                                           ":/images/linecolor.png",
                                           qvariant_cast<QColor>(lineAction->data())));
          lineButtonTriggered();
      }

      void MainWindow::textButtonTriggered()
      {
          scene->setTextColor(qvariant_cast<QColor>(textAction->data()));
      }

      void MainWindow::fillButtonTriggered()
      {
          scene->setItemColor(qvariant_cast<QColor>(fillAction->data()));
      }

      void MainWindow::lineButtonTriggered()
      {
          scene->setLineColor(qvariant_cast<QColor>(lineAction->data()));
      }

      void MainWindow::handleFontChange()
      {
          QFont font = fontCombo->currentFont();
          font.setPointSize(fontSizeCombo->currentText().toInt());
          font.setWeight(boldAction->isChecked() ? QFont::Bold : QFont::Normal);
          font.setItalic(italicAction->isChecked());
          font.setUnderline(underlineAction->isChecked());

          scene->setFont(font);
      }

      void MainWindow::itemSelected(QGraphicsItem *item)
      {
          DiagramTextItem *textItem =
          qgraphicsitem_cast<DiagramTextItem *>(item);

          QFont font = textItem->font();
          fontCombo->setCurrentFont(font);
          fontSizeCombo->setEditText(QString().setNum(font.pointSize()));
          boldAction->setChecked(font.weight() == QFont::Bold);
          italicAction->setChecked(font.italic());
          underlineAction->setChecked(font.underline());
      }

      void MainWindow::about()
      {
          QMessageBox::about(this, tr("About Diagram Scene"),
                             tr("The <b>Diagram Scene</b> example shows "
                                "use of the graphics framework."));
      }

      void MainWindow::createToolBox()
      {
          buttonGroup = new QButtonGroup(this);
          buttonGroup->setExclusive(false);
          connect(buttonGroup, SIGNAL(buttonClicked(int)),
                  this, SLOT(buttonGroupClicked(int)));
          QGridLayout *layout = new QGridLayout;
          layout->addWidget(createCellWidget(tr("Conditional"), DiagramItem::Conditional), 0, 0);
          layout->addWidget(createCellWidget(tr("Process"), DiagramItem::Step),0, 1);
          layout->addWidget(createCellWidget(tr("Input/Output"), DiagramItem::Io), 1, 0);

          QToolButton *textButton = new QToolButton;
          textButton->setCheckable(true);
          buttonGroup->addButton(textButton, InsertTextButton);
          textButton->setIcon(QIcon(QPixmap(":/images/textpointer.png")));
          textButton->setIconSize(QSize(50, 50));
          QGridLayout *textLayout = new QGridLayout;
          textLayout->addWidget(textButton, 0, 0, Qt::AlignHCenter);
          textLayout->addWidget(new QLabel(tr("Text")), 1, 0, Qt::AlignCenter);
          QWidget *textWidget = new QWidget;
          textWidget->setLayout(textLayout);
          layout->addWidget(textWidget, 1, 1);

          layout->setRowStretch(3, 10);
          layout->setColumnStretch(2, 10);

          QWidget *itemWidget = new QWidget;
          itemWidget->setLayout(layout);

          backgroundButtonGroup = new QButtonGroup(this);
          connect(backgroundButtonGroup, SIGNAL(buttonClicked(QAbstractButton*)),
                  this, SLOT(backgroundButtonGroupClicked(QAbstractButton*)));

          QGridLayout *backgroundLayout = new QGridLayout;
          backgroundLayout->addWidget(createBackgroundCellWidget(tr("Blue Grid"),
                                                                 ":/images/background1.png"), 0, 0);
          backgroundLayout->addWidget(createBackgroundCellWidget(tr("White Grid"),
                                                                 ":/images/background2.png"), 0, 1);
          backgroundLayout->addWidget(createBackgroundCellWidget(tr("Gray Grid"),
                                                                 ":/images/background3.png"), 1, 0);
          backgroundLayout->addWidget(createBackgroundCellWidget(tr("No Grid"),
                                                                 ":/images/background4.png"), 1, 1);

          backgroundLayout->setRowStretch(2, 10);
          backgroundLayout->setColumnStretch(2, 10);

          QWidget *backgroundWidget = new QWidget;
          backgroundWidget->setLayout(backgroundLayout);

          toolBox = new QToolBox;
          toolBox->setSizePolicy(QSizePolicy(QSizePolicy::Maximum, QSizePolicy::Ignored));
          toolBox->setMinimumWidth(itemWidget->sizeHint().width());
          toolBox->addItem(itemWidget, tr("Basic Flowchart Shapes"));
          toolBox->addItem(backgroundWidget, tr("Backgrounds"));
      }

      void MainWindow::createActions()
      {
          toFrontAction = new QAction(QIcon(":/images/bringtofront.png"),
                                      tr("Bring to &Front"), this);
          toFrontAction->setShortcut(tr("Ctrl+F"));
          toFrontAction->setStatusTip(tr("Bring item to front"));
          connect(toFrontAction, SIGNAL(triggered()), this, SLOT(bringToFront()));

          sendBackAction = new QAction(QIcon(":/images/sendtoback.png"), tr("Send to &Back"), this);
          sendBackAction->setShortcut(tr("Ctrl+T"));
          sendBackAction->setStatusTip(tr("Send item to back"));
          connect(sendBackAction, SIGNAL(triggered()), this, SLOT(sendToBack()));

          deleteAction = new QAction(QIcon(":/images/delete.png"), tr("&Delete"), this);
          deleteAction->setShortcut(tr("Delete"));
          deleteAction->setStatusTip(tr("Delete item from diagram"));
          connect(deleteAction, SIGNAL(triggered()), this, SLOT(deleteItem()));

          exitAction = new QAction(tr("E&xit"), this);
          exitAction->setShortcuts(QKeySequence::Quit);
          exitAction->setStatusTip(tr("Quit Scenediagram example"));
          connect(exitAction, SIGNAL(triggered()), this, SLOT(close()));

          boldAction = new QAction(tr("Bold"), this);
          boldAction->setCheckable(true);
          QPixmap pixmap(":/images/bold.png");
          boldAction->setIcon(QIcon(pixmap));
          boldAction->setShortcut(tr("Ctrl+B"));
          connect(boldAction, SIGNAL(triggered()), this, SLOT(handleFontChange()));

          italicAction = new QAction(QIcon(":/images/italic.png"), tr("Italic"), this);
          italicAction->setCheckable(true);
          italicAction->setShortcut(tr("Ctrl+I"));
          connect(italicAction, SIGNAL(triggered()), this, SLOT(handleFontChange()));

          underlineAction = new QAction(QIcon(":/images/underline.png"), tr("Underline"), this);
          underlineAction->setCheckable(true);
          underlineAction->setShortcut(tr("Ctrl+U"));
          connect(underlineAction, SIGNAL(triggered()), this, SLOT(handleFontChange()));

          aboutAction = new QAction(tr("A&bout"), this);
          aboutAction->setShortcut(tr("F1"));
          connect(aboutAction, SIGNAL(triggered()), this, SLOT(about()));
      }

      void MainWindow::createMenus()
      {
          fileMenu = menuBar()->addMenu(tr("&File"));
          fileMenu->addAction(exitAction);

          itemMenu = menuBar()->addMenu(tr("&Item"));
          itemMenu->addAction(deleteAction);
          itemMenu->addSeparator();
          itemMenu->addAction(toFrontAction);
          itemMenu->addAction(sendBackAction);

          aboutMenu = menuBar()->addMenu(tr("&Help"));
          aboutMenu->addAction(aboutAction);
      }

      void MainWindow::createToolbars()
      {
          editToolBar = addToolBar(tr("Edit"));
          editToolBar->addAction(deleteAction);
          editToolBar->addAction(toFrontAction);
          editToolBar->addAction(sendBackAction);

          fontCombo = new QFontComboBox();
          connect(fontCombo, SIGNAL(currentFontChanged(QFont)),
                  this, SLOT(currentFontChanged(QFont)));

          fontSizeCombo = new QComboBox;
          fontSizeCombo->setEditable(true);
          for (int i = 8; i < 30; i = i + 2)
              fontSizeCombo->addItem(QString().setNum(i));
          QIntValidator *validator = new QIntValidator(2, 64, this);
          fontSizeCombo->setValidator(validator);
          connect(fontSizeCombo, SIGNAL(currentIndexChanged(QString)),
                  this, SLOT(fontSizeChanged(QString)));

          fontColorToolButton = new QToolButton;
          fontColorToolButton->setPopupMode(QToolButton::MenuButtonPopup);
          fontColorToolButton->setMenu(createColorMenu(SLOT(textColorChanged()), Qt::black));
          textAction = fontColorToolButton->menu()->defaultAction();
          fontColorToolButton->setIcon(createColorToolButtonIcon(":/images/textpointer.png", Qt::black));
          fontColorToolButton->setAutoFillBackground(true);
          connect(fontColorToolButton, SIGNAL(clicked()),
                  this, SLOT(textButtonTriggered()));

          fillColorToolButton = new QToolButton;
          fillColorToolButton->setPopupMode(QToolButton::MenuButtonPopup);
          fillColorToolButton->setMenu(createColorMenu(SLOT(itemColorChanged()), Qt::white));
          fillAction = fillColorToolButton->menu()->defaultAction();
          fillColorToolButton->setIcon(createColorToolButtonIcon(
                                           ":/images/floodfill.png", Qt::white));
          connect(fillColorToolButton, SIGNAL(clicked()),
                  this, SLOT(fillButtonTriggered()));

          lineColorToolButton = new QToolButton;
          lineColorToolButton->setPopupMode(QToolButton::MenuButtonPopup);
          lineColorToolButton->setMenu(createColorMenu(SLOT(lineColorChanged()), Qt::black));
          lineAction = lineColorToolButton->menu()->defaultAction();
          lineColorToolButton->setIcon(createColorToolButtonIcon(
                                           ":/images/linecolor.png", Qt::black));
          connect(lineColorToolButton, SIGNAL(clicked()),
                  this, SLOT(lineButtonTriggered()));

          textToolBar = addToolBar(tr("Font"));
          textToolBar->addWidget(fontCombo);
          textToolBar->addWidget(fontSizeCombo);
          textToolBar->addAction(boldAction);
          textToolBar->addAction(italicAction);
          textToolBar->addAction(underlineAction);

          colorToolBar = addToolBar(tr("Color"));
          colorToolBar->addWidget(fontColorToolButton);
          colorToolBar->addWidget(fillColorToolButton);
          colorToolBar->addWidget(lineColorToolButton);

          QToolButton *pointerButton = new QToolButton;
          pointerButton->setCheckable(true);
          pointerButton->setChecked(true);
          pointerButton->setIcon(QIcon(":/images/pointer.png"));
          QToolButton *linePointerButton = new QToolButton;
          linePointerButton->setCheckable(true);
          linePointerButton->setIcon(QIcon(":/images/linepointer.png"));

          pointerTypeGroup = new QButtonGroup(this);
          pointerTypeGroup->addButton(pointerButton, int(DiagramScene::MoveItem));
          pointerTypeGroup->addButton(linePointerButton, int(DiagramScene::InsertLine));
          connect(pointerTypeGroup, SIGNAL(buttonClicked(int)),
                  this, SLOT(pointerGroupClicked(int)));

          sceneScaleCombo = new QComboBox;
          QStringList scales;
          scales << tr("50%") << tr("75%") << tr("100%") << tr("125%") << tr("150%");
          sceneScaleCombo->addItems(scales);
          sceneScaleCombo->setCurrentIndex(2);
          connect(sceneScaleCombo, SIGNAL(currentIndexChanged(QString)),
                  this, SLOT(sceneScaleChanged(QString)));

          pointerToolbar = addToolBar(tr("Pointer type"));
          pointerToolbar->addWidget(pointerButton);
          pointerToolbar->addWidget(linePointerButton);
          pointerToolbar->addWidget(sceneScaleCombo);
      }

      QWidget *MainWindow::createBackgroundCellWidget(const QString &text, const QString &image)
      {
          QToolButton *button = new QToolButton;
          button->setText(text);
          button->setIcon(QIcon(image));
          button->setIconSize(QSize(50, 50));
          button->setCheckable(true);
          backgroundButtonGroup->addButton(button);

          QGridLayout *layout = new QGridLayout;
          layout->addWidget(button, 0, 0, Qt::AlignHCenter);
          layout->addWidget(new QLabel(text), 1, 0, Qt::AlignCenter);

          QWidget *widget = new QWidget;
          widget->setLayout(layout);

          return widget;
      }

      QWidget *MainWindow::createCellWidget(const QString &text, DiagramItem::DiagramType type)
      {

          DiagramItem item(type, itemMenu);
          QIcon icon(item.image());

          QToolButton *button = new QToolButton;
          button->setIcon(icon);
          button->setIconSize(QSize(50, 50));
          button->setCheckable(true);
          buttonGroup->addButton(button, int(type));

          QGridLayout *layout = new QGridLayout;
          layout->addWidget(button, 0, 0, Qt::AlignHCenter);
          layout->addWidget(new QLabel(text), 1, 0, Qt::AlignCenter);

          QWidget *widget = new QWidget;
          widget->setLayout(layout);

          return widget;
      }

      QMenu *MainWindow::createColorMenu(const char *slot, QColor defaultColor)
      {
          QList<QColor> colors;
          colors << Qt::black << Qt::white << Qt::red << Qt::blue << Qt::yellow;
          QStringList names;
          names << tr("black") << tr("white") << tr("red") << tr("blue")
                << tr("yellow");

          QMenu *colorMenu = new QMenu(this);
          for (int i = 0; i < colors.count(); ++i) {
              QAction *action = new QAction(names.at(i), this);
              action->setData(colors.at(i));
              action->setIcon(createColorIcon(colors.at(i)));
              connect(action, SIGNAL(triggered()), this, slot);
              colorMenu->addAction(action);
              if (colors.at(i) == defaultColor)
                  colorMenu->setDefaultAction(action);
          }
          return colorMenu;
      }

      QIcon MainWindow::createColorToolButtonIcon(const QString &imageFile, QColor color)
      {
          QPixmap pixmap(50, 80);
          pixmap.fill(Qt::transparent);
          QPainter painter(&pixmap);
          QPixmap image(imageFile);
          // Draw icon centred horizontally on button.
          QRect target(4, 0, 42, 43);
          QRect source(0, 0, 42, 43);
          painter.fillRect(QRect(0, 60, 50, 80), color);
          painter.drawPixmap(target, image, source);

          return QIcon(pixmap);
      }

      QIcon MainWindow::createColorIcon(QColor color)
      {
          QPixmap pixmap(20, 20);
          QPainter painter(&pixmap);
          painter.setPen(Qt::NoPen);
          painter.fillRect(QRect(0, 0, 20, 20), color);

          return QIcon(pixmap);
      }