Qt 5.7Qt WidgetsDiagram Scene Examplemainwindow.cpp Example File
Qt 5.7.1 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);
  }

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