Border Layout Example | Qt Widgets 5.12.7

Qt 5.12 | Qt Widgets | Border Layout Example

Qt 5.12.7 Reference Documentation

# Border Layout Example

Shows how to arrange child widgets along a border.

Border Layout implements a layout that arranges child widgets to surround the main area.

The constructor of the Window class creates a QTextBrowser object, to which a BorderLayout named `layout` is added. The declaration of the BorderLayout class is quoted at the end of this document.

      Window::Window()
      {
          QTextBrowser *centralWidget = new QTextBrowser;
          centralWidget->setPlainText(tr("Central widget"));

          BorderLayout *layout = new BorderLayout;

Several labeled widgets are added to `layout` with the orientation `Center`, `North`, `West`, `East 1`, `East 2`, and `South`.

          layout->addWidget(centralWidget, BorderLayout::Center);
          layout->addWidget(createLabel("North"), BorderLayout::North);
          layout->addWidget(createLabel("West"), BorderLayout::West);
          layout->addWidget(createLabel("East 1"), BorderLayout::East);
          layout->addWidget(createLabel("East 2") , BorderLayout::East);
          layout->addWidget(createLabel("South"), BorderLayout::South);
          setLayout(layout);

          setWindowTitle(tr("Border Layout"));

createLabel() in class `Window` sets the text of the labeled widgets and the style.

      QLabel *Window::createLabel(const QString &text)
      {
          QLabel *label = new QLabel(text);
          label->setFrameStyle(QFrame::Box | QFrame::Raised);
          return label;
      }

Class BorderLayout contains all the utilitarian functions for formatting the widgets it contains.

      class BorderLayout : public QLayout
      {
      public:
          enum Position { West, North, South, East, Center };

          explicit BorderLayout(QWidget *parent, int margin = 0, int spacing = -1);
          BorderLayout(int spacing = -1);
          ~BorderLayout();

          void addItem(QLayoutItem *item) override;
          void addWidget(QWidget *widget, Position position);
          Qt::Orientations expandingDirections() const override;
          bool hasHeightForWidth() const override;
          int count() const override;
          QLayoutItem *itemAt(int index) const override;
          QSize minimumSize() const override;
          void setGeometry(const QRect &rect) override;
          QSize sizeHint() const override;
          QLayoutItem *takeAt(int index) override;

          void add(QLayoutItem *item, Position position);

      private:
          struct ItemWrapper
          {
              ItemWrapper(QLayoutItem *i, Position p) {
                  item = i;
                  position = p;
              }

              QLayoutItem *item;
              Position position;
          };

          enum SizeType { MinimumSize, SizeHint };
          QSize calculateSize(SizeType sizeType) const;

          QList<ItemWrapper *> list;
      };

For more information, visit the Layout Management page.

## Running the Example

To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

Files:

- layouts/borderlayout/borderlayout.cpp
- layouts/borderlayout/borderlayout.h
- layouts/borderlayout/borderlayout.pro
- layouts/borderlayout/main.cpp
- layouts/borderlayout/window.cpp
- layouts/borderlayout/window.h