Qt 5.6 | Qt Widgets | Border Layout Example | borderlayout.cpp Example File

Qt 5.6.2 Reference Documentation

# borderlayout.cpp Example File

layouts/borderlayout/borderlayout.cpp

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      ** This file is part of the examples of the Qt Toolkit.
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      #include "borderlayout.h"

      BorderLayout::BorderLayout(QWidget *parent, int margin, int spacing)
          : QLayout(parent)
      {
          setMargin(margin);
          setSpacing(spacing);
      }

      BorderLayout::BorderLayout(int spacing)
      {
          setSpacing(spacing);
      }

      BorderLayout::~BorderLayout()
      {
          QLayoutItem *l;
          while ((l = takeAt(0)))
              delete l;
      }

      void BorderLayout::addItem(QLayoutItem *item)
      {
          add(item, West);
      }

      void BorderLayout::addWidget(QWidget *widget, Position position)
      {
          add(new QWidgetItem(widget), position);
      }

      Qt::Orientations BorderLayout::expandingDirections() const
      {
          return Qt::Horizontal | Qt::Vertical;
      }

      bool BorderLayout::hasHeightForWidth() const
      {
          return false;
      }

      int BorderLayout::count() const
      {
          return list.size();
      }

      QLayoutItem *BorderLayout::itemAt(int index) const
      {
          ItemWrapper *wrapper = list.value(index);
          if (wrapper)
              return wrapper->item;
          else
              return 0;
      }

      QSize BorderLayout::minimumSize() const
      {
          return calculateSize(MinimumSize);
      }

      void BorderLayout::setGeometry(const QRect &rect)
      {
          ItemWrapper *center = 0;
          int eastWidth = 0;
          int westWidth = 0;
          int northHeight = 0;
          int southHeight = 0;
          int centerHeight = 0;
          int i;

          QLayout::setGeometry(rect);

          for (i = 0; i < list.size(); ++i) {
              ItemWrapper *wrapper = list.at(i);
              QLayoutItem *item = wrapper->item;
              Position position = wrapper->position;

              if (position == North) {
                  item->setGeometry(QRect(rect.x(), northHeight, rect.width(),
                                          item->sizeHint().height()));

                  northHeight += item->geometry().height() + spacing();
              } else if (position == South) {
                  item->setGeometry(QRect(item->geometry().x(),
                                          item->geometry().y(), rect.width(),
                                          item->sizeHint().height()));

                  southHeight += item->geometry().height() + spacing();

                  item->setGeometry(QRect(rect.x(),
                                    rect.y() + rect.height() - southHeight + spacing(),
                                    item->geometry().width(),
                                    item->geometry().height()));
              } else if (position == Center) {
                  center = wrapper;
              }
          }

          centerHeight = rect.height() - northHeight - southHeight;

          for (i = 0; i < list.size(); ++i) {
              ItemWrapper *wrapper = list.at(i);
              QLayoutItem *item = wrapper->item;
              Position position = wrapper->position;

              if (position == West) {
                  item->setGeometry(QRect(rect.x() + westWidth, northHeight,
                                          item->sizeHint().width(), centerHeight));

                  westWidth += item->geometry().width() + spacing();
              } else if (position == East) {
                  item->setGeometry(QRect(item->geometry().x(), item->geometry().y(),
                                          item->sizeHint().width(), centerHeight));

                  eastWidth += item->geometry().width() + spacing();

                  item->setGeometry(QRect(
                                    rect.x() + rect.width() - eastWidth + spacing(),
                                    northHeight, item->geometry().width(),
                                    item->geometry().height()));
              }
          }

          if (center)
              center->item->setGeometry(QRect(westWidth, northHeight,
                                              rect.width() - eastWidth - westWidth,
                                              centerHeight));
      }

      QSize BorderLayout::sizeHint() const
      {
          return calculateSize(SizeHint);
      }

      QLayoutItem *BorderLayout::takeAt(int index)
      {
          if (index >= 0 && index < list.size()) {
              ItemWrapper *layoutStruct = list.takeAt(index);
              return layoutStruct->item;
          }
          return 0;
      }

      void BorderLayout::add(QLayoutItem *item, Position position)
      {
          list.append(new ItemWrapper(item, position));
      }

      QSize BorderLayout::calculateSize(SizeType sizeType) const
      {
          QSize totalSize;

          for (int i = 0; i < list.size(); ++i) {
              ItemWrapper *wrapper = list.at(i);
              Position position = wrapper->position;
              QSize itemSize;

              if (sizeType == MinimumSize)
                  itemSize = wrapper->item->minimumSize();
              else // (sizeType == SizeHint)
                  itemSize = wrapper->item->sizeHint();

              if (position == North || position == South || position == Center)
                  totalSize.rheight() += itemSize.height();

              if (position == West || position == East || position == Center)
                  totalSize.rwidth() += itemSize.width();
          }
          return totalSize;
      }