Qt 5.9 | Qt Widgets | Frozen Column Example | freezetablewidget.cpp Example File

Qt 5.9.9 Reference Documentation

# freezetablewidget.cpp Example File

itemviews/frozencolumn/freezetablewidget.cpp

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      #include "freezetablewidget.h"

      #include <QScrollBar>
      #include <QHeaderView>

      FreezeTableWidget::FreezeTableWidget(QAbstractItemModel * model)
      {
            setModel(model);
            frozenTableView = new QTableView(this);

            init();

            //connect the headers and scrollbars of both tableviews together
            connect(horizontalHeader(),&QHeaderView::sectionResized, this,
                    &FreezeTableWidget::updateSectionWidth);
            connect(verticalHeader(),&QHeaderView::sectionResized, this,
                    &FreezeTableWidget::updateSectionHeight);

            connect(frozenTableView->verticalScrollBar(), &QAbstractSlider::valueChanged,
                    verticalScrollBar(), &QAbstractSlider::setValue);
            connect(verticalScrollBar(), &QAbstractSlider::valueChanged,
                    frozenTableView->verticalScrollBar(), &QAbstractSlider::setValue);

      }

      FreezeTableWidget::~FreezeTableWidget()
      {
            delete frozenTableView;
      }

      void FreezeTableWidget::init()
      {
            frozenTableView->setModel(model());
            frozenTableView->setFocusPolicy(Qt::NoFocus);
            frozenTableView->verticalHeader()->hide();
            frozenTableView->horizontalHeader()->setSectionResizeMode(QHeaderView::Fixed);

            viewport()->stackUnder(frozenTableView);

            frozenTableView->setStyleSheet("QTableView { border: none;"
                                           "background-color: #8EDE21;"
                                           "selection-background-color: #999}"); //for demo purposes
            frozenTableView->setSelectionModel(selectionModel());
            for (int col = 1; col < model()->columnCount(); ++col)
                  frozenTableView->setColumnHidden(col, true);

            frozenTableView->setColumnWidth(0, columnWidth(0) );

            frozenTableView->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
            frozenTableView->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
            frozenTableView->show();

            updateFrozenTableGeometry();

            setHorizontalScrollMode(ScrollPerPixel);
            setVerticalScrollMode(ScrollPerPixel);
            frozenTableView->setVerticalScrollMode(ScrollPerPixel);
      }

      void FreezeTableWidget::updateSectionWidth(int logicalIndex, int /* oldSize */, int newSize)
      {
            if (logicalIndex == 0){
                  frozenTableView->setColumnWidth(0, newSize);
                  updateFrozenTableGeometry();
            }
      }

      void FreezeTableWidget::updateSectionHeight(int logicalIndex, int /* oldSize */, int newSize)
      {
            frozenTableView->setRowHeight(logicalIndex, newSize);
      }

      void FreezeTableWidget::resizeEvent(QResizeEvent * event)
      {
            QTableView::resizeEvent(event);
            updateFrozenTableGeometry();
       }

      QModelIndex FreezeTableWidget::moveCursor(CursorAction cursorAction,
                                                Qt::KeyboardModifiers modifiers)
      {
            QModelIndex current = QTableView::moveCursor(cursorAction, modifiers);

            if (cursorAction == MoveLeft && current.column() > 0
                    && visualRect(current).topLeft().x() < frozenTableView->columnWidth(0) ){
                  const int newValue = horizontalScrollBar()->value() + visualRect(current).topLeft().x()
                                       - frozenTableView->columnWidth(0);
                  horizontalScrollBar()->setValue(newValue);
            }
            return current;
      }

      void FreezeTableWidget::scrollTo (const QModelIndex & index, ScrollHint hint){
          if (index.column() > 0)
              QTableView::scrollTo(index, hint);
      }

      void FreezeTableWidget::updateFrozenTableGeometry()
      {
            frozenTableView->setGeometry(verticalHeader()->width() + frameWidth(),
                                         frameWidth(), columnWidth(0),
                                         viewport()->height()+horizontalHeader()->height());
      }