qt-creator/src/libs/utils/treeviewcombobox.cpp

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#include "treeviewcombobox.h"

#include <QWheelEvent>

using namespace Utils;

TreeViewComboBoxView::TreeViewComboBoxView(QWidget *parent)
    : QTreeView(parent)
{
    // TODO: Disable the root for all items (with a custom delegate?)
    setRootIsDecorated(false);
}

void TreeViewComboBoxView::adjustWidth(int width)
{
    setMaximumWidth(width);
    setMinimumWidth(qMin(qMax(sizeHintForColumn(0), minimumSizeHint().width()), width));
}


TreeViewComboBox::TreeViewComboBox(QWidget *parent)
    : QComboBox(parent), m_skipNextHide(false)
{
    m_view = new TreeViewComboBoxView;
    m_view->setHeaderHidden(true);
    m_view->setItemsExpandable(true);
    setView(m_view);
    m_view->viewport()->installEventFilter(this);
}

void TreeViewComboBox::wheelEvent(QWheelEvent *e)
{
    QModelIndex index = m_view->currentIndex();
    if (e->delta() > 0) {
        do
            index = m_view->indexAbove(index);
        while (index.isValid() && !(model()->flags(index) & Qt::ItemIsSelectable));
    } else if (e->delta() < 0) {
        do
            index = m_view->indexBelow(index);
        while (index.isValid() && !(model()->flags(index) & Qt::ItemIsSelectable));
    }
    e->accept();
    if (!index.isValid())
        return;

    setCurrentIndex(index);

    // for compatibility we emit activated with a useless row parameter
    emit activated(index.row());
}

void TreeViewComboBox::setCurrentIndex(const QModelIndex &index)
{
    setRootModelIndex(model()->parent(index));
    QComboBox::setCurrentIndex(index.row());
    setRootModelIndex(QModelIndex());
    m_view->setCurrentIndex(index);
}

bool TreeViewComboBox::eventFilter(QObject *object, QEvent *event)
{
    if (event->type() == QEvent::MouseButtonPress && object == view()->viewport()) {
        QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(event);
        QModelIndex index = view()->indexAt(mouseEvent->pos());
        if (!view()->visualRect(index).contains(mouseEvent->pos()))
            m_skipNextHide = true;
    }
    return false;
}

void TreeViewComboBox::showPopup()
{
    m_view->adjustWidth(topLevelWidget()->geometry().width());
    QComboBox::showPopup();
}

void TreeViewComboBox::hidePopup()
{
    if (m_skipNextHide)
        m_skipNextHide = false;
    else
        QComboBox::hidePopup();
}

TreeViewComboBoxView *TreeViewComboBox::view() const
{
    return m_view;
}