qcolumnview.cpp

奇趣公司比较新的qt/emd版本

    default:
        break;
    }

    return QModelIndex();
}

/*!
    \reimp
*/
void QColumnView::resizeEvent(QResizeEvent *event)
{
    Q_D(QColumnView);
    d->doLayout();
    d->updateScrollbars();
    if (!isRightToLeft()) {
        int diff = event->oldSize().width() - event->size().width();
        if (diff < 0 && horizontalScrollBar()->isVisible()
            && horizontalScrollBar()->value() == horizontalScrollBar()->maximum()) {
            horizontalScrollBar()->setMaximum(horizontalScrollBar()->maximum() + diff);
        }
    }
    QAbstractItemView::resizeEvent(event);
}

/*!
    \internal
*/
void QColumnViewPrivate::updateScrollbars()
{
    Q_Q(QColumnView);
    if (currentAnimation.state() == QTimeLine::Running)
        return;

    // find the total horizontal length of the laid out columns
    int horizontalLength = 0;
    if (!columns.isEmpty()) {
        horizontalLength = (columns.last()->x() + columns.last()->width()) - columns.first()->x();
        if (horizontalLength <= 0) // reverse mode
            horizontalLength = (columns.first()->x() + columns.first()->width()) - columns.last()->x();
    }

    QSize viewportSize = q->viewport()->size();
    if (horizontalLength < viewportSize.width() && q->horizontalScrollBar()->value() == 0) {
        q->horizontalScrollBar()->setRange(0, 0);
    } else {
        int visibleLength = qMin(horizontalLength + q->horizontalOffset(), viewportSize.width());
        int hiddenLength = horizontalLength - visibleLength;
        if (hiddenLength != q->horizontalScrollBar()->maximum())
            q->horizontalScrollBar()->setRange(0, hiddenLength);
    }
    if (!columns.isEmpty()) {
        int pageStepSize = columns.at(0)->width();
        if (pageStepSize != q->horizontalScrollBar()->pageStep())
            q->horizontalScrollBar()->setPageStep(pageStepSize);
    }
    bool visible = (q->horizontalScrollBar()->maximum() > 0);
    if (visible != q->horizontalScrollBar()->isVisible())
        q->horizontalScrollBar()->setVisible(visible);
}

/*!
    \reimp
*/
int QColumnView::horizontalOffset() const
{
    Q_D(const QColumnView);
    return d->offset;
}

/*!
    \reimp
*/
int QColumnView::verticalOffset() const
{
    return 0;
}

/*!
    \reimp
*/
QRegion QColumnView::visualRegionForSelection(const QItemSelection &selection) const
{
    int ranges = selection.count();

    if (ranges == 0)
        return QRect();

    // Note that we use the top and bottom functions of the selection range
    // since the data is stored in rows.
    int firstRow = selection.at(0).top();
    int lastRow = selection.at(0).top();
    for (int i = 0; i < ranges; ++i) {
        firstRow = qMin(firstRow, selection.at(i).top());
        lastRow = qMax(lastRow, selection.at(i).bottom());
    }

    QModelIndex firstIdx = model()->index(qMin(firstRow, lastRow), 0, rootIndex());
    QModelIndex lastIdx = model()->index(qMax(firstRow, lastRow), 0, rootIndex());

    if (firstIdx == lastIdx)
        return visualRect(firstIdx);

    QRegion firstRegion = visualRect(firstIdx);
    QRegion lastRegion = visualRect(lastIdx);
    return firstRegion.unite(lastRegion);
}

/*!
    \reimp
*/
void QColumnView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)
{
    Q_UNUSED(rect);
    Q_UNUSED(command);
}

/*!
    \reimp
*/
void QColumnView::setSelectionModel(QItemSelectionModel * newSelectionModel)
{
    Q_D(const QColumnView);
    for (int i = 0; i < d->columns.size(); ++i) {
        if (d->columns.at(i)->selectionModel() == selectionModel()) {
            d->columns.at(i)->setSelectionModel(newSelectionModel);
            break;
        }
    }
    QAbstractItemView::setSelectionModel(newSelectionModel);
}

/*!
    \reimp
*/
QSize QColumnView::sizeHint() const
{
    Q_D(const QColumnView);
    QSize sizeHint;
    for (int i = 0; i < d->columns.size(); ++i) {
        sizeHint += d->columns.at(i)->sizeHint();
    }
    return sizeHint.expandedTo(QAbstractItemView::sizeHint());
}

/*!
    \internal
    Move all widgets from the corner grip and to the right
  */
void QColumnViewPrivate::_q_gripMoved(int offset)
{
    Q_Q(QColumnView);

    QObject *grip = q->sender();
    Q_ASSERT(grip);

    if (q->isRightToLeft())
        offset = -1 * offset;

    bool found = false;
    for (int i = 0; i < columns.size(); ++i) {
        if (!found && columns.at(i)->cornerWidget() == grip) {
            found = true;
            columnSizes[i] = columns.at(i)->width();
            if (q->isRightToLeft())
                columns.at(i)->move(columns.at(i)->x() + offset, 0);
            continue;
        }
        if (!found)
            continue;

        int currentX = columns.at(i)->x();
        columns.at(i)->move(currentX + offset, 0);
    }

    updateScrollbars();
}

/*!
    \internal

    Find where the current columns intersect parent's columns

    Delete any extra columns and insert any needed columns.
  */
void QColumnViewPrivate::closeColumns(const QModelIndex &parent, bool build)
{
    if (columns.isEmpty())
        return;

    bool clearAll = !parent.isValid();
    bool passThroughRoot = false;

    QList<QModelIndex> dirsToAppend;

    // Find the last column that matches the parent's tree
    int currentColumn = -1;
    QModelIndex parentIndex = parent;
    while (currentColumn == -1 && parentIndex.isValid()) {
        if (columns.isEmpty())
            break;
        parentIndex = parentIndex.parent();
        if (root == parentIndex)
            passThroughRoot = true;
        if (!parentIndex.isValid())
            break;
        for (int i = columns.size() - 1; i >= 0; --i) {
            if (columns.at(i)->rootIndex() == parentIndex) {
                currentColumn = i;
                break;
            }
        }
        if (currentColumn == -1)
            dirsToAppend.append(parentIndex);
    }

    // Someone wants to go to an index that can be reached without changing
    // the root index, don't allow them
    if (!clearAll && !passThroughRoot && currentColumn == -1)
        return;

    if (currentColumn == -1 && parent.isValid())
        currentColumn = 0;

    // Optimization so we don't go deleting and then creating the same thing
    bool alreadyExists = false;
    if (build && columns.size() > currentColumn + 1) {
        bool viewingParent = (columns.at(currentColumn + 1)->rootIndex() == parent);
        bool viewingChild = (!model->hasChildren(parent)
                             && !columns.at(currentColumn + 1)->rootIndex().isValid());
        if (viewingParent || viewingChild) {
            currentColumn++;
            alreadyExists = true;
        }
    }

    // Delete columns that don't match our path
    for (int i = columns.size() - 1; i > currentColumn; --i) {
        QAbstractItemView* notShownAnymore = columns.at(i);
        columns.removeAt(i);
        notShownAnymore->setVisible(false);
        if (notShownAnymore != previewColumn)
            notShownAnymore->deleteLater();
    }

    if (columns.isEmpty()) {
        offset = 0;
        updateScrollbars();
    }

    // Now fill in missing columns
    while (!dirsToAppend.isEmpty()) {
        QAbstractItemView *newView = createColumn(dirsToAppend.takeLast(), true);
        if (!dirsToAppend.isEmpty())
            newView->setCurrentIndex(dirsToAppend.last());
    }

    if (build && !alreadyExists)
        createColumn(parent, false);
}

void QColumnViewPrivate::_q_clicked(const QModelIndex &index)
{
    Q_Q(QColumnView);
    QModelIndex parent = index.parent();
    QAbstractItemView *columnClicked = 0;
    for (int column = 0; column < columns.count(); ++column) {
        if (columns.at(column)->rootIndex() == parent) {
            columnClicked = columns[column];
            break;
        }
    }
    if (q->selectionModel() && columnClicked) {
        QItemSelectionModel::SelectionFlags flags = QItemSelectionModel::Current;
        if (columnClicked->selectionModel()->isSelected(index))
            flags |= QItemSelectionModel::Select;
        q->selectionModel()->setCurrentIndex(index, flags);
    }
}

/*!
    \internal
    Create a new column for \a index.  A grip is attached if requested and it is shown
    if requested.

    Return the new view

    \sa createColumn() setPreviewWidget()
    \sa doLayout()
*/
QAbstractItemView *QColumnViewPrivate::createColumn(const QModelIndex &index, bool show)
{
    Q_Q(QColumnView);
    QAbstractItemView *view = 0;
    if (model->hasChildren(index)) {
        view = q->createColumn(index);
        q->connect(view, SIGNAL(clicked(const QModelIndex &)),
                   q, SLOT(_q_clicked(const QModelIndex &)));
    } else {
        if (!previewColumn)
            setPreviewWidget(new QWidget(q));
        view = previewColumn;
        view->setMinimumWidth(qMax(view->minimumWidth(), previewWidget->minimumWidth()));
    }

    q->connect(view, SIGNAL(activated(const QModelIndex &)),
            q, SIGNAL(activated(const QModelIndex &)));
    q->connect(view, SIGNAL(clicked(const QModelIndex &)),
            q, SIGNAL(clicked(const QModelIndex &)));
    q->connect(view, SIGNAL(doubleClicked(const QModelIndex &)),
            q, SIGNAL(doubleClicked(const QModelIndex &)));
    q->connect(view, SIGNAL(entered(const QModelIndex &)),
            q, SIGNAL(entered(const QModelIndex &)));
    q->connect(view, SIGNAL(pressed(const QModelIndex &)),
            q, SIGNAL(pressed(const QModelIndex &)));

    view->setFocusPolicy(Qt::NoFocus);
    view->setParent(q->viewport());
    Q_ASSERT(view);

    // Setup corner grip
    if (showResizeGrips) {
        QColumnViewGrip *grip = new QColumnViewGrip(view);
        view->setCornerWidget(grip);
        q->connect(grip, SIGNAL(gripMoved(int)), q, SLOT(_q_gripMoved(int)));
    }

    if (columnSizes.count() > columns.count()) {
        view->setGeometry(0, 0, columnSizes.at(columns.count()), q->viewport()->height());
    } else {
        int initialWidth = view->sizeHint().width();
        if (q->isRightToLeft())
            view->setGeometry(q->viewport()->width() - initialWidth, 0, initialWidth, q->viewport()->height());
        else
            view->setGeometry(0, 0, initialWidth, q->viewport()->height());
        columnSizes.resize(qMax(columnSizes.count(), columns.count() + 1));
        columnSizes[columns.count()] = initialWidth;
    }
    if (!columns.isEmpty() && columns.last()->isHidden())
        columns.last()->setVisible(true);

    columns.append(view);
    doLayout();
    updateScrollbars();
    if (show && view->isHidden())
        view->setVisible(true);
    return view;
}

/*!
    \fn void QColumnView::updatePreviewWidget(const QModelIndex &index)

    This signal is emitted when the preview widget should be updated to
    provide rich information about \a index

    \sa previewWidget()
 */

/*!
    To use a custom widget for the final column when you select
    an item overload this function and return a widget.
    \a index is the root index that will be assigned to the view.

    Return the new view.  QColumnView will automatically take ownership of the widget.

    \sa setPreviewWidget()
 */