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qtreeview.cpp

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**
** This file is part of the QtGui module of the Qt Toolkit.
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#include "qtreeview.h"

#ifndef QT_NO_TREEVIEW
#include <qheaderview.h>
#include <qitemdelegate.h>
#include <qapplication.h>
#include <qscrollbar.h>
#include <qpainter.h>
#include <qstack.h>
#include <qstyle.h>
#include <qstyleoption.h>
#include <qevent.h>
#include <qpen.h>
#include <qdebug.h>

#include <private/qtreeview_p.h>

/*!
    \class QTreeView
    \brief The QTreeView class provides a default model/view implementation of a tree view.

    \ingroup model-view
    \mainclass

    A QTreeView implements a tree representation of items from a
    model. This class is used to provide standard hierarchical lists that
    were previously provided by the \c QListView class, but using the more
    flexible approach provided by Qt's model/view architecture.

    The QTreeView class is one of the \l{Model/View Classes} and is part of
    Qt's \l{Model/View Programming}{model/view framework}.

    QTreeView implements the interfaces defined by the
    QAbstractItemView class to allow it to display data provided by
    models derived from the QAbstractItemModel class.

    It is simple to construct a tree view displaying data from a
    model. In the following example, the contents of a directory are
    supplied by a QDirModel and displayed as a tree:

    \quotefromfile snippets/shareddirmodel/main.cpp
    \skipto QDirModel *model
    \printuntil QTreeView *tree
    \skipto tree->setModel(
    \printuntil tree->setModel(

    The model/view architecture ensures that the contents of the tree view
    are updated as the model changes.

    Items that have children can be in an expanded (children are
    visible) or collapsed (children are hidden) state. When this state
    changes a collapsed() or expanded() signal is emitted with the
    model index of the relevant item.

    The amount of indentation used to indicate levels of hierarchy is
    controlled by the \l indentation property.

    Headers in tree views are constructed using the QHeaderView class
    and can be hidden using header()->hide(). Note that each header
    is configured with its \l{QHeaderView::}{stretchLastSection}
    property set to true, ensuring that the view does not waste any
    of the space assigned to it for its header.

    \section1 Key Bindings

    QTreeView supports a set of key bindings that enable the user to
    navigate in the view and interact with the contents of items:

    \table
    \header \o Key \o Action
    \row \o UpArrow   \o Moves the cursor to the item in the same column on
         the previous row. If the parent of the current item has no more rows to
         navigate to, the cursor moves to the relevant item in the last row
         of the sibling that precedes the parent.
    \row \o DownArrow \o Moves the cursor to the item in the same column on
         the next row. If the parent of the current item has no more rows to
         navigate to, the cursor moves to the relevant item in the first row
         of the sibling that follows the parent.
    \row \o LeftArrow  \o Hides the children of the current item (if present)
         by collapsing a branch.
    \row \o Minus  \o Same as LeftArrow.
    \row \o RightArrow \o Reveals the children of the current item (if present)
         by expanding a branch.
    \row \o Plus  \o Same as RightArrow.
    \row \o Asterisk  \o Expands all children of the current item (if present).
    \row \o PageUp   \o Moves the cursor up one page.
    \row \o PageDown \o Moves the cursor down one page.
    \row \o Home \o Moves the cursor to an item in the same column of the first
         row of the first top-level item in the model.
    \row \o End  \o Moves the cursor to an item in the same column of the last
         row of the last top-level item in the model.
    \row \o F2   \o In editable models, this opens the current item for editing.
         The Escape key can be used to cancel the editing process and revert
         any changes to the data displayed.
    \endtable

    \omit
    Describe the expanding/collapsing concept if not covered elsewhere.
    \endomit

    \table 100%
    \row \o \inlineimage windowsxp-treeview.png Screenshot of a Windows XP style tree view
         \o \inlineimage macintosh-treeview.png Screenshot of a Macintosh style tree view
         \o \inlineimage plastique-treeview.png Screenshot of a Plastique style tree view
    \row \o A \l{Windows XP Style Widget Gallery}{Windows XP style} tree view.
         \o A \l{Macintosh Style Widget Gallery}{Macintosh style} tree view.
         \o A \l{Plastique Style Widget Gallery}{Plastique style} tree view.
    \endtable

    \sa QListView, QTreeWidget, {View Classes}, QAbstractItemModel, QAbstractItemView,
        {Dir View Example}
*/


/*!
  \fn void QTreeView::expanded(const QModelIndex &index)

  This signal is emitted when the item specified by \a index is expanded.
*/


/*!
  \fn void QTreeView::collapsed(const QModelIndex &index)

  This signal is emitted when the item specified by \a index is collapsed.
*/

/*!
    Constructs a table view with a \a parent to represent a model's
    data. Use setModel() to set the model.

    \sa QAbstractItemModel
*/
00156 QTreeView::QTreeView(QWidget *parent)
    : QAbstractItemView(*new QTreeViewPrivate, parent)
{
    Q_D(QTreeView);
    d->initialize();
}

/*!
  \internal
*/
00166 QTreeView::QTreeView(QTreeViewPrivate &dd, QWidget *parent)
    : QAbstractItemView(dd, parent)
{
    Q_D(QTreeView);
    d->initialize();
}

/*!
  Destroys the tree view.
*/
00176 QTreeView::~QTreeView()
{
}

/*!
  \reimp
*/
00183 void QTreeView::setModel(QAbstractItemModel *model)
{
    Q_D(QTreeView);
    if (d->selectionModel) { // support row editing
        disconnect(d->selectionModel, SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
                   d->model, SLOT(submit()));
        disconnect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                   this, SLOT(rowsRemoved(QModelIndex,int,int)));
    }
    d->viewItems.clear();
    d->expandedIndexes.clear();
    d->hiddenIndexes.clear();
    d->header->setModel(model);
    QAbstractItemView::setModel(model);

    // QAbstractItemView connects to a private slot
    disconnect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
               this, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
    // do header layout after the tree
    disconnect(d->model, SIGNAL(layoutChanged()),
               d->header, SLOT(doItemsLayout()));
    // QTreeView has a public slot for this
    connect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
            this, SLOT(rowsRemoved(QModelIndex,int,int)));

    connect(d->model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
            this, SLOT(_q_columnsAboutToBeRemoved(QModelIndex,int,int)));
    connect(d->model, SIGNAL(columnsRemoved(QModelIndex,int,int)),
            this, SLOT(_q_columnsRemoved(QModelIndex,int,int)));

    if (d->sortingEnabled)
        sortByColumn(header()->sortIndicatorSection());
}

/*!
  \reimp
*/
00220 void QTreeView::setRootIndex(const QModelIndex &index)
{
    Q_D(QTreeView);
    d->header->setRootIndex(index);
    QAbstractItemView::setRootIndex(index);
}

/*!
  \reimp
*/
00230 void QTreeView::setSelectionModel(QItemSelectionModel *selectionModel)
{
    Q_D(QTreeView);
    Q_ASSERT(selectionModel);
    if (d->selectionModel) {
        if (d->allColumnsShowFocus) {
            QObject::disconnect(d->selectionModel, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
                                this, SLOT(_q_currentChanged(QModelIndex,QModelIndex)));
        }
        // support row editing
        disconnect(d->selectionModel, SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
                   d->model, SLOT(submit()));
    }

    d->header->setSelectionModel(selectionModel);
    QAbstractItemView::setSelectionModel(selectionModel);

    if (d->selectionModel) {
        if (d->allColumnsShowFocus) {
            QObject::connect(d->selectionModel, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
                             this, SLOT(_q_currentChanged(QModelIndex,QModelIndex)));
        }
        // support row editing
        connect(d->selectionModel, SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
                d->model, SLOT(submit()));
    }
}

/*!
  Returns the header for the tree view.

  \sa QAbstractItemModel::headerData()
*/
00263 QHeaderView *QTreeView::header() const
{
    Q_D(const QTreeView);
    return d->header;
}

/*!
    Sets the header for the tree view, to the given \a header.

    The view takes ownership over the given \a header and deletes it
    when a new header is set.

    \sa QAbstractItemModel::headerData()
*/
00277 void QTreeView::setHeader(QHeaderView *header)
{
    Q_D(QTreeView);
    if (header == d->header || !header)
        return;
    if (d->header && d->header->parent() == this)
        delete d->header;
    d->header = header;
    d->header->setParent(this);

    if (!d->header->model()) {
        d->header->setModel(d->model);
        if (d->selectionModel)
            d->header->setSelectionModel(d->selectionModel);
    }

    connect(d->header, SIGNAL(sectionResized(int,int,int)),
            this, SLOT(columnResized(int,int,int)));
    connect(d->header, SIGNAL(sectionMoved(int,int,int)),
            this, SLOT(columnMoved()));
    connect(d->header, SIGNAL(sectionCountChanged(int,int)),
            this, SLOT(columnCountChanged(int,int)));
    connect(d->header, SIGNAL(sectionHandleDoubleClicked(int)),
            this, SLOT(resizeColumnToContents(int)));
    connect(d->header, SIGNAL(geometriesChanged()),
            this, SLOT(updateGeometries()));

    setSortingEnabled(d->sortingEnabled);
}

/*!
  \property QTreeView::autoExpandDelay
  \brief delay time before items in a tree is opened during a DND operation.

  This property holds the amount of time that the user must wait over
  an node before that node will automatically open or close.  If the time is
  set to less then 0 then it will not be activated.
*/
int QTreeView::autoExpandDelay() const
{
    Q_D(const QTreeView);
    return d->autoExpandDelay;
}

void QTreeView::setAutoExpandDelay(int delay)
{
    Q_D(QTreeView);
    d->autoExpandDelay = delay;
}

/*!
  \property QTreeView::indentation
  \brief indentation of the items in the tree view.

  This property holds the indentation measured in pixels of the items for each
  level in the tree view. For top-level items, the indentation specifies the
  horizontal distance from the viewport edge to the items in the first column;
  for child items, it specifies their indentation from their parent items.
*/
int QTreeView::indentation() const
{
    Q_D(const QTreeView);
    return d->indent;
}

void QTreeView::setIndentation(int i)
{
    Q_D(QTreeView);
    if (i != d->indent) {
        d->indent = i;
        d->viewport->update();
    }
}

/*!
  \property QTreeView::rootIsDecorated
  \brief whether to show controls for expanding and collapsing top-level items

  Items with children are typically shown with controls to expand and collapse
  them, allowing their children to be shown or hidden. If this property is
  false, these controls are not shown for top-level items. This can be used to
  make a single level tree structure appear like a simple list of items.

  By default, this property is true.
*/
bool QTreeView::rootIsDecorated() const
{
    Q_D(const QTreeView);
    return d->rootDecoration;
}

void QTreeView::setRootIsDecorated(bool show)
{
    Q_D(QTreeView);
    if (show != d->rootDecoration) {
        d->rootDecoration = show;
        d->viewport->update();
    }
}

/*!
  \property QTreeView::uniformRowHeights
  \brief whether all items in the treeview have the same height

  This property should only be set to true if it is guaranteed that all items
  in the view has the same height. This enables the view to do some
  optimizations.
*/
bool QTreeView::uniformRowHeights() const
{
    Q_D(const QTreeView);
    return d->uniformRowHeights;
}

void QTreeView::setUniformRowHeights(bool uniform)
{
    Q_D(QTreeView);
    d->uniformRowHeights = uniform;
}

/*!
  \property QTreeView::itemsExpandable
  \brief whether the items are expandable by the user.

  This property holds whether the user can expand and collapse items
  interactively.

*/
bool QTreeView::itemsExpandable() const
{
    Q_D(const QTreeView);
    return d->itemsExpandable;
}

void QTreeView::setItemsExpandable(bool enable)
{
    Q_D(QTreeView);
    d->itemsExpandable = enable;
}

/*!
  Returns the horizontal position of the \a column in the viewport.
*/
00420 int QTreeView::columnViewportPosition(int column) const
{
    Q_D(const QTreeView);
    return d->header->sectionViewportPosition(column);
}

/*!
  Returns the width of the \a column.

  \sa resizeColumnToContents(), setColumnWidth()
*/
00431 int QTreeView::columnWidth(int column) const
{
    Q_D(const QTreeView);
    return d->header->sectionSize(column);
}

/*!
  \since 4.2

  Sets the width of the given \a column to the \a width specified.

  \sa columnWidth(), resizeColumnToContents()
*/
00444 void QTreeView::setColumnWidth(int column, int width)
{
    Q_D(QTreeView);
    d->header->resizeSection(column, width);
}

/*!
  Returns the column in the tree view whose header covers the \a x
  coordinate given.
*/
00454 int QTreeView::columnAt(int x) const
{
    Q_D(const QTreeView);
    return d->header->logicalIndexAt(x);
}

/*!
    Returns true if the \a column is hidden; otherwise returns false.

    \sa hideColumn(), isRowHidden()
*/
00465 bool QTreeView::isColumnHidden(int column) const
{
    Q_D(const QTreeView);
    return d->header->isSectionHidden(column);
}

/*!
  If \a hide is true the \a column is hidden, otherwise the \a column is shown.

  \sa hideColumn(), setRowHidden()
*/
00476 void QTreeView::setColumnHidden(int column, bool hide)
{
    Q_D(QTreeView);
    if (column < 0 || column >= d->header->count())
        return;
    d->header->setSectionHidden(column, hide);
}

/*!
    Returns true if the item in the given \a row of the \a parent is hidden;
    otherwise returns false.

    \sa setRowHidden(), isColumnHidden()
*/
00490 bool QTreeView::isRowHidden(int row, const QModelIndex &parent) const
{
    Q_D(const QTreeView);
    if (d->hiddenIndexes.isEmpty() || !d->model)
        return false;
    QModelIndex index = d->model->index(row, 0, parent);
    for (int i = 0; i < d->hiddenIndexes.count(); ++i)
        if (d->hiddenIndexes.at(i) == index)
            return true;
    return false;
}

/*!
  If \a hide is true the \a row with the given \a parent is hidden, otherwise the \a row is shown.

  \sa isRowHidden(), setColumnHidden()
*/
00507 void QTreeView::setRowHidden(int row, const QModelIndex &parent, bool hide)
{
    Q_D(QTreeView);
    if (!d->model)
        return;
    QModelIndex index = d->model->index(row, 0, parent);
    if (!index.isValid())
        return;

    if (hide) {
        QPersistentModelIndex persistent(index);
        if (!d->hiddenIndexes.contains(persistent))
            d->hiddenIndexes.append(persistent);
    } else {
        QPersistentModelIndex persistent(index);
        int i = d->hiddenIndexes.indexOf(persistent);
        if (i >= 0)
            d->hiddenIndexes.remove(i);
    }

    if (hide && isVisible()) {
        int p = d->viewIndex(parent);
        if (p >= 0) {
            const int first = p + 1;
            const int last = first + d->viewItems.at(p).total - 1;
            for (int i = first; i <= last; ) {
                const int count = d->viewItems.at(i).total + 1;
                if (d->viewItems.at(i).index == index) {
                    // remove child and its children
                    d->viewItems.remove(i, count);
                    // update children count of ancestors
                    d->updateChildCount(p, -count);
                    break;
                } else {
                    i += count;
                }
            }
            updateGeometries();
            d->viewport->update();
        } else {
            d->doDelayedItemsLayout();
        }
    } else {
        d->doDelayedItemsLayout();
    }
}

/*!
  \since 4.3

  Returns true if the item in first column in the given \a row
  of the \a parent is spanning all the columns; otherwise returns false.

  \sa setRowSpanning()
*/
00562 bool QTreeView::isRowSpanning(int row, const QModelIndex &parent) const
{
    Q_D(const QTreeView);
    if (d->spanningIndexes.isEmpty() || !d->model)
        return false;
    QModelIndex index = d->model->index(row, 0, parent);
    for (int i = 0; i < d->spanningIndexes.count(); ++i)
        if (d->spanningIndexes.at(i) == index)
            return true;
    return false;
}

/*!
  \since 4.3

  If \a span is true the item in the first column in the \a row
  with the given \a parent is set to span all columns, otherwise all items
  on the \a row are shown.

  \sa isRowSpanning()
*/
00583 void QTreeView::setRowSpanning(int row, const QModelIndex &parent, bool span)
{
    Q_D(QTreeView);
    if (!d->model)
        return;
    QModelIndex index = d->model->index(row, 0, parent);
    if (!index.isValid())
        return;

    if (span) {
        QPersistentModelIndex persistent(index);
        if (!d->spanningIndexes.contains(persistent))
            d->spanningIndexes.append(persistent);
    } else {
        QPersistentModelIndex persistent(index);
        int i = d->spanningIndexes.indexOf(persistent);
        if (i >= 0)
            d->spanningIndexes.remove(i);
    }

    int i = d->viewIndex(index);
    if (i >= 0)
        d->viewItems[i].spanning = span;

    d->viewport->update();
}

/*!
  \reimp
*/
00613 void QTreeView::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight)
{
    Q_D(QTreeView);

    // if we are going to do a complete realyout anyway, there is no need to update
    if (d->delayedLayout.isActive())
        return;

    // refresh the height cache here; we don't really lose anything by getting the size hint,
    // since QAbstractItemView::dataChanged() will get the visualRect for the items anyway

    QModelIndex top = (topLeft.column() == 0)
                      ? topLeft
                      : d->model->sibling(topLeft.row(), 0, topLeft);
    int topViewIndex = d->viewIndex(top);
    bool sizeChanged = false;
    if (topViewIndex != -1) {
        if (topLeft == bottomRight) {
            int oldHeight = d->itemHeight(topViewIndex);
            d->invalidateHeightCache(topViewIndex);
            sizeChanged = (oldHeight != d->itemHeight(topViewIndex));
        } else {
            QModelIndex bottom = (bottomRight.column() == 0) ? bottomRight
                                 : d->model->sibling(bottomRight.row(), 0, bottomRight);
            int bottomViewIndex = d->viewIndex(bottom);
            for (int i = topViewIndex; i <= bottomViewIndex; ++i) {
                int oldHeight = d->itemHeight(i);
                d->invalidateHeightCache(i);
                sizeChanged |= (oldHeight != d->itemHeight(i));
            }
        }
    }

    if (sizeChanged) {
        d->updateScrollBars();
        d->viewport->update();
    }
    QAbstractItemView::dataChanged(topLeft, bottomRight);
}

/*!
  Hides the \a column given.

  \sa showColumn(), setColumnHidden()
*/
00658 void QTreeView::hideColumn(int column)
{
    Q_D(QTreeView);
    d->header->hideSection(column);
}

/*!
  Shows the given \a column in the tree view.

  \sa hideColumn(), setColumnHidden()
*/
00669 void QTreeView::showColumn(int column)
{
    Q_D(QTreeView);
    d->header->showSection(column);
}

/*!
  \fn void QTreeView::expand(const QModelIndex &index)

  Expands the model item specified by the \a index.

  \sa expanded()
*/
00682 void QTreeView::expand(const QModelIndex &index)
{
    Q_D(QTreeView);
    if (!d->isIndexValid(index))
        return;
    int i = d->viewIndex(index);
    if (i != -1) { // is visible
        d->expand(i, true);
        if (!d->isAnimating()) {
            updateGeometries();
            d->viewport->update();
        }
    } else if (!d->expandedIndexes.contains(index)) {
        d->expandedIndexes.append(index);
        emit expanded(index);
    }
}

/*!
  \fn void QTreeView::collapse(const QModelIndex &index)

  Collapses the model item specified by the \a index.

  \sa collapsed()
*/
00707 void QTreeView::collapse(const QModelIndex &index)
{
    Q_D(QTreeView);
    if (!d->isIndexValid(index))
        return;
    int i = d->viewIndex(index);
    if (i != -1) { // is visible
        d->collapse(i, true);
        if (!d->isAnimating()) {
            updateGeometries();
            viewport()->update();
        }
    } else {
        int i = d->expandedIndexes.indexOf(index);
        if (i != -1) {
            d->expandedIndexes.remove(i);
            emit collapsed(index);
        }
    }
}

/*!
  \fn bool QTreeView::isExpanded(const QModelIndex &index) const

  Returns true if the model item \a index is expanded; otherwise returns
  false.

  \sa expand(), expanded(), setExpanded()
*/
00736 bool QTreeView::isExpanded(const QModelIndex &index) const
{
    Q_D(const QTreeView);
    int i = d->viewIndex(index);
    if (i != -1) // is visible
        return d->viewItems.at(i).expanded;
    return d->expandedIndexes.contains(index);
}

/*!
  Sets the item referred to by \a index to either collapse or expanded,
  depending on the value of \a expanded.

  \sa expanded(), expand(), isExpanded()
*/
00751 void QTreeView::setExpanded(const QModelIndex &index, bool expanded)
{
    if (expanded)
        this->expand(index);
    else
        this->collapse(index);
}

/*!
    \since Qt 4.2
    \property QTreeView::sortingEnabled
    \brief whether sorting is enabled

    If this property is true, sorting is enabled for the tree; if the property
    is false, sorting is not enabled. The default value is false.

    \sa sortByColumn()
*/

void QTreeView::setSortingEnabled(bool enable)
{
    Q_D(QTreeView);
    d->sortingEnabled = enable;
    header()->setSortIndicatorShown(enable);
    header()->setClickable(enable);
    if (enable) {
        connect(header(), SIGNAL(sectionClicked(int)), this, SLOT(sortByColumn(int)));
        sortByColumn(header()->sortIndicatorSection());
    } else {
        disconnect(header(), SIGNAL(sectionClicked(int)), this, SLOT(sortByColumn(int)));
    }
}

bool QTreeView::isSortingEnabled() const
{
    Q_D(const QTreeView);
    return d->sortingEnabled;
}

/*!
    \since Qt 4.2
    \property QTreeView::animated
    \brief whether animations are enabled

    If this property is true the treeview will animate expandsion
    and collasping of branches. If this property is false, the treeview
    will expand or collapse branches immediately without showing
    the animation.
*/

void QTreeView::setAnimated(bool animate)
{
    Q_D(QTreeView);
    d->animationsEnabled = animate;
}

bool QTreeView::isAnimated() const
{
    Q_D(const QTreeView);
    return d->animationsEnabled;
}

/*!
    \since 4.2
    \property QTreeView::allColumnsShowFocus
    \brief whether items should show keyboard focus using all columns

    If this property is true all columns will show focus and selection
    states, otherwise only one column will show focus.

    The default is false.
*/

void QTreeView::setAllColumnsShowFocus(bool enable)
{
    Q_D(QTreeView);
    if (d->allColumnsShowFocus == enable)
        return;
    if (d->selectionModel) {
        if (enable) {
            QObject::connect(d->selectionModel, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
                             this, SLOT(_q_currentChanged(QModelIndex,QModelIndex)));
        } else {
            QObject::disconnect(d->selectionModel, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
                                this, SLOT(_q_currentChanged(QModelIndex,QModelIndex)));
        }
    }
    d->allColumnsShowFocus = enable;
    d->viewport->update();
}

bool QTreeView::allColumnsShowFocus() const
{
    Q_D(const QTreeView);
    return d->allColumnsShowFocus;
}

/*!
    \property QTreeView::wordWrap
    \brief the item text word-wrapping policy
    \since 4.3

    If this property is true then item text text is wrapped where
    necessary at word-breaks; otherwise it is not wrapped at all.
    This property is false by default.
*/
void QTreeView::setWordWrap(bool on)
{
    Q_D(QTreeView);
    if (d->wrapItemText == on)
        return;
    d->wrapItemText = on;
    d->doDelayedItemsLayout();
}

bool QTreeView::wordWrap() const
{
    Q_D(const QTreeView);
    return d->wrapItemText;
}


/*!
  \reimp
 */
00876 void QTreeView::keyboardSearch(const QString &search)
{
    Q_D(QTreeView);
    if (!d->model->rowCount(d->root) || !d->model->columnCount(d->root))
        return;

    QModelIndex start;
    if (currentIndex().isValid())
        start = currentIndex();
    else
        start = d->model->index(0, 0, d->root);

    QTime now(QTime::currentTime());
    bool skipRow = false;
    if (search.isEmpty()
        || (d->keyboardInputTime.msecsTo(now) > QApplication::keyboardInputInterval())) {
        d->keyboardInput = search;
        skipRow = true;
    } else {
        d->keyboardInput += search;
    }
    d->keyboardInputTime = now;

    // special case for searches with same key like 'aaaaa'
    bool sameKey = false;
    if (d->keyboardInput.length() > 1) {
        int c = d->keyboardInput.count(d->keyboardInput.at(d->keyboardInput.length() - 1));
        sameKey = (c == d->keyboardInput.length());
        if (sameKey)
            skipRow = true;
    }

    // skip if we are searching for the same key or a new search started
    if (skipRow) {
        if (indexBelow(start).isValid())
            start = indexBelow(start);
        else
            start = d->model->index(0, start.column(), d->root);
    }

    int startIndex = d->viewIndex(start);
    if (startIndex <= -1)
        return;

    int previousLevel = -1;
    int bestAbove = -1;
    int bestBelow = -1;
    QString searchString = sameKey ? QString(d->keyboardInput.at(0)) : d->keyboardInput;
    for (int i = 0; i < d->viewItems.count(); ++i) {
        if ((int)d->viewItems.at(i).level > previousLevel) {
            QModelIndex searchFrom = d->viewItems.at(i).index;
            if (searchFrom.parent() == start.parent())
                searchFrom = start;
            QModelIndexList match = d->model->match(searchFrom, Qt::DisplayRole, searchString);
            if (match.count()) {
                int hitIndex = d->viewIndex(match.at(0));
                if (hitIndex >= 0 && hitIndex < startIndex)
                    bestAbove = bestAbove == -1 ? hitIndex : qMin(hitIndex, bestAbove);
                else if (hitIndex >= startIndex)
                    bestBelow = bestBelow == -1 ? hitIndex : qMin(hitIndex, bestBelow);
            }
        }
        previousLevel = d->viewItems.at(i).level;
    }

    QModelIndex index;
    if (bestBelow > -1)
        index = d->viewItems.at(bestBelow).index;
    else if (bestAbove > -1)
        index = d->viewItems.at(bestAbove).index;

    if (index.isValid()) {
        QItemSelectionModel::SelectionFlags flags = (d->selectionMode == SingleSelection
                                                     ? QItemSelectionModel::SelectionFlags(
                                                         QItemSelectionModel::ClearAndSelect
                                                         |d->selectionBehaviorFlags())
                                                     : QItemSelectionModel::SelectionFlags(
                                                         QItemSelectionModel::NoUpdate));
        selectionModel()->setCurrentIndex(index, flags);
    }
}

/*!
  Returns the rectangle on the viewport occupied by the item at \a index.
  If the index is not visible or explicitly hidden, the returned rectangle is invalid.
*/
00962 QRect QTreeView::visualRect(const QModelIndex &index) const
{
    Q_D(const QTreeView);

    if (!d->isIndexValid(index) || isIndexHidden(index))
        return QRect();

    d->executePostedLayout();

    int vi = d->viewIndex(index);
    if (vi < 0)
        return QRect();

    bool spanning = (d->header && d->viewItems.at(vi).spanning);
    if (spanning && index.column() > 0)
        return QRect();

    int x = columnViewportPosition(index.column());
    int w = (spanning ? d->header->length() : columnWidth(index.column()));

    if (index.column() == 0) {
        int i = d->indentationForItem(vi);
        x += i;
        w -= i;
    }
    int y = d->coordinateForItem(vi);
    int h = d->itemHeight(vi);

    return QRect(x, y, w, h);
}

/*!
    Scroll the contents of the tree view until the given model item
    \a index is visible. The \a hint parameter specifies more
    precisely where the item should be located after the
    operation.
    If any of the parents of the model item are collapsed, they will
    be expanded to ensure that the model item is visible.
*/
01001 void QTreeView::scrollTo(const QModelIndex &index, ScrollHint hint)
{
    Q_D(QTreeView);

    if (!d->isIndexValid(index))
        return;

    d->executePostedLayout();
    d->updateScrollBars();

    // Expand all parents if the parent(s) of the node are not expanded.
    QModelIndex parent = index.parent();
    while (parent.isValid() && state() == NoState && d->itemsExpandable) {
        if (!isExpanded(parent))
            expand(parent);
        parent = d->model->parent(parent);
    }

    int item = d->viewIndex(index);
    if (item < 0)
        return;

    QRect area = d->viewport->rect();

    // vertical
    if (verticalScrollMode() == QAbstractItemView::ScrollPerItem) {
        int top = verticalScrollBar()->value();
        int bottom = top + verticalScrollBar()->pageStep();
        if (hint == EnsureVisible && item >= top && item < bottom) {
            return; // nothing to do
        } else if (hint == PositionAtTop || item < top) {
            verticalScrollBar()->setValue(item);
        } else { // PositionAtBottom or PositionAtCenter
            int y = (hint == PositionAtCenter
                     ? area.height() / 2
                     : area.height());
            while (y > 0 && item > 0)
                y -= d->itemHeight(item--);
            item += 1 + ((y < 0) ? 1 : 0);
            verticalScrollBar()->setValue(item);
        }
    } else { // ScrollPerPixel
        QRect rect(columnViewportPosition(index.column()),
                   d->coordinateForItem(item), // ### slow for items outside the view
                   columnWidth(index.column()),
                   d->itemHeight(item));

        if (rect.isEmpty())
            return;
        if (hint == EnsureVisible && area.contains(rect)) {
            d->setDirtyRegion(rect);
            return; // nothing to do
        }

        bool above = (hint == EnsureVisible
                      && (rect.top() < area.top()
                          || area.height() < rect.height()));
        bool below = (hint == EnsureVisible
                      && rect.bottom() > area.bottom()
                      && rect.height() < area.height());

        int verticalValue = verticalScrollBar()->value();
        if (hint == PositionAtTop || above)
            verticalValue += rect.top();
        else if (hint == PositionAtBottom || below)
            verticalValue += rect.bottom() - area.height();
        else if (hint == PositionAtCenter)
            verticalValue += rect.top() - ((area.height() - rect.height()) / 2);
        verticalScrollBar()->setValue(verticalValue);
    }

    // horizontal
    int viewportWidth = d->viewport->width();
    int horizontalOffset = d->header->offset();
    int horizontalPosition = d->header->sectionPosition(index.column());
    int cellWidth = d->header->sectionSize(index.column());

    if (hint == PositionAtCenter) {
        horizontalScrollBar()->setValue(horizontalPosition - ((viewportWidth - cellWidth) / 2));
    } else {
        if (horizontalPosition - horizontalOffset < 0 || cellWidth > viewportWidth)
            horizontalScrollBar()->setValue(horizontalPosition);
        else if (horizontalPosition - horizontalOffset + cellWidth > viewportWidth)
            horizontalScrollBar()->setValue(horizontalPosition - viewportWidth + cellWidth);
    }
}

/*!
  \reimp
*/
01091 void QTreeView::timerEvent(QTimerEvent *event)
{
    Q_D(QTreeView);
    if (event->timerId() == d->columnResizeTimerID) {
        updateGeometries();
        killTimer(d->columnResizeTimerID);
        d->columnResizeTimerID = 0;
        QRect rect;
        int viewportHeight = d->viewport->height();
        int viewportWidth = d->viewport->width();
        for (int i = d->columnsToUpdate.size() - 1; i >= 0; --i) {
            int column = d->columnsToUpdate.at(i);
            int x = columnViewportPosition(column);
            if (isRightToLeft())
                rect |= QRect(0, 0, x + columnWidth(column), viewportHeight);
            else
                rect |= QRect(x, 0, viewportWidth - x, viewportHeight);
        }
        d->viewport->update(rect.normalized());
        d->columnsToUpdate.clear();
    } else if (event->timerId() == d->openTimer.timerId()) {
        QPoint pos = d->viewport->mapFromGlobal(QCursor::pos());
        if (state() == QAbstractItemView::DraggingState
            && d->viewport->rect().contains(pos)) {
            QModelIndex index = indexAt(pos);
            setExpanded(index, !isExpanded(index));
        }
        d->openTimer.stop();
    }

    QAbstractItemView::timerEvent(event);
}

/*!
  \reimp
*/
#ifndef QT_NO_DRAGANDDROP
01128 void QTreeView::dragMoveEvent(QDragMoveEvent *event)
{
    Q_D(QTreeView);
    if (d->autoExpandDelay >= 0)
        d->openTimer.start(d->autoExpandDelay, this);
    QAbstractItemView::dragMoveEvent(event);
}
#endif

/*!
  \reimp
*/
01140 bool QTreeView::viewportEvent(QEvent *event)
{
    Q_D(QTreeView);
    switch (event->type()) {
    case QEvent::HoverEnter:
    case QEvent::HoverLeave:
    case QEvent::HoverMove: {
        QHoverEvent *he = static_cast<QHoverEvent*>(event);
        int oldBranch = d->hoverBranch;
        d->hoverBranch = d->itemDecorationAt(he->pos());
        if (oldBranch != d->hoverBranch) {
            QRect oldRect = visualRect(d->modelIndex(oldBranch));
            QRect newRect = visualRect(d->modelIndex(d->hoverBranch));
            viewport()->update(oldRect.left() - d->indent, oldRect.top(), d->indent, oldRect.height());
            viewport()->update(newRect.left() - d->indent, newRect.top(), d->indent, newRect.height());
        }
        break; }
    default:
        break;
    }
    return QAbstractItemView::viewportEvent(event);
}

/*!
  \reimp
*/
01166 void QTreeView::paintEvent(QPaintEvent *event)
{
    Q_D(QTreeView);
    bool layout = d->delayedLayout.isActive();
    d->delayedLayout.stop();
    QPainter painter(viewport());
    if (d->isAnimating()) {
        drawTree(&painter, event->region() - d->animationRect());
        d->drawAnimatedOperation(&painter);
    } else {
        drawTree(&painter, event->region());
#ifndef QT_NO_DRAGANDDROP
        d->paintDropIndicator(&painter);
#endif
    }
    if (layout)
        d->doDelayedItemsLayout();
}

/*!
  \since 4.2
  Draws the part of the tree intersecting the given \a region using the specified
  \a painter.

  \sa paintEvent()
*/
01192 void QTreeView::drawTree(QPainter *painter, const QRegion &region) const
{
    Q_D(const QTreeView);
    const QVector<QTreeViewItem> viewItems = d->viewItems;

    if (viewItems.count() == 0 || d->header->count() == 0 || !d->itemDelegate) {
        return;
    }

    QStyleOptionViewItemV3 option = d->viewOptionsV3();
    const QStyle::State state = option.state;

    int firstVisibleItemOffset = 0;
    const int firstVisibleItem = d->firstVisibleItem(&firstVisibleItemOffset);
    if (firstVisibleItem < 0)
        return;

    QVector<QRect> rects = region.rects();
    for (int a = 0; a < rects.size(); ++a) {

        const QRect area = rects.at(a);
        d->leftAndRight = d->startAndEndColumns(area);

        int i = firstVisibleItem; // the first item at the top of the viewport
        int y = firstVisibleItemOffset; // we may only see part of the first item

        // start at the top of the viewport  and iterate down to the update area
        for (; i < viewItems.count(); ++i) {
            const int itemHeight = d->itemHeight(i);
            if (y + itemHeight >= area.top())
                break;
            y += itemHeight;
        }

        // paint the visible rows
        for (; i < viewItems.count() && y <= area.bottom(); ++i) {
            const int itemHeight = d->itemHeight(i);
            option.rect.setRect(0, y, 0, itemHeight);
            option.state = state | (viewItems.at(i).expanded
                                    ? QStyle::State_Open : QStyle::State_None);
            d->current = i;
            d->spanning = viewItems.at(i).spanning;
            drawRow(painter, option, viewItems.at(i).index);
            y += itemHeight;
        }
    }
}

/// ### move to QObject :)
static inline bool ancestorOf(QObject *widget, QObject *other)
{
    for (QObject *parent = other; parent != 0; parent = parent->parent()) {
        if (parent == widget)
            return true;
    }
    return false;
}

/*!
    Draws the row in the tree view that contains the model item \a index,
    using the \a painter given. The \a option control how the item is
    displayed.

    \sa setAlternatingRowColors()
*/
01257 void QTreeView::drawRow(QPainter *painter, const QStyleOptionViewItem &option,
                        const QModelIndex &index) const
{
    Q_D(const QTreeView);
    QStyleOptionViewItemV3 opt = option;
    const QPoint offset = d->scrollDelayOffset;
    const int y = option.rect.y() + offset.y();
    const QModelIndex parent = index.parent();
    const QHeaderView *header = d->header;
    const QModelIndex current = currentIndex();
    const QModelIndex hover = d->hover;
    const bool reverse = isRightToLeft();
    const QStyle::State state = opt.state;
    const bool spanning = d->spanning;
    const int left = (spanning ? 0 : d->leftAndRight.first);
    const int right = (spanning ? 0 : d->leftAndRight.second);
    const bool alternate = d->alternatingColors;
    const bool enabled = (state & QStyle::State_Enabled) != 0;
    const bool allColumnsShowFocus = d->allColumnsShowFocus;

    // when the row contains an index widget which has focus,
    // we want to paint the entire row as active
    bool indexWidgetHasFocus = false;
    if ((current.row() == index.row()) && !d->editors.isEmpty()) {
        const int r = index.row();
        QWidget *fw = QApplication::focusWidget();
        for (int c = 0; c < header->count(); ++c) {
            if (QWidget *editor = indexWidget(index.sibling(r, c))) {
                if (ancestorOf(editor, fw)) {
                    indexWidgetHasFocus = true;
                    break;
                }
            }
        }
    }

    bool currentRowHasFocus = false;
    if (allColumnsShowFocus && current.isValid()) { // check if the focus index is before or after the visible columns
        const int r = index.row();
        for (int c = 0; c < left && !currentRowHasFocus; ++c)
            currentRowHasFocus = (index.sibling(r, c) == current);
        QModelIndex parent = d->model->parent(index);
        for (int c = right; c < header->count() && !currentRowHasFocus; ++c) {
            currentRowHasFocus = (d->model->index(r, c, parent) == current);
        }
    }

    // ### special case: treeviews with multiple columns draw
    // the selections differently than with only one column
    opt.showDecorationSelected = (d->selectionBehavior & SelectRows)
                                 || option.showDecorationSelected;

    int width, height = option.rect.height();
    int position;
    int headerSection;
    QModelIndex modelIndex;

    const bool widgetHasFocus = hasFocus();
    for (int headerIndex = left; headerIndex <= right; ++headerIndex) {
        headerSection = header->logicalIndex(headerIndex);
        if (header->isSectionHidden(headerSection))
            continue;
        position = columnViewportPosition(headerSection) + offset.x();
        width = (spanning ? header->length() : header->sectionSize(headerSection));
        modelIndex = d->model->index(index.row(), headerSection, parent);
        if (!modelIndex.isValid())
            continue;
        opt.state = state;

        // fake activeness when row editor has focus
        if (indexWidgetHasFocus)
            opt.state |= QStyle::State_Active;

        if (d->selectionModel->isSelected(modelIndex))
            opt.state |= QStyle::State_Selected;
        if (widgetHasFocus && (current == modelIndex)) {
            if (allColumnsShowFocus)
                currentRowHasFocus = true;
            else
                opt.state |= QStyle::State_HasFocus;
        }
        if (modelIndex == hover)
            opt.state |= QStyle::State_MouseOver;
        else
            opt.state &= ~QStyle::State_MouseOver;

        if (enabled) {
            QPalette::ColorGroup cg;
            if ((d->model->flags(index) & Qt::ItemIsEnabled) == 0) {
                opt.state &= ~QStyle::State_Enabled;
                cg = QPalette::Disabled;
            } else {
                cg = QPalette::Active;
            }
            opt.palette.setCurrentColorGroup(cg);
        }

        if (alternate) {
            if (d->current & 1) {
                opt.features |= QStyleOptionViewItemV2::Alternate;
            } else {
                opt.features &= ~QStyleOptionViewItemV2::Alternate;
            }
        }

        if (headerSection == 0) {
            const int i = d->indentationForItem(d->current);
            opt.rect.setRect(reverse ? position : i + position, y, width - i, height);
            if (alternate && (d->current & 1))
                painter->fillRect(opt.rect, opt.palette.alternateBase());
            QRect branches(reverse ? position + width - i : position, y, i, height);
            QPalette::ColorGroup cg = opt.state & QStyle::State_Enabled
                              ? QPalette::Active : QPalette::Disabled;
            if (cg == QPalette::Active && !(opt.state & QStyle::State_Active))
                cg = QPalette::Inactive;

            if ((opt.state & QStyle::State_Selected) && option.showDecorationSelected)
                painter->fillRect(branches, opt.palette.brush(cg, QPalette::Highlight));
            else if (alternate && (d->current & 1))
                painter->fillRect(branches, opt.palette.alternateBase());
            drawBranches(painter, branches, index);
        } else {
            opt.rect.setRect(position, y, width, height);
            if (alternate & (d->current & 1)) {
                painter->fillRect(opt.rect, opt.palette.alternateBase());
            }
        }
        d->delegateForIndex(modelIndex)->paint(painter, opt, modelIndex);
    }

    if (currentRowHasFocus) {
        QStyleOptionFocusRect o;
        o.QStyleOption::operator=(option);
        o.state |= QStyle::State_KeyboardFocusChange;
        QPalette::ColorGroup cg = (option.state & QStyle::State_Enabled)
                                  ? QPalette::Normal : QPalette::Disabled;
        o.backgroundColor = option.palette.color(cg, d->selectionModel->isSelected(index)
                                                 ? QPalette::Highlight : QPalette::Background);
        int x = header->sectionPosition(0); // not always 0
        if (!option.showDecorationSelected)
            x += d->indentationForItem(d->current);
        o.rect.setRect(x - header->offset(), y, header->length() - x, height);
        style()->drawPrimitive(QStyle::PE_FrameFocusRect, &o, painter);
    }
}

/*!
  Draws the branches in the tree view on the same row as the model item
  \a index, using the \a painter given. The branches are drawn in the
  rectangle specified by \a rect.
*/
01408 void QTreeView::drawBranches(QPainter *painter, const QRect &rect,
                             const QModelIndex &index) const
{
    Q_D(const QTreeView);
    const bool reverse = isRightToLeft();
    const int indent = d->indent;
    const int outer = d->rootDecoration ? 0 : 1;
    const int item = d->current;
    const QTreeViewItem &viewItem = d->viewItems.at(item);
    int level = viewItem.level;
    QRect primitive(reverse ? rect.left() : rect.right(), rect.top(), indent, rect.height());

    QModelIndex parent = index.parent();
    QModelIndex current = parent;
    QModelIndex ancestor = current.parent();

    QStyleOption opt;
    opt.initFrom(this);
    QStyle::State extraFlags = QStyle::State_None;
    if (isEnabled())
        extraFlags |= QStyle::State_Enabled;
    if (window()->isActiveWindow())
        extraFlags |= QStyle::State_Active;
    QPoint oldBO = painter->brushOrigin();
    if (verticalScrollMode() == QAbstractItemView::ScrollPerPixel)
        painter->setBrushOrigin(QPoint(0, verticalOffset()));

    if (level >= outer) {
        // start with the innermost branch
        primitive.moveLeft(reverse ? primitive.left() : primitive.left() - indent);
        opt.rect = primitive;

        const bool expanded = viewItem.expanded;
        const bool children = (((expanded && viewItem.total > 0)) // already laid out and has children
                                || d->hasVisibleChildren(index)); // not laid out yet, so we don't know
        bool moreSiblings = false;
        if (d->hiddenIndexes.isEmpty())
            moreSiblings = (d->model->rowCount(parent) - 1 > index.row());
        else
            moreSiblings = ((d->viewItems.size() > item +1)
                            && (d->viewItems.at(item + 1).index.parent() == parent));

        opt.state = QStyle::State_Item | extraFlags
                    | (moreSiblings ? QStyle::State_Sibling : QStyle::State_None)
                    | (children ? QStyle::State_Children : QStyle::State_None)
                    | (expanded ? QStyle::State_Open : QStyle::State_None);
        if (item == d->hoverBranch)
            opt.state |= QStyle::State_MouseOver;
        else
            opt.state &= ~QStyle::State_MouseOver;
        style()->drawPrimitive(QStyle::PE_IndicatorBranch, &opt, painter, this);
    }
    // then go out level by level
    for (--level; level >= outer; --level) { // we have already drawn the innermost branch
        primitive.moveLeft(reverse ? primitive.left() + indent : primitive.left() - indent);
        opt.rect = primitive;
        opt.state = extraFlags;
        bool moreSiblings = false;
        if (d->hiddenIndexes.isEmpty()) {
            moreSiblings = (d->model->rowCount(ancestor) - 1 > current.row());
        } else {
            int successor = item + viewItem.total + 1;
            while (successor < d->viewItems.size()
                   && d->viewItems.at(successor).level >= uint(level)) {
                const QTreeViewItem &successorItem = d->viewItems.at(successor);
                if (successorItem.level == uint(level)) {
                    moreSiblings = true;
                    break;
                }
                successor += successorItem.total + 1;
            }
        }
        if (moreSiblings)
            opt.state |= QStyle::State_Sibling;
        style()->drawPrimitive(QStyle::PE_IndicatorBranch, &opt, painter, this);
        current = ancestor;
        ancestor = current.parent();
    }
    painter->setBrushOrigin(oldBO);
}

/*!
  \reimp
*/
01492 void QTreeView::mousePressEvent(QMouseEvent *event)
{
    Q_D(QTreeView);
    // we want to handle mousePress in EditingState (persistent editors)
    if ((state() != NoState && state() != EditingState) || !d->viewport->rect().contains(event->pos())) {
        return;
    }
    int i = d->itemDecorationAt(event->pos());
    if (i == -1) {
        QAbstractItemView::mousePressEvent(event);
    } else if (itemsExpandable() && d->hasVisibleChildren(d->viewItems.at(i).index)) {
        if (d->viewItems.at(i).expanded)
            d->collapse(i, true);
        else
            d->expand(i, true);
        if (!d->isAnimating()) {
            updateGeometries();
            viewport()->update();
        }
    }
}

/*!
  \reimp
*/
01517 void QTreeView::mouseReleaseEvent(QMouseEvent *event)
{
    Q_D(QTreeView);
    if (d->itemDecorationAt(event->pos()) == -1) { // ### what about expanding/collapsing state ?
        QAbstractItemView::mouseReleaseEvent(event);
    } else {
        if (state() == QAbstractItemView::DragSelectingState)
            setState(QAbstractItemView::NoState);
    }
}

/*!
  \reimp
*/
01531 void QTreeView::mouseDoubleClickEvent(QMouseEvent *event)
{
    Q_D(QTreeView);
    if (state() != NoState || !d->viewport->rect().contains(event->pos()))
        return;

    int i = d->itemDecorationAt(event->pos());
    if (i == -1) {
        i = d->itemAtCoordinate(event->y());
        if (i == -1)
            return; // user clicked outside the items

        const QModelIndex &index = d->viewItems.at(i).index;

        int column = d->header->logicalIndexAt(event->x());
        QPersistentModelIndex persistent = index.sibling(index.row(), column);

        if (d->pressedIndex != persistent) {
            mousePressEvent(event);
            return;
        }

        // signal handlers may change the model
        emit doubleClicked(persistent);

        if (!persistent.isValid())
            return;

        if (edit(persistent, DoubleClicked, event) || state() != NoState)
            return; // the double click triggered editing

        if (!style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, 0, this))
            emit activated(persistent);

        d->executePostedLayout(); // we need to make sure viewItems is updated
        if (d->itemsExpandable && d->hasVisibleChildren(persistent)) {
            if (!((i < d->viewItems.count()) && (d->viewItems.at(i).index == persistent))) {
                // find the new index of the item
                for (i = 0; i < d->viewItems.count(); ++i) {
                    if (d->viewItems.at(i).index == persistent)
                        break;
                }
                if (i == d->viewItems.count())
                    return;
            }
            if (d->viewItems.at(i).expanded)
                d->collapse(i, true);
            else
                d->expand(i, true);
            updateGeometries();
            viewport()->update();
        }
    }
}

/*!
  \reimp
*/
01589 void QTreeView::mouseMoveEvent(QMouseEvent *event)
{
    Q_D(QTreeView);
    if (d->itemDecorationAt(event->pos()) == -1) // ### what about expanding/collapsing state ?
        QAbstractItemView::mouseMoveEvent(event);
}

/*!
  \reimp
*/
01599 void QTreeView::keyPressEvent(QKeyEvent *event)
{
    Q_D(QTreeView);
    QModelIndex current = currentIndex();
    if (d->isIndexValid(current) && d->model) {
        switch (event->key()) {
        case Qt::Key_Asterisk: {
            QStack<QModelIndex> parents;
            parents.push(current);
            if (d->itemsExpandable) {
                while (!parents.isEmpty()) {
                    QModelIndex parent = parents.pop();
                    for (int row = 0; row < d->model->rowCount(parent); ++row) {
                        QModelIndex child = d->model->index(row, 0, parent);
                        if (!d->isIndexValid(child))
                            break;
                        parents.push(child);
                        expand(child);
                    }
                }
                expand(current);
            }
            break; }
        case Qt::Key_Plus:
            expand(current);
            break;
        case Qt::Key_Minus:
            collapse(current);
            break;
        }
    }

    QAbstractItemView::keyPressEvent(event);
}

/*!
  \reimp
*/
01637 QModelIndex QTreeView::indexAt(const QPoint &point) const
{
    Q_D(const QTreeView);
    d->executePostedLayout();

    int visualIndex = d->itemAtCoordinate(point.y());
    QModelIndex idx = d->modelIndex(visualIndex);
    if (!idx.isValid())
        return QModelIndex();

    if (d->viewItems.at(visualIndex).spanning)
        return idx;

    int column = d->columnAt(point.x());
    if (column == idx.column())
        return idx;
    if (column < 0)
        return QModelIndex();
    return d->model->sibling(idx.row(), column, idx);
}

/*!
  Returns the model index of the item above \a index.
*/
01661 QModelIndex QTreeView::indexAbove(const QModelIndex &index) const
{
    Q_D(const QTreeView);
    if (!d->isIndexValid(index))
        return QModelIndex();
    d->executePostedLayout();
    int i = d->viewIndex(index);
    if (--i < 0)
        return QModelIndex();
    return d->viewItems.at(i).index;
}

/*!
  Returns the model index of the item below \a index.
*/
01676 QModelIndex QTreeView::indexBelow(const QModelIndex &index) const
{
    Q_D(const QTreeView);
    if (!d->isIndexValid(index))
        return QModelIndex();
    d->executePostedLayout();
    int i = d->viewIndex(index);
    if (++i >= d->viewItems.count())
        return QModelIndex();
    return d->viewItems.at(i).index;
}

/*!
    \internal

    Lays out the items in the tree view.
*/
01693 void QTreeView::doItemsLayout()
{
    Q_D(QTreeView);
    d->viewItems.clear(); // prepare for new layout
    QModelIndex parent = d->root;
    if (d->model->hasChildren(parent)) {
        QModelIndex index = d->model->index(0, 0, parent);
        d->defaultItemHeight = indexRowSizeHint(index);
        d->layout(-1);
        d->reexpandChildren(parent);
    }
    QAbstractItemView::doItemsLayout();
    d->header->doItemsLayout();
}

/*!
  \reimp
*/
01711 void QTreeView::reset()
{
    Q_D(QTreeView);
    d->expandedIndexes.clear();
    d->hiddenIndexes.clear();
    d->spanningIndexes.clear();
    d->viewItems.clear();
    QAbstractItemView::reset();
}

/*!
  Returns the horizontal offset of the items in the treeview.

  Note that the tree view uses the horizontal header section
  positions to determine the positions of columns in the view.

  \sa verticalOffset()
*/
01729 int QTreeView::horizontalOffset() const
{
    Q_D(const QTreeView);
    return d->header->offset();
}

/*!
  Returns the vertical offset of the items in the tree view.

  \sa horizontalOffset()
*/
01740 int QTreeView::verticalOffset() const
{
    Q_D(const QTreeView);
    if (verticalScrollMode() == QAbstractItemView::ScrollPerItem) {
        if (uniformRowHeights())
            return verticalScrollBar()->value() * d->defaultItemHeight;
        // If we are scrolling per item and have non-uniform row heights,
        // finding the vertical offset in pixels is going to be relatively slow.
        // ### find a faster way to do this
        int offset = 0;
        for (int i = 0; i < d->viewItems.count(); ++i) {
            if (i == verticalScrollBar()->value())
                return offset;
            offset += d->itemHeight(i);
        }
        return 0;
    }
    // scroll per pixel
    return verticalScrollBar()->value();
}

/*!
    Move the cursor in the way described by \a cursorAction, using the
    information provided by the button \a modifiers.
*/
01765 QModelIndex QTreeView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifiers modifiers)
{
    Q_D(QTreeView);
    Q_UNUSED(modifiers);

    d->executePostedLayout();

    QModelIndex current = currentIndex();
    if (!current.isValid()) {
        int i = 0;
        while (i < d->viewItems.count() && d->hiddenIndexes.contains(d->viewItems.at(i).index))
            ++i;
        return d->viewItems.value(i).index;
    }
    int vi = qMax(0, d->viewIndex(current));
    switch (cursorAction) {
    case MoveNext:
    case MoveDown:
#ifdef QT_KEYPAD_NAVIGATION
        if (vi == d->viewItems.count()-1 && QApplication::keypadNavigationEnabled())
            return d->model->index(0, 0, d->root);
#endif
        return d->modelIndex(d->below(vi));
    case MovePrevious:
    case MoveUp:
#ifdef QT_KEYPAD_NAVIGATION
        if (vi == 0 && QApplication::keypadNavigationEnabled())
            return d->modelIndex(d->viewItems.count() - 1);
#endif
        return d->modelIndex(d->above(vi));
    case MoveLeft: {
        QScrollBar *sb = horizontalScrollBar();
        if (d->viewItems.at(vi).expanded && d->itemsExpandable && sb->value() == sb->minimum())
            d->collapse(vi, true);
        else
           sb->setValue(sb->value() - sb->singleStep());
        updateGeometries();
        viewport()->update();
        break;
    }
    case MoveRight:
        if (!d->viewItems.at(vi).expanded && d->itemsExpandable) {
            d->expand(vi, true);
        }
        else {
           QScrollBar *sb = horizontalScrollBar();
           sb->setValue(sb->value() + sb->singleStep());
        }
        updateGeometries();
        viewport()->update();
        break;
    case MovePageUp:
        return d->modelIndex(d->pageUp(vi));
    case MovePageDown:
        return d->modelIndex(d->pageDown(vi));
    case MoveHome:
        return d->model->index(0, 0, d->root);
    case MoveEnd:
        return d->modelIndex(d->viewItems.count() - 1);
    }
    return current;
}

/*!
  Applies the selection \a command to the items in or touched by the
  rectangle, \a rect.

  \sa selectionCommand()
*/
01834 void QTreeView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)
{
    Q_D(QTreeView);
    if (!selectionModel() || rect.isNull())
        return;

    QPoint tl(isRightToLeft() ? qMax(rect.left(), rect.right())
              : qMin(rect.left(), rect.right()), qMin(rect.top(), rect.bottom()));
    QPoint br(isRightToLeft() ? qMin(rect.left(), rect.right()) :
              qMax(rect.left(), rect.right()), qMax(rect.top(), rect.bottom()));
    QModelIndex topLeft = indexAt(tl);
    QModelIndex bottomRight = indexAt(br);
    if (!topLeft.isValid() && !bottomRight.isValid())
        return;
    if (!topLeft.isValid() && !d->viewItems.isEmpty())
        topLeft = d->viewItems.first().index;
    if (!bottomRight.isValid() && !d->viewItems.isEmpty()) {
        const int column = d->header->logicalIndex(d->header->count() - 1);
        const QModelIndex index = d->viewItems.last().index;
        bottomRight = index.sibling(index.row(), column);
    }

    if (selectionBehavior() != SelectRows) {
        QItemSelection selection;
        if (topLeft.isValid() && bottomRight.isValid()) {
            selection.append(QItemSelectionRange(topLeft, bottomRight));
            selectionModel()->select(selection, command);
        }
    } else {
        d->select(d->viewIndex(topLeft), d->viewIndex(bottomRight), command);
    }
}

/*!
  Returns the rectangle from the viewport of the items in the given
  \a selection.
*/
01871 QRegion QTreeView::visualRegionForSelection(const QItemSelection &selection) const
{
    Q_D(const QTreeView);
    if (selection.isEmpty())
        return QRegion();

    QRegion selectionRegion;
    for (int i = 0; i < selection.count(); ++i) {
        QItemSelectionRange range = selection.at(i);
        if (!range.isValid())
            continue;
        QModelIndex parent = range.parent();
        QModelIndex leftIndex = range.topLeft();
        int columnCount = d->model->columnCount(parent);
        while (leftIndex.isValid() && isIndexHidden(leftIndex)) {
            if (leftIndex.column() + 1 < columnCount)
                leftIndex = d->model->index(leftIndex.row(), leftIndex.column() + 1, parent);
            else
                leftIndex = QModelIndex();
        }
        if (!leftIndex.isValid())
            continue;
        const QRect leftRect = visualRect(leftIndex);
        int top = leftRect.top();
        QModelIndex rightIndex = range.bottomRight();
        while (rightIndex.isValid() && isIndexHidden(rightIndex)) {
            if (rightIndex.column() - 1 >= 0)
                rightIndex = d->model->index(rightIndex.row(), rightIndex.column() - 1, parent);
            else
                rightIndex = QModelIndex();
        }
        if (!rightIndex.isValid())
            continue;
        const QRect rightRect = visualRect(rightIndex);
        int bottom = rightRect.bottom();
        if (top > bottom)
            qSwap<int>(top, bottom);
        int height = bottom - top + 1;
        if (d->header->sectionsMoved()) {
            for (int c = range.left(); c <= range.right(); ++c)
                selectionRegion += QRegion(QRect(columnViewportPosition(c), top,
                                                 columnWidth(c), height));
        } else {
            QRect combined = leftRect|rightRect;
            combined.setX(columnViewportPosition(range.left()));
            selectionRegion += combined;
        }
    }
    return selectionRegion;
}

/*!
  \reimp
*/
01925 QModelIndexList QTreeView::selectedIndexes() const
{
    QModelIndexList viewSelected;
    QModelIndexList modelSelected;
    if (selectionModel())
        modelSelected = selectionModel()->selectedIndexes();
    for (int i = 0; i < modelSelected.count(); ++i) {
        // check that neither the parents nor the index is hidden before we add
        QModelIndex index = modelSelected.at(i);
        while (index.isValid() && !isIndexHidden(index))
            index = index.parent();
        if (index.isValid())
            continue;
        viewSelected.append(modelSelected.at(i));
    }
    return viewSelected;
}

/*!
  Scrolls the contents of the tree view by (\a dx, \a dy).
*/
01946 void QTreeView::scrollContentsBy(int dx, int dy)
{
    Q_D(QTreeView);
    dx = isRightToLeft() ? -dx : dx;
    if (dx) {
        if (horizontalScrollMode() == QAbstractItemView::ScrollPerItem) {
            int oldOffset = d->header->offset();
            if (horizontalScrollBar()->value() == horizontalScrollBar()->maximum())
                d->header->setOffsetToLastSection();
            else
                d->header->setOffsetToSectionPosition(horizontalScrollBar()->value());
            int newOffset = d->header->offset();
            dx = isRightToLeft() ? newOffset - oldOffset : oldOffset - newOffset;
        } else {
            d->header->setOffset(horizontalScrollBar()->value());
        }
    }

    if (d->viewItems.isEmpty() || d->defaultItemHeight == 0)
        return;

    // guestimate the number of items in the viewport
    int viewCount = d->viewport->height() / d->defaultItemHeight;
    int maxDeltaY = qMin(d->viewItems.count(), viewCount);
    // no need to do a lot of work if we are going to redraw the whole thing anyway
    if (qAbs(dy) > qAbs(maxDeltaY) && d->editors.isEmpty()) {
        verticalScrollBar()->repaint();
        d->viewport->update();
        return;
    }

    if (dy && verticalScrollMode() == QAbstractItemView::ScrollPerItem) {
        int currentScrollbarValue = verticalScrollBar()->value();
        int previousScrollbarValue = currentScrollbarValue + dy; // -(-dy)
        int currentViewIndex = currentScrollbarValue; // the first visible item
        int previousViewIndex = previousScrollbarValue;
        const QVector<QTreeViewItem> viewItems = d->viewItems;
        dy = 0;
        if (previousViewIndex < currentViewIndex) { // scrolling down
            for (int i = previousViewIndex; i < currentViewIndex; ++i) {
                if (i < d->viewItems.count())
                    dy -= d->itemHeight(i);
            }
        } else if (previousViewIndex > currentViewIndex) { // scrolling up
            for (int i = previousViewIndex - 1; i >= currentViewIndex; --i) {
                if (i < d->viewItems.count())
                    dy += d->itemHeight(i);
            }
        }
    }

    d->scrollContentsBy(dx, dy);
}

/*!
  This slot is called whenever a column has been moved.
*/
02003 void QTreeView::columnMoved()
{
    QAbstractItemView::dataChanged(QModelIndex(), QModelIndex());
}

/*!
  \internal
*/
02011 void QTreeView::reexpand()
{
    // do nothing
}

/*!
  \internal
*/
static bool treeViewItemLessThan(const QTreeViewItem &i1,
                                 const QTreeViewItem &i2)
{
    if (i1.level < i2.level)
        return false;
    else if (i2.level < i1.level)
        return true;
    return (i1.index.row() < i2.index.row());
}

/*!
  Informs the view that the rows from the \a start row to the \a end row
  inclusive have been inserted into the \a parent model item.
*/
02033 void QTreeView::rowsInserted(const QModelIndex &parent, int start, int end)
{
    Q_D(QTreeView);
    const int parentItem = d->viewIndex(parent);
    if (((parentItem != -1) && d->viewItems.at(parentItem).expanded && updatesEnabled())
        || (parent == d->root)) {
        const uint childLevel = (parentItem == -1)
                                ? uint(0) : d->viewItems.at(parentItem).level + 1;
        const int firstChildItem = parentItem + 1;
        const int lastChildItem = firstChildItem + ((parentItem == -1)
                                                    ? d->viewItems.count()
                                                    : d->viewItems.at(parentItem).total) - 1;

        int firstColumn = 0;
        while (isColumnHidden(firstColumn) && firstColumn < header()->count())
            ++firstColumn;

        const int delta = end - start + 1;
        QVector<QTreeViewItem> insertedItems(delta);
        for (int i = 0; i < delta; ++i) {
            insertedItems[i].index = d->model->index(i + start, firstColumn, parent);
            insertedItems[i].level = childLevel;
        }

        int insertPos;
        if (lastChildItem < firstChildItem) { // no children
            insertPos = firstChildItem;
        } else {
            // do a binary search to figure out where to insert
            QVector<QTreeViewItem>::iterator it;
            it = qLowerBound(d->viewItems.begin() + firstChildItem,
                             d->viewItems.begin() + lastChildItem + 1,
                             insertedItems.at(0), treeViewItemLessThan);
            insertPos = it - d->viewItems.begin();

            // update stale model indexes of siblings
            for (int item = insertPos; item <= lastChildItem; ) {
                Q_ASSERT(d->viewItems.at(item).level == childLevel);
                const QModelIndex modelIndex = d->viewItems.at(item).index;
                //Q_ASSERT(modelIndex.parent() == parent);
                d->viewItems[item].index = d->model->index(
                    modelIndex.row() + delta, modelIndex.column(), parent);
                item += d->viewItems.at(item).total + 1;
            }
        }

        d->viewItems.insert(insertPos, delta, insertedItems.at(0));
        if (delta > 1) {
            qCopy(insertedItems.begin() + 1, insertedItems.end(),
                  d->viewItems.begin() + insertPos + 1);
        }

        d->updateChildCount(parentItem, delta);
        d->doDelayedItemsLayout();
    } else if ((parentItem != -1) && d->viewItems.at(parentItem).expanded) {
        d->doDelayedItemsLayout();
    }
    QAbstractItemView::rowsInserted(parent, start, end);
}

/*!
  Informs the view that the rows from the \a start row to the \a end row
  inclusive are about to removed from the given \a parent model item.
*/
02097 void QTreeView::rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end)
{
    Q_D(QTreeView);
    d->rowsRemoved(parent, start, end, false);
    QAbstractItemView::rowsAboutToBeRemoved(parent, start, end);
}

/*!
    \since 4.1

    Informs the view that the rows from the \a start row to the \a end row
    inclusive have been removed from the given \a parent model item.
*/
02110 void QTreeView::rowsRemoved(const QModelIndex &parent, int start, int end)
{
    Q_D(QTreeView);
    d->rowsRemoved(parent, start, end, true);
}

/*!
  Informs the tree view that the number of columns in the tree view has
  changed from \a oldCount to \a newCount.
*/
02120 void QTreeView::columnCountChanged(int, int)
{
    if (isVisible())
        updateGeometries();
      viewport()->update();
}

/*!
  Resizes the \a column given to the size of its contents.

  \sa columnWidth(), setColumnWidth()
*/
02132 void QTreeView::resizeColumnToContents(int column)
{
    Q_D(QTreeView);
    d->executePostedLayout();
    if (column < 0 || column >= d->header->count())
        return;
    int contents = sizeHintForColumn(column);
    int header = d->header->isHidden() ? 0 : d->header->sectionSizeHint(column);
    d->header->resizeSection(column, qMax(contents, header));
}

/*!
  \obsolete
  \overload

  Sorts the model by the values in the given \a column.
*/
02149 void QTreeView::sortByColumn(int column)
{
    Q_D(QTreeView);
    if (column == -1)
        return;
    d->model->sort(column, d->header->sortIndicatorOrder());
}

/*!
  \since 4.2

  Sorts the model by the values in the given \a column in the given \a order.

  \sa sortingEnabled
*/
02164 void QTreeView::sortByColumn(int column, Qt::SortOrder order)
{
    Q_D(QTreeView);
    d->header->setSortIndicator(column, order);
    sortByColumn(column);
}

/*!
    Selects all the items in the underlying model.
*/
02174 void QTreeView::selectAll()
{
    Q_D(QTreeView);
    if (!selectionModel())
        return;
    d->select(0, d->viewItems.count() - 1,
              QItemSelectionModel::ClearAndSelect
              |QItemSelectionModel::Rows);
}

/*!
  \since 4.2
  Expands all expandable items.

  Warning: if the model contains a large number of items,
  this function will be take time to execute.

  \sa collapseAll() expand()  collapse() setExpanded()
*/
02193 void QTreeView::expandAll()
{
    Q_D(QTreeView);
    d->viewItems.clear();
    d->expandedIndexes.clear();
    d->delayedLayout.stop();
    d->layout(-1);
    for (int i = 0; i < d->viewItems.count(); ++i) {
        d->viewItems[i].expanded = true;
        d->layout(i);
        d->expandedIndexes.append(d->viewItems.at(i).index);
    }
    updateGeometries();
    d->viewport->update();
}

/*!
  \since 4.2

  Collapses all expanded items.

  \sa expandAll() expand()  collapse() setExpanded()
*/
02216 void QTreeView::collapseAll()
{
    Q_D(QTreeView);
    d->expandedIndexes.clear();
    doItemsLayout();
}

/*!
  \since 4.3
  Expands all expandable items to the given \a depth.

  \sa expandAll() collapseAll() expand()  collapse() setExpanded()
*/
02229 void QTreeView::expandTo(int depth)
{
    Q_D(QTreeView);
    d->viewItems.clear();
    d->expandedIndexes.clear();
    d->delayedLayout.stop();
    d->layout(-1);
    for (int i = 0; i < d->viewItems.count(); ++i) {
        if (d->viewItems.at(i).level <= (uint)depth) {
            d->viewItems[i].expanded = true;
            d->layout(i);
            d->expandedIndexes.append(d->viewItems.at(i).index);
        }
    }
    updateGeometries();
    d->viewport->update();
}

/*!
    This function is called whenever \a{column}'s size is changed in
    the header. \a oldSize and \a newSize give the previous size and
    the new size in pixels.

    \sa setColumnWidth()
*/
02254 void QTreeView::columnResized(int column, int /* oldSize */, int /* newSize */)
{
    Q_D(QTreeView);
    d->columnsToUpdate.append(column);
    if (d->columnResizeTimerID == 0)
        d->columnResizeTimerID = startTimer(0);
}

/*!
  Updates the items in the tree view.
  \internal
*/
02266 void QTreeView::updateGeometries()
{
    Q_D(QTreeView);
    if (d->header) {
        QSize hint = d->header->isHidden() ? QSize(0, 0) : d->header->sizeHint();
        setViewportMargins(0, hint.height(), 0, 0);
        QRect vg = d->viewport->geometry();
        QRect geometryRect(vg.left(), vg.top() - hint.height(), vg.width(), hint.height());
        d->header->setGeometry(geometryRect);
        //d->header->setOffset(horizontalScrollBar()->value()); // ### bug ???
        QMetaObject::invokeMethod(d->header, "updateGeometries");
        d->updateScrollBars();
    }
    QAbstractItemView::updateGeometries();
}

/*!
  Returns the size hint for the \a column's width or -1 if there is no
  model.

  If you need to set the width of a given column to a fixed value, call
  QHeaderView::resizeSection() on the view's header.

  If you reimplement this function in a subclass, note that the value you
  return is only used when resizeColumnToContents() is called. In that case,
  if a larger column width is required by either the view's header or
  the item delegate, that width will be used instead.

  \sa QWidget::sizeHint, header()
*/
02296 int QTreeView::sizeHintForColumn(int column) const
{
    Q_D(const QTreeView);
    d->executePostedLayout();
    if (d->viewItems.isEmpty())
        return -1;
    int w = 0;
    QStyleOptionViewItemV3 option = d->viewOptionsV3();
    const QVector<QTreeViewItem> viewItems = d->viewItems;
    for (int i = 0; i < viewItems.count(); ++i) {
        QModelIndex index = viewItems.at(i).index;
        if (index.column() != column)
            index = index.sibling(index.row(), column);
        int width = d->delegateForIndex(index)->sizeHint(option, index).width();
        w = qMax(w, width + (column == 0 ? d->indentationForItem(i) : 0));
    }
    return w;
}

/*!
  Returns the size hint for the row indicated by \a index.

  \sa sizeHintForColumn(), uniformRowHeights()
*/
02320 int QTreeView::indexRowSizeHint(const QModelIndex &index) const
{
    Q_D(const QTreeView);
    if (!d->isIndexValid(index) || !d->itemDelegate)
        return 0;

    int start = -1;
    int end = -1;
    int count = d->header->count();
    if (count && isVisible()) {
        // If the sections have moved, we end up checking too many or too few
        start = d->header->visualIndexAt(0);
        end = d->header->visualIndexAt(viewport()->width());
    } else {
        // If the header has not been laid out yet, we use the model directly
        count = d->model->columnCount(index.parent());
    }

    if (isRightToLeft()) {
        start = (start == -1 ? count - 1 : start);
        end = (end == -1 ? 0 : end);
    } else {
        start = (start == -1 ? 0 : start);
        end = (end == -1 ? count - 1 : end);
    }

    int tmp = start;
    start = qMin(start, end);
    end = qMax(tmp, end);

    int height = -1;
    QStyleOptionViewItemV3 option = d->viewOptionsV3();
    // ### If we want word wrapping in the items,
    // ### we need to go through all the columns
    // ### and set the width of the column

    // ### Temporary hack to speed up the function
    option.rect.setWidth(-1);
    QModelIndex parent = d->model->parent(index);
    bool emptyHeader = (d->header->count() == 0);
    for (int column = start; column <= end; ++column) {
        int logicalColumn = emptyHeader ? column : d->header->logicalIndex(column);
        if (d->header->isSectionHidden(logicalColumn))
            continue;
        QModelIndex idx = d->model->index(index.row(), logicalColumn, parent);
        if (idx.isValid()) {
            if (QWidget *editor = d->editorForIndex(idx))
                height = qMax(height, editor->size().height());
            int hint = d->delegateForIndex(idx)->sizeHint(option, idx).height();
            height = qMax(height, hint);
        }
    }

    return height;
}

/*!
    \since 4.3
    Returns the height of the row indicated by the given \a index.
    \sa indexRowSizeHint()
*/
02381 int QTreeView::indexRowHeight(const QModelIndex &index) const
{
    Q_D(const QTreeView);
    int i = d->viewIndex(index);
    if (i == -1)
        return 0;
    return d->itemHeight(i);
}

/*!
  \reimp
*/
02393 void QTreeView::horizontalScrollbarAction(int action)
{
    QAbstractItemView::horizontalScrollbarAction(action);
}

/*!
  \reimp
*/
02401 bool QTreeView::isIndexHidden(const QModelIndex &index) const
{
    return (isColumnHidden(index.column()) || isRowHidden(index.row(), index.parent()));
}

/*
  private implementation
*/
void QTreeViewPrivate::initialize()
{
    Q_Q(QTreeView);
    q->setSelectionBehavior(QAbstractItemView::SelectRows);
    q->setSelectionMode(QAbstractItemView::SingleSelection);
    q->setHorizontalScrollMode(QAbstractItemView::ScrollPerPixel);
    q->setAttribute(Qt::WA_MacShowFocusRect);

    QHeaderView *header = new QHeaderView(Qt::Horizontal, q);
    header->setMovable(true);
    header->setStretchLastSection(true);
    header->setDefaultAlignment(Qt::AlignLeft|Qt::AlignVCenter);
    q->setHeader(header);

    // animation
    QObject::connect(&timeline, SIGNAL(frameChanged(int)), viewport, SLOT(update()));
    QObject::connect(&timeline, SIGNAL(finished()), q, SLOT(_q_endAnimatedOperation()));
}

void QTreeViewPrivate::expand(int item, bool emitSignal)
{
    Q_Q(QTreeView);

    if (item == -1 || viewItems.at(item).expanded)
        return;

    if (emitSignal && animationsEnabled)
        prepareAnimatedOperation(item, AnimatedOperation::Expand);

    QAbstractItemView::State oldState = q->state();
    q->setState(QAbstractItemView::ExpandingState);
    const QModelIndex index = viewItems.at(item).index;
    expandedIndexes.append(index);
    viewItems[item].expanded = true;
    layout(item);
    if (model->hasChildren(index))
        reexpandChildren(index); // will call expand with emitSignal == false
    q->setState(oldState);

    if (emitSignal) {
        if (animationsEnabled)
            beginAnimatedOperation();
        else
            emit q->expanded(index);
    }
    if (model->canFetchMore(index))
        model->fetchMore(index);
}

void QTreeViewPrivate::collapse(int item, bool emitSignal)
{
    Q_Q(QTreeView);

    if (item == -1 || expandedIndexes.isEmpty())
        return;

    int total = viewItems.at(item).total;
    const QModelIndex &modelIndex = viewItems.at(item).index;
    int index = expandedIndexes.indexOf(modelIndex);
    if (index == -1 || viewItems.at(item).expanded == false)
        return; // nothing to do

    if (emitSignal && animationsEnabled)
        prepareAnimatedOperation(item, AnimatedOperation::Collapse);

    QAbstractItemView::State oldState = q->state();
    q->setState(QAbstractItemView::CollapsingState);
    expandedIndexes.remove(index);
    viewItems[item].expanded = false;
    index = item;
    QModelIndex parent = modelIndex;
    while (parent.isValid() && parent != root) {
        Q_ASSERT(index > -1);
        viewItems[index].total -= total;
        parent = parent.parent();
        index = viewIndex(parent);
    }
    viewItems.remove(item + 1, total); // collapse
    q->setState(oldState);

    if (emitSignal) {
        if (animationsEnabled)
            beginAnimatedOperation();
        else
            emit q->collapsed(modelIndex);
    }
}

void QTreeViewPrivate::prepareAnimatedOperation(int item, AnimatedOperation::Type type)
{
    animatedOperation.item = item;
    animatedOperation.type = type;

    int top = coordinateForItem(item) + itemHeight(item);
    QRect rect = viewport->rect();
    if (type == AnimatedOperation::Collapse) {
        int h = 0;
        int c = item + viewItems.at(item).total + 1;
        for (int i = item + 1; i < c; ++i)
            h += itemHeight(i);
        rect.setHeight(h);
        animatedOperation.duration = h;
    }
    rect.moveTop(top);
    animatedOperation.top = top;
}

void QTreeViewPrivate::beginAnimatedOperation()
{
    Q_Q(QTreeView);

    QRect rect = viewport->rect();
    if (animatedOperation.type == AnimatedOperation::Expand) {
        int h = 0;
        int c = animatedOperation.item + viewItems.at(animatedOperation.item).total + 1;
        for (int i = animatedOperation.item + 1; i < c; ++i)
            h += itemHeight(i);
        rect.setHeight(h);
        animatedOperation.duration = h;
    }
    rect.moveTop(animatedOperation.top);

    animatedOperation.after = renderTreeToPixmap(rect);

    timeline.stop();
    timeline.setDuration(1000);
    timeline.setFrameRange(animatedOperation.top, animatedOperation.top + animatedOperation.duration);
    timeline.start();

    q->setState(QAbstractItemView::AnimatingState);
}

void QTreeViewPrivate::_q_endAnimatedOperation()
{
    Q_Q(QTreeView);
    animatedOperation.before = QPixmap();
    animatedOperation.after = QPixmap();
    q->setState(QAbstractItemView::NoState);
    if (animatedOperation.type == AnimatedOperation::Expand)
        emit q->expanded(viewItems.at(animatedOperation.item).index);
    else // operation == AnimatedOperation::Collapse
        emit q->collapsed(viewItems.at(animatedOperation.item).index);
    q->updateGeometries();
    viewport->update();
}

void QTreeViewPrivate::drawAnimatedOperation(QPainter *painter) const
{
    int start = timeline.startFrame();
    int end = timeline.endFrame();
    bool collapsing = animatedOperation.type == AnimatedOperation::Collapse;
    int current = collapsing ? end - timeline.currentFrame() + start : timeline.currentFrame();
    const QPixmap top = collapsing ? animatedOperation.before : animatedOperation.after;
    painter->drawPixmap(0, start, top, 0, end - current - 1, top.width(), top.height());
    const QPixmap bottom = collapsing ? animatedOperation.after : animatedOperation.before;
    painter->drawPixmap(0, current, bottom);
}

QPixmap QTreeViewPrivate::renderTreeToPixmap(const QRect &rect) const
{
    Q_Q(const QTreeView);
    QPixmap pixmap(rect.size());
    QPainter painter(&pixmap);
    painter.fillRect(QRect(QPoint(0,0), rect.size()), q->palette().base());
    painter.translate(0, -rect.top());
    q->drawTree(&painter, QRegion(rect));
    painter.end();
    return pixmap;
}

void QTreeViewPrivate::_q_currentChanged(const QModelIndex &current, const QModelIndex &previous)
{
    Q_Q(QTreeView);
    if (previous.isValid()) {
        QRect previousRect = q->visualRect(previous);
        if (allColumnsShowFocus) {
            previousRect.setX(0);
            previousRect.setWidth(viewport->width());
        }
        viewport->update(previousRect);
    }
    if (current.isValid()) {
        QRect currentRect = q->visualRect(current);
        if (allColumnsShowFocus) {
            currentRect.setX(0);
            currentRect.setWidth(viewport->width());
        }
        viewport->update(currentRect);
    }
}

void QTreeViewPrivate::_q_columnsAboutToBeRemoved(const QModelIndex &parent, int start, int end)
{
    Q_UNUSED(parent);
    if (start <= 0 && 0 <= end)
        viewItems.clear();
}

void QTreeViewPrivate::_q_columnsRemoved(const QModelIndex &parent, int start, int end)
{
    Q_UNUSED(parent);
    if (start <= 0 && 0 <= end)
        doDelayedItemsLayout();
}

void QTreeViewPrivate::layout(int i)
{
    Q_Q(QTreeView);
    QModelIndex current;
    QModelIndex parent = (i < 0) ? (QModelIndex)root : modelIndex(i);
    // modelIndex() will return an index that don't have a parent if column 0 is hidden,
    // so we must make sure that parent points to the actual parent that has children.
    if (parent != root)
        parent = model->index(parent.row(), 0, parent.parent());
    
    if (i>=0 && !parent.isValid()) {
        //modelIndex() should never return something invalid for the real items. 
        //This can happen if columncount has been set to 0.
        //To avoid infinite loop we stop here.
        return;
    }

    int count = 0;
    if (model->hasChildren(parent))
        count = model->rowCount(parent);

    if (i == -1) {
        viewItems.resize(count);
    } else {
        if (viewItems[i].total != (uint)count)
            viewItems.insert(i + 1, count, QTreeViewItem()); // expand
    }

    int first = i + 1;
    int level = (i >= 0 ? viewItems.at(i).level + 1 : 0);
    int hidden = 0;
    int last = 0;

    int firstColumn = 0;
    while (header->isSectionHidden(firstColumn) && firstColumn < header->count())
        ++firstColumn;

    for (int j = first; j < first + count; ++j) {
        current = model->index(j - first, firstColumn, parent);
        if (q->isRowHidden(current.row(), parent)) { // ### slow with lots of hidden rows
            ++hidden;
            last = j - hidden;
        } else {
            last = j - hidden;
            viewItems[last].index = current;
            viewItems[last].level = level;
            viewItems[last].spanning = q->isRowSpanning(current.row(), parent);
        }
    }

    // remove hidden items
    if (hidden > 0)
        viewItems.remove(last + 1, hidden); // collapse

    while (parent != root) {
        Q_ASSERT(i > -1);
        viewItems[i].total += count - hidden;
        parent = parent.parent();
        i = viewIndex(parent);
    }
}

int QTreeViewPrivate::pageUp(int i) const
{
    int index = itemAtCoordinate(coordinateForItem(i) - viewport->height());
    return index == -1 ? 0 : index;
}

int QTreeViewPrivate::pageDown(int i) const
{
    int index = itemAtCoordinate(coordinateForItem(i) + viewport->height());
    return index == -1 ? viewItems.count() - 1 : index;
}

int QTreeViewPrivate::indentationForItem(int item) const
{
    if (item < 0 || item >= viewItems.count())
        return 0;
    int level = viewItems.at(item).level;
    if (rootDecoration)
        ++level;
    return level * indent;
}

int QTreeViewPrivate::itemHeight(int item) const
{
    if (uniformRowHeights)
        return defaultItemHeight;
    if (viewItems.isEmpty())
        return 0;
    const QModelIndex &index = viewItems.at(item).index;
    int height = viewItems.at(item).height;
    if (height <= 0 && index.isValid()) {
        height = q_func()->indexRowSizeHint(index);
        viewItems[item].height = height;
    }
    if (!index.isValid() || height < 0)
        return 0;
    return height;
}


/*!
  \internal
  Returns the viewport y coordinate for \a item.
*/
int QTreeViewPrivate::coordinateForItem(int item) const
{
    Q_Q(const QTreeView);
    if (verticalScrollMode == QAbstractItemView::ScrollPerPixel) {
        if (uniformRowHeights)
            return (item * defaultItemHeight) - q->verticalScrollBar()->value();
        // ### optimize (spans or caching)
        int y = 0;
        for (int i = 0; i < viewItems.count(); ++i) {
            if (i == item)
                return y - q->verticalScrollBar()->value();
            y += itemHeight(i);
        }
    } else { // ScrollPerItem
        int topViewItemIndex = q->verticalScrollBar()->value();
        if (uniformRowHeights)
            return defaultItemHeight * (item - topViewItemIndex);
        if (item >= topViewItemIndex) {
            // search in the visible area first and continue down
            // ### slow if the item is not visible
            int viewItemCoordinate = 0;
            int viewItemIndex = topViewItemIndex;
            while (viewItemIndex < viewItems.count()) {
                if (viewItemIndex == item)
                    return viewItemCoordinate;
                viewItemCoordinate += itemHeight(viewItemIndex);
                ++viewItemIndex;
            }
            // below the last item in the view
            Q_ASSERT(false);
            return viewItemCoordinate;
        } else {
            // search the area above the viewport (used for editor widgets)
            int viewItemCoordinate = 0;
            for (int viewItemIndex = topViewItemIndex; viewItemIndex > 0; --viewItemIndex) {
                if (viewItemIndex == item)
                    return viewItemCoordinate;
                viewItemCoordinate -= itemHeight(viewItemIndex - 1);
            }
            return viewItemCoordinate;
        }
    }
    return 0;
}

/*!
  \internal
  Returns the index of the view item at the
  given viewport \a coordinate.

  \sa modelIndex()
*/
int QTreeViewPrivate::itemAtCoordinate(int coordinate) const
{
    Q_Q(const QTreeView);
    const int itemCount = viewItems.count();
    if (itemCount == 0)
        return -1;
    if (uniformRowHeights && defaultItemHeight <= 0)
        return -1;
    if (verticalScrollMode == QAbstractItemView::ScrollPerPixel) {
        if (uniformRowHeights) {
            const int viewItemIndex = (coordinate + q->verticalScrollBar()->value()) / defaultItemHeight;
            return (viewItemIndex >= itemCount ? -1 : viewItemIndex);
        }
        // ### optimize
        int viewItemCoordinate = 0;
        const int contentsCoordinate = coordinate + q->verticalScrollBar()->value();
        for (int viewItemIndex = 0; viewItemIndex < viewItems.count(); ++viewItemIndex) {
            viewItemCoordinate += itemHeight(viewItemIndex);
            if (viewItemCoordinate >= contentsCoordinate)
                return (viewItemIndex >= itemCount ? -1 : viewItemIndex);
        }
    } else { // ScrollPerItem
        int topViewItemIndex = q->verticalScrollBar()->value();
        if (uniformRowHeights) {
            if (coordinate < 0)
                coordinate -= defaultItemHeight - 1;
            const int viewItemIndex = topViewItemIndex + (coordinate / defaultItemHeight);
            return (viewItemIndex >= itemCount ? -1 : viewItemIndex);
        }
        if (coordinate >= 0) {
            // the coordinate is in or below the viewport
            int viewItemCoordinate = 0;
            for (int viewItemIndex = topViewItemIndex; viewItemIndex < viewItems.count(); ++viewItemIndex) {
                viewItemCoordinate += itemHeight(viewItemIndex);
                if (viewItemCoordinate > coordinate)
                    return (viewItemIndex >= itemCount ? -1 : viewItemIndex);
            }
        } else {
            // the coordinate is above the viewport
            int viewItemCoordinate = 0;
            for (int viewItemIndex = topViewItemIndex; viewItemIndex >= 0; --viewItemIndex) {
                if (viewItemCoordinate <= coordinate)
                    return (viewItemIndex >= itemCount ? -1 : viewItemIndex);
                viewItemCoordinate -= itemHeight(viewItemIndex);
            }
        }
    }
    return -1;
}

int QTreeViewPrivate::viewIndex(const QModelIndex &index) const
{
    if (!index.isValid() || viewItems.isEmpty())
        return -1;

    const int totalCount = viewItems.count();
    const QModelIndex parent = index.parent();

    // A quick check near the last item to see if we are just incrementing
    const int start = lastViewedItem > 2 ? lastViewedItem - 2 : 0;
    const int end = lastViewedItem < totalCount - 2 ? lastViewedItem + 2 : totalCount;
    for (int i = start; i < end; ++i) {
        const QModelIndex idx = viewItems.at(i).index;
        if (idx.row() == index.row()) {
            if (idx.internalId() == index.internalId() || idx.parent() == parent) {// ignore column
                lastViewedItem = i;
                return i;
            }
        }
    }

    // NOTE: this function is slow if the item is outside the visible area
    // search in visible items first and below
    int t = firstVisibleItem();
    t = t > 100 ? t - 100 : 0; // start 100 items above the visible area

    for (int i = t; i < totalCount; ++i) {
        const QModelIndex idx = viewItems.at(i).index;
        if (idx.row() == index.row()) {
            if (idx.internalId() == index.internalId() || idx.parent() == parent) {// ignore column
                lastViewedItem = i;
                return i;
            }
        }
    }
    // search from top to first visible
    for (int j = 0; j < t; ++j) {
        const QModelIndex idx = viewItems.at(j).index;
        if (idx.row() == index.row()) {
            if (idx.internalId() == index.internalId() || idx.parent() == parent) { // ignore column
                lastViewedItem = j;
                return j;
            }
        }
    }
    // nothing found
    return -1;
}

QModelIndex QTreeViewPrivate::modelIndex(int i) const
{
    return ((i < 0 || i >= viewItems.count())
            ? QModelIndex() : viewItems.at(i).index);
}

int QTreeViewPrivate::firstVisibleItem(int *offset) const
{
    Q_Q(const QTreeView);
    const int value = q->verticalScrollBar()->value();
    if (verticalScrollMode == QAbstractItemView::ScrollPerItem) {
        if (offset)
            *offset = 0;
        return (value < 0 || value >= viewItems.count()) ? -1 : value;
    }
    // ScrollMode == ScrollPerPixel
    if (uniformRowHeights) {
        if (offset)
            *offset = -(value % defaultItemHeight);
        return value / defaultItemHeight;
    }
    int y = 0; // ### optimize (use spans ?)
    for (int i = 0; i < viewItems.count(); ++i) {
        y += itemHeight(i); // the height value is cached
        if (y > value) {
            if (offset)
                *offset = y - value - itemHeight(i);
            return i;
        }
    }
    return -1;
}

int QTreeViewPrivate::columnAt(int x) const
{
    return header->logicalIndexAt(x); 
}

void QTreeViewPrivate::relayout(const QModelIndex &parent)
{
    Q_Q(QTreeView);
    // do a local relayout of the items
    if (parent.isValid()) {
        int parentViewIndex = viewIndex(parent);
        if (parentViewIndex > -1 && viewItems.at(parentViewIndex).expanded) {
            collapse(parentViewIndex, false); // remove the current layout
            expand(parentViewIndex, false); // do the relayout
            q->updateGeometries();
            viewport->update();
        }
    } else {
        viewItems.clear();
        q->doItemsLayout();
    }
}

void QTreeViewPrivate::reexpandChildren(const QModelIndex &parent)
{
    if (!model)
        return;
    // ### optimize
    QVector<int> toBeExpanded;
    QVector<QPersistentModelIndex>::iterator it;
    for (it = expandedIndexes.begin(); it != expandedIndexes.end(); ) {
        QModelIndex index = *it;
        if (!index.isValid()) {
            it = expandedIndexes.erase(it);
        } else if (model->parent(index) == parent) {
            int v = viewIndex(index);
            if (v >= 0) {
                toBeExpanded.append(v);
                it = expandedIndexes.erase(it);
            } else {
                ++it;
            }
        } else {
            ++it;
        }
    }
    qSort(toBeExpanded.begin(), toBeExpanded.end(), qGreater<int>());
    for (int i = 0; i < toBeExpanded.count(); ++i)
        expand(toBeExpanded.at(i), false);
}

void QTreeViewPrivate::updateScrollBars()
{
    Q_Q(QTreeView);
    QSize viewportSize = viewport->size();
    if (!viewportSize.isValid())
        viewportSize = QSize(0, 0);

    if (verticalScrollMode == QAbstractItemView::ScrollPerItem) {
        int itemsInViewport = 0;
        if (uniformRowHeights) {
            if (defaultItemHeight <= 0)
                itemsInViewport = viewItems.count();
            else
                itemsInViewport = viewportSize.height() / defaultItemHeight;
        } else {
            const int itemsCount = viewItems.count();
            const int viewportHeight = viewportSize.height();
            for (int height = 0, item = itemsCount - 1; item >= 0; --item) {
                height += itemHeight(item);
                if (height > viewportHeight)
                    break;
                ++itemsInViewport;
            }
        }
        if (!viewItems.isEmpty())
            itemsInViewport = qMax(1, itemsInViewport);
        q->verticalScrollBar()->setRange(0, viewItems.count() - itemsInViewport);
        q->verticalScrollBar()->setPageStep(itemsInViewport);
    } else { // scroll per pixel
        int contentsHeight = 0;
        if (uniformRowHeights) {
            contentsHeight = defaultItemHeight * viewItems.count();
        } else { // ### optimize (spans or caching)
            for (int i = 0; i < viewItems.count(); ++i)
                contentsHeight += itemHeight(i);
        }
        q->verticalScrollBar()->setRange(0, contentsHeight - viewportSize.height());
        q->verticalScrollBar()->setPageStep(viewportSize.height());
    }

    if (horizontalScrollMode == QAbstractItemView::ScrollPerItem) {
        const int columnCount = header->count();
        const int viewportWidth = viewportSize.width();
        int columnsInViewport = 0;
        for (int width = 0, column = columnCount - 1; column >= 0; --column) {
            int logical = header->logicalIndex(column);
            width += header->sectionSize(logical);
            if (width > viewportWidth)
                break;
            ++columnsInViewport;
        }
        if (columnCount > 0)
            columnsInViewport = qMax(1, columnsInViewport);
        q->horizontalScrollBar()->setRange(0, columnCount - columnsInViewport);
        q->horizontalScrollBar()->setPageStep(columnsInViewport);
    } else { // scroll per pixel
        const int horizontalLength = header->length();
        const QSize maxSize = q->maximumViewportSize();
        if (maxSize.width() >= horizontalLength && q->verticalScrollBar()->maximum() <= 0)
            viewportSize = maxSize;
        q->horizontalScrollBar()->setPageStep(viewportSize.width());

        QWidget *w = q;
        while (w->parentWidget())
            w = w->parentWidget();

        q->horizontalScrollBar()->setRange(0, qMax(horizontalLength - viewportSize.width(), 0));
    }
}

int QTreeViewPrivate::itemDecorationAt(const QPoint &pos) const
{
    Q_Q(const QTreeView);
    int x = pos.x();
    int column = header->logicalIndexAt(x);
    if (column == -1)
        return -1; // no logical index at x
    int position = header->sectionViewportPosition(column);
    int size = header->sectionSize(column);
    int cx = (q->isRightToLeft() ? size - x + position : x - position);
    int viewItemIndex = itemAtCoordinate(pos.y());
    int itemIndentation = indentationForItem(viewItemIndex);
    QModelIndex index = modelIndex(viewItemIndex);

    if (!index.isValid() || column != 0
        || cx < (itemIndentation - indent) || cx > itemIndentation)
        return -1; // pos is outside the decoration rect

    if (!rootDecoration && index.parent() == root)
        return -1; // no decoration at root

    QRect rect;
    if (q->isRightToLeft())
        rect = QRect(position + size - itemIndentation, coordinateForItem(viewItemIndex),
                     indent, itemHeight(viewItemIndex));
    else
        rect = QRect(position + itemIndentation - indent, coordinateForItem(viewItemIndex),
                     indent, itemHeight(viewItemIndex));
    QStyleOption opt;
    opt.initFrom(q);
    opt.rect = rect;
    QRect returning = q->style()->subElementRect(QStyle::SE_TreeViewDisclosureItem, &opt, q);
    if (!returning.contains(pos))
        return -1;

    return viewItemIndex;
}

void QTreeViewPrivate::select(int top, int bottom,
                              QItemSelectionModel::SelectionFlags command)
{
    Q_Q(QTreeView);
    QModelIndex previous;
    QItemSelectionRange currentRange;
    QStack<QItemSelectionRange> rangeStack;
    QItemSelection selection;
    for (int i = top; i <= bottom; ++i) {
        QModelIndex index = modelIndex(i);
        QModelIndex parent = index.parent();
        if (previous.isValid() && parent == previous.parent()) {
            // same parent
            QModelIndex tl = model->index(currentRange.top(), currentRange.left(),
                                          currentRange.parent());
            currentRange = QItemSelectionRange(tl, index);
        } else if (previous.isValid() && parent == model->sibling(previous.row(), 0, previous)) {
            // item is child of previous
            rangeStack.push(currentRange);
            currentRange = QItemSelectionRange(index);
        } else {
            if (currentRange.isValid())
                selection.append(currentRange);
            if (rangeStack.isEmpty()) {
                currentRange = QItemSelectionRange(index);
            } else {
                currentRange = rangeStack.pop();
                if (parent == currentRange.parent()) {
                    QModelIndex tl = model->index(currentRange.top(),
                                                  currentRange.left(),
                                                  currentRange.parent());
                    currentRange = QItemSelectionRange(tl, index);
                } else {
                    selection.append(currentRange);
                    currentRange = QItemSelectionRange(index);
                }
            }
        }
        previous = index;
    }
    if (currentRange.isValid())
        selection.append(currentRange);
    for (int i = 0; i < rangeStack.count(); ++i)
        selection.append(rangeStack.at(i));
    q->selectionModel()->select(selection, command);
}

QPair<int,int> QTreeViewPrivate::startAndEndColumns(const QRect &rect) const
{
    Q_Q(const QTreeView);
    int start = header->visualIndexAt(rect.left());
    int end = header->visualIndexAt(rect.right());
    if (q->isRightToLeft()) {
        start = (start == -1 ? header->count() - 1 : start);
        end = (end == -1 ? 0 : end);
    } else {
        start = (start == -1 ? 0 : start);
        end = (end == -1 ? header->count() - 1 : end);
    }
    return qMakePair<int,int>(qMin(start, end), qMax(start, end));
}

bool QTreeViewPrivate::hasVisibleChildren(const QModelIndex& parent) const
{
    Q_Q(const QTreeView);
    if (model->hasChildren(parent)) {
        if (hiddenIndexes.isEmpty())
            return true;
        if (q->isIndexHidden(parent))
            return false;
        int rowCount = model->rowCount(parent);
        for (int i = 0; i < rowCount; ++i) {
            if (!q->isRowHidden(i, parent))
                return true;
        }
        if (rowCount == 0)
            return true;
    }
    return false;
}

void QTreeViewPrivate::rowsRemoved(const QModelIndex &parent,
                                   int start, int end, bool after)
{
    Q_Q(QTreeView);
    const int parentItem = viewIndex(parent);
    if ((parentItem != -1) || (parent == root)) {

        const uint childLevel = (parentItem == -1)
                                ? uint(0) : viewItems.at(parentItem).level + 1;
        const int firstChildItem = parentItem + 1;
        int lastChildItem = firstChildItem + ((parentItem == -1)
                                              ? viewItems.count()
                                              : viewItems.at(parentItem).total) - 1;
        const int delta = end - start + 1;

        int removedCount = 0;
        for (int item = firstChildItem; item <= lastChildItem; ) {
            Q_ASSERT(viewItems.at(item).level == childLevel);
            const QModelIndex modelIndex = viewItems.at(item).index;
            Q_ASSERT(modelIndex.parent() == parent);
            const int count = viewItems.at(item).total + 1;
            if (modelIndex.row() < start) {
                // not affected by the removal
                item += count;
            } else if (modelIndex.row() <= end) {
                // removed
                viewItems.remove(item, count);
                removedCount += count;
                lastChildItem -= count;
            } else {
                if (after) {
                    // moved; update the model index
                    viewItems[item].index = model->index(
                        modelIndex.row() - delta, modelIndex.column(), parent);
                }
                item += count;
            }
        }

        updateChildCount(parentItem, -removedCount);
        if (after) {
            q->updateGeometries();
            viewport->update();
        } else {
            //we have removed items: we should at least update the scroll bar values.
            // They are used to determine the item geometry.
            updateScrollBars(); 
        }
    }
}

void QTreeViewPrivate::updateChildCount(const int parentItem, const int delta)
{
    if ((parentItem != -1) && delta) {
        int level = viewItems.at(parentItem).level;
        int item = parentItem;
        do {
            Q_ASSERT(item >= 0);
            for ( ; int(viewItems.at(item).level) != level; --item) ;
            viewItems[item].total += delta;
            --level;
        } while (level >= 0);
    }
}

#include "moc_qtreeview.cpp"

#endif // QT_NO_TREEVIEW

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