src/gui/itemviews/qheaderview.cpp

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/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
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****************************************************************************/

#include "qheaderview.h"

#ifndef QT_NO_ITEMVIEWS
#include <qbitarray.h>
#include <qbrush.h>
#include <qdebug.h>
#include <qevent.h>
#include <qpainter.h>
#include <qscrollbar.h>
#include <qtooltip.h>
#include <qwhatsthis.h>
#include <qstyle.h>
#include <qstyleoption.h>
#include <qvector.h>
#include <qapplication.h>
#include <qvarlengtharray.h>
#include <qabstractitemdelegate.h>
#include <qvariant.h>
#include <private/qheaderview_p.h>

// ### Qt 5: change to sectionAutoResized()

QHeaderView::QHeaderView(Qt::Orientation orientation, QWidget *parent)
    : QAbstractItemView(*new QHeaderViewPrivate, parent)
{
    Q_D(QHeaderView);
    d->setDefaultValues(orientation);
    initialize();
}

QHeaderView::QHeaderView(QHeaderViewPrivate &dd,
                         Qt::Orientation orientation, QWidget *parent)
    : QAbstractItemView(dd, parent)
{
    Q_D(QHeaderView);
    d->setDefaultValues(orientation);
    initialize();
}

QHeaderView::~QHeaderView()
{
}

void QHeaderView::initialize()
{
    Q_D(QHeaderView);
    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setFrameStyle(NoFrame);
    d->viewport->setMouseTracking(true);
    d->viewport->setBackgroundRole(QPalette::Button);
    d->textElideMode = Qt::ElideNone;
    delete d->itemDelegate;
}

void QHeaderView::setModel(QAbstractItemModel *model)
{
    // Don't optimize away:
    // if (model == this->model())
    //      return;
    // This is the only way to reset moved sections
    Q_D(QHeaderView);
    if (d->orientation == Qt::Horizontal) {
        QObject::disconnect(d->model, SIGNAL(columnsInserted(QModelIndex,int,int)),
                            this, SLOT(sectionsInserted(QModelIndex,int,int)));
        QObject::disconnect(d->model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
                            this, SLOT(sectionsAboutToBeRemoved(QModelIndex,int,int)));
        QObject::disconnect(d->model, SIGNAL(columnsRemoved(QModelIndex,int,int)),
                            this, SLOT(_q_sectionsRemoved(QModelIndex,int,int)));
    } else {
        QObject::disconnect(d->model, SIGNAL(rowsInserted(QModelIndex,int,int)),
                            this, SLOT(sectionsInserted(QModelIndex,int,int)));
        QObject::disconnect(d->model, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
                            this, SLOT(sectionsAboutToBeRemoved(QModelIndex,int,int)));
        QObject::disconnect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                            this, SLOT(_q_sectionsRemoved(QModelIndex,int,int)));
    }
    QObject::disconnect(d->model, SIGNAL(headerDataChanged(Qt::Orientation,int,int)),
                        this, SLOT(headerDataChanged(Qt::Orientation,int,int)));

    if (model) {
        if (d->orientation == Qt::Horizontal) {
            QObject::connect(model, SIGNAL(columnsInserted(QModelIndex,int,int)),
                             this, SLOT(sectionsInserted(QModelIndex,int,int)));
            QObject::connect(model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
                this, SLOT(sectionsAboutToBeRemoved(QModelIndex,int,int)));
            QObject::connect(model, SIGNAL(columnsRemoved(QModelIndex,int,int)),
                this, SLOT(_q_sectionsRemoved(QModelIndex,int,int)));
        } else {
            QObject::connect(model, SIGNAL(rowsInserted(QModelIndex,int,int)),
                             this, SLOT(sectionsInserted(QModelIndex,int,int)));
            QObject::connect(model, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
                             this, SLOT(sectionsAboutToBeRemoved(QModelIndex,int,int)));
            QObject::connect(model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                             this, SLOT(_q_sectionsRemoved(QModelIndex,int,int)));
        }
        QObject::connect(model, SIGNAL(headerDataChanged(Qt::Orientation,int,int)),
                         this, SLOT(headerDataChanged(Qt::Orientation,int,int)));
    }
    d->clear();

    QAbstractItemView::setModel(model);
    // Users want to set sizes and modes before the widget is shown.
    // Thus, we have to initialize when the model is set,
    // and not lazily like we do in the other views.
    initializeSections();
}

Qt::Orientation QHeaderView::orientation() const
{
    Q_D(const QHeaderView);
    return d->orientation;
}

int QHeaderView::offset() const
{
    Q_D(const QHeaderView);
    return d->offset;
}

void QHeaderView::setOffset(int newOffset)
{
    Q_D(QHeaderView);
    if (d->offset == (uint)newOffset)
        return;
    int ndelta = d->offset - newOffset;
    d->offset = newOffset;
    if (d->orientation == Qt::Horizontal)
        d->viewport->scroll(isRightToLeft() ? -ndelta : ndelta, 0);
    else
        d->viewport->scroll(0, ndelta);
    if (d->state == QHeaderViewPrivate::ResizeSection) {
        QPoint cursorPos = QCursor::pos();
        if (d->orientation == Qt::Horizontal)
            QCursor::setPos(cursorPos.x() + ndelta, cursorPos.y());
        else
            QCursor::setPos(cursorPos.x(), cursorPos.y() + ndelta);
        d->firstPos += ndelta;
        d->lastPos += ndelta;
    }
}

void QHeaderView::setOffsetToSectionPosition(int visualIndex)
{
    Q_D(QHeaderView);
    if (visualIndex > -1 && visualIndex < d->sectionCount) {
        int position = d->headerSectionPosition(d->adjustedVisualIndex(visualIndex));
        setOffset(position);
    }
}

int QHeaderView::length() const
{
    Q_D(const QHeaderView);
    //Q_ASSERT(d->headerLength() == d->length);
    return d->length;
}

QSize QHeaderView::sizeHint() const
{
    Q_D(const QHeaderView);
    if (count() < 1)
        return QSize(0, 0);
    if (d->cachedSizeHint.isValid())
        return d->cachedSizeHint;
    int width = 0;
    int height = 0;
    // get size hint for the first n sections
    int c = qMin(count(), 100);
    for (int i = 0; i < c; ++i) {
        QSize hint = sectionSizeFromContents(i);
        width = qMax(hint.width(), width);
        height = qMax(hint.height(), height);
    }
    // get size hint for the last n sections
    c = qMax(count() - 100, c);
    for (int j = count() - 1; j >= c; --j) {
        QSize hint = sectionSizeFromContents(j);
        width = qMax(hint.width(), width);
        height = qMax(hint.height(), height);
    }
    d->cachedSizeHint = QSize(width, height);
    return d->cachedSizeHint;
}

int QHeaderView::sectionSizeHint(int logicalIndex) const
{
    Q_D(const QHeaderView);
    if (logicalIndex < 0 || logicalIndex >= count())
        return -1;
    QSize size = sectionSizeFromContents(logicalIndex);
    int hint = d->orientation == Qt::Horizontal ? size.width() : size.height();
    return qMax(minimumSectionSize(), hint);
}

int QHeaderView::visualIndexAt(int position) const
{
    Q_D(const QHeaderView);
    uint vposition = position;
    d->executePostedLayout();
    const int count = d->sectionCount;
    if (count < 1)
        return -1;

    if (d->reverse())
        vposition = d->viewport->width() - vposition;
    vposition += d->offset;

    if (vposition > d->length)
        return -1;
    int visual = d->headerVisualIndexAt(vposition);
    if (visual < 0)
        return -1;

    while (d->isVisualIndexHidden(visual)){
        ++visual;
        if (visual >= count)
            return -1;
    }
    return visual;
}

int QHeaderView::logicalIndexAt(int position) const
{
    const int visual = visualIndexAt(position);
    if (visual > -1)
        return logicalIndex(visual);
    return -1;
}

int QHeaderView::sectionSize(int logicalIndex) const
{
    Q_D(const QHeaderView);
    if (logicalIndex < 0 || logicalIndex >= count())
        return 0;
    if (isSectionHidden(logicalIndex))
        return 0;
    int visual = visualIndex(logicalIndex);
    if (visual == -1)
        return 0;
    return d->headerSectionSize(visual);
}

int QHeaderView::sectionPosition(int logicalIndex) const
{
    Q_D(const QHeaderView);
    int visual = visualIndex(logicalIndex);
    // in some cases users may change the selections
    // before we have a chance to do the layout
    if (visual == -1)
        return -1;
    return d->headerSectionPosition(visual);
}

int QHeaderView::sectionViewportPosition(int logicalIndex) const
{
    Q_D(const QHeaderView);
    if (logicalIndex < 0 || logicalIndex >= count())
        return -1;
    int position = sectionPosition(logicalIndex);
    if (position < 0)
        return position; // the section was hidden
    int offsetPosition = position - d->offset;
    if (d->reverse())
        return d->viewport->width() - (offsetPosition + sectionSize(logicalIndex));
    return offsetPosition;
}

void QHeaderView::moveSection(int from, int to)
{
    Q_D(QHeaderView);

    d->executePostedLayout();
    if (from < 0 || from >= d->sectionCount || to < 0 || to >= d->sectionCount)
        return;

    if (from == to) {
        int logical = logicalIndex(from);
        Q_ASSERT(logical != -1);
        updateSection(logical);
        return;
    }

    //int oldHeaderLength = length(); // ### for debugging; remove later
    d->initializeIndexMapping();

    QBitArray sectionHidden = d->sectionHidden;
    int *visualIndices = d->visualIndices.data();
    int *logicalIndices = d->logicalIndices.data();
    int logical = logicalIndices[from];
    int visual = from;

    int affected_count = qAbs(to - from) + 1;
    QVarLengthArray<int> sizes(affected_count);
    QVarLengthArray<ResizeMode> modes(affected_count);

    // move sections and indices
    if (to > from) {
        sizes[to - from] = d->headerSectionSize(from);
        modes[to - from] = d->headerSectionResizeMode(from);
        while (visual < to) {
            sizes[visual - from] = d->headerSectionSize(visual + 1);
            modes[visual - from] = d->headerSectionResizeMode(visual + 1);
            if (!sectionHidden.isEmpty())
                sectionHidden.setBit(visual, sectionHidden.testBit(visual + 1));
            visualIndices[logicalIndices[visual + 1]] = visual;
            logicalIndices[visual] = logicalIndices[visual + 1];
            ++visual;
        }
    } else {
        sizes[0] = d->headerSectionSize(from);
        modes[0] = d->headerSectionResizeMode(from);
        while (visual > to) {
            sizes[visual - to] = d->headerSectionSize(visual - 1);
            modes[visual - to] = d->headerSectionResizeMode(visual - 1);
            if (!sectionHidden.isEmpty())
                sectionHidden.setBit(visual, sectionHidden.testBit(visual - 1));
            visualIndices[logicalIndices[visual - 1]] = visual;
            logicalIndices[visual] = logicalIndices[visual - 1];
            --visual;
        }
    }
    if (!sectionHidden.isEmpty()) {
        sectionHidden.setBit(to, d->sectionHidden.testBit(from));
        d->sectionHidden = sectionHidden;
    }
    visualIndices[logical] = to;
    logicalIndices[to] = logical;

    //Q_ASSERT(oldHeaderLength == length());
    // move sizes
    // ### check for spans of section sizes here
    if (to > from) {
        for (visual = from; visual <= to; ++visual) {
            int size = sizes[visual - from];
            ResizeMode mode = modes[visual - from];
            d->createSectionSpan(visual, visual, size, mode);
        }
    } else {
        for (visual = to; visual <= from; ++visual) {
            int size = sizes[visual - to];
            ResizeMode mode = modes[visual - to];
            d->createSectionSpan(visual, visual, size, mode);
        }
    }
    //Q_ASSERT(d->headerLength() == length());
    //Q_ASSERT(oldHeaderLength == length());

    d->viewport->update();
    emit sectionMoved(logical, from, to);
}

void QHeaderView::swapSections(int first, int second)
{
    Q_D(QHeaderView);

    if (first == second)
        return;
    d->executePostedLayout();
    if (first < 0 || first >= d->sectionCount || second < 0 || second >= d->sectionCount)
        return;

    int firstSize = d->headerSectionSize(first);
    ResizeMode firstMode = d->headerSectionResizeMode(first);
    int firstLogical = d->logicalIndex(first);

    int secondSize = d->headerSectionSize(second);
    ResizeMode secondMode = d->headerSectionResizeMode(second);
    int secondLogical = d->logicalIndex(second);

    d->createSectionSpan(second, second, firstSize, firstMode);
    d->createSectionSpan(first, first, secondSize, secondMode);

    d->initializeIndexMapping();

    d->visualIndices[firstLogical] = second;
    d->logicalIndices[second] = firstLogical;

    d->visualIndices[secondLogical] = first;
    d->logicalIndices[first] = secondLogical;

    if (!d->sectionHidden.isEmpty()) {
        bool firstHidden = d->sectionHidden.testBit(first);
        bool secondHidden = d->sectionHidden.testBit(second);
        d->sectionHidden.setBit(first, secondHidden);
        d->sectionHidden.setBit(second, firstHidden);
    }

    d->viewport->update();
    emit sectionMoved(firstLogical, first, second);
    emit sectionMoved(secondLogical, second, first);
}

void QHeaderView::resizeSection(int logical, int size)
{
    Q_D(QHeaderView);
    if (logical < 0 || logical >= count())
        return;

    if (isSectionHidden(logical))
        return;

    int oldSize = sectionSize(logical);
    if (oldSize == size)
        return;

    d->executePostedLayout();
    d->invalidateCachedSizeHint();

    int visual = visualIndex(logical);
    Q_ASSERT(visual != -1);

    if (stretchLastSection() && visual == count() - 1)
        d->lastSectionSize = size;

    if (size != oldSize)
        d->createSectionSpan(visual, visual, size, d->headerSectionResizeMode(visual));

    int w = d->viewport->width();
    int h = d->viewport->height();
    int pos = sectionViewportPosition(logical);
    QRect r;
    if (orientation() == Qt::Horizontal)
        if (isRightToLeft())
            r.setRect(0, 0, pos + size, h);
        else
            r.setRect(pos, 0, w - pos, h);
    else
        r.setRect(0, pos, w, h - pos);

    if (d->hasAutoResizeSections()) {
        resizeSections();
        r = d->viewport->rect();
    }
    d->viewport->update(r.normalized());
    emit sectionResized(logical, oldSize, size);
}

void QHeaderView::resizeSections(QHeaderView::ResizeMode mode)
{
    Q_D(QHeaderView);
    d->resizeSections(mode, true);
}

bool QHeaderView::isSectionHidden(int logicalIndex) const
{
    Q_D(const QHeaderView);
    if (logicalIndex >= d->sectionHidden.count() || logicalIndex < 0 || logicalIndex >= d->sectionCount)
        return false;
    d->executePostedLayout();
    int visual = visualIndex(logicalIndex);
    Q_ASSERT(visual != -1);
    return d->sectionHidden.testBit(visual);
}

int QHeaderView::hiddenSectionCount() const
{
    Q_D(const QHeaderView);
    return d->hiddenSectionSize.count();
}

void QHeaderView::setSectionHidden(int logicalIndex, bool hide)
{
    Q_D(QHeaderView);
    if (logicalIndex < 0 || logicalIndex >= count())
        return;

    d->executePostedLayout();
    int visual = visualIndex(logicalIndex);
    Q_ASSERT(visual != -1);
    if (hide && d->isVisualIndexHidden(visual))
        return;
    if (hide) {
        int size = sectionSize(logicalIndex);
        if (!d->hasAutoResizeSections())
            resizeSection(logicalIndex, 0);
        d->hiddenSectionSize.insert(logicalIndex, size);
        if (d->sectionHidden.count() < count())
            d->sectionHidden.resize(count());
        d->sectionHidden.setBit(visual, true);
        if (d->hasAutoResizeSections())
            resizeSections();
    } else if (d->isVisualIndexHidden(visual)) {
        int size = d->hiddenSectionSize.value(logicalIndex, d->defaultSectionSize);
        d->hiddenSectionSize.remove(logicalIndex);
        if (d->hiddenSectionSize.isEmpty()) {
            d->sectionHidden.clear();
        } else {
            Q_ASSERT(visual <= d->sectionHidden.count());
            d->sectionHidden.setBit(visual, false);
        }
        resizeSection(logicalIndex, size);
    }
}

int QHeaderView::count() const
{
    Q_D(const QHeaderView);
    //Q_ASSERT(d->sectionCount == d->headerSectionCount());
    // ### this may affect the lazy layout
    d->executePostedLayout();
    return d->sectionCount;
}

int QHeaderView::visualIndex(int logicalIndex) const
{
    Q_D(const QHeaderView);
    if (logicalIndex < 0)
        return -1;
    d->executePostedLayout();
    if (d->visualIndices.isEmpty()) { // nothing has been moved, so we have no mapping
        if (logicalIndex < d->sectionCount)
            return logicalIndex;
    } else if (logicalIndex < d->visualIndices.count()) {
        int visual = d->visualIndices.at(logicalIndex);
        Q_ASSERT(visual < d->sectionCount);
        return visual;
    }
    return -1;
}

int QHeaderView::logicalIndex(int visualIndex) const
{
    Q_D(const QHeaderView);
    if (visualIndex < 0 || visualIndex >= d->sectionCount)
        return -1;
    return d->logicalIndex(visualIndex);
}

// ### Qt 5: change to setSectionsMovable()
void QHeaderView::setMovable(bool movable)
{
    Q_D(QHeaderView);
    d->movableSections = movable;
}

// ### Qt 5: change to sectionsMovable()
bool QHeaderView::isMovable() const
{
    Q_D(const QHeaderView);
    return d->movableSections;
}

// ### Qt 5: change to setSectionsClickable()
void QHeaderView::setClickable(bool clickable)
{
    Q_D(QHeaderView);
    d->clickableSections = clickable;
}

// ### Qt 5: change to sectionsClickable()
bool QHeaderView::isClickable() const
{
    Q_D(const QHeaderView);
    return d->clickableSections;
}

void QHeaderView::setHighlightSections(bool highlight)
{
    Q_D(QHeaderView);
    d->highlightSelected = highlight;
}

bool QHeaderView::highlightSections() const
{
    Q_D(const QHeaderView);
    return d->highlightSelected;
}

void QHeaderView::setResizeMode(ResizeMode mode)
{
    Q_D(QHeaderView);
    initializeSections();
    d->stretchSections = (mode == Stretch ? count() : 0);
    d->contentsSections =  (mode == ResizeToContents ? count() : 0);
    d->setGlobalHeaderResizeMode(mode);
    if (d->hasAutoResizeSections())
        resizeSections(); // section sizes may change as a result of the new mode
}

// ### Qt 5: change to setSectionResizeMode()
void QHeaderView::setResizeMode(int logicalIndex, ResizeMode mode)
{
    Q_D(QHeaderView);
    int visual = visualIndex(logicalIndex);
    Q_ASSERT(visual != -1);

    ResizeMode old = d->headerSectionResizeMode(visual);
    d->setHeaderSectionResizeMode(visual, mode);

    if (mode == Stretch && old != Stretch)
        ++d->stretchSections;
    else if (mode == ResizeToContents && old != ResizeToContents)
        ++d->contentsSections;
    else if (mode != Stretch && old == Stretch)
        --d->stretchSections;
    else if (mode != ResizeToContents && old == ResizeToContents)
        --d->contentsSections;

    if (d->hasAutoResizeSections() && d->state == QHeaderViewPrivate::NoState)
        resizeSections(); // section sizes may change as a result of the new mode
}

QHeaderView::ResizeMode QHeaderView::resizeMode(int logicalIndex) const
{
    Q_D(const QHeaderView);
    int visual = visualIndex(logicalIndex);
    Q_ASSERT(visual != -1);
    return d->visualIndexResizeMode(visual);
}

int QHeaderView::stretchSectionCount() const
{
    Q_D(const QHeaderView);
    return d->stretchSections;
}

void QHeaderView::setSortIndicatorShown(bool show)
{
    Q_D(QHeaderView);
    d->sortIndicatorShown = show;

    if (sortIndicatorSection() < 0 || sortIndicatorSection() > count())
        return;

    if (d->visualIndexResizeMode(sortIndicatorSection()) == ResizeToContents) {
        resizeSections();
        d->viewport->update();
    }
}

bool QHeaderView::isSortIndicatorShown() const
{
    Q_D(const QHeaderView);
    return d->sortIndicatorShown;
}

void QHeaderView::setSortIndicator(int logicalIndex, Qt::SortOrder order)
{
    Q_D(QHeaderView);

    Q_ASSERT(logicalIndex >= 0);

    // This is so that people can set the position of the sort indicator before the fill the model
    int old = d->sortIndicatorSection;
    d->sortIndicatorSection = logicalIndex;
    d->sortIndicatorOrder = order;

    if (logicalIndex >= d->sectionCount)
        return; // nothing to do

    if (old != logicalIndex && resizeMode(logicalIndex) == ResizeToContents) {
        resizeSections();
        d->viewport->update();
    } else {
        if (old != logicalIndex)
            updateSection(old);
        updateSection(logicalIndex);
    }
}

int QHeaderView::sortIndicatorSection() const
{
    Q_D(const QHeaderView);
    return d->sortIndicatorSection;
}

Qt::SortOrder QHeaderView::sortIndicatorOrder() const
{
    Q_D(const QHeaderView);
    return d->sortIndicatorOrder;
}

bool QHeaderView::stretchLastSection() const
{
    Q_D(const QHeaderView);
    return d->stretchLastSection;
}

void QHeaderView::setStretchLastSection(bool stretch)
{
    Q_D(QHeaderView);
    d->stretchLastSection = stretch;
    if (d->state != QHeaderViewPrivate::NoState)
        return;
    if (stretch)
        resizeSections();
    else if (count())
        resizeSection(count() - 1, d->defaultSectionSize);
}

bool QHeaderView::cascadingSectionResizes() const
{
    Q_D(const QHeaderView);
    return d->cascadingResizing;
}

void QHeaderView::setCascadingSectionResizes(bool enable)
{
    Q_D(QHeaderView);
    d->cascadingResizing = enable;
}

int QHeaderView::defaultSectionSize() const
{
    Q_D(const QHeaderView);
    return d->defaultSectionSize;
}

void QHeaderView::setDefaultSectionSize(int size)
{
    Q_D(QHeaderView);
    d->defaultSectionSize = size;
}

int QHeaderView::minimumSectionSize() const
{
    Q_D(const QHeaderView);
    if (d->minimumSectionSize == -1) {
        QSize strut = QApplication::globalStrut();
        int margin = style()->pixelMetric(QStyle::PM_HeaderMargin);
        if (orientation() == Qt::Horizontal)
            return qMax(strut.width(), (fontMetrics().maxWidth() + margin));
        return qMax(strut.height(), (fontMetrics().lineSpacing() + margin));
    }
    return d->minimumSectionSize;
}

void QHeaderView::setMinimumSectionSize(int size)
{
    Q_D(QHeaderView);
    d->minimumSectionSize = size;
}

Qt::Alignment QHeaderView::defaultAlignment() const
{
    Q_D(const QHeaderView);
    return d->defaultAlignment;
}

void QHeaderView::setDefaultAlignment(Qt::Alignment alignment)
{
    Q_D(QHeaderView);
    d->defaultAlignment = alignment;
}

void QHeaderView::doItemsLayout()
{
    initializeSections();
    QAbstractItemView::doItemsLayout();
}

bool QHeaderView::sectionsMoved() const
{
    Q_D(const QHeaderView);
    return !d->visualIndices.isEmpty();
}

bool QHeaderView::sectionsHidden() const
{
    Q_D(const QHeaderView);
    return !d->hiddenSectionSize.isEmpty();
}

void QHeaderView::headerDataChanged(Qt::Orientation orientation, int logicalFirst, int logicalLast)
{
    Q_D(QHeaderView);
    if (d->orientation != orientation)
        return;

    if (logicalFirst < 0 || logicalLast < 0 || logicalFirst >= count() || logicalLast >= count())
        return;

    d->invalidateCachedSizeHint();

    if (orientation == Qt::Horizontal) {
        int left = sectionViewportPosition(logicalFirst);
        int right = sectionViewportPosition(logicalLast);
        right += sectionSize(logicalLast);
        d->viewport->update(left, 0, right - left, d->viewport->height());
    } else {
        int top = sectionViewportPosition(logicalFirst);
        int bottom = sectionViewportPosition(logicalLast);
        bottom += sectionSize(logicalLast);
        d->viewport->update(0, top, d->viewport->width(), bottom - top);
    }
}

void QHeaderView::updateSection(int logicalIndex)
{
    Q_D(QHeaderView);
    if (orientation() == Qt::Horizontal)
        d->viewport->update(QRect(sectionViewportPosition(logicalIndex),
                                  0, sectionSize(logicalIndex), d->viewport->height()));
    else
        d->viewport->update(QRect(0, sectionViewportPosition(logicalIndex),
                                  d->viewport->width(), sectionSize(logicalIndex)));
}

void QHeaderView::resizeSections()
{
    Q_D(QHeaderView);
    if (d->hasAutoResizeSections())
        d->resizeSections(Interactive, false); // no global resize mode
}

void QHeaderView::sectionsInserted(const QModelIndex &parent, int logicalFirst, int)
{
    Q_D(QHeaderView);
    if (parent != d->root)
        return; // we only handle changes in the top level
    int lastSection;
    if (d->orientation == Qt::Horizontal)
        lastSection = qMax(d->model->columnCount(d->root) - 1, 0);
    else
        lastSection = qMax(d->model->rowCount(d->root) -  1, 0);
    int oldCount = d->sectionCount;
    int oldLastSection = qMax(oldCount - 1, 0);
    initializeSections(qMin(oldLastSection + 1, logicalFirst), lastSection);
    resizeSections();
    emit sectionCountChanged(oldCount, count());
}

void QHeaderView::sectionsAboutToBeRemoved(const QModelIndex &parent,
                                           int logicalFirst, int logicalLast)
{
    Q_UNUSED(parent);
    Q_UNUSED(logicalFirst);
    Q_UNUSED(logicalLast);
}

void QHeaderViewPrivate::_q_sectionsRemoved(const QModelIndex &parent,
                                            int logicalFirst, int logicalLast)
{
    Q_Q(QHeaderView);
    if (parent != root)
        return; // we only handle changes in the top level
    if (qMin(logicalFirst, logicalLast) < 0
        || qMax(logicalLast, logicalFirst) >= sectionCount)
        return;
    int oldCount = q->count();
    int changeCount = logicalLast - logicalFirst + 1;
    if (visualIndices.isEmpty() && logicalIndices.isEmpty()) {
        for (int i = logicalFirst; i <= changeCount+logicalFirst; ++i)
            hiddenSectionSize.remove(i);
        //Q_ASSERT(headerSectionCount() == sectionCount);
        removeSectionsFromSpans(logicalFirst, logicalLast);
    } else {
        for (int l = logicalLast; l >= logicalFirst; --l) {
            int visual = visualIndices.at(l);
            for (int v = 0; v < sectionCount; ++v) {
                if (v > visual) {
                    int logical = logicalIndex(v);
                    --(visualIndices[logical]);
                }
                if (logicalIndex(v) > l) // no need to move the positions before l
                    --(logicalIndices[v]);
            }
            hiddenSectionSize.remove(l);
            logicalIndices.remove(visual);
            visualIndices.remove(l);
            //Q_ASSERT(headerSectionCount() == sectionCount);
            removeSectionsFromSpans(visual, visual);
        }
        // ### handle sectionSelection, sectionHidden
    }
    sectionCount -= changeCount;

    // if we only have the last section (the "end" position) left, the header is empty
    if (sectionCount <= 0)
        clear();
    invalidateCachedSizeHint();
    emit q->sectionCountChanged(oldCount, q->count());
    viewport->update();
}

void QHeaderView::initializeSections()
{
    Q_D(QHeaderView);
    if (d->orientation == Qt::Horizontal) {
        int c = d->model->columnCount(d->root);
        if (c == 0) {
            int oldCount = count();
            d->clear();
            emit sectionCountChanged(oldCount, 0);
        } else if (c != count() && c > 0) {
            initializeSections(0, c - 1);
        }
    } else {
        int r = d->model->rowCount(d->root);
        if (r == 0) {
            int oldCount = count();
            d->clear();
            emit sectionCountChanged(oldCount, 0);
        } else if (r != count() && r > 0) {
            initializeSections(0, r - 1);
        }
    }
    if (stretchLastSection())
        d->lastSectionSize = sectionSizeHint(logicalIndex(count() - 1));
}

void QHeaderView::initializeSections(int start, int end)
{
    Q_D(QHeaderView);

    Q_ASSERT(start >= 0);
    Q_ASSERT(end >= 0);

    d->invalidateCachedSizeHint();

    // Edge case such as when a model emits layoutChanged when removing items
    if (end < count())
        d->removeSectionsFromSpans(end + 1, count());

    int oldCount = d->sectionCount;
    d->sectionCount = end + 1;

    if (!d->logicalIndices.isEmpty()) {
        d->logicalIndices.resize(d->sectionCount);
        d->visualIndices.resize(d->sectionCount);
        for (int i = start; i < d->sectionCount; ++i){
            d->logicalIndices[i] = i;
            d->visualIndices[i] = i;
        }
    }

    if (d->globalResizeMode == Stretch)
        d->stretchSections = d->sectionCount;
    else if (d->globalResizeMode == ResizeToContents)
         d->contentsSections = d->sectionCount;
    if (!d->sectionHidden.isEmpty())
        d->sectionHidden.resize(d->sectionCount);

    d->createSectionSpan(start, end, (end - start + 1) * d->defaultSectionSize, d->globalResizeMode);
    //Q_ASSERT(d->headerLength() == d->length);

    emit sectionCountChanged(oldCount,  d->sectionCount);
    d->viewport->update();
}

void QHeaderView::currentChanged(const QModelIndex &current, const QModelIndex &old)
{
    Q_D(QHeaderView);

    if (d->orientation == Qt::Horizontal && current.column() != old.column()) {
        if (old.isValid() && old.parent() == d->root)
            d->setDirtyRegion(QRect(sectionViewportPosition(old.column()), 0,
                                    sectionSize(old.column()), d->viewport->height()));
        if (current.isValid() && current.parent() == d->root)
            d->setDirtyRegion(QRect(sectionViewportPosition(current.column()), 0,
                                    sectionSize(current.column()), d->viewport->height()));
    } else if (d->orientation == Qt::Vertical && current.row() != old.row()) {
        if (old.isValid() && old.parent() == d->root)
            d->setDirtyRegion(QRect(0, sectionViewportPosition(old.row()),
                                    d->viewport->width(), sectionSize(old.row())));
        if (current.isValid() && current.parent() == d->root)
            d->setDirtyRegion(QRect(0, sectionViewportPosition(current.row()),
                                    d->viewport->width(), sectionSize(current.row())));
    }
    d->updateDirtyRegion();
}


bool QHeaderView::event(QEvent *e)
{
    Q_D(QHeaderView);
    switch (e->type()) {
    case QEvent::HoverEnter: {
        QHoverEvent *he = static_cast<QHoverEvent*>(e);
        d->hover = logicalIndexAt(he->pos());
        if (d->hover != -1)
            updateSection(d->hover);
        break; }
    case QEvent::HoverLeave: {
        if (d->hover != -1)
            updateSection(d->hover);
        d->hover = -1;
        break; }
    case QEvent::HoverMove: {
        QHoverEvent *he = static_cast<QHoverEvent*>(e);
        int oldHover = d->hover;
        d->hover = logicalIndexAt(he->pos());
        if (d->hover != oldHover) {
            if (oldHover != -1)
                updateSection(oldHover);
            if (d->hover != -1)
                updateSection(d->hover);
        }
        break; }
    default:
        break;
    }
    return QAbstractItemView::event(e);
}

void QHeaderView::paintEvent(QPaintEvent *e)
{
    Q_D(QHeaderView);

    if (count() == 0)
        return;

    QPainter painter(d->viewport);
    const QPoint offset = d->scrollDelayOffset;
    QRect translatedEventRect = e->rect();
    translatedEventRect.translate(offset);

    int start = -1;
    int end = -1;
    if (orientation() == Qt::Horizontal) {
        start = visualIndexAt(translatedEventRect.left());
        end = visualIndexAt(translatedEventRect.right());
    } else {
        start = visualIndexAt(translatedEventRect.top());
        end = visualIndexAt(translatedEventRect.bottom());
    }

    if (d->reverse()) {
        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);

    d->prepareSectionSelected(); // clear and resize the bit array

    QRect currentSectionRect;
    int logical;
    const int width = d->viewport->width();
    const int height = d->viewport->height();
    const bool active = isActiveWindow();
    for (int i = start; i <= end; ++i) {
        if (d->isVisualIndexHidden(i))
            continue;
        painter.save();
        logical = logicalIndex(i);
        bool highlight = false;
        if (orientation() == Qt::Horizontal) {
            currentSectionRect.setRect(sectionViewportPosition(logical), 0, sectionSize(logical), height);
            if (d->highlightSelected && active)
                highlight = d->columnIntersectsSelection(logical);
        } else {
            currentSectionRect.setRect(0, sectionViewportPosition(logical), width, sectionSize(logical));
            if (d->highlightSelected && active)
                highlight = d->rowIntersectsSelection(logical);
        }
        currentSectionRect.translate(offset);

        QVariant variant = d->model->headerData(logical, orientation(),
                                                Qt::FontRole);
        if (variant.isValid() && qVariantCanConvert<QFont>(variant)) {
            QFont sectionFont = qvariant_cast<QFont>(variant);
            if (highlight)
                sectionFont.setBold(true);
            painter.setFont(sectionFont);
        }
        paintSection(&painter, currentSectionRect, logical);
        painter.restore();
    }

    // Paint the area beyond where there are indexes
    if (d->reverse()) {
        if (currentSectionRect.left() > translatedEventRect.left())
            painter.fillRect(translatedEventRect.left(), 0,
                             currentSectionRect.left() - translatedEventRect.left(), height,
                             palette().background());
    } else if (currentSectionRect.right() < translatedEventRect.right()) {
        // paint to the right
        painter.fillRect(currentSectionRect.right() + 1, 0,
                         translatedEventRect.right() - currentSectionRect.right(), height,
                         palette().background());
    } else if (currentSectionRect.bottom() < translatedEventRect.bottom()) {
        painter.fillRect(0, currentSectionRect.bottom() + 1,
                         width, height - currentSectionRect.bottom() - 1,
                         palette().background());
    }

#if 0
    // ### visualize section spans
    for (int a = 0, i = 0; i < d->sectionSpans.count(); ++i) {
        QColor color((i & 4 ? 255 : 0), (i & 2 ? 255 : 0), (i & 1 ? 255 : 0));
        if (orientation() == Qt::Horizontal)
            painter.fillRect(a - d->offset, 0, d->sectionSpans.at(i).size, 4, color);
        else
            painter.fillRect(0, a - d->offset, 4, d->sectionSpans.at(i).size, color);
        a += d->sectionSpans.at(i).size;
    }

#endif
}

void QHeaderView::mousePressEvent(QMouseEvent *e)
{
    Q_D(QHeaderView);
    if (d->state != QHeaderViewPrivate::NoState || e->button() != Qt::LeftButton)
        return;
    int pos = orientation() == Qt::Horizontal ? e->x() : e->y();
    int handle = d->sectionHandleAt(pos);
    while (handle > -1 && isSectionHidden(handle)) --handle;
    if (handle == -1) {
        d->pressed = logicalIndexAt(pos);
        if (d->movableSections) {
            d->section = d->target = d->pressed;
            if (d->section == -1)
                return;
            d->state = QHeaderViewPrivate::MoveSection;
            d->setupSectionIndicator(d->section, pos);
        }
        if (d->clickableSections && d->pressed != -1) {
            updateSection(d->pressed);
            emit sectionPressed(d->pressed);
        }
    } else if (resizeMode(handle) == Interactive) {
        Q_ASSERT(d->originalSize == -1);
        d->originalSize = sectionSize(handle);
        d->state = QHeaderViewPrivate::ResizeSection;
        d->section = handle;
    }

    d->firstPos = pos;
    d->lastPos = pos;

    d->clearCascadingSections();
}

void QHeaderView::mouseMoveEvent(QMouseEvent *e)
{
    Q_D(QHeaderView);
    int pos = orientation() == Qt::Horizontal ? e->x() : e->y();
    if (pos < 0)
        return;
    if (e->buttons() == Qt::NoButton) {
        d->state = QHeaderViewPrivate::NoState;
        d->pressed = -1;
    }
    switch (d->state) {
        case QHeaderViewPrivate::ResizeSection: {
            Q_ASSERT(d->originalSize != -1);
            if (d->cascadingResizing) {
                int delta = d->reverse() ? d->lastPos - pos : pos - d->lastPos;
                int visual = visualIndex(d->section);
                d->cascadingResize(visual, d->headerSectionSize(visual) + delta);
            } else {
                int delta = d->reverse() ? d->firstPos - pos : pos - d->firstPos;
                resizeSection(d->section, qMax(d->originalSize + delta, minimumSectionSize()));
            }
            d->lastPos = pos;
            return;
        }
        case QHeaderViewPrivate::MoveSection: {
            if (qAbs(pos - d->firstPos) >= QApplication::startDragDistance()) {
                int indicatorCenter = (orientation() == Qt::Horizontal
                                       ? d->sectionIndicator->width()
                                       : d->sectionIndicator->height()) / 2;
                int centerOffset = indicatorCenter - d->sectionIndicatorOffset;
                // This will drop the moved section to the position under the center of the indicator.
                // If centerOffset is 0, the section will be moved to the position of the mouse cursor.
                int visual = visualIndexAt(pos + centerOffset);
                if (visual == -1)
                    return;
                d->target = d->logicalIndex(visual);
                d->updateSectionIndicator(d->section, pos);
            } else {
                int visual = visualIndexAt(d->firstPos);
                if (visual == -1)
                    return;
                d->target = d->logicalIndex(visual);
                d->updateSectionIndicator(d->section, d->firstPos);
            }
            return;
        }
        case QHeaderViewPrivate::NoState: {
#ifndef QT_NO_CURSOR
            int handle = d->sectionHandleAt(pos);
            if (handle != -1 && (resizeMode(handle) == Interactive))
                setCursor(orientation() == Qt::Horizontal ? Qt::SplitHCursor : Qt::SplitVCursor);
            else
                setCursor(Qt::ArrowCursor);
#endif
            return;
        }
    }
}

void QHeaderView::mouseReleaseEvent(QMouseEvent *e)
{
    Q_D(QHeaderView);
    int pos = orientation() == Qt::Horizontal ? e->x() : e->y();
    switch (d->state) {
    case QHeaderViewPrivate::MoveSection:
        if (!d->sectionIndicator->isHidden()) { // moving
            int from = visualIndex(d->section);
            Q_ASSERT(from != -1);
            int to = visualIndex(d->target);
            Q_ASSERT(to != -1);
            moveSection(from, to);
            d->section = d->target = -1;
            d->updateSectionIndicator(d->section, pos);
            break;
        } // not moving
    case QHeaderViewPrivate::NoState:
        if (d->clickableSections) {
            int section = logicalIndexAt(pos);
            if (section != -1 && section == d->pressed) {
                if (d->sortIndicatorShown)
                    d->flipSortIndicator(section);
                emit sectionClicked(logicalIndexAt(pos));
            }
            if (d->pressed != -1)
                updateSection(d->pressed);
        }
        break;
    case QHeaderViewPrivate::ResizeSection:
        d->originalSize = -1;
        d->clearCascadingSections();
        break;
    }
    d->state = QHeaderViewPrivate::NoState;
    d->pressed = -1;
}

void QHeaderView::mouseDoubleClickEvent(QMouseEvent *e)
{
    Q_D(QHeaderView);
    int pos = orientation() == Qt::Horizontal ? e->x() : e->y();
    int handle = d->sectionHandleAt(pos);
    while (handle > -1 && isSectionHidden(handle)) handle--;
    if (handle > -1 && resizeMode(handle) == Interactive) {
        emit sectionHandleDoubleClicked(handle);
#ifndef QT_NO_CURSOR
        Qt::CursorShape splitCursor = (orientation() == Qt::Horizontal)
                                      ? Qt::SplitHCursor : Qt::SplitVCursor;
        if (cursor().shape() == splitCursor) {
            // signal handlers may have changed the section size
            handle = d->sectionHandleAt(pos);
            while (handle > -1 && isSectionHidden(handle)) handle--;
            if (!(handle > -1 && resizeMode(handle) == Interactive))
                setCursor(Qt::ArrowCursor);
        }
#endif
    } else {
        emit sectionDoubleClicked(logicalIndexAt(e->pos()));
    }
}

bool QHeaderView::viewportEvent(QEvent *e)
{
    Q_D(QHeaderView);
    switch (e->type()) {
#ifndef QT_NO_TOOLTIP
    case QEvent::ToolTip: {
        if (!isActiveWindow())
            break;
        QHelpEvent *he = static_cast<QHelpEvent*>(e);
        int logical = logicalIndexAt(he->pos());
        if (logical != -1) {
            QVariant variant = d->model->headerData(logical, orientation(), Qt::ToolTipRole);
            if (variant.isValid()) {
                QToolTip::showText(he->globalPos(), variant.toString(), this);
                return true;
            }
        }
        break; }
#endif
#ifndef QT_NO_WHATSTHIS
    case QEvent::QueryWhatsThis: {
        QHelpEvent *he = static_cast<QHelpEvent*>(e);
        int logical = logicalIndexAt(he->pos());
        if (logical != -1
            && d->model->headerData(logical, orientation(), Qt::WhatsThisRole).isValid())
            return true;
        break; }
    case QEvent::WhatsThis: {
        QHelpEvent *he = static_cast<QHelpEvent*>(e);
        int logical = logicalIndexAt(he->pos());
        if (logical != -1) {
             QVariant whatsthis = d->model->headerData(logical, orientation(),
                                                      Qt::WhatsThisRole);
             if (whatsthis.isValid()) {
                 QWhatsThis::showText(he->globalPos(), whatsthis.toString(), this);
                 return true;
             }
        }
        break; }
#endif // QT_NO_WHATSTHIS
#ifndef QT_NO_STATUSTIP
    case QEvent::StatusTip: {
        QHelpEvent *he = static_cast<QHelpEvent*>(e);
        int logical = logicalIndexAt(he->pos());
        if (logical != -1) {
            QString statustip = d->model->headerData(logical, orientation(),
                                                    Qt::StatusTipRole).toString();
            if (!statustip.isEmpty())
                setStatusTip(statustip);
        }
        return true; }
#endif // QT_NO_STATUSTIP
    case QEvent::Hide:
    case QEvent::Show:
    case QEvent::FontChange:
        resizeSections();
        emit geometriesChanged();
        break;
    case QEvent::ContextMenu: {
        d->state = QHeaderViewPrivate::NoState;
        d->pressed =d->section = d->target = -1;
        d->updateSectionIndicator(d->section, -1);
    }
    default:
        break;
    }
    return QAbstractItemView::viewportEvent(e);
}

void QHeaderView::paintSection(QPainter *painter, const QRect &rect, int logicalIndex) const
{
    Q_D(const QHeaderView);
    if (!rect.isValid())
        return;
    // get the state of the section
    QStyleOptionHeader opt = d->getStyleOption();
    QStyle::State state = QStyle::State_None;
    if (isEnabled())
        state |= QStyle::State_Enabled;
    if (window()->isActiveWindow())
        state |= QStyle::State_Active;
    if (d->clickableSections) {
        if (logicalIndex == d->hover)
            state |= QStyle::State_MouseOver;
        if (logicalIndex == d->pressed)
            state |= QStyle::State_Sunken;
        else if (d->highlightSelected && d->isSectionSelected(logicalIndex))
            state |= QStyle::State_On | QStyle::State_Sunken;
    }
    if (isSortIndicatorShown() && sortIndicatorSection() == logicalIndex)
        opt.sortIndicator = (sortIndicatorOrder() == Qt::AscendingOrder)
                            ? QStyleOptionHeader::SortDown : QStyleOptionHeader::SortUp;

    // setup the style options structure
    QVariant textAlignment = d->model->headerData(logicalIndex, orientation(),
                                                  Qt::TextAlignmentRole);
    opt.rect = rect;
    opt.section = logicalIndex;
    opt.state |= state;
    opt.textAlignment = Qt::Alignment(textAlignment.isValid()
                                      ? Qt::Alignment(textAlignment.toInt())
                                      : d->defaultAlignment);
    opt.iconAlignment = Qt::AlignVCenter;
    opt.text = d->model->headerData(logicalIndex, orientation(),
                                    Qt::DisplayRole).toString();
    if (d->textElideMode != Qt::ElideNone)
        opt.text = opt.fontMetrics.elidedText(opt.text, d->textElideMode , rect.width() - 4);

    QVariant variant = d->model->headerData(logicalIndex, orientation(),
                                    Qt::DecorationRole);
    opt.icon = qvariant_cast<QIcon>(variant);
    if (opt.icon.isNull())
        opt.icon = qvariant_cast<QPixmap>(variant);
    QVariant foregroundBrush = d->model->headerData(logicalIndex, orientation(),
                                                    Qt::ForegroundRole);
    if (qVariantCanConvert<QBrush>(foregroundBrush))
        opt.palette.setBrush(QPalette::ButtonText, qvariant_cast<QBrush>(foregroundBrush));

    QPointF oldBO = painter->brushOrigin();
    QVariant backgroundBrush = d->model->headerData(logicalIndex, orientation(),
                                                    Qt::BackgroundRole);
    if (qVariantCanConvert<QBrush>(backgroundBrush)) {
        opt.palette.setBrush(QPalette::Button, qvariant_cast<QBrush>(backgroundBrush));
        opt.palette.setBrush(QPalette::Window, qvariant_cast<QBrush>(backgroundBrush));
        painter->setBrushOrigin(opt.rect.topLeft());
    }

    // the section position
    int visual = visualIndex(logicalIndex);
    Q_ASSERT(visual != -1);
    if (count() == 1)
        opt.position = QStyleOptionHeader::OnlyOneSection;
    else if (visual == 0)
        opt.position = QStyleOptionHeader::Beginning;
    else if (visual == count() - 1)
        opt.position = QStyleOptionHeader::End;
    else
        opt.position = QStyleOptionHeader::Middle;
    opt.orientation = d->orientation;
    // the selected position
    bool previousSelected = d->isSectionSelected(this->logicalIndex(visual - 1));
    bool nextSelected =  d->isSectionSelected(this->logicalIndex(visual + 1));
    if (previousSelected && nextSelected)
        opt.selectedPosition = QStyleOptionHeader::NextAndPreviousAreSelected;
    else if (previousSelected)
        opt.selectedPosition = QStyleOptionHeader::PreviousIsSelected;
    else if (nextSelected)
        opt.selectedPosition = QStyleOptionHeader::NextIsSelected;
    else
        opt.selectedPosition = QStyleOptionHeader::NotAdjacent;
    // draw the section
    style()->drawControl(QStyle::CE_Header, &opt, painter, this);

    painter->setBrushOrigin(oldBO);
}

QSize QHeaderView::sectionSizeFromContents(int logicalIndex) const
{
    Q_D(const QHeaderView);
    Q_ASSERT(logicalIndex >= 0);
    QSize size(100, 30); // ### make this depend on the font size

    // use SizeHintRole
    QVariant variant = d->model->headerData(logicalIndex, orientation(), Qt::SizeHintRole);
    if (variant.isValid())
        return qvariant_cast<QSize>(variant);

    // otherwise use the contents
    QStyleOptionHeader opt = d->getStyleOption();
    QVariant var = d->model->headerData(logicalIndex, orientation(),
                                            Qt::FontRole);
    QFont fnt;
    if (var.isValid() && qVariantCanConvert<QFont>(var))
        fnt = qvariant_cast<QFont>(var);
    else
        fnt = font();
    fnt.setBold(true);
    opt.fontMetrics = QFontMetrics(fnt);
    opt.text = d->model->headerData(logicalIndex, orientation(),
                                    Qt::DisplayRole).toString();
    variant = d->model->headerData(logicalIndex, orientation(), Qt::DecorationRole);
    opt.icon = qvariant_cast<QIcon>(variant);
    if (opt.icon.isNull())
        opt.icon = qvariant_cast<QPixmap>(variant);
    size = style()->sizeFromContents(QStyle::CT_HeaderSection, &opt, size, this);

    if (isSortIndicatorShown() && sortIndicatorSection() == logicalIndex) {
        int margin = style()->pixelMetric(QStyle::PM_HeaderMargin);
        if (orientation() == Qt::Horizontal)
            size.rwidth() += size.height() + margin;
        else
            size.rheight() += size.width() + margin;
    }
    return size;
}

int QHeaderView::horizontalOffset() const
{
    Q_D(const QHeaderView);
    if (orientation() == Qt::Horizontal)
        return d->offset;
    return 0;
}

int QHeaderView::verticalOffset() const
{
    Q_D(const QHeaderView);
    if (orientation() == Qt::Vertical)
        return d->offset;
    return 0;
}

void QHeaderView::updateGeometries()
{
    Q_D(QHeaderView);
    d->layoutChildren();
    if (d->hasAutoResizeSections())
        resizeSections();
}

void QHeaderView::scrollContentsBy(int dx, int dy)
{
    Q_D(QHeaderView);
    d->scrollDirtyRegion(dx, dy);
}

void QHeaderView::dataChanged(const QModelIndex &, const QModelIndex &)
{
    Q_D(QHeaderView);
    d->invalidateCachedSizeHint();
}

void QHeaderView::rowsInserted(const QModelIndex &, int, int)
{
    // do nothing
}

QRect QHeaderView::visualRect(const QModelIndex &) const
{
    return QRect();
}

void QHeaderView::scrollTo(const QModelIndex &, ScrollHint)
{
    // do nothing - the header only displays sections
}

QModelIndex QHeaderView::indexAt(const QPoint &) const
{
    return QModelIndex();
}

bool QHeaderView::isIndexHidden(const QModelIndex &) const
{
    return true; // the header view has no items, just sections
}

QModelIndex QHeaderView::moveCursor(CursorAction, Qt::KeyboardModifiers)
{
    return QModelIndex();
}

void QHeaderView::setSelection(const QRect&, QItemSelectionModel::SelectionFlags)
{
    // do nothing
}

QRegion QHeaderView::visualRegionForSelection(const QItemSelection &selection) const
{
    Q_D(const QHeaderView);
    if (orientation() == Qt::Horizontal) {
        int left = d->model->columnCount(d->root) - 1;
        int right = 0;
        int rangeLeft, rangeRight;

        for (int i = 0; i < selection.count(); ++i) {
            QItemSelectionRange r = selection.at(i);
            if (r.parent().isValid() || !r.isValid())
                continue; // we only know about toplevel items and we don't want invalid ranges
            // FIXME an item inside the range may be the leftmost or rightmost
            rangeLeft = visualIndex(r.left());
            if (rangeLeft == -1) // in some cases users may change the selections
                continue;        // before we have a chance to do the layout
            rangeRight = visualIndex(r.right());
            if (rangeRight == -1) // in some cases users may change the selections
                continue;         // before we have a chance to do the layout
            if (rangeLeft < left)
                left = rangeLeft;
            if (rangeRight > right)
                right = rangeRight;
        }

        int logicalLeft = logicalIndex(left);
        int logicalRight = logicalIndex(right);

        if (logicalLeft < 0  || logicalLeft >= count() ||
            logicalRight < 0 || logicalRight >= count())
            return QRegion();

        int leftPos = sectionViewportPosition(logicalLeft);
        int rightPos = sectionViewportPosition(logicalRight);
        rightPos += sectionSize(logicalRight);
        return QRect(leftPos, 0, rightPos - leftPos, height());
    }
    // orientation() == Qt::Vertical
    int top = d->model->rowCount(d->root) - 1;
    int bottom = 0;
    int rangeTop, rangeBottom;

    for (int i = 0; i < selection.count(); ++i) {
        QItemSelectionRange r = selection.at(i);
        if (r.parent().isValid() || !r.isValid())
            continue; // we only know about toplevel items
        // FIXME an item inside the range may be the leftmost or rightmost
        rangeTop = visualIndex(r.top());
        if (rangeTop == -1) // in some cases users may change the selections
            continue;       // before we have a chance to do the layout
        rangeBottom = visualIndex(r.bottom());
        if (rangeBottom == -1) // in some cases users may change the selections
            continue;          // before we have a chance to do the layout
        if (rangeTop < top)
            top = rangeTop;
        if (rangeBottom > bottom)
            bottom = rangeBottom;
    }

    int logicalTop = logicalIndex(top);
    int logicalBottom = logicalIndex(bottom);

    if (logicalTop == -1 || logicalBottom == -1)
        return QRect();

    int topPos = sectionViewportPosition(logicalTop);
    int bottomPos = sectionViewportPosition(logicalBottom) + sectionSize(logicalBottom);

    return QRect(0, topPos, width(), bottomPos - topPos);
}


// private implementation

int QHeaderViewPrivate::sectionHandleAt(int position)
{
    Q_Q(QHeaderView);
    int visual = q->visualIndexAt(position);
    if (visual == -1)
        return -1;
    int log = logicalIndex(visual);
    int pos = q->sectionViewportPosition(log);
    int grip = q->style()->pixelMetric(QStyle::PM_HeaderGripMargin);
    if (reverse()) {
        if (position < pos + grip)
            return log;
        if (visual > 0 && position > pos + q->sectionSize(log) - grip)
            return q->logicalIndex(visual - 1);
    } else {
        if (visual > 0 && position < pos + grip)
            return q->logicalIndex(visual - 1);
        if (position > pos + q->sectionSize(log) - grip)
            return log;
    }
    return -1;
}

void QHeaderViewPrivate::setupSectionIndicator(int section, int position)
{
    Q_Q(QHeaderView);
    if (!sectionIndicator) {
        sectionIndicator = new QLabel(viewport);
        sectionIndicator->setWindowOpacity(0.75);
    }

    int x, y, w, h;
    int p = q->sectionViewportPosition(section);
    if (orientation == Qt::Horizontal) {
        x = p;
        y = 0;
        w = q->sectionSize(section);
        h = viewport->height();
    } else {
        x = 0;
        y = p;
        w = viewport->width();
        h = q->sectionSize(section);
    }
    sectionIndicator->resize(w, h);
    QPixmap pix = QPixmap::grabWidget(viewport, x, y, w, h);
    sectionIndicator->setPixmap(pix);
    sectionIndicatorOffset = position - qMax(p, 0);

}

void QHeaderViewPrivate::updateSectionIndicator(int section, int position)
{
    if (!sectionIndicator)
        return;

    if (section == -1 || target == -1) {
        sectionIndicator->hide();
        return;
    }

    if (orientation == Qt::Horizontal)
        sectionIndicator->move(position - sectionIndicatorOffset, 0);
    else
        sectionIndicator->move(0, position - sectionIndicatorOffset);

    sectionIndicator->show();
}

QStyleOptionHeader QHeaderViewPrivate::getStyleOption() const
{
    Q_Q(const QHeaderView);
    QStyleOptionHeader opt;
    opt.initFrom(q);
    opt.state = QStyle::State_None | QStyle::State_Raised;
    opt.orientation = orientation;
    if (orientation == Qt::Horizontal)
        opt.state |= QStyle::State_Horizontal;
    if (q->isEnabled())
        opt.state |= QStyle::State_Enabled;
    opt.section = 0;
    return opt;
}

bool QHeaderViewPrivate::isSectionSelected(int section) const
{
    int i = section * 2;
    if (i < 0 || i >= sectionSelected.count())
        return false;
    if (sectionSelected.testBit(i)) // if the value was cached
        return sectionSelected.testBit(i + 1);
    bool s = false;
    if (orientation == Qt::Horizontal)
        s = isColumnSelected(section);
    else
        s = isRowSelected(section);
    sectionSelected.setBit(i + 1, s); // selection state
    sectionSelected.setBit(i, true); // cache state
    return s;
}

void QHeaderViewPrivate::resizeSections(QHeaderView::ResizeMode globalMode, bool useGlobalMode)
{
    Q_Q(QHeaderView);

    executePostedLayout();
    if (sectionCount == 0)
        return;
    invalidateCachedSizeHint();

    // find stretchLastSection if we have it
    int stretchSection = -1;
    if (stretchLastSection && !useGlobalMode) {
        for (int i = sectionCount - 1; i >= 0; --i) {
            if (!isVisualIndexHidden(i)) {
                stretchSection = i;
                break;
            }
        }
    }

    // count up the number of strected sections and how much space left for them
    int lengthToStrech = (orientation == Qt::Horizontal ? viewport->width() : viewport->height());
    int numberOfStretchedSections = 0;
    QList<int> section_sizes;
    for (int i = 0; i < sectionCount; ++i) {
        if (isVisualIndexHidden(i))
            continue;

        QHeaderView::ResizeMode resizeMode;
        if (useGlobalMode && (i != stretchSection))
            resizeMode = globalMode;
        else
            resizeMode = (i == stretchSection ? QHeaderView::Stretch : visualIndexResizeMode(i));

        if (resizeMode == QHeaderView::Stretch) {
            ++numberOfStretchedSections;
            continue;
        }

        // because it isn't stretch, determine its width and remove that from lengthToStrech
        int sectionSize = 0;
        if (resizeMode == QHeaderView::Interactive || resizeMode == QHeaderView::Fixed) {
            sectionSize = headerSectionSize(i);
        } else { // resizeMode == QHeaderView::ResizeToContents
            int logicalIndex = q->logicalIndex(i);
            sectionSize = qMax(viewSectionSizeHint(logicalIndex),
                               q->sectionSizeHint(logicalIndex));
        }
        section_sizes.append(sectionSize);
        lengthToStrech -= sectionSize;
    }

    // calculate the new length for all of the stretched sections
    int stretchSectionLength = 0;
    int pixelReminder = 0;
    if (numberOfStretchedSections > 0) {
        int hintLengthForEveryStretchedSection = lengthToStrech / numberOfStretchedSections;
        stretchSectionLength = qMax(hintLengthForEveryStretchedSection, q->minimumSectionSize());
        pixelReminder = lengthToStrech % numberOfStretchedSections;
    }

    int spanStartSection = 0;
    int previousSectionLength = 0;
    QHeaderView::ResizeMode previousSectionResizeMode = QHeaderView::Interactive;

    // resize each section along the total length
    for (int i = 0; i < sectionCount; ++i) {
        int oldSectionLength = headerSectionSize(i);
        int newSectionLength = -1;
        QHeaderView::ResizeMode newSectionResizeMode = headerSectionResizeMode(i);

        if (isVisualIndexHidden(i)) {
            newSectionLength = 0;
        } else {
            QHeaderView::ResizeMode resizeMode;
            if (useGlobalMode)
                resizeMode = globalMode;
            else
                resizeMode = (i == stretchSection
                              ? QHeaderView::Stretch
                              : visualIndexResizeMode(i));
            if (resizeMode == QHeaderView::Stretch) {
                if (i == sectionCount - 1)
                    newSectionLength = qMax(stretchSectionLength, lastSectionSize);
                else
                    newSectionLength = stretchSectionLength;
                if (pixelReminder > 0) {
                    newSectionLength += 1;
                    --pixelReminder;
                }
            } else {
                newSectionLength = section_sizes.front();
                section_sizes.removeFirst();
            }
        }

        //Q_ASSERT(newSectionLength > 0);
        if ((previousSectionResizeMode != newSectionResizeMode
            || previousSectionLength != newSectionLength) && i > 0) {
            int spanLength = (i - spanStartSection) * previousSectionLength;
            createSectionSpan(spanStartSection, i - 1, spanLength, previousSectionResizeMode);
            //Q_ASSERT(headerLength() == length);
            spanStartSection = i;
        }

        if (newSectionLength != oldSectionLength)
            emit q->sectionResized(i, oldSectionLength, newSectionLength);

        previousSectionLength = newSectionLength;
        previousSectionResizeMode = newSectionResizeMode;
    }

    createSectionSpan(spanStartSection, sectionCount - 1,
                      (sectionCount - spanStartSection) * previousSectionLength,
                      previousSectionResizeMode);
    //Q_ASSERT(headerLength() == length);

    viewport->update();
}

void QHeaderViewPrivate::createSectionSpan(int start, int end, int size, QHeaderView::ResizeMode mode)
{
    // ### the code for merging spans does not merge at all opertuneties
    // ### what if the number of sections is reduced ?

    SectionSpan span(size, (end - start) + 1, mode);
    int start_section = 0;
#ifndef QT_NO_DEBUG
    int initial_section_count = headerSectionCount(); // ### debug code
#endif

    QList<int> spansToRemove;
    for (int i = 0; i < sectionSpans.count(); ++i) {
        int end_section = start_section + sectionSpans.at(i).count - 1;
        int section_count = sectionSpans.at(i).count;
        if (start <= start_section && end > end_section) {
            // the existing span is entirely coveded by the new span
            spansToRemove.append(i);
        } else if (start < start_section && end >= end_section) {
            // the existing span is entirely coveded by the new span
            spansToRemove.append(i);
        } else if (start == start_section && end == end_section) {
            // the new span is covered by an existin span
            length -= sectionSpans.at(i).size;
            length += size;
            sectionSpans[i].size = size;
            sectionSpans[i].resizeMode = mode;
            // ### check if we can merge the section with any of its neighbours
            removeSpans(spansToRemove);
            Q_ASSERT(initial_section_count == headerSectionCount());
            return;
        } else if (start > start_section && end < end_section) {
            if (sectionSpans.at(i).sectionSize() == span.sectionSize()
                && sectionSpans.at(i).resizeMode == span.resizeMode) {
                Q_ASSERT(initial_section_count == headerSectionCount());
                return;
            }
            // the new span is in the middle of the old span, so we have to split it
            length -= sectionSpans.at(i).size;
            int section_size = sectionSpans.at(i).sectionSize();
#ifndef QT_NO_DEBUG
            int span_count = sectionSpans.at(i).count;
#endif
            QHeaderView::ResizeMode span_mode = sectionSpans.at(i).resizeMode;
            // first span
            int first_span_count = start - start_section;
            int first_span_size = section_size * first_span_count;
            sectionSpans[i].count = first_span_count;
            sectionSpans[i].size = first_span_size;
            sectionSpans[i].resizeMode = span_mode;
            length += first_span_size;
            // middle span (the new span)
#ifndef QT_NO_DEBUG
            int mid_span_count = span.count;
#endif
            int mid_span_size = span.size;
            sectionSpans.insert(i + 1, span);
            length += mid_span_size;
            // last span
            int last_span_count = end_section - end;
            int last_span_size = section_size * last_span_count;
            sectionSpans.insert(i + 2, SectionSpan(last_span_size, last_span_count, span_mode));
            length += last_span_size;
            Q_ASSERT(span_count == first_span_count + mid_span_count + last_span_count);
            removeSpans(spansToRemove);
            Q_ASSERT(initial_section_count == headerSectionCount());
            return;
        } else if (start > start_section && start <= end_section && end >= end_section) {
            // the new span covers the last part of the existing span
            length -= sectionSpans.at(i).size;
            int removed_count = (end_section - start + 1);
            int span_count = sectionSpans.at(i).count - removed_count;
            int section_size = sectionSpans.at(i).sectionSize();
            int span_size = section_size * span_count;
            sectionSpans[i].count = span_count;
            sectionSpans[i].size = span_size;
            length += span_size;
            if (end == end_section) {
                sectionSpans.insert(i + 1, span); // insert after
                length += span.size;
                removeSpans(spansToRemove);
                Q_ASSERT(initial_section_count == headerSectionCount());
                return;
            }
        } else if (end < end_section && end >= start_section && start <= start_section) {
            // the new span covers the first part of the existing span
            length -= sectionSpans.at(i).size;
            int removed_count = (end - start_section + 1);
            int section_size = sectionSpans.at(i).sectionSize();
            int span_count = sectionSpans.at(i).count - removed_count;
            int span_size = section_size * span_count;
            sectionSpans[i].count = span_count;
            sectionSpans[i].size = span_size;
            length += span_size;
            sectionSpans.insert(i, span); // insert before
            length += span.size;
            removeSpans(spansToRemove);
            Q_ASSERT(initial_section_count == headerSectionCount());
            return;
        }
        start_section += section_count;
    }

    // ### adding and removing _ sections_  in addition to spans
    // ### add some more checks here

    if (spansToRemove.isEmpty()) {
        if (!sectionSpans.isEmpty()
            && sectionSpans.last().sectionSize() == span.sectionSize()
            && sectionSpans.last().resizeMode == span.resizeMode) {
            length += span.size;
            int last = sectionSpans.count() - 1;
            sectionSpans[last].count += span.count;
            sectionSpans[last].size += span.size;
            sectionSpans[last].resizeMode = span.resizeMode;
        } else {
            length += span.size;
            sectionSpans.append(span);
        }
    } else {
        removeSpans(spansToRemove);
        length += span.size;
        sectionSpans.insert(spansToRemove.first(), span);
        //Q_ASSERT(initial_section_count == headerSectionCount());
    }
}

void QHeaderViewPrivate::removeSectionsFromSpans(int start, int end)
{
    // remove sections
    int start_section = 0;
    QList<int> spansToRemove;
    for (int i = 0; i < sectionSpans.count(); ++i) {
        int end_section = start_section + sectionSpans.at(i).count - 1;
        int section_size = sectionSpans.at(i).sectionSize();
        int section_count = sectionSpans.at(i).count;
        if (start <= start_section && end >= end_section) {
            // the change covers the entire span
            spansToRemove.append(i);
            if (end == end_section)
                break;
        } else if (start > start_section && end < end_section) {
            // all the removed sections are inside the span
            int change = (end - start + 1);
            sectionSpans[i].count -= change;
            sectionSpans[i].size = section_size * sectionSpans.at(i).count;
            length -= (change * section_size);
            break;
        } else if (start >= start_section && start <= end_section) {
            // the some of the removed sections are inside the span,at the end
            int change = qMin(end_section - start + 1, end - start + 1);
            sectionSpans[i].count -= change;
            sectionSpans[i].size = section_size * sectionSpans.at(i).count;
            start += change;
            length -= (change * section_size);
            // the change affects several spans
        } else if (end >= start_section && end <= end_section) {
            // the some of the removed sections are inside the span, at the beginning
            int change = qMin((end - start_section + 1), end - start + 1);
            sectionSpans[i].count -= change;
            sectionSpans[i].size = section_size * sectionSpans.at(i).count;
            length -= (change * section_size);
            break;
        }
        start_section += section_count;
    }

    for (int i = spansToRemove.count() - 1; i >= 0; --i) {
        int s = spansToRemove.at(i);
        length -= sectionSpans.at(s).size;
        sectionSpans.remove(s);
        // ### merge remaining spans
    }
}

void QHeaderViewPrivate::clear()
{
    length = 0;
    sectionCount = 0;
    visualIndices.clear();
    logicalIndices.clear();
    sectionSelected.clear();
    sectionHidden.clear();
    hiddenSectionSize.clear();
    sectionSpans.clear();
}

void QHeaderViewPrivate::flipSortIndicator(int section)
{
    Q_Q(QHeaderView);
    bool ascending = (sortIndicatorSection != section
                      || sortIndicatorOrder == Qt::DescendingOrder);
    q->setSortIndicator(section, ascending ? Qt::AscendingOrder : Qt::DescendingOrder);
}

void QHeaderViewPrivate::cascadingResize(int visual, int newSize)
{
    Q_Q(QHeaderView);
    const int minimumSize = q->minimumSectionSize();
    const int oldSize = headerSectionSize(visual);
    int delta = newSize - oldSize;

    if (delta > 0) { // larger
        bool sectionResized = false;

        // restore old section sizes
        for (int i = firstCascadingSection; i < visual; ++i) {
            if (cascadingSectionSize.contains(i)) {
                int currentSectionSize = headerSectionSize(i);
                int originalSectionSize = cascadingSectionSize.value(i);
                if (currentSectionSize < originalSectionSize) {
                    int newSectionSize = currentSectionSize + delta;
                    resizeSectionSpan(i, currentSectionSize, newSectionSize);
                    if (newSectionSize >= originalSectionSize && false)
                        cascadingSectionSize.remove(i); // the section is now restored
                    sectionResized = true;
                    break;
                }
            }

        }

        // resize the section
        if (!sectionResized) {
            newSize = qMax(newSize, minimumSize);
            if (oldSize != newSize)
                resizeSectionSpan(visual, oldSize, newSize);
        }

        // cascade the section size change
        for (int i = visual + 1; i < sectionCount; ++i) {
            if (!sectionIsCascadable(i))
                continue;
            int currentSectionSize = headerSectionSize(i);
            if (currentSectionSize <= minimumSize)
                continue;
            int newSectionSize = qMax(currentSectionSize - delta, minimumSize);
            //qDebug() << "### cascading to" << i << newSectionSize - currentSectionSize << delta;
            resizeSectionSpan(i, currentSectionSize, newSectionSize);
            saveCascadingSectionSize(i, currentSectionSize);
            delta = delta - (currentSectionSize - newSectionSize);
            //qDebug() << "new delta" << delta;
            //if (newSectionSize != minimumSize)
            if (delta <= 0)
                break;
        }
    } else { // smaller
        bool sectionResized = false;

        // restore old section sizes
        for (int i = lastCascadingSection; i > visual; --i) {
            if (!cascadingSectionSize.contains(i))
                continue;
            int currentSectionSize = headerSectionSize(i);
            int originalSectionSize = cascadingSectionSize.value(i);
            if (currentSectionSize >= originalSectionSize)
                continue;
            int newSectionSize = currentSectionSize - delta;
            resizeSectionSpan(i, currentSectionSize, newSectionSize);
            if (newSectionSize >= originalSectionSize && false) {
                //qDebug() << "section" << i << "restored to" << originalSectionSize;
                cascadingSectionSize.remove(i); // the section is now restored
            }
            sectionResized = true;
            break;
        }

        // resize the section
        resizeSectionSpan(visual, oldSize, qMax(newSize, minimumSize));

        // cascade the section size change
        if (delta < 0 && newSize < minimumSize) {
            for (int i = visual - 1; i >= 0; --i) {
                if (!sectionIsCascadable(i))
                    continue;
                int sectionSize = headerSectionSize(i);
                if (sectionSize <= minimumSize)
                    continue;
                resizeSectionSpan(i, sectionSize, qMax(sectionSize + delta, minimumSize));
                saveCascadingSectionSize(i, sectionSize);
                break;
            }
        }

        // let the next section get the space from the resized section
        if (!sectionResized) {
            for (int i = visual + 1; i < sectionCount; ++i) {
                if (!sectionIsCascadable(i))
                    continue;
                int currentSectionSize = headerSectionSize(i);
                int newSectionSize = qMax(currentSectionSize - delta, minimumSize);
                resizeSectionSpan(i, currentSectionSize, newSectionSize);
                break;
            }
        }
    }

    if (hasAutoResizeSections())
        q->resizeSections();

    viewport->update();
}

void QHeaderViewPrivate::resizeSectionSpan(int visualIndex, uint oldSize, uint newSize)
{
    Q_Q(QHeaderView);
    QHeaderView::ResizeMode mode = headerSectionResizeMode(visualIndex);
    createSectionSpan(visualIndex, visualIndex, newSize, mode);
    emit q->sectionResized(logicalIndex(visualIndex), oldSize, newSize);
}

int QHeaderViewPrivate::headerSectionSize(int visual) const
{
    // ### stupid iteration
    int section_start = 0;
    for (int i = 0; i < sectionSpans.count(); ++i) {
        int section_end = section_start + sectionSpans.at(i).count - 1;
        if (visual >= section_start && visual <= section_end)
            return sectionSpans.at(i).sectionSize();
        section_start = section_end + 1;
    }
    return -1;
}

int QHeaderViewPrivate::headerSectionPosition(int visual) const
{
    // ### stupid iteration
    int section_start = 0;
    int span_position = 0;
    for (int i = 0; i < sectionSpans.count(); ++i) {
        int section_end = section_start + sectionSpans.at(i).count - 1;
        if (visual >= section_start && visual <= section_end)
            return span_position + (visual - section_start) * sectionSpans.at(i).sectionSize();
        section_start = section_end + 1;
        span_position += sectionSpans.at(i).size;
    }
    return -1;
}

int QHeaderViewPrivate::headerVisualIndexAt(uint position) const
{
    // ### stupid iteration
    uint span_start_section = 0;
    uint span_position = 0;
    for (int i = 0; i < sectionSpans.count(); ++i) {
        uint next_span_start_section = span_start_section + sectionSpans.at(i).count;
        uint next_span_position = span_position + sectionSpans.at(i).size;
        if (position == span_position)
            return span_start_section; // spans with no size
        if (position > span_position && position < next_span_position) {
            uint position_in_span = position - span_position;
            return span_start_section + (position_in_span / sectionSpans.at(i).sectionSize());
        }
        span_start_section = next_span_start_section;
        span_position = next_span_position;
    }
    return -1;
}

void QHeaderViewPrivate::setHeaderSectionResizeMode(int visual, QHeaderView::ResizeMode mode)
{
    int size = headerSectionSize(visual);
    createSectionSpan(visual, visual, size, mode);
}

QHeaderView::ResizeMode QHeaderViewPrivate::headerSectionResizeMode(int visual) const
{
    int span = sectionSpanIndex(visual);
    if (span == -1)
        return globalResizeMode;
    return sectionSpans.at(span).resizeMode;
}

void QHeaderViewPrivate::setGlobalHeaderResizeMode(QHeaderView::ResizeMode mode)
{
    globalResizeMode = mode;
    for (int i = 0; i < sectionSpans.count(); ++i)
        sectionSpans[i].resizeMode = mode;
}

int QHeaderViewPrivate::viewSectionSizeHint(int logical) const
{
    Q_Q(const QHeaderView);
    if (QAbstractItemView *parent = ::qobject_cast<QAbstractItemView*>(q->parent())) {
        return (orientation == Qt::Horizontal
                ? parent->sizeHintForColumn(logical)
                : parent->sizeHintForRow(logical));
    }
    return 0;
}

int QHeaderViewPrivate::adjustedVisualIndex(int visualIndex) const
{
    if (hiddenSectionSize.count() > 0) {
        int adjustedVisualIndex = visualIndex;
        int currentVisualIndex = 0;
        for (int i = 0; i < sectionSpans.count(); ++i) {
            if (sectionSpans.at(i).size == 0)
                adjustedVisualIndex += sectionSpans.at(i).count;
            else
                currentVisualIndex += sectionSpans.at(i).count;
            if (currentVisualIndex >= visualIndex)
                break;
        }
        visualIndex = adjustedVisualIndex;
    }
    return visualIndex;
}

#endif // QT_NO_ITEMVIEWS

#include "moc_qheaderview.cpp"

---