qheaderview.cpp

奇趣公司比较新的qt/emd版本

            }
        }
        sectionHidden = newSectionHidden;
    }

    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 >= logicalIndices.count())
                    continue; // the section doesn't exist
                if (v > visual) {
                    int logical = logicalIndices.at(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 QHeaderViewPrivate::_q_layoutAboutToBeChanged()
{
    for (int i = 0; i < sectionHidden.count(); ++i)
        if (sectionHidden.testBit(i)) // ### note that we are using column or row 0
            persistentHiddenSections.append(orientation == Qt::Horizontal
                                            ? model->index(0, logicalIndex(i), root)
                                            : model->index(logicalIndex(i), 0, root));
}

void QHeaderViewPrivate::_q_layoutChanged()
{
    Q_Q(QHeaderView);
    if (persistentHiddenSections.isEmpty()) {
        if (modelSectionCount() != sectionCount)
            q->initializeSections();
        return;
    }
    bool sectionCountChanged = false;
    for (int i = 0; i < persistentHiddenSections.count(); ++i) {
        QModelIndex index = persistentHiddenSections.at(i);
        if (index.isValid()) {
            const int logical = (orientation == Qt::Horizontal
                                 ? index.column()
                                 : index.row());
            sectionHidden.setBit(visualIndex(logical));
        } else if (!sectionCountChanged && (modelSectionCount() != sectionCount)) {
            sectionCountChanged = true;
            break;
        } // if the index was invalidated, but the section count is unchanged,
          // let the section be in the same hidden state as before
    }
    persistentHiddenSections.clear();

    // the number of sections changed; we need to reread the state of the model
    if (sectionCountChanged)
        q->initializeSections();
}

/*!
  \internal
*/

void QHeaderView::initializeSections()
{
    Q_D(QHeaderView);
    const int oldCount = d->sectionCount;
    const int newCount = d->modelSectionCount();
    if (newCount <= 0) {
        d->clear();
        emit sectionCountChanged(oldCount, 0);
    } else if (newCount != oldCount) {
        const int min = qBound(0, oldCount, newCount - 1);
        initializeSections(min, newCount - 1);
        if (stretchLastSection()) // we've already gotten the size hint
            d->lastSectionSize = sectionSize(logicalIndex(d->sectionCount - 1));
    } else if (d->forceInitializing) {
        initializeSections(0, newCount - 1);
        d->forceInitializing = false;
    }
}

/*!
    \internal
*/

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

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

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

    if (end < d->sectionCount) {
        int newCount = end + 1;
        d->removeSectionsFromSpans(newCount, d->sectionCount);
        if (!d->hiddenSectionSize.isEmpty()) {
            if (d->sectionCount - newCount > d->hiddenSectionSize.count()) {
                for (int i = end + 1; i < d->sectionCount; ++i)
                    d->hiddenSectionSize.remove(i);
            } else {
                QHash<int, int>::iterator it = d->hiddenSectionSize.begin();
                while (it != d->hiddenSectionSize.constEnd()) {
                    if (it.key() >= start && it.key() <= end)
                        it = d->hiddenSectionSize.erase(it);
                    else
                        ++it;
                }
            }
        }
    }

    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);

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

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

/*!
  \reimp
*/

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();
}


/*!
  \reimp
*/

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);
}

/*!
  \reimp
*/

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 (d->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();
    for (int i = start; i <= end; ++i) {
        if (d->isVisualIndexHidden(i))
            continue;
        painter.save();
        logical = logicalIndex(i);
        if (d->orientation == Qt::Horizontal) {
            currentSectionRect.setRect(sectionViewportPosition(logical), 0, sectionSize(logical), height);
        } else {
            currentSectionRect.setRect(0, sectionViewportPosition(logical), width, sectionSize(logical));
        }
        currentSectionRect.translate(offset);

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

    QStyleOption opt;
    opt.init(this);
    // Paint the area beyond where there are indexes
    if (d->reverse()) {
        opt.state |= QStyle::State_Horizontal;
        if (currentSectionRect.left() > translatedEventRect.left()) {
            opt.rect = QRect(translatedEventRect.left(), 0,
                             currentSectionRect.left() - translatedEventRect.left(), height);
            style()->drawControl(QStyle::CE_HeaderEmptyArea, &opt, &painter, this);
        }
    } else if (currentSectionRect.right() < translatedEventRect.right()) {
        // paint to the right
        opt.state |= QStyle::State_Horizontal;
        opt.rect = QRect(currentSectionRect.right() + 1, 0,
                         translatedEventRect.right() - currentSectionRect.right(), height);
        style()->drawControl(QStyle::CE_HeaderEmptyArea, &opt, &painter, this);
    } else if (currentSectionRect.bottom() < translatedEventRect.bottom()) {
        // paint the bottom section
        opt.state &= ~QStyle::State_Horizontal;
        opt.rect = QRect(0, currentSectionRect.bottom() + 1,
                         width, height - currentSectionRect.bottom() - 1);
        style()->drawControl(QStyle::CE_HeaderEmptyArea, &opt, &painter, this);
    }

#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 (d->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
}

/*!
  \reimp
*/

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

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

    d->clearCascadingSections();
}

/*!
  \reimp
*/

void QHeaderView::mouseMoveEvent(QMouseEvent *e)
{
    Q_D(QHeaderView);
    int pos = d->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 = (d->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;