qgraphicsanchorlayout.cpp

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#include "qgraphicsanchorlayout_p.h"
#ifndef QT_NO_GRAPHICSVIEW
QT_BEGIN_NAMESPACE

QGraphicsAnchor::QGraphicsAnchor(QGraphicsAnchorLayout *parentLayout)
    : QObject(*(new QGraphicsAnchorPrivate))
{
    Q_D(QGraphicsAnchor);
    Q_ASSERT(parentLayout);
    d->layoutPrivate = parentLayout->d_func();
}

QGraphicsAnchor::~QGraphicsAnchor()
{
}

void QGraphicsAnchor::setSizePolicy(QSizePolicy::Policy policy)
{
    Q_D(QGraphicsAnchor);
    d->setSizePolicy(policy);
}

QSizePolicy::Policy QGraphicsAnchor::sizePolicy() const
{
    Q_D(const QGraphicsAnchor);
    return d->sizePolicy;
}

void QGraphicsAnchor::setSpacing(qreal spacing)
{
    Q_D(QGraphicsAnchor);
    d->setSpacing(spacing);
}

qreal QGraphicsAnchor::spacing() const
{
    Q_D(const QGraphicsAnchor);
    return d->spacing();
}

void QGraphicsAnchor::unsetSpacing()
{
    Q_D(QGraphicsAnchor);
    d->unsetSpacing();
}

QGraphicsAnchorLayout::QGraphicsAnchorLayout(QGraphicsLayoutItem *parent)
    : QGraphicsLayout(*new QGraphicsAnchorLayoutPrivate(), parent)
{
    Q_D(QGraphicsAnchorLayout);
    d->createLayoutEdges();
}

QGraphicsAnchorLayout::~QGraphicsAnchorLayout()
{
    Q_D(QGraphicsAnchorLayout);

    for (int i = count() - 1; i >= 0; --i) {
        QGraphicsLayoutItem *item = d->items.at(i);
        removeAt(i);
        if (item) {
            if (item->ownedByLayout())
                delete item;
        }
    }

    d->removeCenterConstraints(this, QGraphicsAnchorLayoutPrivate::Horizontal);
    d->removeCenterConstraints(this, QGraphicsAnchorLayoutPrivate::Vertical);
    d->deleteLayoutEdges();

    Q_ASSERT(d->itemCenterConstraints[0].isEmpty());
    Q_ASSERT(d->itemCenterConstraints[1].isEmpty());
    Q_ASSERT(d->items.isEmpty());
    Q_ASSERT(d->m_vertexList.isEmpty());
}

QGraphicsAnchor *
QGraphicsAnchorLayout::addAnchor(QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                                 QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge)
{
    Q_D(QGraphicsAnchorLayout);
    QGraphicsAnchor *a = d->addAnchor(firstItem, firstEdge, secondItem, secondEdge);
    invalidate();
    return a;
}

QGraphicsAnchor *
QGraphicsAnchorLayout::anchor(QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                              QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge)
{
    Q_D(QGraphicsAnchorLayout);
    return d->getAnchor(firstItem, firstEdge, secondItem, secondEdge);
}

void QGraphicsAnchorLayout::addCornerAnchors(QGraphicsLayoutItem *firstItem,
                                             Qt::Corner firstCorner,
                                             QGraphicsLayoutItem *secondItem,
                                             Qt::Corner secondCorner)
{
    Q_D(QGraphicsAnchorLayout);

    // Horizontal anchor
    Qt::AnchorPoint firstEdge = (firstCorner & 1 ? Qt::AnchorRight: Qt::AnchorLeft);
    Qt::AnchorPoint secondEdge = (secondCorner & 1 ? Qt::AnchorRight: Qt::AnchorLeft);
    if (d->addAnchor(firstItem, firstEdge, secondItem, secondEdge)) {
        // Vertical anchor
        firstEdge = (firstCorner & 2 ? Qt::AnchorBottom: Qt::AnchorTop);
        secondEdge = (secondCorner & 2 ? Qt::AnchorBottom: Qt::AnchorTop);
        d->addAnchor(firstItem, firstEdge, secondItem, secondEdge);

        invalidate();
    }
}

void QGraphicsAnchorLayout::addAnchors(QGraphicsLayoutItem *firstItem,
                                       QGraphicsLayoutItem *secondItem,
                                       Qt::Orientations orientations)
{
    bool ok = true;
    if (orientations & Qt::Horizontal) {
        // Currently, if the first is ok, then the rest of the calls should be ok
        ok = addAnchor(secondItem, Qt::AnchorLeft, firstItem, Qt::AnchorLeft) != 0;
        if (ok)
            addAnchor(firstItem, Qt::AnchorRight, secondItem, Qt::AnchorRight);
    }
    if (orientations & Qt::Vertical && ok) {
        addAnchor(secondItem, Qt::AnchorTop, firstItem, Qt::AnchorTop);
        addAnchor(firstItem, Qt::AnchorBottom, secondItem, Qt::AnchorBottom);
    }
}

void QGraphicsAnchorLayout::setHorizontalSpacing(qreal spacing)
{
    Q_D(QGraphicsAnchorLayout);

    d->spacings[0] = spacing;
    invalidate();
}

void QGraphicsAnchorLayout::setVerticalSpacing(qreal spacing)
{
    Q_D(QGraphicsAnchorLayout);

    d->spacings[1] = spacing;
    invalidate();
}

void QGraphicsAnchorLayout::setSpacing(qreal spacing)
{
    Q_D(QGraphicsAnchorLayout);

    d->spacings[0] = d->spacings[1] = spacing;
    invalidate();
}

qreal QGraphicsAnchorLayout::horizontalSpacing() const
{
    Q_D(const QGraphicsAnchorLayout);
    return d->styleInfo().defaultSpacing(Qt::Horizontal);
}

qreal QGraphicsAnchorLayout::verticalSpacing() const
{
    Q_D(const QGraphicsAnchorLayout);
    return d->styleInfo().defaultSpacing(Qt::Vertical);
}

void QGraphicsAnchorLayout::setGeometry(const QRectF &geom)
{
    Q_D(QGraphicsAnchorLayout);

    QGraphicsLayout::setGeometry(geom);
    d->calculateVertexPositions(QGraphicsAnchorLayoutPrivate::Horizontal);
    d->calculateVertexPositions(QGraphicsAnchorLayoutPrivate::Vertical);
    d->setItemsGeometries(geom);
}

void QGraphicsAnchorLayout::removeAt(int index)
{
    Q_D(QGraphicsAnchorLayout);
    QGraphicsLayoutItem *item = d->items.value(index);

    if (!item)
        return;

    // Removing an item affects both horizontal and vertical graphs
    d->removeCenterConstraints(item, QGraphicsAnchorLayoutPrivate::Horizontal);
    d->removeCenterConstraints(item, QGraphicsAnchorLayoutPrivate::Vertical);
    d->removeAnchors(item);
    d->items.remove(index);

    item->setParentLayoutItem(0);
    invalidate();
}

int QGraphicsAnchorLayout::count() const
{
    Q_D(const QGraphicsAnchorLayout);
    return d->items.size();
}

QGraphicsLayoutItem *QGraphicsAnchorLayout::itemAt(int index) const
{
    Q_D(const QGraphicsAnchorLayout);
    return d->items.value(index);
}

void QGraphicsAnchorLayout::invalidate()
{
    Q_D(QGraphicsAnchorLayout);
    QGraphicsLayout::invalidate();
    d->calculateGraphCacheDirty = true;
    d->styleInfoDirty = true;
}

QSizeF QGraphicsAnchorLayout::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
{
    Q_UNUSED(constraint);
    Q_D(const QGraphicsAnchorLayout);

    // Some setup calculations are delayed until the information is
    // actually needed, avoiding unnecessary recalculations when
    // adding multiple anchors.

    // sizeHint() / effectiveSizeHint() already have a cache
    // mechanism, using invalidate() to force recalculation. However
    // sizeHint() is called three times after invalidation (for max,
    // min and pref), but we just need do our setup once.

    const_cast<QGraphicsAnchorLayoutPrivate *>(d)->calculateGraphs();

    // ### apply constraint!
    QSizeF engineSizeHint(
        d->sizeHints[QGraphicsAnchorLayoutPrivate::Horizontal][which],
        d->sizeHints[QGraphicsAnchorLayoutPrivate::Vertical][which]);

    qreal left, top, right, bottom;
    getContentsMargins(&left, &top, &right, &bottom);

    return engineSizeHint + QSizeF(left + right, top + bottom);
}

QT_END_NAMESPACE
#endif //QT_NO_GRAPHICSVIEW