QGraphicsAnchorLayout Class

  layout->addAnchor(b, Qt::AnchorLeft, a, Qt::AnchorRight);
  layout->addAnchor(b, Qt::AnchorTop, a, Qt::AnchorBottom);

  layout->addCornerAnchors(a, Qt::TopLeftCorner, layout, Qt::TopLeftCorner);

Member Function Documentation

QGraphicsAnchorLayout::QGraphicsAnchorLayout(QGraphicsLayoutItem *parent = Q_NULLPTR)

Constructs a QGraphicsAnchorLayout instance. parent is passed to QGraphicsLayout's constructor.

[virtual] QGraphicsAnchorLayout::~QGraphicsAnchorLayout()

Destroys the QGraphicsAnchorLayout object.

QGraphicsAnchor *QGraphicsAnchorLayout::addAnchor(QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge, QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge)

Creates an anchor between the edge firstEdge of item firstItem and the edge secondEdge of item secondItem. The spacing of the anchor is picked up from the style. Anchors between a layout edge and an item edge will have a size of 0. If there is already an anchor between the edges, the new anchor will replace the old one.

firstItem and secondItem are automatically added to the layout if they are not part of the layout. This means that count() can increase by up to 2.

The spacing an anchor will get depends on the type of anchor. For instance, anchors from the Right edge of one item to the Left edge of another (or vice versa) will use the default horizontal spacing. The same behaviour applies to Bottom to Top anchors, (but they will use the default vertical spacing). For all other anchor combinations, the spacing will be 0. All anchoring functions will follow this rule.

The spacing can also be set manually by using QGraphicsAnchor::setSpacing() method.

Calling this function where firstItem or secondItem are ancestors of the layout have undefined behaviour.

See also addAnchors() and addCornerAnchors().

void QGraphicsAnchorLayout::addAnchors(QGraphicsLayoutItem *firstItem, QGraphicsLayoutItem *secondItem, Qt::Orientations orientations = Qt::Horizontal | Qt::Vertical)

Anchors two or four edges of firstItem with the corresponding edges of secondItem, so that firstItem has the same size as secondItem in the dimensions specified by orientations.

For example, the following example anchors the left and right edges of two items to match their widths:

  layout->addAnchor(b, Qt::AnchorLeft, c, Qt::AnchorLeft);
  layout->addAnchor(b, Qt::AnchorRight, c, Qt::AnchorRight);

This can also be achieved using the following line of code:

  layout->addAnchors(b, c, Qt::Horizontal);

See also addAnchor() and addCornerAnchors().

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

Creates two anchors between firstItem and secondItem specified by the corners, firstCorner and secondCorner, where one is for the horizontal edge and another one for the vertical edge.

This is a convenience function, since anchoring corners can be expressed as anchoring two edges. For instance:

  layout->addAnchor(a, Qt::AnchorTop, layout, Qt::AnchorTop);
  layout->addAnchor(a, Qt::AnchorLeft, layout, Qt::AnchorLeft);

This can also be achieved with the following line of code:

  layout->addCornerAnchors(a, Qt::TopLeftCorner, layout, Qt::TopLeftCorner);

If there is already an anchor between the edge pairs, it will be replaced by the anchors that this function specifies.

firstItem and secondItem are automatically added to the layout if they are not part of the layout. This means that count() can increase by up to 2.

See also addAnchor() and addAnchors().

QGraphicsAnchor *QGraphicsAnchorLayout::anchor(QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge, QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge)

Returns the anchor between the anchor points defined by firstItem and firstEdge and secondItem and secondEdge. If there is no such anchor, the function will return 0.

[virtual] int QGraphicsAnchorLayout::count() const

Reimplemented from QGraphicsLayout::count().

qreal QGraphicsAnchorLayout::horizontalSpacing() const

Returns the default horizontal spacing for the anchor layout.

See also verticalSpacing() and setHorizontalSpacing().

[virtual] void QGraphicsAnchorLayout::invalidate()

Reimplemented from QGraphicsLayout::invalidate().

[virtual] QGraphicsLayoutItem *QGraphicsAnchorLayout::itemAt(int index) const

Reimplemented from QGraphicsLayout::itemAt().

[virtual] void QGraphicsAnchorLayout::removeAt(int index)

Reimplemented from QGraphicsLayout::removeAt().

Removes the layout item at index without destroying it. Ownership of the item is transferred to the caller.

Removing an item will also remove any of the anchors associated with it.

See also itemAt() and count().

[virtual] void QGraphicsAnchorLayout::setGeometry(const QRectF &geom)

Reimplemented from QGraphicsLayoutItem::setGeometry().

void QGraphicsAnchorLayout::setHorizontalSpacing(qreal spacing)

Sets the default horizontal spacing for the anchor layout to spacing.

See also horizontalSpacing(), setVerticalSpacing(), and setSpacing().

void QGraphicsAnchorLayout::setSpacing(qreal spacing)

Sets the default horizontal and the default vertical spacing for the anchor layout to spacing.

If an item is anchored with no spacing associated with the anchor, it will use the default spacing.

QGraphicsAnchorLayout does not support negative spacings. Setting a negative value will unset the previous spacing and make the layout use the spacing provided by the current widget style.

See also setHorizontalSpacing() and setVerticalSpacing().

void QGraphicsAnchorLayout::setVerticalSpacing(qreal spacing)

Sets the default vertical spacing for the anchor layout to spacing.

See also verticalSpacing(), setHorizontalSpacing(), and setSpacing().

[virtual protected] QSizeF QGraphicsAnchorLayout::sizeHint(Qt::SizeHint which, const QSizeF &constraint = QSizeF()) const

Reimplemented from QGraphicsLayoutItem::sizeHint().

qreal QGraphicsAnchorLayout::verticalSpacing() const

Returns the default vertical spacing for the anchor layout.

See also horizontalSpacing() and setVerticalSpacing().