void SVGLayoutSupport::layoutChildren(LayoutObject* firstChild,
bool forceLayout,
bool screenScalingFactorChanged,
bool layoutSizeChanged) {
for (LayoutObject* child = firstChild; child; child = child->nextSibling()) {
bool forceChildLayout = forceLayout;
if (screenScalingFactorChanged) {
// If the screen scaling factor changed we need to update the text
// metrics (note: this also happens for layoutSizeChanged=true).
if (child->isSVGText())
toLayoutSVGText(child)->setNeedsTextMetricsUpdate();
forceChildLayout = true;
}
if (layoutSizeChanged) {
// When selfNeedsLayout is false and the layout size changed, we have to
// check whether this child uses relative lengths
if (SVGElement* element =
child->node()->isSVGElement() ? toSVGElement(child->node()) : 0) {
if (element->hasRelativeLengths()) {
// FIXME: this should be done on invalidation, not during layout.
// When the layout size changed and when using relative values tell
// the LayoutSVGShape to update its shape object
if (child->isSVGShape()) {
toLayoutSVGShape(child)->setNeedsShapeUpdate();
} else if (child->isSVGText()) {
toLayoutSVGText(child)->setNeedsTextMetricsUpdate();
toLayoutSVGText(child)->setNeedsPositioningValuesUpdate();
}
forceChildLayout = true;
}
}
}
// Resource containers are nasty: they can invalidate clients outside the
// current SubtreeLayoutScope.
// Since they only care about viewport size changes (to resolve their
// relative lengths), we trigger their invalidation directly from
// SVGSVGElement::svgAttributeChange() or at a higher SubtreeLayoutScope (in
// LayoutView::layout()). We do not create a SubtreeLayoutScope for
// resources because their ability to reference each other leads to circular
// layout. We protect against that within the layout code for resources, but
// it causes assertions if we use a SubTreeLayoutScope for them.
if (child->isSVGResourceContainer()) {
// Lay out any referenced resources before the child.
layoutResourcesIfNeeded(child);
child->layoutIfNeeded();
} else {
SubtreeLayoutScope layoutScope(*child);
if (forceChildLayout)
layoutScope.setNeedsLayout(child, LayoutInvalidationReason::SvgChanged);
// Lay out any referenced resources before the child.
layoutResourcesIfNeeded(child);
child->layoutIfNeeded();
}
}
}
void SVGLayoutSupport::layoutChildren(LayoutObject* start, bool selfNeedsLayout)
{
// When hasRelativeLengths() is false, no descendants have relative lengths
// (hence no one is interested in viewport size changes).
bool layoutSizeChanged = toSVGElement(start->node())->hasRelativeLengths()
&& layoutSizeOfNearestViewportChanged(start);
bool transformChanged = transformToRootChanged(start);
for (LayoutObject* child = start->slowFirstChild(); child; child = child->nextSibling()) {
bool forceLayout = selfNeedsLayout;
if (transformChanged) {
// If the transform changed we need to update the text metrics (note: this also happens for layoutSizeChanged=true).
if (child->isSVGText())
toLayoutSVGText(child)->setNeedsTextMetricsUpdate();
forceLayout = true;
}
if (layoutSizeChanged) {
// When selfNeedsLayout is false and the layout size changed, we have to check whether this child uses relative lengths
if (SVGElement* element = child->node()->isSVGElement() ? toSVGElement(child->node()) : 0) {
if (element->hasRelativeLengths()) {
// FIXME: this should be done on invalidation, not during layout.
// When the layout size changed and when using relative values tell the LayoutSVGShape to update its shape object
if (child->isSVGShape()) {
toLayoutSVGShape(child)->setNeedsShapeUpdate();
} else if (child->isSVGText()) {
toLayoutSVGText(child)->setNeedsTextMetricsUpdate();
toLayoutSVGText(child)->setNeedsPositioningValuesUpdate();
}
forceLayout = true;
}
}
}
SubtreeLayoutScope layoutScope(*child);
// Resource containers are nasty: they can invalidate clients outside the current SubtreeLayoutScope.
// Since they only care about viewport size changes (to resolve their relative lengths), we trigger
// their invalidation directly from SVGSVGElement::svgAttributeChange() or at a higher
// SubtreeLayoutScope (in LayoutView::layout()).
if (forceLayout && !child->isSVGResourceContainer())
layoutScope.setNeedsLayout(child, LayoutInvalidationReason::SvgChanged);
// Lay out any referenced resources before the child.
layoutResourcesIfNeeded(child);
child->layoutIfNeeded();
}
}
void SVGLayoutSupport::computeContainerBoundingBoxes(const LayoutObject* container, FloatRect& objectBoundingBox, bool& objectBoundingBoxValid, FloatRect& strokeBoundingBox, FloatRect& paintInvalidationBoundingBox)
{
objectBoundingBox = FloatRect();
objectBoundingBoxValid = false;
strokeBoundingBox = FloatRect();
// When computing the strokeBoundingBox, we use the paintInvalidationRects of the container's children so that the container's stroke includes
// the resources applied to the children (such as clips and filters). This allows filters applied to containers to correctly bound
// the children, and also improves inlining of SVG content, as the stroke bound is used in that situation also.
for (LayoutObject* current = container->slowFirstChild(); current; current = current->nextSibling()) {
if (current->isSVGHiddenContainer())
continue;
// Don't include elements in the union that do not layout.
if (current->isSVGShape() && toLayoutSVGShape(current)->isShapeEmpty())
continue;
if (current->isSVGText() && !toLayoutSVGText(current)->isObjectBoundingBoxValid())
continue;
const AffineTransform& transform = current->localToSVGParentTransform();
updateObjectBoundingBox(objectBoundingBox, objectBoundingBoxValid, current,
transform.mapRect(current->objectBoundingBox()));
strokeBoundingBox.unite(transform.mapRect(current->paintInvalidationRectInLocalSVGCoordinates()));
}
paintInvalidationBoundingBox = strokeBoundingBox;
}
const LayoutSVGText* LayoutSVGText::locateLayoutSVGTextAncestor(const LayoutObject* start)
{
ASSERT(start);
while (start && !start->isSVGText())
start = start->parent();
if (!start || !start->isSVGText())
return nullptr;
return toLayoutSVGText(start);
}
