| /* |
| * Copyright (C) 2007, 2008 Rob Buis <buis@kde.org> |
| * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org> |
| * Copyright (C) 2007 Eric Seidel <eric@webkit.org> |
| * Copyright (C) 2009 Google, Inc. All rights reserved. |
| * Copyright (C) 2009 Dirk Schulze <krit@webkit.org> |
| * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| */ |
| |
| #include "third_party/blink/renderer/core/layout/svg/svg_layout_support.h" |
| |
| #include "third_party/blink/renderer/core/layout/layout_geometry_map.h" |
| #include "third_party/blink/renderer/core/layout/subtree_layout_scope.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_foreign_object.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_inline_text.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_resource_clipper.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_resource_filter.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_resource_masker.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_root.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_shape.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_text.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_transformable_container.h" |
| #include "third_party/blink/renderer/core/layout/svg/layout_svg_viewport_container.h" |
| #include "third_party/blink/renderer/core/layout/svg/svg_resources.h" |
| #include "third_party/blink/renderer/core/layout/svg/svg_resources_cache.h" |
| #include "third_party/blink/renderer/core/page/page.h" |
| #include "third_party/blink/renderer/core/paint/paint_layer.h" |
| #include "third_party/blink/renderer/core/style/shape_clip_path_operation.h" |
| #include "third_party/blink/renderer/core/svg/svg_element.h" |
| #include "third_party/blink/renderer/core/svg/svg_length_context.h" |
| #include "third_party/blink/renderer/platform/graphics/stroke_data.h" |
| #include "third_party/blink/renderer/platform/transforms/transform_state.h" |
| #include "third_party/blink/renderer/platform/wtf/math_extras.h" |
| |
| namespace blink { |
| |
| struct SearchCandidate { |
| SearchCandidate() |
| : layout_object(nullptr), distance(std::numeric_limits<float>::max()) {} |
| SearchCandidate(LayoutObject* layout_object, float distance) |
| : layout_object(layout_object), distance(distance) {} |
| LayoutObject* layout_object; |
| float distance; |
| }; |
| |
| FloatRect SVGLayoutSupport::LocalVisualRect(const LayoutObject& object) { |
| // For LayoutSVGRoot, use LayoutSVGRoot::localVisualRect() instead. |
| DCHECK(!object.IsSVGRoot()); |
| |
| // Return early for any cases where we don't actually paint |
| if (object.StyleRef().Visibility() != EVisibility::kVisible && |
| !object.EnclosingLayer()->HasVisibleContent()) |
| return FloatRect(); |
| |
| FloatRect visual_rect = object.VisualRectInLocalSVGCoordinates(); |
| if (int outline_outset = object.StyleRef().OutlineOutsetExtent()) |
| visual_rect.Inflate(outline_outset); |
| return visual_rect; |
| } |
| |
| LayoutRect SVGLayoutSupport::VisualRectInAncestorSpace( |
| const LayoutObject& object, |
| const LayoutBoxModelObject& ancestor) { |
| LayoutRect rect; |
| MapToVisualRectInAncestorSpace(object, &ancestor, LocalVisualRect(object), |
| rect); |
| return rect; |
| } |
| |
| LayoutRect SVGLayoutSupport::TransformVisualRect( |
| const LayoutObject& object, |
| const AffineTransform& root_transform, |
| const FloatRect& local_rect) { |
| FloatRect adjusted_rect = root_transform.MapRect(local_rect); |
| |
| if (adjusted_rect.IsEmpty()) |
| return LayoutRect(); |
| |
| // Use enclosingIntRect because we cannot properly apply subpixel offset of |
| // the SVGRoot since we don't know the desired subpixel accumulation at this |
| // point. |
| return LayoutRect(EnclosingIntRect(adjusted_rect)); |
| } |
| |
| static const LayoutSVGRoot& ComputeTransformToSVGRoot( |
| const LayoutObject& object, |
| AffineTransform& root_border_box_transform) { |
| DCHECK(object.IsSVGChild()); |
| |
| const LayoutObject* parent; |
| for (parent = &object; !parent->IsSVGRoot(); parent = parent->Parent()) |
| root_border_box_transform.PreMultiply(parent->LocalToSVGParentTransform()); |
| |
| const LayoutSVGRoot& svg_root = ToLayoutSVGRoot(*parent); |
| root_border_box_transform.PreMultiply(svg_root.LocalToBorderBoxTransform()); |
| return svg_root; |
| } |
| |
| bool SVGLayoutSupport::MapToVisualRectInAncestorSpace( |
| const LayoutObject& object, |
| const LayoutBoxModelObject* ancestor, |
| const FloatRect& local_visual_rect, |
| LayoutRect& result_rect, |
| VisualRectFlags visual_rect_flags) { |
| AffineTransform root_border_box_transform; |
| const LayoutSVGRoot& svg_root = |
| ComputeTransformToSVGRoot(object, root_border_box_transform); |
| result_rect = |
| TransformVisualRect(object, root_border_box_transform, local_visual_rect); |
| |
| // Apply initial viewport clip. |
| if (svg_root.ShouldApplyViewportClip()) { |
| LayoutRect clip_rect(svg_root.OverflowClipRect(LayoutPoint())); |
| if (visual_rect_flags & kEdgeInclusive) { |
| if (!result_rect.InclusiveIntersect(clip_rect)) |
| return false; |
| } else { |
| result_rect.Intersect(clip_rect); |
| } |
| } |
| return svg_root.MapToVisualRectInAncestorSpace(ancestor, result_rect, |
| visual_rect_flags); |
| } |
| |
| void SVGLayoutSupport::MapLocalToAncestor(const LayoutObject* object, |
| const LayoutBoxModelObject* ancestor, |
| TransformState& transform_state, |
| MapCoordinatesFlags flags) { |
| transform_state.ApplyTransform(object->LocalToSVGParentTransform()); |
| |
| LayoutObject* parent = object->Parent(); |
| |
| // At the SVG/HTML boundary (aka LayoutSVGRoot), we apply the |
| // localToBorderBoxTransform to map an element from SVG viewport coordinates |
| // to CSS box coordinates. |
| // LayoutSVGRoot's mapLocalToAncestor method expects CSS box coordinates. |
| if (parent->IsSVGRoot()) |
| transform_state.ApplyTransform( |
| ToLayoutSVGRoot(parent)->LocalToBorderBoxTransform()); |
| |
| parent->MapLocalToAncestor(ancestor, transform_state, flags); |
| } |
| |
| void SVGLayoutSupport::MapAncestorToLocal(const LayoutObject& object, |
| const LayoutBoxModelObject* ancestor, |
| TransformState& transform_state, |
| MapCoordinatesFlags flags) { |
| // |object| is either a LayoutSVGModelObject or a LayoutSVGBlock here. In |
| // the former case, |object| can never be an ancestor while in the latter |
| // the caller is responsible for doing the ancestor check. Because of this, |
| // computing the transform to the SVG root is always what we want to do here. |
| DCHECK_NE(ancestor, &object); |
| DCHECK(object.IsSVGContainer() || object.IsSVGShape() || |
| object.IsSVGImage() || object.IsSVGText() || |
| object.IsSVGForeignObject()); |
| AffineTransform local_to_svg_root; |
| const LayoutSVGRoot& svg_root = |
| ComputeTransformToSVGRoot(object, local_to_svg_root); |
| |
| MapCoordinatesFlags mode = flags | kUseTransforms | kApplyContainerFlip; |
| svg_root.MapAncestorToLocal(ancestor, transform_state, mode); |
| |
| transform_state.ApplyTransform(local_to_svg_root); |
| } |
| |
| const LayoutObject* SVGLayoutSupport::PushMappingToContainer( |
| const LayoutObject* object, |
| const LayoutBoxModelObject* ancestor_to_stop_at, |
| LayoutGeometryMap& geometry_map) { |
| DCHECK_NE(ancestor_to_stop_at, object); |
| |
| LayoutObject* parent = object->Parent(); |
| |
| // At the SVG/HTML boundary (aka LayoutSVGRoot), we apply the |
| // localToBorderBoxTransform to map an element from SVG viewport coordinates |
| // to CSS box coordinates. |
| // LayoutSVGRoot's mapLocalToAncestor method expects CSS box coordinates. |
| if (parent->IsSVGRoot()) { |
| TransformationMatrix matrix( |
| ToLayoutSVGRoot(parent)->LocalToBorderBoxTransform()); |
| matrix.Multiply(object->LocalToSVGParentTransform()); |
| geometry_map.Push(object, matrix); |
| } else { |
| geometry_map.Push(object, object->LocalToSVGParentTransform()); |
| } |
| |
| return parent; |
| } |
| |
| // Update a bounding box taking into account the validity of the other bounding |
| // box. |
| inline void SVGLayoutSupport::UpdateObjectBoundingBox( |
| FloatRect& object_bounding_box, |
| bool& object_bounding_box_valid, |
| LayoutObject* other, |
| FloatRect other_bounding_box) { |
| bool other_valid = |
| other->IsSVGContainer() |
| ? ToLayoutSVGContainer(other)->IsObjectBoundingBoxValid() |
| : true; |
| if (!other_valid) |
| return; |
| |
| if (!object_bounding_box_valid) { |
| object_bounding_box = other_bounding_box; |
| object_bounding_box_valid = true; |
| return; |
| } |
| |
| object_bounding_box.UniteEvenIfEmpty(other_bounding_box); |
| } |
| |
| void SVGLayoutSupport::ComputeContainerBoundingBoxes( |
| const LayoutObject* container, |
| FloatRect& object_bounding_box, |
| bool& object_bounding_box_valid, |
| FloatRect& stroke_bounding_box, |
| FloatRect& local_visual_rect) { |
| object_bounding_box = FloatRect(); |
| object_bounding_box_valid = false; |
| stroke_bounding_box = FloatRect(); |
| |
| // When computing the strokeBoundingBox, we use the visualRects 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(object_bounding_box, object_bounding_box_valid, |
| current, |
| transform.MapRect(current->ObjectBoundingBox())); |
| stroke_bounding_box.Unite( |
| transform.MapRect(current->VisualRectInLocalSVGCoordinates())); |
| } |
| |
| local_visual_rect = stroke_bounding_box; |
| AdjustVisualRectWithResources(*container, object_bounding_box, |
| local_visual_rect); |
| } |
| |
| const LayoutSVGRoot* SVGLayoutSupport::FindTreeRootObject( |
| const LayoutObject* start) { |
| while (start && !start->IsSVGRoot()) |
| start = start->Parent(); |
| |
| DCHECK(start); |
| DCHECK(start->IsSVGRoot()); |
| return ToLayoutSVGRoot(start); |
| } |
| |
| bool SVGLayoutSupport::LayoutSizeOfNearestViewportChanged( |
| const LayoutObject* start) { |
| for (; start; start = start->Parent()) { |
| if (start->IsSVGRoot()) |
| return ToLayoutSVGRoot(start)->IsLayoutSizeChanged(); |
| if (start->IsSVGViewportContainer()) |
| return ToLayoutSVGViewportContainer(start)->IsLayoutSizeChanged(); |
| } |
| NOTREACHED(); |
| return false; |
| } |
| |
| bool SVGLayoutSupport::ScreenScaleFactorChanged(const LayoutObject* ancestor) { |
| for (; ancestor; ancestor = ancestor->Parent()) { |
| if (ancestor->IsSVGRoot()) |
| return ToLayoutSVGRoot(ancestor)->DidScreenScaleFactorChange(); |
| if (ancestor->IsSVGTransformableContainer()) |
| return ToLayoutSVGTransformableContainer(ancestor) |
| ->DidScreenScaleFactorChange(); |
| if (ancestor->IsSVGViewportContainer()) |
| return ToLayoutSVGViewportContainer(ancestor) |
| ->DidScreenScaleFactorChange(); |
| } |
| NOTREACHED(); |
| return false; |
| } |
| |
| void SVGLayoutSupport::LayoutChildren(LayoutObject* first_child, |
| bool force_layout, |
| bool screen_scaling_factor_changed, |
| bool layout_size_changed) { |
| for (LayoutObject* child = first_child; child; child = child->NextSibling()) { |
| bool force_child_layout = force_layout; |
| |
| if (screen_scaling_factor_changed) { |
| // 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(); |
| force_child_layout = true; |
| } |
| |
| if (layout_size_changed) { |
| // When selfNeedsLayout is false and the layout size changed, we have to |
| // check whether this child uses relative lengths |
| if (SVGElement* element = child->GetNode()->IsSVGElement() |
| ? ToSVGElement(child->GetNode()) |
| : nullptr) { |
| 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(); |
| } |
| |
| force_child_layout = 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 layout_scope(*child); |
| if (force_child_layout) |
| layout_scope.SetNeedsLayout(child, |
| LayoutInvalidationReason::kSvgChanged); |
| |
| // Lay out any referenced resources before the child. |
| LayoutResourcesIfNeeded(*child); |
| child->LayoutIfNeeded(); |
| } |
| } |
| } |
| |
| void SVGLayoutSupport::LayoutResourcesIfNeeded(const LayoutObject& object) { |
| SVGResources* resources = |
| SVGResourcesCache::CachedResourcesForLayoutObject(object); |
| if (resources) |
| resources->LayoutIfNeeded(); |
| } |
| |
| bool SVGLayoutSupport::IsOverflowHidden(const LayoutObject& object) { |
| // LayoutSVGRoot should never query for overflow state - it should always clip |
| // itself to the initial viewport size. |
| DCHECK(!object.IsDocumentElement()); |
| return IsOverflowHidden(object.StyleRef()); |
| } |
| |
| bool SVGLayoutSupport::IsOverflowHidden(const ComputedStyle& style) { |
| return style.OverflowX() == EOverflow::kHidden || |
| style.OverflowX() == EOverflow::kScroll; |
| } |
| |
| void SVGLayoutSupport::AdjustVisualRectWithResources( |
| const LayoutObject& layout_object, |
| const FloatRect& object_bounding_box, |
| FloatRect& visual_rect) { |
| SVGResources* resources = |
| SVGResourcesCache::CachedResourcesForLayoutObject(layout_object); |
| if (!resources) |
| return; |
| |
| if (LayoutSVGResourceFilter* filter = resources->Filter()) |
| visual_rect = filter->ResourceBoundingBox(object_bounding_box); |
| |
| if (LayoutSVGResourceClipper* clipper = resources->Clipper()) |
| visual_rect.Intersect(clipper->ResourceBoundingBox(object_bounding_box)); |
| |
| if (LayoutSVGResourceMasker* masker = resources->Masker()) |
| visual_rect.Intersect(masker->ResourceBoundingBox(object_bounding_box)); |
| } |
| |
| bool SVGLayoutSupport::HasFilterResource(const LayoutObject& object) { |
| SVGResources* resources = |
| SVGResourcesCache::CachedResourcesForLayoutObject(object); |
| return resources && resources->Filter(); |
| } |
| |
| bool SVGLayoutSupport::IntersectsClipPath(const LayoutObject& object, |
| const HitTestLocation& location) { |
| ClipPathOperation* clip_path_operation = object.StyleRef().ClipPath(); |
| if (!clip_path_operation) |
| return true; |
| const FloatRect& reference_box = object.ObjectBoundingBox(); |
| if (clip_path_operation->GetType() == ClipPathOperation::SHAPE) { |
| ShapeClipPathOperation& clip_path = |
| ToShapeClipPathOperation(*clip_path_operation); |
| return clip_path.GetPath(reference_box) |
| .Contains(location.TransformedPoint()); |
| } |
| DCHECK_EQ(clip_path_operation->GetType(), ClipPathOperation::REFERENCE); |
| SVGResources* resources = |
| SVGResourcesCache::CachedResourcesForLayoutObject(object); |
| if (!resources || !resources->Clipper()) |
| return true; |
| return resources->Clipper()->HitTestClipContent(reference_box, location); |
| } |
| |
| bool SVGLayoutSupport::HitTestChildren(LayoutObject* last_child, |
| HitTestResult& result, |
| const HitTestLocation& location, |
| const LayoutPoint& accumulated_offset, |
| HitTestAction hit_test_action) { |
| for (LayoutObject* child = last_child; child; |
| child = child->PreviousSibling()) { |
| if (child->IsSVGForeignObject()) { |
| if (ToLayoutSVGForeignObject(child)->NodeAtPointFromSVG( |
| result, location, accumulated_offset, hit_test_action)) |
| return true; |
| } else { |
| if (child->NodeAtPoint(result, location, accumulated_offset, |
| hit_test_action)) |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| DashArray SVGLayoutSupport::ResolveSVGDashArray( |
| const SVGDashArray& svg_dash_array, |
| const ComputedStyle& style, |
| const SVGLengthContext& length_context) { |
| DashArray dash_array; |
| for (const Length& dash_length : svg_dash_array.GetVector()) |
| dash_array.push_back(length_context.ValueForLength(dash_length, style)); |
| return dash_array; |
| } |
| |
| void SVGLayoutSupport::ApplyStrokeStyleToStrokeData(StrokeData& stroke_data, |
| const ComputedStyle& style, |
| const LayoutObject& object, |
| float dash_scale_factor) { |
| DCHECK(object.GetNode()); |
| DCHECK(object.GetNode()->IsSVGElement()); |
| |
| const SVGComputedStyle& svg_style = style.SvgStyle(); |
| |
| SVGLengthContext length_context(ToSVGElement(object.GetNode())); |
| stroke_data.SetThickness( |
| length_context.ValueForLength(svg_style.StrokeWidth())); |
| stroke_data.SetLineCap(svg_style.CapStyle()); |
| stroke_data.SetLineJoin(svg_style.JoinStyle()); |
| stroke_data.SetMiterLimit(svg_style.StrokeMiterLimit()); |
| |
| DashArray dash_array = |
| ResolveSVGDashArray(*svg_style.StrokeDashArray(), style, length_context); |
| float dash_offset = |
| length_context.ValueForLength(svg_style.StrokeDashOffset(), style); |
| // Apply scaling from 'pathLength'. |
| if (dash_scale_factor != 1) { |
| DCHECK_GE(dash_scale_factor, 0); |
| dash_offset *= dash_scale_factor; |
| for (auto& dash_item : dash_array) |
| dash_item *= dash_scale_factor; |
| } |
| stroke_data.SetLineDash(dash_array, dash_offset); |
| } |
| |
| bool SVGLayoutSupport::IsLayoutableTextNode(const LayoutObject* object) { |
| DCHECK(object->IsText()); |
| // <br> is marked as text, but is not handled by the SVG layout code-path. |
| return object->IsSVGInlineText() && |
| !ToLayoutSVGInlineText(object)->HasEmptyText(); |
| } |
| |
| bool SVGLayoutSupport::WillIsolateBlendingDescendantsForStyle( |
| const ComputedStyle& style) { |
| const SVGComputedStyle& svg_style = style.SvgStyle(); |
| |
| return style.HasIsolation() || style.HasOpacity() || style.HasBlendMode() || |
| style.HasFilter() || svg_style.HasMasker() || style.ClipPath(); |
| } |
| |
| bool SVGLayoutSupport::WillIsolateBlendingDescendantsForObject( |
| const LayoutObject* object) { |
| if (object->IsSVGHiddenContainer()) |
| return false; |
| if (!object->IsSVGRoot() && !object->IsSVGContainer()) |
| return false; |
| return WillIsolateBlendingDescendantsForStyle(object->StyleRef()); |
| } |
| |
| bool SVGLayoutSupport::IsIsolationRequired(const LayoutObject* object) { |
| return WillIsolateBlendingDescendantsForObject(object) && |
| object->HasNonIsolatedBlendingDescendants(); |
| } |
| |
| AffineTransform::Transform |
| SubtreeContentTransformScope::current_content_transformation_ = |
| IDENTITY_TRANSFORM; |
| |
| SubtreeContentTransformScope::SubtreeContentTransformScope( |
| const AffineTransform& subtree_content_transformation) |
| : saved_content_transformation_(current_content_transformation_) { |
| AffineTransform content_transformation = |
| subtree_content_transformation * |
| AffineTransform(current_content_transformation_); |
| content_transformation.CopyTransformTo(current_content_transformation_); |
| } |
| |
| SubtreeContentTransformScope::~SubtreeContentTransformScope() { |
| saved_content_transformation_.CopyTransformTo( |
| current_content_transformation_); |
| } |
| |
| AffineTransform SVGLayoutSupport::DeprecatedCalculateTransformToLayer( |
| const LayoutObject* layout_object) { |
| AffineTransform transform; |
| while (layout_object) { |
| transform = layout_object->LocalToSVGParentTransform() * transform; |
| if (layout_object->IsSVGRoot()) |
| break; |
| layout_object = layout_object->Parent(); |
| } |
| |
| // Continue walking up the layer tree, accumulating CSS transforms. |
| // FIXME: this queries layer compositing state - which is not |
| // supported during layout. Hence, the result may not include all CSS |
| // transforms. |
| PaintLayer* layer = layout_object ? layout_object->EnclosingLayer() : nullptr; |
| while (layer && layer->IsAllowedToQueryCompositingState()) { |
| // We can stop at compositing layers, to match the backing resolution. |
| // FIXME: should we be computing the transform to the nearest composited |
| // layer, or the nearest composited layer that does not paint into its |
| // ancestor? I think this is the nearest composited ancestor since we will |
| // inherit its transforms in the composited layer tree. |
| if (layer->GetCompositingState() != kNotComposited) |
| break; |
| |
| if (TransformationMatrix* layer_transform = layer->Transform()) |
| transform = layer_transform->ToAffineTransform() * transform; |
| |
| layer = layer->Parent(); |
| } |
| |
| return transform; |
| } |
| |
| float SVGLayoutSupport::CalculateScreenFontSizeScalingFactor( |
| const LayoutObject* layout_object) { |
| DCHECK(layout_object); |
| |
| // FIXME: trying to compute a device space transform at record time is wrong. |
| // All clients should be updated to avoid relying on this information, and the |
| // method should be removed. |
| AffineTransform ctm = |
| DeprecatedCalculateTransformToLayer(layout_object) * |
| SubtreeContentTransformScope::CurrentContentTransformation(); |
| ctm.Scale( |
| layout_object->GetDocument().GetPage()->DeviceScaleFactorDeprecated()); |
| |
| return clampTo<float>(sqrt((ctm.XScaleSquared() + ctm.YScaleSquared()) / 2)); |
| } |
| |
| static inline bool CompareCandidateDistance(const SearchCandidate& r1, |
| const SearchCandidate& r2) { |
| return r1.distance < r2.distance; |
| } |
| |
| static inline float DistanceToChildLayoutObject(LayoutObject* child, |
| const FloatPoint& point) { |
| const AffineTransform& local_to_parent_transform = |
| child->LocalToSVGParentTransform(); |
| if (!local_to_parent_transform.IsInvertible()) |
| return std::numeric_limits<float>::max(); |
| FloatPoint child_local_point = |
| local_to_parent_transform.Inverse().MapPoint(point); |
| return child->ObjectBoundingBox().SquaredDistanceTo(child_local_point); |
| } |
| |
| static SearchCandidate SearchTreeForFindClosestLayoutSVGText( |
| const LayoutObject* layout_object, |
| const FloatPoint& point) { |
| // Try to find the closest LayoutSVGText. |
| SearchCandidate closest_text; |
| Vector<SearchCandidate> candidates; |
| |
| // Find the closest LayoutSVGText on this tree level, and also collect any |
| // containers that could contain LayoutSVGTexts that are closer. |
| for (LayoutObject* child = layout_object->SlowLastChild(); child; |
| child = child->PreviousSibling()) { |
| if (child->IsSVGText()) { |
| float distance = DistanceToChildLayoutObject(child, point); |
| if (distance >= closest_text.distance) |
| continue; |
| candidates.clear(); |
| closest_text.layout_object = child; |
| closest_text.distance = distance; |
| continue; |
| } |
| |
| if (child->IsSVGContainer() && !layout_object->IsSVGHiddenContainer()) { |
| float distance = DistanceToChildLayoutObject(child, point); |
| if (distance > closest_text.distance) |
| continue; |
| candidates.push_back(SearchCandidate(child, distance)); |
| } |
| } |
| |
| // If a LayoutSVGText was found and there are no potentially closer sub-trees, |
| // just return |closestText|. |
| if (closest_text.layout_object && candidates.IsEmpty()) |
| return closest_text; |
| |
| std::stable_sort(candidates.begin(), candidates.end(), |
| CompareCandidateDistance); |
| |
| // Find the closest LayoutSVGText in the sub-trees in |candidates|. |
| // If a LayoutSVGText is found that is strictly closer than any previous |
| // candidate, then end the search. |
| for (const SearchCandidate& search_candidate : candidates) { |
| if (closest_text.distance < search_candidate.distance) |
| break; |
| LayoutObject* candidate_layout_object = search_candidate.layout_object; |
| FloatPoint candidate_local_point = |
| candidate_layout_object->LocalToSVGParentTransform().Inverse().MapPoint( |
| point); |
| |
| SearchCandidate candidate_text = SearchTreeForFindClosestLayoutSVGText( |
| candidate_layout_object, candidate_local_point); |
| |
| if (candidate_text.distance < closest_text.distance) |
| closest_text = candidate_text; |
| } |
| |
| return closest_text; |
| } |
| |
| LayoutObject* SVGLayoutSupport::FindClosestLayoutSVGText( |
| const LayoutObject* layout_object, |
| const FloatPoint& point) { |
| return SearchTreeForFindClosestLayoutSVGText(layout_object, point) |
| .layout_object; |
| } |
| |
| } // namespace blink |
