| /* |
| * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org> |
| * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org> |
| * Copyright (C) 2007 Apple Inc. All rights reserved. |
| * Copyright (C) Research In Motion Limited 2011. 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/svg/svg_length_context.h" |
| |
| #include "third_party/blink/renderer/core/css/css_primitive_value.h" |
| #include "third_party/blink/renderer/core/css/css_resolution_units.h" |
| #include "third_party/blink/renderer/core/css/css_to_length_conversion_data.h" |
| #include "third_party/blink/renderer/core/dom/node_computed_style.h" |
| #include "third_party/blink/renderer/core/frame/local_frame_view.h" |
| #include "third_party/blink/renderer/core/layout/layout_object.h" |
| #include "third_party/blink/renderer/core/style/computed_style.h" |
| #include "third_party/blink/renderer/core/svg/svg_svg_element.h" |
| #include "third_party/blink/renderer/platform/fonts/font_metrics.h" |
| #include "third_party/blink/renderer/platform/geometry/length_functions.h" |
| |
| namespace blink { |
| |
| static inline float DimensionForLengthMode(SVGLengthMode mode, |
| const FloatSize& viewport_size) { |
| switch (mode) { |
| case SVGLengthMode::kWidth: |
| return viewport_size.Width(); |
| case SVGLengthMode::kHeight: |
| return viewport_size.Height(); |
| case SVGLengthMode::kOther: |
| return sqrtf(viewport_size.DiagonalLengthSquared() / 2); |
| } |
| NOTREACHED(); |
| return 0; |
| } |
| |
| static float ConvertValueFromPercentageToUserUnits( |
| const SVGLength& value, |
| const FloatSize& viewport_size) { |
| return CSSPrimitiveValue::ClampToCSSLengthRange(value.ScaleByPercentage( |
| DimensionForLengthMode(value.UnitMode(), viewport_size))); |
| } |
| |
| static const ComputedStyle* ComputedStyleForLengthResolving( |
| const SVGElement* context) { |
| if (!context) |
| return nullptr; |
| |
| const ContainerNode* current_context = context; |
| do { |
| if (current_context->GetLayoutObject()) |
| return current_context->GetLayoutObject()->Style(); |
| current_context = current_context->parentNode(); |
| } while (current_context); |
| |
| // We can end up here if trying to resolve values for elements in an |
| // inactive document. |
| return nullptr; |
| } |
| |
| static const ComputedStyle* RootElementStyle(const Node* context) { |
| if (!context) |
| return nullptr; |
| |
| const Document& document = context->GetDocument(); |
| Node* document_element = document.documentElement(); |
| const ComputedStyle* document_style = document.GetComputedStyle(); |
| const ComputedStyle* style = document_element && context != document_element |
| ? document_element->GetComputedStyle() |
| : document_style; |
| if (!style) |
| style = document_style; |
| return style; |
| } |
| |
| static float ConvertValueFromUserUnitsToEMS(const ComputedStyle* style, |
| float value) { |
| if (!style) |
| return 0; |
| float font_size = style->SpecifiedFontSize(); |
| if (!font_size) |
| return 0; |
| return value / font_size; |
| } |
| |
| static float ConvertValueFromEMSToUserUnits(const ComputedStyle* style, |
| float value) { |
| if (!style) |
| return 0; |
| return value * style->SpecifiedFontSize(); |
| } |
| |
| static inline float ViewportLengthPercent(const float width_or_height) { |
| return width_or_height / 100; |
| } |
| |
| static inline float ViewportMinPercent(const FloatSize& viewport_size) { |
| return std::min(viewport_size.Width(), viewport_size.Height()) / 100; |
| } |
| |
| static inline float ViewportMaxPercent(const FloatSize& viewport_size) { |
| return std::max(viewport_size.Width(), viewport_size.Height()) / 100; |
| } |
| |
| static inline float DimensionForViewportUnit(const SVGElement* context, |
| CSSPrimitiveValue::UnitType unit) { |
| if (!context) |
| return 0; |
| |
| const Document& document = context->GetDocument(); |
| LocalFrameView* view = document.View(); |
| if (!view) |
| return 0; |
| |
| const ComputedStyle* style = ComputedStyleForLengthResolving(context); |
| if (!style) |
| return 0; |
| |
| FloatSize viewport_size(view->Width(), view->Height()); |
| |
| switch (unit) { |
| case CSSPrimitiveValue::UnitType::kViewportWidth: |
| return ViewportLengthPercent(viewport_size.Width()) / |
| style->EffectiveZoom(); |
| |
| case CSSPrimitiveValue::UnitType::kViewportHeight: |
| return ViewportLengthPercent(viewport_size.Height()) / |
| style->EffectiveZoom(); |
| |
| case CSSPrimitiveValue::UnitType::kViewportMin: |
| return ViewportMinPercent(viewport_size) / style->EffectiveZoom(); |
| |
| case CSSPrimitiveValue::UnitType::kViewportMax: |
| return ViewportMaxPercent(viewport_size) / style->EffectiveZoom(); |
| default: |
| break; |
| } |
| |
| NOTREACHED(); |
| return 0; |
| } |
| |
| SVGLengthContext::SVGLengthContext(const SVGElement* context) |
| : context_(context) {} |
| |
| FloatRect SVGLengthContext::ResolveRectangle(const SVGElement* context, |
| SVGUnitTypes::SVGUnitType type, |
| const FloatRect& viewport, |
| const SVGLength& x, |
| const SVGLength& y, |
| const SVGLength& width, |
| const SVGLength& height) { |
| DCHECK_NE(SVGUnitTypes::kSvgUnitTypeUnknown, type); |
| if (type != SVGUnitTypes::kSvgUnitTypeUserspaceonuse) { |
| const FloatSize& viewport_size = viewport.Size(); |
| return FloatRect( |
| ConvertValueFromPercentageToUserUnits(x, viewport_size) + viewport.X(), |
| ConvertValueFromPercentageToUserUnits(y, viewport_size) + viewport.Y(), |
| ConvertValueFromPercentageToUserUnits(width, viewport_size), |
| ConvertValueFromPercentageToUserUnits(height, viewport_size)); |
| } |
| |
| SVGLengthContext length_context(context); |
| return FloatRect(x.Value(length_context), y.Value(length_context), |
| width.Value(length_context), height.Value(length_context)); |
| } |
| |
| FloatPoint SVGLengthContext::ResolvePoint(const SVGElement* context, |
| SVGUnitTypes::SVGUnitType type, |
| const SVGLength& x, |
| const SVGLength& y) { |
| DCHECK_NE(SVGUnitTypes::kSvgUnitTypeUnknown, type); |
| if (type == SVGUnitTypes::kSvgUnitTypeUserspaceonuse) { |
| SVGLengthContext length_context(context); |
| return FloatPoint(x.Value(length_context), y.Value(length_context)); |
| } |
| |
| // FIXME: valueAsPercentage() won't be correct for eg. cm units. They need to |
| // be resolved in user space and then be considered in objectBoundingBox |
| // space. |
| return FloatPoint(x.ValueAsPercentage(), y.ValueAsPercentage()); |
| } |
| |
| FloatPoint SVGLengthContext::ResolveLengthPair( |
| const Length& x_length, |
| const Length& y_length, |
| const ComputedStyle& style) const { |
| FloatSize viewport_size; |
| if (x_length.IsPercentOrCalc() || y_length.IsPercentOrCalc()) |
| DetermineViewport(viewport_size); |
| |
| float zoom = style.EffectiveZoom(); |
| return FloatPoint(ValueForLength(x_length, zoom, viewport_size.Width()), |
| ValueForLength(y_length, zoom, viewport_size.Height())); |
| } |
| |
| float SVGLengthContext::ResolveLength(const SVGElement* context, |
| SVGUnitTypes::SVGUnitType type, |
| const SVGLength& x) { |
| DCHECK_NE(SVGUnitTypes::kSvgUnitTypeUnknown, type); |
| if (type == SVGUnitTypes::kSvgUnitTypeUserspaceonuse) { |
| SVGLengthContext length_context(context); |
| return x.Value(length_context); |
| } |
| |
| // FIXME: valueAsPercentage() won't be correct for eg. cm units. They need to |
| // be resolved in user space and then be considered in objectBoundingBox |
| // space. |
| return x.ValueAsPercentage(); |
| } |
| |
| float SVGLengthContext::ValueForLength(const UnzoomedLength& unzoomed_length, |
| SVGLengthMode mode) const { |
| return ValueForLength(unzoomed_length.length(), 1, mode); |
| } |
| |
| float SVGLengthContext::ValueForLength(const Length& length, |
| const ComputedStyle& style, |
| SVGLengthMode mode) const { |
| return ValueForLength(length, style.EffectiveZoom(), mode); |
| } |
| |
| float SVGLengthContext::ValueForLength(const Length& length, |
| float zoom, |
| SVGLengthMode mode) const { |
| float dimension = 0; |
| if (length.IsPercentOrCalc()) { |
| FloatSize viewport_size; |
| DetermineViewport(viewport_size); |
| // The viewport will be unaffected by zoom. |
| dimension = DimensionForLengthMode(mode, viewport_size); |
| } |
| return ValueForLength(length, zoom, dimension); |
| } |
| |
| float SVGLengthContext::ValueForLength(const Length& length, |
| const ComputedStyle& style, |
| float dimension) { |
| return ValueForLength(length, style.EffectiveZoom(), dimension); |
| } |
| |
| float SVGLengthContext::ValueForLength(const Length& length, |
| float zoom, |
| float dimension) { |
| DCHECK_NE(zoom, 0); |
| // isIntrinsic can occur for 'width' and 'height', but has no |
| // real meaning for svg. |
| if (length.IsIntrinsic()) |
| return 0; |
| return FloatValueForLength(length, dimension * zoom) / zoom; |
| } |
| |
| float SVGLengthContext::ConvertValueToUserUnits( |
| float value, |
| SVGLengthMode mode, |
| CSSPrimitiveValue::UnitType from_unit) const { |
| double user_units = value; |
| switch (from_unit) { |
| case CSSPrimitiveValue::UnitType::kPixels: |
| case CSSPrimitiveValue::UnitType::kNumber: |
| case CSSPrimitiveValue::UnitType::kInteger: |
| case CSSPrimitiveValue::UnitType::kUserUnits: |
| user_units = value; |
| break; |
| case CSSPrimitiveValue::UnitType::kPercentage: { |
| FloatSize viewport_size; |
| if (!DetermineViewport(viewport_size)) |
| return 0; |
| user_units = value * DimensionForLengthMode(mode, viewport_size) / 100; |
| break; |
| } |
| case CSSPrimitiveValue::UnitType::kEms: |
| user_units = ConvertValueFromEMSToUserUnits( |
| ComputedStyleForLengthResolving(context_), value); |
| break; |
| case CSSPrimitiveValue::UnitType::kExs: |
| user_units = ConvertValueFromEXSToUserUnits(value); |
| break; |
| case CSSPrimitiveValue::UnitType::kCentimeters: |
| user_units = value * kCssPixelsPerCentimeter; |
| break; |
| case CSSPrimitiveValue::UnitType::kMillimeters: |
| user_units = value * kCssPixelsPerMillimeter; |
| break; |
| case CSSPrimitiveValue::UnitType::kQuarterMillimeters: |
| user_units = value * kCssPixelsPerQuarterMillimeter; |
| break; |
| case CSSPrimitiveValue::UnitType::kInches: |
| user_units = value * kCssPixelsPerInch; |
| break; |
| case CSSPrimitiveValue::UnitType::kPoints: |
| user_units = value * kCssPixelsPerPoint; |
| break; |
| case CSSPrimitiveValue::UnitType::kPicas: |
| user_units = value * kCssPixelsPerPica; |
| break; |
| case CSSPrimitiveValue::UnitType::kRems: |
| user_units = |
| ConvertValueFromEMSToUserUnits(RootElementStyle(context_), value); |
| break; |
| case CSSPrimitiveValue::UnitType::kChs: |
| user_units = ConvertValueFromCHSToUserUnits(value); |
| break; |
| case CSSPrimitiveValue::UnitType::kViewportWidth: |
| case CSSPrimitiveValue::UnitType::kViewportHeight: |
| case CSSPrimitiveValue::UnitType::kViewportMin: |
| case CSSPrimitiveValue::UnitType::kViewportMax: |
| user_units = value * DimensionForViewportUnit(context_, from_unit); |
| break; |
| default: |
| NOTREACHED(); |
| break; |
| } |
| |
| // Since we mix css <length> values with svg's length values we need to |
| // clamp values to the narrowest range, otherwise it can result in |
| // rendering issues. |
| return CSSPrimitiveValue::ClampToCSSLengthRange(user_units); |
| } |
| |
| float SVGLengthContext::ConvertValueFromUserUnits( |
| float value, |
| SVGLengthMode mode, |
| CSSPrimitiveValue::UnitType to_unit) const { |
| switch (to_unit) { |
| case CSSPrimitiveValue::UnitType::kPixels: |
| case CSSPrimitiveValue::UnitType::kNumber: |
| case CSSPrimitiveValue::UnitType::kInteger: |
| case CSSPrimitiveValue::UnitType::kUserUnits: |
| return value; |
| case CSSPrimitiveValue::UnitType::kPercentage: { |
| FloatSize viewport_size; |
| if (!DetermineViewport(viewport_size)) |
| return 0; |
| float dimension = DimensionForLengthMode(mode, viewport_size); |
| if (!dimension) |
| return 0; |
| // LengthTypePercentage is represented with 100% = 100.0. |
| // Good for accuracy but could eventually be changed. |
| return value * 100 / dimension; |
| } |
| case CSSPrimitiveValue::UnitType::kEms: |
| return ConvertValueFromUserUnitsToEMS( |
| ComputedStyleForLengthResolving(context_), value); |
| case CSSPrimitiveValue::UnitType::kExs: |
| return ConvertValueFromUserUnitsToEXS(value); |
| case CSSPrimitiveValue::UnitType::kRems: |
| return ConvertValueFromUserUnitsToEMS(RootElementStyle(context_), value); |
| case CSSPrimitiveValue::UnitType::kChs: |
| return ConvertValueFromUserUnitsToCHS(value); |
| case CSSPrimitiveValue::UnitType::kCentimeters: |
| return value / kCssPixelsPerCentimeter; |
| case CSSPrimitiveValue::UnitType::kMillimeters: |
| return value / kCssPixelsPerMillimeter; |
| case CSSPrimitiveValue::UnitType::kQuarterMillimeters: |
| return value / kCssPixelsPerQuarterMillimeter; |
| case CSSPrimitiveValue::UnitType::kInches: |
| return value / kCssPixelsPerInch; |
| case CSSPrimitiveValue::UnitType::kPoints: |
| return value / kCssPixelsPerPoint; |
| case CSSPrimitiveValue::UnitType::kPicas: |
| return value / kCssPixelsPerPica; |
| case CSSPrimitiveValue::UnitType::kViewportWidth: |
| case CSSPrimitiveValue::UnitType::kViewportHeight: |
| case CSSPrimitiveValue::UnitType::kViewportMin: |
| case CSSPrimitiveValue::UnitType::kViewportMax: |
| return value / DimensionForViewportUnit(context_, to_unit); |
| default: |
| break; |
| } |
| |
| NOTREACHED(); |
| return 0; |
| } |
| |
| float SVGLengthContext::ConvertValueFromUserUnitsToCHS(float value) const { |
| const ComputedStyle* style = ComputedStyleForLengthResolving(context_); |
| if (!style) |
| return 0; |
| const SimpleFontData* font_data = style->GetFont().PrimaryFont(); |
| if (!font_data) |
| return 0; |
| float zero_width = |
| font_data->GetFontMetrics().ZeroWidth() / style->EffectiveZoom(); |
| if (!zero_width) |
| return 0; |
| return value / zero_width; |
| } |
| |
| float SVGLengthContext::ConvertValueFromCHSToUserUnits(float value) const { |
| const ComputedStyle* style = ComputedStyleForLengthResolving(context_); |
| if (!style) |
| return 0; |
| const SimpleFontData* font_data = style->GetFont().PrimaryFont(); |
| if (!font_data) |
| return 0; |
| return value * font_data->GetFontMetrics().ZeroWidth() / |
| style->EffectiveZoom(); |
| } |
| |
| float SVGLengthContext::ConvertValueFromUserUnitsToEXS(float value) const { |
| const ComputedStyle* style = ComputedStyleForLengthResolving(context_); |
| if (!style) |
| return 0; |
| const SimpleFontData* font_data = style->GetFont().PrimaryFont(); |
| if (!font_data) |
| return 0; |
| // Use of ceil allows a pixel match to the W3Cs expected output of |
| // coords-units-03-b.svg, if this causes problems in real world cases maybe it |
| // would be best to remove this. |
| float x_height = |
| ceilf(font_data->GetFontMetrics().XHeight() / style->EffectiveZoom()); |
| if (!x_height) |
| return 0; |
| return value / x_height; |
| } |
| |
| float SVGLengthContext::ConvertValueFromEXSToUserUnits(float value) const { |
| const ComputedStyle* style = ComputedStyleForLengthResolving(context_); |
| if (!style) |
| return 0; |
| const SimpleFontData* font_data = style->GetFont().PrimaryFont(); |
| if (!font_data) |
| return 0; |
| // Use of ceil allows a pixel match to the W3Cs expected output of |
| // coords-units-03-b.svg, if this causes problems in real world cases maybe it |
| // would be best to remove this. |
| return value * |
| ceilf(font_data->GetFontMetrics().XHeight() / style->EffectiveZoom()); |
| } |
| |
| bool SVGLengthContext::DetermineViewport(FloatSize& viewport_size) const { |
| if (!context_) |
| return false; |
| |
| // Root <svg> element lengths are resolved against the top level viewport. |
| if (context_->IsOutermostSVGSVGElement()) { |
| viewport_size = To<SVGSVGElement>(context_.Get())->CurrentViewportSize(); |
| return true; |
| } |
| |
| // Take size from nearest viewport element. |
| SVGElement* viewport_element = context_->viewportElement(); |
| const auto* svg = DynamicTo<SVGSVGElement>(viewport_element); |
| if (!svg) |
| return false; |
| |
| viewport_size = svg->CurrentViewBoxRect().Size(); |
| if (viewport_size.IsEmpty()) |
| viewport_size = svg->CurrentViewportSize(); |
| |
| return true; |
| } |
| |
| float SVGLengthContext::ResolveValue(const CSSPrimitiveValue& primitive_value, |
| SVGLengthMode mode) const { |
| const ComputedStyle* style = ComputedStyleForLengthResolving(context_); |
| if (!style) |
| return 0; |
| |
| const ComputedStyle* root_style = RootElementStyle(context_); |
| if (!root_style) |
| return 0; |
| |
| CSSToLengthConversionData conversion_data = CSSToLengthConversionData( |
| style, root_style, context_->GetDocument().GetLayoutView(), 1.0f); |
| Length length = primitive_value.ConvertToLength(conversion_data); |
| return ValueForLength(length, 1.0f, mode); |
| } |
| } // namespace blink |