InlineTextBoxStyle.cpp [plain text]
#include "config.h"
#include "InlineTextBoxStyle.h"
#include "FontCascade.h"
#include "InlineTextBox.h"
#include "RootInlineBox.h"
#include "TextUnderlineOffset.h"
namespace WebCore {
float computeUnderlineOffset(TextUnderlinePosition underlinePosition, TextUnderlineOffset underlineOffset, const FontMetrics& fontMetrics, const InlineTextBox* inlineTextBox, float defaultGap)
{
float gap = std::max<int>(1, std::ceil(defaultGap / 2.0f));
auto resolvedUnderlinePosition = underlinePosition;
if (resolvedUnderlinePosition == TextUnderlinePosition::Auto && underlineOffset.isAuto()) {
if (inlineTextBox)
resolvedUnderlinePosition = inlineTextBox->root().baselineType() == IdeographicBaseline ? TextUnderlinePosition::Under : TextUnderlinePosition::Auto;
else
resolvedUnderlinePosition = TextUnderlinePosition::Auto;
}
switch (resolvedUnderlinePosition) {
case TextUnderlinePosition::Auto:
if (underlineOffset.isAuto())
return fontMetrics.ascent() + gap;
return fontMetrics.ascent() + std::max(0.0f, underlineOffset.lengthValue());
case TextUnderlinePosition::FromFont:
return fontMetrics.ascent() + std::max(0.0f, fontMetrics.underlinePosition() + underlineOffset.lengthOr(0));
case TextUnderlinePosition::Under: {
ASSERT(inlineTextBox);
const RootInlineBox& rootBox = inlineTextBox->root();
const RenderElement* decorationRenderer = inlineTextBox->parent()->renderer().enclosingRendererWithTextDecoration(TextDecoration::Underline, inlineTextBox->isFirstLine());
float offset;
if (inlineTextBox->renderer().style().isFlippedLinesWritingMode()) {
offset = inlineTextBox->logicalTop();
rootBox.minLogicalTopForTextDecorationLine(offset, decorationRenderer, TextDecoration::Underline);
offset = inlineTextBox->logicalTop() - offset;
} else {
offset = inlineTextBox->logicalBottom();
rootBox.maxLogicalBottomForTextDecorationLine(offset, decorationRenderer, TextDecoration::Underline);
offset -= inlineTextBox->logicalBottom();
}
auto desiredOffset = inlineTextBox->logicalHeight() + gap + std::max(offset, 0.0f) + underlineOffset.lengthOr(0);
return std::max<float>(desiredOffset, fontMetrics.ascent());
}
}
ASSERT_NOT_REACHED();
return fontMetrics.ascent() + gap;
}
WavyStrokeParameters getWavyStrokeParameters(float fontSize)
{
WavyStrokeParameters result;
result.controlPointDistance = fontSize * 1.5 / 16;
result.step = fontSize / 4.5;
return result;
}
static inline void extendIntToFloat(int& extendMe, float extendTo)
{
extendMe = std::max(extendMe, static_cast<int>(ceilf(extendTo)));
}
GlyphOverflow visualOverflowForDecorations(const RenderStyle& lineStyle, const InlineTextBox* inlineTextBox)
{
ASSERT(!inlineTextBox || inlineTextBox->lineStyle() == lineStyle);
auto decoration = lineStyle.textDecorationsInEffect();
if (decoration.isEmpty())
return GlyphOverflow();
float strokeThickness = lineStyle.textDecorationThickness().resolve(lineStyle.computedFontSize(), lineStyle.fontMetrics());
WavyStrokeParameters wavyStrokeParameters;
float wavyOffset = 0;
TextDecorationStyle decorationStyle = lineStyle.textDecorationStyle();
float height = lineStyle.fontCascade().fontMetrics().floatHeight();
GlyphOverflow overflowResult;
if (decorationStyle == TextDecorationStyle::Wavy) {
wavyStrokeParameters = getWavyStrokeParameters(lineStyle.computedFontPixelSize());
wavyOffset = wavyOffsetFromDecoration();
overflowResult.left = strokeThickness;
overflowResult.right = strokeThickness;
}
if (decoration & TextDecoration::Underline) {
int underlineOffset = 1;
float textDecorationBaseFontSize = 16;
auto defaultGap = lineStyle.computedFontSize() / textDecorationBaseFontSize;
underlineOffset += computeUnderlineOffset(lineStyle.textUnderlinePosition(), lineStyle.textUnderlineOffset(), lineStyle.fontMetrics(), inlineTextBox, defaultGap);
if (decorationStyle == TextDecorationStyle::Wavy) {
extendIntToFloat(overflowResult.bottom, underlineOffset + wavyOffset + wavyStrokeParameters.controlPointDistance + strokeThickness - height);
extendIntToFloat(overflowResult.top, -(underlineOffset + wavyOffset - wavyStrokeParameters.controlPointDistance - strokeThickness));
} else {
extendIntToFloat(overflowResult.bottom, underlineOffset + strokeThickness - height);
extendIntToFloat(overflowResult.top, -underlineOffset);
}
}
if (decoration & TextDecoration::Overline) {
FloatRect rect(FloatPoint(), FloatSize(1, strokeThickness));
float autoTextDecorationThickness = TextDecorationThickness::createWithAuto().resolve(lineStyle.computedFontSize(), lineStyle.fontMetrics());
rect.move(0, autoTextDecorationThickness - strokeThickness - wavyOffset);
if (decorationStyle == TextDecorationStyle::Wavy) {
FloatBoxExtent wavyExpansion;
wavyExpansion.setTop(wavyStrokeParameters.controlPointDistance);
wavyExpansion.setBottom(wavyStrokeParameters.controlPointDistance);
rect.expand(wavyExpansion);
}
extendIntToFloat(overflowResult.top, -rect.y());
extendIntToFloat(overflowResult.bottom, rect.maxY() - height);
}
if (decoration & TextDecoration::LineThrough) {
FloatRect rect(FloatPoint(), FloatSize(1, strokeThickness));
float autoTextDecorationThickness = TextDecorationThickness::createWithAuto().resolve(lineStyle.computedFontSize(), lineStyle.fontMetrics());
auto center = 2 * lineStyle.fontMetrics().floatAscent() / 3 + autoTextDecorationThickness / 2;
rect.move(0, center - strokeThickness / 2);
if (decorationStyle == TextDecorationStyle::Wavy) {
FloatBoxExtent wavyExpansion;
wavyExpansion.setTop(wavyStrokeParameters.controlPointDistance);
wavyExpansion.setBottom(wavyStrokeParameters.controlPointDistance);
rect.expand(wavyExpansion);
}
extendIntToFloat(overflowResult.top, -rect.y());
extendIntToFloat(overflowResult.bottom, rect.maxY() - height);
}
return overflowResult;
}
}