GlyphOverflow visualOverflowForDecorations(const RenderStyle& lineStyle, const InlineTextBox* inlineTextBox)
{
ASSERT(!inlineTextBox || inlineTextBox->lineStyle() == lineStyle);
TextDecoration decoration = lineStyle.textDecorationsInEffect();
if (decoration == TextDecorationNone)
return GlyphOverflow();
float strokeThickness = textDecorationStrokeThickness(lineStyle.fontSize());
float controlPointDistance;
float step;
float wavyOffset;
TextDecorationStyle decorationStyle = lineStyle.textDecorationStyle();
float height = lineStyle.fontCascade().fontMetrics().floatHeight();
GlyphOverflow overflowResult;
if (decorationStyle == TextDecorationStyleWavy) {
getWavyStrokeParameters(strokeThickness, controlPointDistance, step);
wavyOffset = wavyOffsetFromDecoration();
overflowResult.left = strokeThickness;
overflowResult.right = strokeThickness;
}
// These metrics must match where underlines get drawn.
if (decoration & TextDecorationUnderline) {
// Compensate for the integral ceiling in GraphicsContext::computeLineBoundsAndAntialiasingModeForText()
int underlineOffset = 1;
underlineOffset += computeUnderlineOffset(lineStyle.textUnderlinePosition(), lineStyle.fontMetrics(), inlineTextBox, strokeThickness);
if (decorationStyle == TextDecorationStyleWavy) {
extendIntToFloat(overflowResult.bottom, underlineOffset + wavyOffset + controlPointDistance + strokeThickness - height);
extendIntToFloat(overflowResult.top, -(underlineOffset + wavyOffset - controlPointDistance - strokeThickness));
} else {
extendIntToFloat(overflowResult.bottom, underlineOffset + strokeThickness - height);
extendIntToFloat(overflowResult.top, -underlineOffset);
}
}
if (decoration & TextDecorationOverline) {
if (decorationStyle == TextDecorationStyleWavy) {
extendIntToFloat(overflowResult.bottom, -wavyOffset + controlPointDistance + strokeThickness - height);
extendIntToFloat(overflowResult.top, wavyOffset + controlPointDistance + strokeThickness);
} else {
extendIntToFloat(overflowResult.bottom, strokeThickness - height);
// top is untouched
}
}
if (decoration & TextDecorationLineThrough) {
float baseline = lineStyle.fontMetrics().floatAscent();
if (decorationStyle == TextDecorationStyleWavy) {
extendIntToFloat(overflowResult.bottom, 2 * baseline / 3 + controlPointDistance + strokeThickness - height);
extendIntToFloat(overflowResult.top, -(2 * baseline / 3 - controlPointDistance - strokeThickness));
} else {
extendIntToFloat(overflowResult.bottom, 2 * baseline / 3 + strokeThickness - height);
extendIntToFloat(overflowResult.top, -(2 * baseline / 3));
}
}
return overflowResult;
}
void TextDecorationPainter::paintTextDecoration(const TextRun& textRun, const FloatPoint& textOrigin, const FloatPoint& boxOrigin)
{
#if !ENABLE(CSS3_TEXT_DECORATION_SKIP_INK)
UNUSED_PARAM(textRun);
UNUSED_PARAM(textOrigin);
#endif
ASSERT(m_font);
float textDecorationThickness = textDecorationStrokeThickness(m_lineStyle.fontSize());
m_context.setStrokeThickness(textDecorationThickness);
FloatPoint localOrigin = boxOrigin;
auto paintDecoration = [&](TextDecoration decoration, TextDecorationStyle style, const Color& color, const FloatPoint& start, const FloatPoint& end, int offset) {
m_context.setStrokeColor(color);
auto strokeStyle = textDecorationStyleToStrokeStyle(style);
if (style == TextDecorationStyleWavy)
strokeWavyTextDecoration(m_context, start, end, textDecorationThickness);
else if (decoration == TextDecorationUnderline || decoration == TextDecorationOverline) {
#if ENABLE(CSS3_TEXT_DECORATION_SKIP_INK)
if ((m_lineStyle.textDecorationSkip() == TextDecorationSkipInk || m_lineStyle.textDecorationSkip() == TextDecorationSkipAuto) && m_isHorizontal) {
if (!m_context.paintingDisabled())
drawSkipInkUnderline(m_context, *m_font, textRun, textOrigin, localOrigin, offset, m_width, m_isPrinting, style == TextDecorationStyleDouble, strokeStyle);
} else
// FIXME: Need to support text-decoration-skip: none.
#endif
m_context.drawLineForText(start, m_width, m_isPrinting, style == TextDecorationStyleDouble, strokeStyle);
} else {
ASSERT(decoration == TextDecorationLineThrough);
m_context.drawLineForText(start, m_width, m_isPrinting, style == TextDecorationStyleDouble, strokeStyle);
}
};
bool linesAreOpaque = !m_isPrinting
&& (!(m_decoration & TextDecorationUnderline) || m_styles.underlineColor.isOpaque())
&& (!(m_decoration & TextDecorationOverline) || m_styles.overlineColor.isOpaque())
&& (!(m_decoration & TextDecorationLineThrough) || m_styles.linethroughColor.isOpaque());
int extraOffset = 0;
bool clipping = !linesAreOpaque && m_shadow && m_shadow->next();
if (clipping) {
FloatRect clipRect(localOrigin, FloatSize(m_width, m_baseline + 2));
for (const ShadowData* shadow = m_shadow; shadow; shadow = shadow->next()) {
int shadowExtent = shadow->paintingExtent();
FloatRect shadowRect(localOrigin, FloatSize(m_width, m_baseline + 2));
shadowRect.inflate(shadowExtent);
int shadowX = m_isHorizontal ? shadow->x() : shadow->y();
int shadowY = m_isHorizontal ? shadow->y() : -shadow->x();
shadowRect.move(shadowX, shadowY);
clipRect.unite(shadowRect);
extraOffset = std::max(extraOffset, std::max(0, shadowY) + shadowExtent);
}
m_context.save();
m_context.clip(clipRect);
extraOffset += m_baseline + 2;
localOrigin.move(0, extraOffset);
}
const ShadowData* shadow = m_shadow;
do {
if (shadow) {
if (!shadow->next()) {
// The last set of lines paints normally inside the clip.
localOrigin.move(0, -extraOffset);
extraOffset = 0;
}
int shadowX = m_isHorizontal ? shadow->x() : shadow->y();
int shadowY = m_isHorizontal ? shadow->y() : -shadow->x();
m_context.setShadow(FloatSize(shadowX, shadowY - extraOffset), shadow->radius(), shadow->color());
shadow = shadow->next();
}
// These decorations should match the visual overflows computed in visualOverflowForDecorations()
if (m_decoration & TextDecorationUnderline) {
const int offset = computeUnderlineOffset(m_lineStyle.textUnderlinePosition(), m_lineStyle.fontMetrics(), m_inlineTextBox, textDecorationThickness);
int wavyOffset = m_styles.underlineStyle == TextDecorationStyleWavy ? m_wavyOffset : 0;
FloatPoint start = localOrigin + FloatSize(0, offset + wavyOffset);
FloatPoint end = localOrigin + FloatSize(m_width, offset + wavyOffset);
paintDecoration(TextDecorationUnderline, m_styles.underlineStyle, m_styles.underlineColor, start, end, offset);
}
if (m_decoration & TextDecorationOverline) {
int wavyOffset = m_styles.overlineStyle == TextDecorationStyleWavy ? m_wavyOffset : 0;
FloatPoint start = localOrigin - FloatSize(0, wavyOffset);
FloatPoint end = localOrigin + FloatSize(m_width, -wavyOffset);
paintDecoration(TextDecorationOverline, m_styles.overlineStyle, m_styles.overlineColor, start, end, 0);
}
if (m_decoration & TextDecorationLineThrough) {
FloatPoint start = localOrigin + FloatSize(0, 2 * m_baseline / 3);
FloatPoint end = localOrigin + FloatSize(m_width, 2 * m_baseline / 3);
paintDecoration(TextDecorationLineThrough, m_styles.linethroughStyle, m_styles.linethroughColor, start, end, 0);
}
} while (shadow);
if (clipping)
m_context.restore();
else if (m_shadow)
m_context.clearShadow();
}