From 828754d15850550b1fd4ded83f3e58fa4230f6c0 Mon Sep 17 00:00:00 2001
From: Jonathan Kew <jkew@mozilla.com>
Date: Thu, 16 Dec 2021 13:47:56 +0000
Subject: [PATCH] Bug 1746187 - Implement rendering support for
 hyphenate-character. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D133890
---
 layout/generic/nsTextFrame.cpp | 21 ++++++++++++++++++---
 layout/style/nsStyleStruct.cpp |  6 ++++--
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/layout/generic/nsTextFrame.cpp b/layout/generic/nsTextFrame.cpp
index 3dad4e5d3991..f8119b4f8584 100644
--- a/layout/generic/nsTextFrame.cpp
+++ b/layout/generic/nsTextFrame.cpp
@@ -2158,8 +2158,17 @@ static already_AddRefed<gfxTextRun> GetHyphenTextRun(nsTextFrame* aTextFrame,
 
   RefPtr<nsFontMetrics> fm =
       nsLayoutUtils::GetInflatedFontMetricsForFrame(aTextFrame);
-  return fm->GetThebesFontGroup()->MakeHyphenTextRun(
-      dt, aTextFrame->PresContext()->AppUnitsPerDevPixel());
+  auto* fontGroup = fm->GetThebesFontGroup();
+  auto appPerDev = aTextFrame->PresContext()->AppUnitsPerDevPixel();
+  const auto& hyphenateChar = aTextFrame->StyleText()->mHyphenateCharacter;
+  if (hyphenateChar.IsAuto()) {
+    return fontGroup->MakeHyphenTextRun(dt, appPerDev);
+  }
+  auto* missingFonts = aTextFrame->PresContext()->MissingFontRecorder();
+  const NS_ConvertUTF8toUTF16 hyphenStr(hyphenateChar.AsString().AsString());
+  return fontGroup->MakeTextRun(hyphenStr.BeginReading(), hyphenStr.Length(),
+                                dt, appPerDev, gfx::ShapedTextFlags(),
+                                nsTextFrameUtils::Flags(), missingFonts);
 }
 
 already_AddRefed<gfxTextRun> BuildTextRunsScanner::BuildTextRunForFrames(
@@ -3641,7 +3650,13 @@ void nsTextFrame::PropertyProvider::CalcTabWidths(Range aRange,
 
 gfxFloat nsTextFrame::PropertyProvider::GetHyphenWidth() const {
   if (mHyphenWidth < 0) {
-    mHyphenWidth = GetFontGroup()->GetHyphenWidth(this);
+    const auto& hyphenateChar = mTextStyle->mHyphenateCharacter;
+    if (hyphenateChar.IsAuto()) {
+      mHyphenWidth = GetFontGroup()->GetHyphenWidth(this);
+    } else {
+      RefPtr<gfxTextRun> hyphRun = GetHyphenTextRun(mFrame, nullptr);
+      mHyphenWidth = hyphRun ? hyphRun->GetAdvanceWidth() : 0;
+    }
   }
   return mHyphenWidth + mLetterSpacing;
 }
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index 149c6ff3333c..36b08fde30d9 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -2962,7 +2962,8 @@ nsStyleText::nsStyleText(const nsStyleText& aSource)
       mTextUnderlinePosition(aSource.mTextUnderlinePosition),
       mWebkitTextStrokeWidth(aSource.mWebkitTextStrokeWidth),
       mTextShadow(aSource.mTextShadow),
-      mTextEmphasisStyle(aSource.mTextEmphasisStyle) {
+      mTextEmphasisStyle(aSource.mTextEmphasisStyle),
+      mHyphenateCharacter(aSource.mHyphenateCharacter) {
   MOZ_COUNT_CTOR(nsStyleText);
 }
 
@@ -2996,7 +2997,8 @@ nsChangeHint nsStyleText::CalcDifference(const nsStyleText& aNewData) const {
       (mTextIndent != aNewData.mTextIndent) ||
       (mTextJustify != aNewData.mTextJustify) ||
       (mWordSpacing != aNewData.mWordSpacing) ||
-      (mTabSize != aNewData.mTabSize)) {
+      (mTabSize != aNewData.mTabSize) ||
+      (mHyphenateCharacter != aNewData.mHyphenateCharacter)) {
     return NS_STYLE_HINT_REFLOW;
   }