From 7e21de3ed5ad0d28f303496deb211c943cb4c15a Mon Sep 17 00:00:00 2001
From: Edgar Chen <echen@mozilla.com>
Date: Mon, 23 May 2016 15:18:34 +0800
Subject: [PATCH] Bug 1274526 - Part 1: Implement support for 'q' absolute
 length units in CSS; r=heycam

MozReview-Commit-ID: vTDufVkAuv
---
 dom/mathml/nsMathMLElement.cpp            | 1 +
 layout/style/nsCSSParser.cpp              | 1 +
 layout/style/nsCSSValue.cpp               | 3 +++
 layout/style/nsCSSValue.h                 | 3 ++-
 layout/style/test/test_pixel_lengths.html | 2 ++
 5 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/dom/mathml/nsMathMLElement.cpp b/dom/mathml/nsMathMLElement.cpp
index 4ae0f89295f3..1882050e9d81 100644
--- a/dom/mathml/nsMathMLElement.cpp
+++ b/dom/mathml/nsMathMLElement.cpp
@@ -473,6 +473,7 @@ nsMathMLElement::ParseNumericValue(const nsString& aString,
   else if (unit.EqualsLiteral("mm")) cssUnit = eCSSUnit_Millimeter;
   else if (unit.EqualsLiteral("pt")) cssUnit = eCSSUnit_Point;
   else if (unit.EqualsLiteral("pc")) cssUnit = eCSSUnit_Pica;
+  else if (unit.EqualsLiteral("q")) cssUnit = eCSSUnit_Quarter;
   else { // unexpected unit
     if (!(aFlags & PARSE_SUPPRESS_WARNINGS)) {
       ReportLengthParseError(aString, aDocument);
diff --git a/layout/style/nsCSSParser.cpp b/layout/style/nsCSSParser.cpp
index 1ec301595c1e..0c6d6bc50538 100644
--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -7475,6 +7475,7 @@ const UnitInfo UnitData[] = {
   { STR_WITH_LEN("vmin"), eCSSUnit_ViewportMin, VARIANT_LENGTH },
   { STR_WITH_LEN("vmax"), eCSSUnit_ViewportMax, VARIANT_LENGTH },
   { STR_WITH_LEN("pc"), eCSSUnit_Pica, VARIANT_LENGTH },
+  { STR_WITH_LEN("q"), eCSSUnit_Quarter, VARIANT_LENGTH },
   { STR_WITH_LEN("deg"), eCSSUnit_Degree, VARIANT_ANGLE },
   { STR_WITH_LEN("grad"), eCSSUnit_Grad, VARIANT_ANGLE },
   { STR_WITH_LEN("rad"), eCSSUnit_Radian, VARIANT_ANGLE },
diff --git a/layout/style/nsCSSValue.cpp b/layout/style/nsCSSValue.cpp
index 03cc26f53eab..7240ecb9aa25 100644
--- a/layout/style/nsCSSValue.cpp
+++ b/layout/style/nsCSSValue.cpp
@@ -346,6 +346,7 @@ nscoord nsCSSValue::GetPixelLength() const
   case eCSSUnit_Inch: scaleFactor = 96.0; break;
   case eCSSUnit_Millimeter: scaleFactor = 96/25.4; break;
   case eCSSUnit_Centimeter: scaleFactor = 96/2.54; break;
+  case eCSSUnit_Quarter: scaleFactor = 96/101.6; break;
   default:
     NS_ERROR("should never get here");
     return 0;
@@ -1798,6 +1799,7 @@ nsCSSValue::AppendToString(nsCSSProperty aProperty, nsAString& aResult,
     case eCSSUnit_Centimeter:   aResult.AppendLiteral("cm");   break;
     case eCSSUnit_Point:        aResult.AppendLiteral("pt");   break;
     case eCSSUnit_Pica:         aResult.AppendLiteral("pc");   break;
+    case eCSSUnit_Quarter:      aResult.AppendLiteral("q");    break;
 
     case eCSSUnit_ViewportWidth:  aResult.AppendLiteral("vw");   break;
     case eCSSUnit_ViewportHeight: aResult.AppendLiteral("vh");   break;
@@ -1982,6 +1984,7 @@ nsCSSValue::SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
     case eCSSUnit_Centimeter:
     case eCSSUnit_Pica:
     case eCSSUnit_Pixel:
+    case eCSSUnit_Quarter:
     case eCSSUnit_Degree:
     case eCSSUnit_Grad:
     case eCSSUnit_Turn:
diff --git a/layout/style/nsCSSValue.h b/layout/style/nsCSSValue.h
index e42c6b931fdf..d198a1ffc533 100644
--- a/layout/style/nsCSSValue.h
+++ b/layout/style/nsCSSValue.h
@@ -396,7 +396,8 @@ enum nsCSSUnit {
   eCSSUnit_Millimeter   = 902,    // (float) 96/25.4 CSS pixels
   eCSSUnit_Centimeter   = 903,    // (float) 96/2.54 CSS pixels
   eCSSUnit_Pica         = 904,    // (float) 12 points == 16 CSS pixls
-  eCSSUnit_Pixel        = 905,    // (float) CSS pixel unit
+  eCSSUnit_Quarter      = 905,    // (float) 96/101.6 CSS pixels
+  eCSSUnit_Pixel        = 906,    // (float) CSS pixel unit
 
   // Angular units
   eCSSUnit_Degree       = 1000,    // (float) 360 per circle
diff --git a/layout/style/test/test_pixel_lengths.html b/layout/style/test/test_pixel_lengths.html
index 03c01777f313..37f9ec83ff0b 100644
--- a/layout/style/test/test_pixel_lengths.html
+++ b/layout/style/test/test_pixel_lengths.html
@@ -13,6 +13,7 @@
 <div id="mm" style="width:25.4mm; height:25.4mm; background:orange;">mm</div>
 <div id="cm" style="width:2.54cm; height:2.54cm; background:purple;">cm</div>
 <div id="in" style="width:1in; height:1in; background:magenta;">in</div>
+<div id="q" style="width:101.6q; height:101.6q; background:blue;">q</div>
 
 <div id="mozmm" style="width:25.4mozmm; height:25.4mozmm; background:cyan;">mozmm</div>
 
@@ -37,6 +38,7 @@ function checkPixelRelativeUnits() {
   check("mm", 96);
   check("cm", 96);
   check("in", 96);
+  check("q", 96);
 }
 
 checkPixelRelativeUnits();