1 files changed, 402 insertions, 0 deletions
diff --git a/gfx/src/nsFontMetrics.cpp b/gfx/src/nsFontMetrics.cpp
new file mode 100644
index 0000000000..a3e4d5e312
--- /dev/null
+++ b/gfx/src/nsFontMetrics.cpp
@@ -0,0 +1,402 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsFontMetrics.h"
+#include <math.h>                // for floor, ceil
+#include <algorithm>             // for max
+#include "gfxContext.h"          // for gfxContext
+#include "gfxFontConstants.h"    // for NS_FONT_SYNTHESIS_*
+#include "gfxPlatform.h"         // for gfxPlatform
+#include "gfxPoint.h"            // for gfxPoint
+#include "gfxRect.h"             // for gfxRect
+#include "gfxTextRun.h"          // for gfxFontGroup
+#include "gfxTypes.h"            // for gfxFloat
+#include "nsAtom.h"              // for nsAtom
+#include "nsBoundingMetrics.h"   // for nsBoundingMetrics
+#include "nsDebug.h"             // for NS_ERROR
+#include "nsDeviceContext.h"     // for nsDeviceContext
+#include "nsMathUtils.h"         // for NS_round
+#include "nsPresContext.h"       // for nsPresContext
+#include "nsString.h"            // for nsString
+#include "nsStyleConsts.h"       // for StyleHyphens::None
+#include "mozilla/Assertions.h"  // for MOZ_ASSERT
+#include "mozilla/UniquePtr.h"   // for UniquePtr
+
+class gfxUserFontSet;
+using namespace mozilla;
+
+namespace {
+
+class AutoTextRun {
+ public:
+  typedef mozilla::gfx::DrawTarget DrawTarget;
+
+  AutoTextRun(const nsFontMetrics* aMetrics, DrawTarget* aDrawTarget,
+              const char* aString, uint32_t aLength) {
+    mTextRun = aMetrics->GetThebesFontGroup()->MakeTextRun(
+        reinterpret_cast<const uint8_t*>(aString), aLength, aDrawTarget,
+        aMetrics->AppUnitsPerDevPixel(), ComputeFlags(aMetrics),
+        nsTextFrameUtils::Flags(), nullptr);
+  }
+
+  AutoTextRun(const nsFontMetrics* aMetrics, DrawTarget* aDrawTarget,
+              const char16_t* aString, uint32_t aLength) {
+    mTextRun = aMetrics->GetThebesFontGroup()->MakeTextRun(
+        aString, aLength, aDrawTarget, aMetrics->AppUnitsPerDevPixel(),
+        ComputeFlags(aMetrics), nsTextFrameUtils::Flags(), nullptr);
+  }
+
+  gfxTextRun* get() const { return mTextRun.get(); }
+  gfxTextRun* operator->() const { return mTextRun.get(); }
+
+ private:
+  static gfx::ShapedTextFlags ComputeFlags(const nsFontMetrics* aMetrics) {
+    gfx::ShapedTextFlags flags = gfx::ShapedTextFlags();
+    if (aMetrics->GetTextRunRTL()) {
+      flags |= gfx::ShapedTextFlags::TEXT_IS_RTL;
+    }
+    if (aMetrics->GetVertical()) {
+      switch (aMetrics->GetTextOrientation()) {
+        case StyleTextOrientation::Mixed:
+          flags |= gfx::ShapedTextFlags::TEXT_ORIENT_VERTICAL_MIXED;
+          break;
+        case StyleTextOrientation::Upright:
+          flags |= gfx::ShapedTextFlags::TEXT_ORIENT_VERTICAL_UPRIGHT;
+          break;
+        case StyleTextOrientation::Sideways:
+          flags |= gfx::ShapedTextFlags::TEXT_ORIENT_VERTICAL_SIDEWAYS_RIGHT;
+          break;
+      }
+    }
+    return flags;
+  }
+
+  RefPtr<gfxTextRun> mTextRun;
+};
+
+class StubPropertyProvider final : public gfxTextRun::PropertyProvider {
+ public:
+  void GetHyphenationBreaks(
+      gfxTextRun::Range aRange,
+      gfxTextRun::HyphenType* aBreakBefore) const override {
+    NS_ERROR(
+        "This shouldn't be called because we never call BreakAndMeasureText");
+  }
+  mozilla::StyleHyphens GetHyphensOption() const override {
+    NS_ERROR(
+        "This shouldn't be called because we never call BreakAndMeasureText");
+    return mozilla::StyleHyphens::None;
+  }
+  gfxFloat GetHyphenWidth() const override {
+    NS_ERROR("This shouldn't be called because we never enable hyphens");
+    return 0;
+  }
+  already_AddRefed<mozilla::gfx::DrawTarget> GetDrawTarget() const override {
+    NS_ERROR("This shouldn't be called because we never enable hyphens");
+    return nullptr;
+  }
+  uint32_t GetAppUnitsPerDevUnit() const override {
+    NS_ERROR("This shouldn't be called because we never enable hyphens");
+    return 60;
+  }
+  void GetSpacing(gfxTextRun::Range aRange, Spacing* aSpacing) const override {
+    NS_ERROR("This shouldn't be called because we never enable spacing");
+  }
+  gfx::ShapedTextFlags GetShapedTextFlags() const override {
+    NS_ERROR("This shouldn't be called because we never enable hyphens");
+    return gfx::ShapedTextFlags();
+  }
+};
+
+}  // namespace
+
+nsFontMetrics::nsFontMetrics(const nsFont& aFont, const Params& aParams,
+                             nsPresContext* aContext)
+    : mFont(aFont),
+      mLanguage(aParams.language),
+      mPresContext(aContext),
+      mP2A(aContext->DeviceContext()->AppUnitsPerDevPixel()),
+      mOrientation(aParams.orientation),
+      mExplicitLanguage(aParams.explicitLanguage),
+      mTextRunRTL(false),
+      mVertical(false),
+      mTextOrientation(mozilla::StyleTextOrientation::Mixed) {
+  gfxFontStyle style(aFont.style, aFont.weight, aFont.stretch,
+                     gfxFloat(aFont.size.ToAppUnits()) / mP2A, aFont.sizeAdjust,
+                     aFont.family.is_system_font,
+                     aContext->DeviceContext()->IsPrinterContext(),
+                     aFont.synthesisWeight == StyleFontSynthesis::Auto,
+                     aFont.synthesisStyle == StyleFontSynthesis::Auto,
+                     aFont.synthesisSmallCaps == StyleFontSynthesis::Auto,
+                     aFont.languageOverride);
+
+  aFont.AddFontFeaturesToStyle(&style, mOrientation == eVertical);
+  style.featureValueLookup = aParams.featureValueLookup;
+
+  aFont.AddFontVariationsToStyle(&style);
+
+  gfxFloat devToCssSize = gfxFloat(mP2A) / gfxFloat(AppUnitsPerCSSPixel());
+  mFontGroup = new gfxFontGroup(
+      mPresContext, aFont.family.families, &style, mLanguage, mExplicitLanguage,
+      aParams.textPerf, aParams.userFontSet, devToCssSize, aFont.variantEmoji);
+}
+
+nsFontMetrics::~nsFontMetrics() {
+  // Should not be dropped by stylo
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mPresContext) {
+    mPresContext->FontMetricsDeleted(this);
+  }
+}
+
+void nsFontMetrics::Destroy() { mPresContext = nullptr; }
+
+// XXXTODO get rid of this macro
+#define ROUND_TO_TWIPS(x) (nscoord) floor(((x)*mP2A) + 0.5)
+#define CEIL_TO_TWIPS(x) (nscoord) ceil((x)*mP2A)
+
+static const gfxFont::Metrics& GetMetrics(
+    const nsFontMetrics* aFontMetrics,
+    nsFontMetrics::FontOrientation aOrientation) {
+  RefPtr<gfxFont> font =
+      aFontMetrics->GetThebesFontGroup()->GetFirstValidFont();
+  return font->GetMetrics(aOrientation);
+}
+
+static const gfxFont::Metrics& GetMetrics(const nsFontMetrics* aFontMetrics) {
+  return GetMetrics(aFontMetrics, aFontMetrics->Orientation());
+}
+
+nscoord nsFontMetrics::XHeight() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).xHeight);
+}
+
+nscoord nsFontMetrics::CapHeight() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).capHeight);
+}
+
+nscoord nsFontMetrics::SuperscriptOffset() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).emHeight *
+                        NS_FONT_SUPERSCRIPT_OFFSET_RATIO);
+}
+
+nscoord nsFontMetrics::SubscriptOffset() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).emHeight *
+                        NS_FONT_SUBSCRIPT_OFFSET_RATIO);
+}
+
+void nsFontMetrics::GetStrikeout(nscoord& aOffset, nscoord& aSize) const {
+  aOffset = ROUND_TO_TWIPS(GetMetrics(this).strikeoutOffset);
+  aSize = ROUND_TO_TWIPS(GetMetrics(this).strikeoutSize);
+}
+
+void nsFontMetrics::GetUnderline(nscoord& aOffset, nscoord& aSize) const {
+  aOffset = ROUND_TO_TWIPS(mFontGroup->GetUnderlineOffset());
+  aSize = ROUND_TO_TWIPS(GetMetrics(this).underlineSize);
+}
+
+// GetMaxAscent/GetMaxDescent/GetMaxHeight must contain the
+// text-decoration lines drawable area. See bug 421353.
+// BE CAREFUL for rounding each values. The logic MUST be same as
+// nsCSSRendering::GetTextDecorationRectInternal's.
+
+static gfxFloat ComputeMaxDescent(const gfxFont::Metrics& aMetrics,
+                                  gfxFontGroup* aFontGroup) {
+  gfxFloat offset = floor(-aFontGroup->GetUnderlineOffset() + 0.5);
+  gfxFloat size = NS_round(aMetrics.underlineSize);
+  gfxFloat minDescent = offset + size;
+  return floor(std::max(minDescent, aMetrics.maxDescent) + 0.5);
+}
+
+static gfxFloat ComputeMaxAscent(const gfxFont::Metrics& aMetrics) {
+  return floor(aMetrics.maxAscent + 0.5);
+}
+
+nscoord nsFontMetrics::InternalLeading() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).internalLeading);
+}
+
+nscoord nsFontMetrics::ExternalLeading() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).externalLeading);
+}
+
+nscoord nsFontMetrics::EmHeight() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).emHeight);
+}
+
+nscoord nsFontMetrics::EmAscent() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).emAscent);
+}
+
+nscoord nsFontMetrics::EmDescent() const {
+  return ROUND_TO_TWIPS(GetMetrics(this).emDescent);
+}
+
+nscoord nsFontMetrics::MaxHeight() const {
+  return CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics(this))) +
+         CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(this), mFontGroup));
+}
+
+nscoord nsFontMetrics::MaxAscent() const {
+  return CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics(this)));
+}
+
+nscoord nsFontMetrics::MaxDescent() const {
+  return CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(this), mFontGroup));
+}
+
+nscoord nsFontMetrics::MaxAdvance() const {
+  return CEIL_TO_TWIPS(GetMetrics(this).maxAdvance);
+}
+
+nscoord nsFontMetrics::AveCharWidth() const {
+  // Use CEIL instead of ROUND for consistency with GetMaxAdvance
+  return CEIL_TO_TWIPS(GetMetrics(this).aveCharWidth);
+}
+
+nscoord nsFontMetrics::ZeroOrAveCharWidth() const {
+  return CEIL_TO_TWIPS(GetMetrics(this).ZeroOrAveCharWidth());
+}
+
+nscoord nsFontMetrics::SpaceWidth() const {
+  // For vertical text with mixed or sideways orientation, we want the
+  // width of a horizontal space (even if we're using vertical line-spacing
+  // metrics, as with "writing-mode:vertical-*;text-orientation:mixed").
+  return CEIL_TO_TWIPS(
+      GetMetrics(this,
+                 mVertical && mTextOrientation == StyleTextOrientation::Upright
+                     ? eVertical
+                     : eHorizontal)
+          .spaceWidth);
+}
+
+int32_t nsFontMetrics::GetMaxStringLength() const {
+  const double x = 32767.0 / std::max(1.0, GetMetrics(this).maxAdvance);
+  int32_t len = (int32_t)floor(x);
+  return std::max(1, len);
+}
+
+nscoord nsFontMetrics::GetWidth(const char* aString, uint32_t aLength,
+                                DrawTarget* aDrawTarget) const {
+  if (aLength == 0) {
+    return 0;
+  }
+  if (aLength == 1 && aString[0] == ' ') {
+    return SpaceWidth();
+  }
+  StubPropertyProvider provider;
+  AutoTextRun textRun(this, aDrawTarget, aString, aLength);
+  if (textRun.get()) {
+    return NSToCoordRound(
+        textRun->GetAdvanceWidth(gfxTextRun::Range(0, aLength), &provider));
+  }
+  return 0;
+}
+
+nscoord nsFontMetrics::GetWidth(const char16_t* aString, uint32_t aLength,
+                                DrawTarget* aDrawTarget) const {
+  if (aLength == 0) {
+    return 0;
+  }
+  if (aLength == 1 && aString[0] == ' ') {
+    return SpaceWidth();
+  }
+  StubPropertyProvider provider;
+  AutoTextRun textRun(this, aDrawTarget, aString, aLength);
+  if (textRun.get()) {
+    return NSToCoordRound(
+        textRun->GetAdvanceWidth(gfxTextRun::Range(0, aLength), &provider));
+  }
+  return 0;
+}
+
+// Draw a string using this font handle on the surface passed in.
+void nsFontMetrics::DrawString(const char* aString, uint32_t aLength,
+                               nscoord aX, nscoord aY,
+                               gfxContext* aContext) const {
+  if (aLength == 0) {
+    return;
+  }
+  StubPropertyProvider provider;
+  AutoTextRun textRun(this, aContext->GetDrawTarget(), aString, aLength);
+  if (!textRun.get()) {
+    return;
+  }
+  gfx::Point pt(aX, aY);
+  gfxTextRun::Range range(0, aLength);
+  if (mTextRunRTL) {
+    if (mVertical) {
+      pt.y += textRun->GetAdvanceWidth(range, &provider);
+    } else {
+      pt.x += textRun->GetAdvanceWidth(range, &provider);
+    }
+  }
+  gfxTextRun::DrawParams params(aContext);
+  params.provider = &provider;
+  textRun->Draw(range, pt, params);
+}
+
+void nsFontMetrics::DrawString(
+    const char16_t* aString, uint32_t aLength, nscoord aX, nscoord aY,
+    gfxContext* aContext, DrawTarget* aTextRunConstructionDrawTarget) const {
+  if (aLength == 0) {
+    return;
+  }
+  StubPropertyProvider provider;
+  AutoTextRun textRun(this, aTextRunConstructionDrawTarget, aString, aLength);
+  if (!textRun.get()) {
+    return;
+  }
+  gfx::Point pt(aX, aY);
+  gfxTextRun::Range range(0, aLength);
+  if (mTextRunRTL) {
+    if (mVertical) {
+      pt.y += textRun->GetAdvanceWidth(range, &provider);
+    } else {
+      pt.x += textRun->GetAdvanceWidth(range, &provider);
+    }
+  }
+  gfxTextRun::DrawParams params(aContext);
+  params.provider = &provider;
+  textRun->Draw(range, pt, params);
+}
+
+static nsBoundingMetrics GetTextBoundingMetrics(
+    const nsFontMetrics* aMetrics, const char16_t* aString, uint32_t aLength,
+    mozilla::gfx::DrawTarget* aDrawTarget, gfxFont::BoundingBoxType aType) {
+  if (aLength == 0) {
+    return nsBoundingMetrics();
+  }
+  StubPropertyProvider provider;
+  AutoTextRun textRun(aMetrics, aDrawTarget, aString, aLength);
+  nsBoundingMetrics m;
+  if (textRun.get()) {
+    gfxTextRun::Metrics theMetrics = textRun->MeasureText(
+        gfxTextRun::Range(0, aLength), aType, aDrawTarget, &provider);
+
+    m.leftBearing = NSToCoordFloor(theMetrics.mBoundingBox.X());
+    m.rightBearing = NSToCoordCeil(theMetrics.mBoundingBox.XMost());
+    m.ascent = NSToCoordCeil(-theMetrics.mBoundingBox.Y());
+    m.descent = NSToCoordCeil(theMetrics.mBoundingBox.YMost());
+    m.width = NSToCoordRound(theMetrics.mAdvanceWidth);
+  }
+  return m;
+}
+
+nsBoundingMetrics nsFontMetrics::GetBoundingMetrics(
+    const char16_t* aString, uint32_t aLength, DrawTarget* aDrawTarget) const {
+  return GetTextBoundingMetrics(this, aString, aLength, aDrawTarget,
+                                gfxFont::TIGHT_HINTED_OUTLINE_EXTENTS);
+}
+
+nsBoundingMetrics nsFontMetrics::GetInkBoundsForInkOverflow(
+    const char16_t* aString, uint32_t aLength, DrawTarget* aDrawTarget) const {
+  return GetTextBoundingMetrics(this, aString, aLength, aDrawTarget,
+                                gfxFont::LOOSE_INK_EXTENTS);
+}
+
+gfxUserFontSet* nsFontMetrics::GetUserFontSet() const {
+  return mFontGroup->GetUserFontSet();
+}