michael@0: /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsFontMetrics.h"
michael@0: #include <math.h>                       // for floor, ceil
michael@0: #include <algorithm>                    // for max
michael@0: #include "gfxPlatform.h"                // for gfxPlatform
michael@0: #include "gfxPoint.h"                   // for gfxPoint
michael@0: #include "gfxRect.h"                    // for gfxRect
michael@0: #include "gfxTypes.h"                   // for gfxFloat
michael@0: #include "nsBoundingMetrics.h"          // for nsBoundingMetrics
michael@0: #include "nsDebug.h"                    // for NS_ERROR, NS_ABORT_IF_FALSE
michael@0: #include "nsDeviceContext.h"            // for nsDeviceContext
michael@0: #include "nsIAtom.h"                    // for nsIAtom
michael@0: #include "nsMathUtils.h"                // for NS_round
michael@0: #include "nsRenderingContext.h"         // for nsRenderingContext
michael@0: #include "nsString.h"               // for nsString
michael@0: #include "nsStyleConsts.h"              // for NS_STYLE_HYPHENS_NONE
michael@0: 
michael@0: class gfxUserFontSet;
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: class AutoTextRun {
michael@0: public:
michael@0:     AutoTextRun(nsFontMetrics* aMetrics, nsRenderingContext* aRC,
michael@0:                 const char* aString, int32_t aLength)
michael@0:     {
michael@0:         mTextRun = aMetrics->GetThebesFontGroup()->MakeTextRun(
michael@0:             reinterpret_cast<const uint8_t*>(aString), aLength,
michael@0:             aRC->ThebesContext(),
michael@0:             aMetrics->AppUnitsPerDevPixel(),
michael@0:             ComputeFlags(aMetrics));
michael@0:     }
michael@0: 
michael@0:     AutoTextRun(nsFontMetrics* aMetrics, nsRenderingContext* aRC,
michael@0:                 const char16_t* aString, int32_t aLength)
michael@0:     {
michael@0:         mTextRun = aMetrics->GetThebesFontGroup()->MakeTextRun(
michael@0:             aString, aLength,
michael@0:             aRC->ThebesContext(),
michael@0:             aMetrics->AppUnitsPerDevPixel(),
michael@0:             ComputeFlags(aMetrics));
michael@0:     }
michael@0: 
michael@0:     gfxTextRun *get() { return mTextRun; }
michael@0:     gfxTextRun *operator->() { return mTextRun; }
michael@0: 
michael@0: private:
michael@0:     static uint32_t ComputeFlags(nsFontMetrics* aMetrics) {
michael@0:         uint32_t flags = 0;
michael@0:         if (aMetrics->GetTextRunRTL()) {
michael@0:             flags |= gfxTextRunFactory::TEXT_IS_RTL;
michael@0:         }
michael@0:         return flags;
michael@0:     }
michael@0: 
michael@0:     nsAutoPtr<gfxTextRun> mTextRun;
michael@0: };
michael@0: 
michael@0: class StubPropertyProvider : public gfxTextRun::PropertyProvider {
michael@0: public:
michael@0:     virtual void GetHyphenationBreaks(uint32_t aStart, uint32_t aLength,
michael@0:                                       bool* aBreakBefore) {
michael@0:         NS_ERROR("This shouldn't be called because we never call BreakAndMeasureText");
michael@0:     }
michael@0:     virtual int8_t GetHyphensOption() {
michael@0:         NS_ERROR("This shouldn't be called because we never call BreakAndMeasureText");
michael@0:         return NS_STYLE_HYPHENS_NONE;
michael@0:     }
michael@0:     virtual gfxFloat GetHyphenWidth() {
michael@0:         NS_ERROR("This shouldn't be called because we never enable hyphens");
michael@0:         return 0;
michael@0:     }
michael@0:     virtual already_AddRefed<gfxContext> GetContext() {
michael@0:         NS_ERROR("This shouldn't be called because we never enable hyphens");
michael@0:         return nullptr;
michael@0:     }
michael@0:     virtual uint32_t GetAppUnitsPerDevUnit() {
michael@0:         NS_ERROR("This shouldn't be called because we never enable hyphens");
michael@0:         return 60;
michael@0:     }
michael@0:     virtual void GetSpacing(uint32_t aStart, uint32_t aLength,
michael@0:                             Spacing* aSpacing) {
michael@0:         NS_ERROR("This shouldn't be called because we never enable spacing");
michael@0:     }
michael@0: };
michael@0: 
michael@0: } // anon namespace
michael@0: 
michael@0: nsFontMetrics::nsFontMetrics()
michael@0:     : mDeviceContext(nullptr), mP2A(0), mTextRunRTL(false)
michael@0: {
michael@0: }
michael@0: 
michael@0: nsFontMetrics::~nsFontMetrics()
michael@0: {
michael@0:     if (mDeviceContext)
michael@0:         mDeviceContext->FontMetricsDeleted(this);
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsFontMetrics::Init(const nsFont& aFont, nsIAtom* aLanguage,
michael@0:                     nsDeviceContext *aContext,
michael@0:                     gfxUserFontSet *aUserFontSet,
michael@0:                     gfxTextPerfMetrics *aTextPerf)
michael@0: {
michael@0:     NS_ABORT_IF_FALSE(mP2A == 0, "already initialized");
michael@0: 
michael@0:     mFont = aFont;
michael@0:     mLanguage = aLanguage;
michael@0:     mDeviceContext = aContext;
michael@0:     mP2A = mDeviceContext->AppUnitsPerDevPixel();
michael@0: 
michael@0:     gfxFontStyle style(aFont.style,
michael@0:                        aFont.weight,
michael@0:                        aFont.stretch,
michael@0:                        gfxFloat(aFont.size) / mP2A,
michael@0:                        aLanguage,
michael@0:                        aFont.sizeAdjust,
michael@0:                        aFont.systemFont,
michael@0:                        mDeviceContext->IsPrinterSurface(),
michael@0:                        aFont.languageOverride);
michael@0: 
michael@0:     aFont.AddFontFeaturesToStyle(&style);
michael@0: 
michael@0:     mFontGroup = gfxPlatform::GetPlatform()->
michael@0:         CreateFontGroup(aFont.name, &style, aUserFontSet);
michael@0:     mFontGroup->SetTextPerfMetrics(aTextPerf);
michael@0:     if (mFontGroup->FontListLength() < 1)
michael@0:         return NS_ERROR_UNEXPECTED;
michael@0: 
michael@0:     return NS_OK;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFontMetrics::Destroy()
michael@0: {
michael@0:     mDeviceContext = nullptr;
michael@0: }
michael@0: 
michael@0: // XXXTODO get rid of this macro
michael@0: #define ROUND_TO_TWIPS(x) (nscoord)floor(((x) * mP2A) + 0.5)
michael@0: #define CEIL_TO_TWIPS(x) (nscoord)ceil((x) * mP2A)
michael@0: 
michael@0: const gfxFont::Metrics& nsFontMetrics::GetMetrics() const
michael@0: {
michael@0:     return mFontGroup->GetFontAt(0)->GetMetrics();
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::XHeight()
michael@0: {
michael@0:     return ROUND_TO_TWIPS(GetMetrics().xHeight);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::SuperscriptOffset()
michael@0: {
michael@0:     return ROUND_TO_TWIPS(GetMetrics().superscriptOffset);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::SubscriptOffset()
michael@0: {
michael@0:     return ROUND_TO_TWIPS(GetMetrics().subscriptOffset);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFontMetrics::GetStrikeout(nscoord& aOffset, nscoord& aSize)
michael@0: {
michael@0:     aOffset = ROUND_TO_TWIPS(GetMetrics().strikeoutOffset);
michael@0:     aSize = ROUND_TO_TWIPS(GetMetrics().strikeoutSize);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFontMetrics::GetUnderline(nscoord& aOffset, nscoord& aSize)
michael@0: {
michael@0:     aOffset = ROUND_TO_TWIPS(mFontGroup->GetUnderlineOffset());
michael@0:     aSize = ROUND_TO_TWIPS(GetMetrics().underlineSize);
michael@0: }
michael@0: 
michael@0: // GetMaxAscent/GetMaxDescent/GetMaxHeight must contain the
michael@0: // text-decoration lines drawable area. See bug 421353.
michael@0: // BE CAREFUL for rounding each values. The logic MUST be same as
michael@0: // nsCSSRendering::GetTextDecorationRectInternal's.
michael@0: 
michael@0: static gfxFloat ComputeMaxDescent(const gfxFont::Metrics& aMetrics,
michael@0:                                   gfxFontGroup* aFontGroup)
michael@0: {
michael@0:     gfxFloat offset = floor(-aFontGroup->GetUnderlineOffset() + 0.5);
michael@0:     gfxFloat size = NS_round(aMetrics.underlineSize);
michael@0:     gfxFloat minDescent = floor(offset + size + 0.5);
michael@0:     return std::max(minDescent, aMetrics.maxDescent);
michael@0: }
michael@0: 
michael@0: static gfxFloat ComputeMaxAscent(const gfxFont::Metrics& aMetrics)
michael@0: {
michael@0:     return floor(aMetrics.maxAscent + 0.5);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::InternalLeading()
michael@0: {
michael@0:     return ROUND_TO_TWIPS(GetMetrics().internalLeading);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::ExternalLeading()
michael@0: {
michael@0:     return ROUND_TO_TWIPS(GetMetrics().externalLeading);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::EmHeight()
michael@0: {
michael@0:     return ROUND_TO_TWIPS(GetMetrics().emHeight);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::EmAscent()
michael@0: {
michael@0:     return ROUND_TO_TWIPS(GetMetrics().emAscent);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::EmDescent()
michael@0: {
michael@0:     return ROUND_TO_TWIPS(GetMetrics().emDescent);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::MaxHeight()
michael@0: {
michael@0:     return CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics())) +
michael@0:         CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::MaxAscent()
michael@0: {
michael@0:     return CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics()));
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::MaxDescent()
michael@0: {
michael@0:     return CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::MaxAdvance()
michael@0: {
michael@0:     return CEIL_TO_TWIPS(GetMetrics().maxAdvance);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::AveCharWidth()
michael@0: {
michael@0:     // Use CEIL instead of ROUND for consistency with GetMaxAdvance
michael@0:     return CEIL_TO_TWIPS(GetMetrics().aveCharWidth);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::SpaceWidth()
michael@0: {
michael@0:     return CEIL_TO_TWIPS(GetMetrics().spaceWidth);
michael@0: }
michael@0: 
michael@0: int32_t
michael@0: nsFontMetrics::GetMaxStringLength()
michael@0: {
michael@0:     const gfxFont::Metrics& m = GetMetrics();
michael@0:     const double x = 32767.0 / m.maxAdvance;
michael@0:     int32_t len = (int32_t)floor(x);
michael@0:     return std::max(1, len);
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::GetWidth(const char* aString, uint32_t aLength,
michael@0:                         nsRenderingContext *aContext)
michael@0: {
michael@0:     if (aLength == 0)
michael@0:         return 0;
michael@0: 
michael@0:     if (aLength == 1 && aString[0] == ' ')
michael@0:         return SpaceWidth();
michael@0: 
michael@0:     StubPropertyProvider provider;
michael@0:     AutoTextRun textRun(this, aContext, aString, aLength);
michael@0:     return textRun.get() ?
michael@0:         NSToCoordRound(textRun->GetAdvanceWidth(0, aLength, &provider)) : 0;
michael@0: }
michael@0: 
michael@0: nscoord
michael@0: nsFontMetrics::GetWidth(const char16_t* aString, uint32_t aLength,
michael@0:                         nsRenderingContext *aContext)
michael@0: {
michael@0:     if (aLength == 0)
michael@0:         return 0;
michael@0: 
michael@0:     if (aLength == 1 && aString[0] == ' ')
michael@0:         return SpaceWidth();
michael@0: 
michael@0:     StubPropertyProvider provider;
michael@0:     AutoTextRun textRun(this, aContext, aString, aLength);
michael@0:     return textRun.get() ?
michael@0:         NSToCoordRound(textRun->GetAdvanceWidth(0, aLength, &provider)) : 0;
michael@0: }
michael@0: 
michael@0: // Draw a string using this font handle on the surface passed in.
michael@0: void
michael@0: nsFontMetrics::DrawString(const char *aString, uint32_t aLength,
michael@0:                           nscoord aX, nscoord aY,
michael@0:                           nsRenderingContext *aContext)
michael@0: {
michael@0:     if (aLength == 0)
michael@0:         return;
michael@0: 
michael@0:     StubPropertyProvider provider;
michael@0:     AutoTextRun textRun(this, aContext, aString, aLength);
michael@0:     if (!textRun.get()) {
michael@0:         return;
michael@0:     }
michael@0:     gfxPoint pt(aX, aY);
michael@0:     if (mTextRunRTL) {
michael@0:         pt.x += textRun->GetAdvanceWidth(0, aLength, &provider);
michael@0:     }
michael@0:     textRun->Draw(aContext->ThebesContext(), pt, DrawMode::GLYPH_FILL, 0, aLength,
michael@0:                   &provider, nullptr, nullptr);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFontMetrics::DrawString(const char16_t* aString, uint32_t aLength,
michael@0:                           nscoord aX, nscoord aY,
michael@0:                           nsRenderingContext *aContext,
michael@0:                           nsRenderingContext *aTextRunConstructionContext)
michael@0: {
michael@0:     if (aLength == 0)
michael@0:         return;
michael@0: 
michael@0:     StubPropertyProvider provider;
michael@0:     AutoTextRun textRun(this, aTextRunConstructionContext, aString, aLength);
michael@0:     if (!textRun.get()) {
michael@0:         return;
michael@0:     }
michael@0:     gfxPoint pt(aX, aY);
michael@0:     if (mTextRunRTL) {
michael@0:         pt.x += textRun->GetAdvanceWidth(0, aLength, &provider);
michael@0:     }
michael@0:     textRun->Draw(aContext->ThebesContext(), pt, DrawMode::GLYPH_FILL, 0, aLength,
michael@0:                   &provider, nullptr, nullptr);
michael@0: }
michael@0: 
michael@0: static nsBoundingMetrics
michael@0: GetTextBoundingMetrics(nsFontMetrics* aMetrics, const char16_t *aString, uint32_t aLength,
michael@0:                        nsRenderingContext *aContext, gfxFont::BoundingBoxType aType)
michael@0: {
michael@0:     if (aLength == 0)
michael@0:         return nsBoundingMetrics();
michael@0: 
michael@0:     StubPropertyProvider provider;
michael@0:     AutoTextRun textRun(aMetrics, aContext, aString, aLength);
michael@0:     nsBoundingMetrics m;
michael@0:     if (textRun.get()) {
michael@0:         gfxTextRun::Metrics theMetrics =
michael@0:             textRun->MeasureText(0, aLength,
michael@0:                                  aType,
michael@0:                                  aContext->ThebesContext(), &provider);
michael@0: 
michael@0:         m.leftBearing  = NSToCoordFloor( theMetrics.mBoundingBox.X());
michael@0:         m.rightBearing = NSToCoordCeil(  theMetrics.mBoundingBox.XMost());
michael@0:         m.ascent       = NSToCoordCeil( -theMetrics.mBoundingBox.Y());
michael@0:         m.descent      = NSToCoordCeil(  theMetrics.mBoundingBox.YMost());
michael@0:         m.width        = NSToCoordRound( theMetrics.mAdvanceWidth);
michael@0:     }
michael@0:     return m;
michael@0: }
michael@0: 
michael@0: nsBoundingMetrics
michael@0: nsFontMetrics::GetBoundingMetrics(const char16_t *aString, uint32_t aLength,
michael@0:                                   nsRenderingContext *aContext)
michael@0: {
michael@0:   return GetTextBoundingMetrics(this, aString, aLength, aContext, gfxFont::TIGHT_HINTED_OUTLINE_EXTENTS);
michael@0:   
michael@0: }
michael@0: 
michael@0: nsBoundingMetrics
michael@0: nsFontMetrics::GetInkBoundsForVisualOverflow(const char16_t *aString, uint32_t aLength,
michael@0:                                              nsRenderingContext *aContext)
michael@0: {
michael@0:   return GetTextBoundingMetrics(this, aString, aLength, aContext, gfxFont::LOOSE_INK_EXTENTS);
michael@0: }
michael@0: