1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/src/nsFontMetrics.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,396 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsFontMetrics.h"
1.10 +#include <math.h> // for floor, ceil
1.11 +#include <algorithm> // for max
1.12 +#include "gfxPlatform.h" // for gfxPlatform
1.13 +#include "gfxPoint.h" // for gfxPoint
1.14 +#include "gfxRect.h" // for gfxRect
1.15 +#include "gfxTypes.h" // for gfxFloat
1.16 +#include "nsBoundingMetrics.h" // for nsBoundingMetrics
1.17 +#include "nsDebug.h" // for NS_ERROR, NS_ABORT_IF_FALSE
1.18 +#include "nsDeviceContext.h" // for nsDeviceContext
1.19 +#include "nsIAtom.h" // for nsIAtom
1.20 +#include "nsMathUtils.h" // for NS_round
1.21 +#include "nsRenderingContext.h" // for nsRenderingContext
1.22 +#include "nsString.h" // for nsString
1.23 +#include "nsStyleConsts.h" // for NS_STYLE_HYPHENS_NONE
1.24 +
1.25 +class gfxUserFontSet;
1.26 +
1.27 +namespace {
1.28 +
1.29 +class AutoTextRun {
1.30 +public:
1.31 + AutoTextRun(nsFontMetrics* aMetrics, nsRenderingContext* aRC,
1.32 + const char* aString, int32_t aLength)
1.33 + {
1.34 + mTextRun = aMetrics->GetThebesFontGroup()->MakeTextRun(
1.35 + reinterpret_cast<const uint8_t*>(aString), aLength,
1.36 + aRC->ThebesContext(),
1.37 + aMetrics->AppUnitsPerDevPixel(),
1.38 + ComputeFlags(aMetrics));
1.39 + }
1.40 +
1.41 + AutoTextRun(nsFontMetrics* aMetrics, nsRenderingContext* aRC,
1.42 + const char16_t* aString, int32_t aLength)
1.43 + {
1.44 + mTextRun = aMetrics->GetThebesFontGroup()->MakeTextRun(
1.45 + aString, aLength,
1.46 + aRC->ThebesContext(),
1.47 + aMetrics->AppUnitsPerDevPixel(),
1.48 + ComputeFlags(aMetrics));
1.49 + }
1.50 +
1.51 + gfxTextRun *get() { return mTextRun; }
1.52 + gfxTextRun *operator->() { return mTextRun; }
1.53 +
1.54 +private:
1.55 + static uint32_t ComputeFlags(nsFontMetrics* aMetrics) {
1.56 + uint32_t flags = 0;
1.57 + if (aMetrics->GetTextRunRTL()) {
1.58 + flags |= gfxTextRunFactory::TEXT_IS_RTL;
1.59 + }
1.60 + return flags;
1.61 + }
1.62 +
1.63 + nsAutoPtr<gfxTextRun> mTextRun;
1.64 +};
1.65 +
1.66 +class StubPropertyProvider : public gfxTextRun::PropertyProvider {
1.67 +public:
1.68 + virtual void GetHyphenationBreaks(uint32_t aStart, uint32_t aLength,
1.69 + bool* aBreakBefore) {
1.70 + NS_ERROR("This shouldn't be called because we never call BreakAndMeasureText");
1.71 + }
1.72 + virtual int8_t GetHyphensOption() {
1.73 + NS_ERROR("This shouldn't be called because we never call BreakAndMeasureText");
1.74 + return NS_STYLE_HYPHENS_NONE;
1.75 + }
1.76 + virtual gfxFloat GetHyphenWidth() {
1.77 + NS_ERROR("This shouldn't be called because we never enable hyphens");
1.78 + return 0;
1.79 + }
1.80 + virtual already_AddRefed<gfxContext> GetContext() {
1.81 + NS_ERROR("This shouldn't be called because we never enable hyphens");
1.82 + return nullptr;
1.83 + }
1.84 + virtual uint32_t GetAppUnitsPerDevUnit() {
1.85 + NS_ERROR("This shouldn't be called because we never enable hyphens");
1.86 + return 60;
1.87 + }
1.88 + virtual void GetSpacing(uint32_t aStart, uint32_t aLength,
1.89 + Spacing* aSpacing) {
1.90 + NS_ERROR("This shouldn't be called because we never enable spacing");
1.91 + }
1.92 +};
1.93 +
1.94 +} // anon namespace
1.95 +
1.96 +nsFontMetrics::nsFontMetrics()
1.97 + : mDeviceContext(nullptr), mP2A(0), mTextRunRTL(false)
1.98 +{
1.99 +}
1.100 +
1.101 +nsFontMetrics::~nsFontMetrics()
1.102 +{
1.103 + if (mDeviceContext)
1.104 + mDeviceContext->FontMetricsDeleted(this);
1.105 +}
1.106 +
1.107 +nsresult
1.108 +nsFontMetrics::Init(const nsFont& aFont, nsIAtom* aLanguage,
1.109 + nsDeviceContext *aContext,
1.110 + gfxUserFontSet *aUserFontSet,
1.111 + gfxTextPerfMetrics *aTextPerf)
1.112 +{
1.113 + NS_ABORT_IF_FALSE(mP2A == 0, "already initialized");
1.114 +
1.115 + mFont = aFont;
1.116 + mLanguage = aLanguage;
1.117 + mDeviceContext = aContext;
1.118 + mP2A = mDeviceContext->AppUnitsPerDevPixel();
1.119 +
1.120 + gfxFontStyle style(aFont.style,
1.121 + aFont.weight,
1.122 + aFont.stretch,
1.123 + gfxFloat(aFont.size) / mP2A,
1.124 + aLanguage,
1.125 + aFont.sizeAdjust,
1.126 + aFont.systemFont,
1.127 + mDeviceContext->IsPrinterSurface(),
1.128 + aFont.languageOverride);
1.129 +
1.130 + aFont.AddFontFeaturesToStyle(&style);
1.131 +
1.132 + mFontGroup = gfxPlatform::GetPlatform()->
1.133 + CreateFontGroup(aFont.name, &style, aUserFontSet);
1.134 + mFontGroup->SetTextPerfMetrics(aTextPerf);
1.135 + if (mFontGroup->FontListLength() < 1)
1.136 + return NS_ERROR_UNEXPECTED;
1.137 +
1.138 + return NS_OK;
1.139 +}
1.140 +
1.141 +void
1.142 +nsFontMetrics::Destroy()
1.143 +{
1.144 + mDeviceContext = nullptr;
1.145 +}
1.146 +
1.147 +// XXXTODO get rid of this macro
1.148 +#define ROUND_TO_TWIPS(x) (nscoord)floor(((x) * mP2A) + 0.5)
1.149 +#define CEIL_TO_TWIPS(x) (nscoord)ceil((x) * mP2A)
1.150 +
1.151 +const gfxFont::Metrics& nsFontMetrics::GetMetrics() const
1.152 +{
1.153 + return mFontGroup->GetFontAt(0)->GetMetrics();
1.154 +}
1.155 +
1.156 +nscoord
1.157 +nsFontMetrics::XHeight()
1.158 +{
1.159 + return ROUND_TO_TWIPS(GetMetrics().xHeight);
1.160 +}
1.161 +
1.162 +nscoord
1.163 +nsFontMetrics::SuperscriptOffset()
1.164 +{
1.165 + return ROUND_TO_TWIPS(GetMetrics().superscriptOffset);
1.166 +}
1.167 +
1.168 +nscoord
1.169 +nsFontMetrics::SubscriptOffset()
1.170 +{
1.171 + return ROUND_TO_TWIPS(GetMetrics().subscriptOffset);
1.172 +}
1.173 +
1.174 +void
1.175 +nsFontMetrics::GetStrikeout(nscoord& aOffset, nscoord& aSize)
1.176 +{
1.177 + aOffset = ROUND_TO_TWIPS(GetMetrics().strikeoutOffset);
1.178 + aSize = ROUND_TO_TWIPS(GetMetrics().strikeoutSize);
1.179 +}
1.180 +
1.181 +void
1.182 +nsFontMetrics::GetUnderline(nscoord& aOffset, nscoord& aSize)
1.183 +{
1.184 + aOffset = ROUND_TO_TWIPS(mFontGroup->GetUnderlineOffset());
1.185 + aSize = ROUND_TO_TWIPS(GetMetrics().underlineSize);
1.186 +}
1.187 +
1.188 +// GetMaxAscent/GetMaxDescent/GetMaxHeight must contain the
1.189 +// text-decoration lines drawable area. See bug 421353.
1.190 +// BE CAREFUL for rounding each values. The logic MUST be same as
1.191 +// nsCSSRendering::GetTextDecorationRectInternal's.
1.192 +
1.193 +static gfxFloat ComputeMaxDescent(const gfxFont::Metrics& aMetrics,
1.194 + gfxFontGroup* aFontGroup)
1.195 +{
1.196 + gfxFloat offset = floor(-aFontGroup->GetUnderlineOffset() + 0.5);
1.197 + gfxFloat size = NS_round(aMetrics.underlineSize);
1.198 + gfxFloat minDescent = floor(offset + size + 0.5);
1.199 + return std::max(minDescent, aMetrics.maxDescent);
1.200 +}
1.201 +
1.202 +static gfxFloat ComputeMaxAscent(const gfxFont::Metrics& aMetrics)
1.203 +{
1.204 + return floor(aMetrics.maxAscent + 0.5);
1.205 +}
1.206 +
1.207 +nscoord
1.208 +nsFontMetrics::InternalLeading()
1.209 +{
1.210 + return ROUND_TO_TWIPS(GetMetrics().internalLeading);
1.211 +}
1.212 +
1.213 +nscoord
1.214 +nsFontMetrics::ExternalLeading()
1.215 +{
1.216 + return ROUND_TO_TWIPS(GetMetrics().externalLeading);
1.217 +}
1.218 +
1.219 +nscoord
1.220 +nsFontMetrics::EmHeight()
1.221 +{
1.222 + return ROUND_TO_TWIPS(GetMetrics().emHeight);
1.223 +}
1.224 +
1.225 +nscoord
1.226 +nsFontMetrics::EmAscent()
1.227 +{
1.228 + return ROUND_TO_TWIPS(GetMetrics().emAscent);
1.229 +}
1.230 +
1.231 +nscoord
1.232 +nsFontMetrics::EmDescent()
1.233 +{
1.234 + return ROUND_TO_TWIPS(GetMetrics().emDescent);
1.235 +}
1.236 +
1.237 +nscoord
1.238 +nsFontMetrics::MaxHeight()
1.239 +{
1.240 + return CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics())) +
1.241 + CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
1.242 +}
1.243 +
1.244 +nscoord
1.245 +nsFontMetrics::MaxAscent()
1.246 +{
1.247 + return CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics()));
1.248 +}
1.249 +
1.250 +nscoord
1.251 +nsFontMetrics::MaxDescent()
1.252 +{
1.253 + return CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
1.254 +}
1.255 +
1.256 +nscoord
1.257 +nsFontMetrics::MaxAdvance()
1.258 +{
1.259 + return CEIL_TO_TWIPS(GetMetrics().maxAdvance);
1.260 +}
1.261 +
1.262 +nscoord
1.263 +nsFontMetrics::AveCharWidth()
1.264 +{
1.265 + // Use CEIL instead of ROUND for consistency with GetMaxAdvance
1.266 + return CEIL_TO_TWIPS(GetMetrics().aveCharWidth);
1.267 +}
1.268 +
1.269 +nscoord
1.270 +nsFontMetrics::SpaceWidth()
1.271 +{
1.272 + return CEIL_TO_TWIPS(GetMetrics().spaceWidth);
1.273 +}
1.274 +
1.275 +int32_t
1.276 +nsFontMetrics::GetMaxStringLength()
1.277 +{
1.278 + const gfxFont::Metrics& m = GetMetrics();
1.279 + const double x = 32767.0 / m.maxAdvance;
1.280 + int32_t len = (int32_t)floor(x);
1.281 + return std::max(1, len);
1.282 +}
1.283 +
1.284 +nscoord
1.285 +nsFontMetrics::GetWidth(const char* aString, uint32_t aLength,
1.286 + nsRenderingContext *aContext)
1.287 +{
1.288 + if (aLength == 0)
1.289 + return 0;
1.290 +
1.291 + if (aLength == 1 && aString[0] == ' ')
1.292 + return SpaceWidth();
1.293 +
1.294 + StubPropertyProvider provider;
1.295 + AutoTextRun textRun(this, aContext, aString, aLength);
1.296 + return textRun.get() ?
1.297 + NSToCoordRound(textRun->GetAdvanceWidth(0, aLength, &provider)) : 0;
1.298 +}
1.299 +
1.300 +nscoord
1.301 +nsFontMetrics::GetWidth(const char16_t* aString, uint32_t aLength,
1.302 + nsRenderingContext *aContext)
1.303 +{
1.304 + if (aLength == 0)
1.305 + return 0;
1.306 +
1.307 + if (aLength == 1 && aString[0] == ' ')
1.308 + return SpaceWidth();
1.309 +
1.310 + StubPropertyProvider provider;
1.311 + AutoTextRun textRun(this, aContext, aString, aLength);
1.312 + return textRun.get() ?
1.313 + NSToCoordRound(textRun->GetAdvanceWidth(0, aLength, &provider)) : 0;
1.314 +}
1.315 +
1.316 +// Draw a string using this font handle on the surface passed in.
1.317 +void
1.318 +nsFontMetrics::DrawString(const char *aString, uint32_t aLength,
1.319 + nscoord aX, nscoord aY,
1.320 + nsRenderingContext *aContext)
1.321 +{
1.322 + if (aLength == 0)
1.323 + return;
1.324 +
1.325 + StubPropertyProvider provider;
1.326 + AutoTextRun textRun(this, aContext, aString, aLength);
1.327 + if (!textRun.get()) {
1.328 + return;
1.329 + }
1.330 + gfxPoint pt(aX, aY);
1.331 + if (mTextRunRTL) {
1.332 + pt.x += textRun->GetAdvanceWidth(0, aLength, &provider);
1.333 + }
1.334 + textRun->Draw(aContext->ThebesContext(), pt, DrawMode::GLYPH_FILL, 0, aLength,
1.335 + &provider, nullptr, nullptr);
1.336 +}
1.337 +
1.338 +void
1.339 +nsFontMetrics::DrawString(const char16_t* aString, uint32_t aLength,
1.340 + nscoord aX, nscoord aY,
1.341 + nsRenderingContext *aContext,
1.342 + nsRenderingContext *aTextRunConstructionContext)
1.343 +{
1.344 + if (aLength == 0)
1.345 + return;
1.346 +
1.347 + StubPropertyProvider provider;
1.348 + AutoTextRun textRun(this, aTextRunConstructionContext, aString, aLength);
1.349 + if (!textRun.get()) {
1.350 + return;
1.351 + }
1.352 + gfxPoint pt(aX, aY);
1.353 + if (mTextRunRTL) {
1.354 + pt.x += textRun->GetAdvanceWidth(0, aLength, &provider);
1.355 + }
1.356 + textRun->Draw(aContext->ThebesContext(), pt, DrawMode::GLYPH_FILL, 0, aLength,
1.357 + &provider, nullptr, nullptr);
1.358 +}
1.359 +
1.360 +static nsBoundingMetrics
1.361 +GetTextBoundingMetrics(nsFontMetrics* aMetrics, const char16_t *aString, uint32_t aLength,
1.362 + nsRenderingContext *aContext, gfxFont::BoundingBoxType aType)
1.363 +{
1.364 + if (aLength == 0)
1.365 + return nsBoundingMetrics();
1.366 +
1.367 + StubPropertyProvider provider;
1.368 + AutoTextRun textRun(aMetrics, aContext, aString, aLength);
1.369 + nsBoundingMetrics m;
1.370 + if (textRun.get()) {
1.371 + gfxTextRun::Metrics theMetrics =
1.372 + textRun->MeasureText(0, aLength,
1.373 + aType,
1.374 + aContext->ThebesContext(), &provider);
1.375 +
1.376 + m.leftBearing = NSToCoordFloor( theMetrics.mBoundingBox.X());
1.377 + m.rightBearing = NSToCoordCeil( theMetrics.mBoundingBox.XMost());
1.378 + m.ascent = NSToCoordCeil( -theMetrics.mBoundingBox.Y());
1.379 + m.descent = NSToCoordCeil( theMetrics.mBoundingBox.YMost());
1.380 + m.width = NSToCoordRound( theMetrics.mAdvanceWidth);
1.381 + }
1.382 + return m;
1.383 +}
1.384 +
1.385 +nsBoundingMetrics
1.386 +nsFontMetrics::GetBoundingMetrics(const char16_t *aString, uint32_t aLength,
1.387 + nsRenderingContext *aContext)
1.388 +{
1.389 + return GetTextBoundingMetrics(this, aString, aLength, aContext, gfxFont::TIGHT_HINTED_OUTLINE_EXTENTS);
1.390 +
1.391 +}
1.392 +
1.393 +nsBoundingMetrics
1.394 +nsFontMetrics::GetInkBoundsForVisualOverflow(const char16_t *aString, uint32_t aLength,
1.395 + nsRenderingContext *aContext)
1.396 +{
1.397 + return GetTextBoundingMetrics(this, aString, aLength, aContext, gfxFont::LOOSE_INK_EXTENTS);
1.398 +}
1.399 +
