gfx/src/thebes/nsThebesFontMetrics.cpp

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
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  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
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  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * mozilla.org.
  19  * Portions created by the Initial Developer are Copyright (C) 2005
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Stuart Parmenter <pavlov@pavlov.net>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
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  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nsThebesFontMetrics.h"
  40 #include "nsFont.h"
  41
  42 #include "nsString.h"
  43 #include <stdio.h>
  44
  45 #include "gfxTextRunCache.h"
  46 #include "gfxPlatform.h"
  47 #include "gfxUserFontSet.h"
  48
  49 NS_IMPL_ISUPPORTS1(nsThebesFontMetrics, nsIFontMetrics)
  50
  51 #include <stdlib.h>
  52
  53 nsThebesFontMetrics::nsThebesFontMetrics()
  54 {
  55     mFontStyle = nsnull;
  56     mFontGroup = nsnull;
  57 }
  58
  59 nsThebesFontMetrics::~nsThebesFontMetrics()
  60 {
  61     if (mDeviceContext)
  62         mDeviceContext->FontMetricsDeleted(this);
  63     delete mFontStyle;
  64     //delete mFontGroup;
  65 }
  66
  67 NS_IMETHODIMP
  68 nsThebesFontMetrics::Init(const nsFont& aFont, nsIAtom* aLanguage,
  69                           nsIDeviceContext *aContext,
  70                           gfxUserFontSet *aUserFontSet)
  71 {
  72     mFont = aFont;
  73     mLanguage = aLanguage;
  74     mDeviceContext = (nsThebesDeviceContext*)aContext;
  75     mP2A = mDeviceContext->AppUnitsPerDevPixel();
  76     mIsRightToLeft = PR_FALSE;
  77     mTextRunRTL = PR_FALSE;
  78
  79     gfxFloat size = gfxFloat(aFont.size) / mP2A;
  80
  81     PRBool printerFont = mDeviceContext->IsPrinterSurface();
  82     mFontStyle = new gfxFontStyle(aFont.style, aFont.weight, aFont.stretch,
  83                                   size, aLanguage,
  84                                   aFont.sizeAdjust, aFont.systemFont,
  85                                   aFont.familyNameQuirks,
  86                                   printerFont,
  87                                   aFont.featureSettings,
  88                                   aFont.languageOverride);
  89
  90     mFontGroup =
  91         gfxPlatform::GetPlatform()->CreateFontGroup(aFont.name, mFontStyle,
  92                                                     aUserFontSet);
  93     if (mFontGroup->FontListLength() < 1)
  94         return NS_ERROR_UNEXPECTED;
  95
  96     return NS_OK;
  97 }
  98
  99 NS_IMETHODIMP
 100 nsThebesFontMetrics::Destroy()
 101 {
 102     mDeviceContext = nsnull;
 103     return NS_OK;
 104 }
 105
 106 // XXXTODO get rid of this macro
 107 #define ROUND_TO_TWIPS(x) (nscoord)floor(((x) * mP2A) + 0.5)
 108 #define CEIL_TO_TWIPS(x) (nscoord)NS_ceil((x) * mP2A)
 109
 110 const gfxFont::Metrics& nsThebesFontMetrics::GetMetrics() const
 111 {
 112     return mFontGroup->GetFontAt(0)->GetMetrics();
 113 }
 114
 115 NS_IMETHODIMP
 116 nsThebesFontMetrics::GetXHeight(nscoord& aResult)
 117 {
 118     aResult = ROUND_TO_TWIPS(GetMetrics().xHeight);
 119     return NS_OK;
 120 }
 121
 122 NS_IMETHODIMP
 123 nsThebesFontMetrics::GetSuperscriptOffset(nscoord& aResult)
 124 {
 125     aResult = ROUND_TO_TWIPS(GetMetrics().superscriptOffset);
 126     return NS_OK;
 127 }
 128
 129 NS_IMETHODIMP
 130 nsThebesFontMetrics::GetSubscriptOffset(nscoord& aResult)
 131 {
 132     aResult = ROUND_TO_TWIPS(GetMetrics().subscriptOffset);
 133     return NS_OK;
 134 }
 135
 136 NS_IMETHODIMP
 137 nsThebesFontMetrics::GetStrikeout(nscoord& aOffset, nscoord& aSize)
 138 {
 139     aOffset = ROUND_TO_TWIPS(GetMetrics().strikeoutOffset);
 140     aSize = ROUND_TO_TWIPS(GetMetrics().strikeoutSize);
 141     return NS_OK;
 142 }
 143
 144 NS_IMETHODIMP
 145 nsThebesFontMetrics::GetUnderline(nscoord& aOffset, nscoord& aSize)
 146 {
 147     aOffset = ROUND_TO_TWIPS(mFontGroup->GetUnderlineOffset());
 148     aSize = ROUND_TO_TWIPS(GetMetrics().underlineSize);
 149
 150     return NS_OK;
 151 }
 152
 153 // GetHeight/GetMaxAscent/GetMaxDescent/GetMaxHeight must contain the
 154 // text-decoration lines drawable area. See bug 421353.
 155 // BE CAREFUL for rounding each values. The logic MUST be same as
 156 // nsCSSRendering::GetTextDecorationRectInternal's.
 157
 158 static gfxFloat ComputeMaxDescent(const gfxFont::Metrics& aMetrics,
 159                                   gfxFontGroup* aFontGroup)
 160 {
 161     gfxFloat offset = NS_floor(-aFontGroup->GetUnderlineOffset() + 0.5);
 162     gfxFloat size = NS_round(aMetrics.underlineSize);
 163     gfxFloat minDescent = NS_floor(offset + size + 0.5);
 164     return PR_MAX(minDescent, aMetrics.maxDescent);
 165 }
 166
 167 static gfxFloat ComputeMaxAscent(const gfxFont::Metrics& aMetrics)
 168 {
 169     return NS_floor(aMetrics.maxAscent + 0.5);
 170 }
 171
 172 NS_IMETHODIMP
 173 nsThebesFontMetrics::GetHeight(nscoord &aHeight)
 174 {
 175     aHeight = CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics())) +
 176         CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
 177     return NS_OK;
 178 }
 179
 180 NS_IMETHODIMP
 181 nsThebesFontMetrics::GetInternalLeading(nscoord &aLeading)
 182 {
 183     aLeading = ROUND_TO_TWIPS(GetMetrics().internalLeading);
 184     return NS_OK;
 185 }
 186
 187 NS_IMETHODIMP
 188 nsThebesFontMetrics::GetExternalLeading(nscoord &aLeading)
 189 {
 190     aLeading = ROUND_TO_TWIPS(GetMetrics().externalLeading);
 191     return NS_OK;
 192 }
 193
 194 NS_IMETHODIMP
 195 nsThebesFontMetrics::GetEmHeight(nscoord &aHeight)
 196 {
 197     aHeight = ROUND_TO_TWIPS(GetMetrics().emHeight);
 198     return NS_OK;
 199 }
 200
 201 NS_IMETHODIMP
 202 nsThebesFontMetrics::GetEmAscent(nscoord &aAscent)
 203 {
 204     aAscent = ROUND_TO_TWIPS(GetMetrics().emAscent);
 205     return NS_OK;
 206 }
 207
 208 NS_IMETHODIMP
 209 nsThebesFontMetrics::GetEmDescent(nscoord &aDescent)
 210 {
 211     aDescent = ROUND_TO_TWIPS(GetMetrics().emDescent);
 212     return NS_OK;
 213 }
 214
 215 NS_IMETHODIMP
 216 nsThebesFontMetrics::GetMaxHeight(nscoord &aHeight)
 217 {
 218     aHeight = CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics())) +
 219         CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
 220     return NS_OK;
 221 }
 222
 223 NS_IMETHODIMP
 224 nsThebesFontMetrics::GetMaxAscent(nscoord &aAscent)
 225 {
 226     aAscent = CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics()));
 227     return NS_OK;
 228 }
 229
 230 NS_IMETHODIMP
 231 nsThebesFontMetrics::GetMaxDescent(nscoord &aDescent)
 232 {
 233     aDescent = CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
 234     return NS_OK;
 235 }
 236
 237 NS_IMETHODIMP
 238 nsThebesFontMetrics::GetMaxAdvance(nscoord &aAdvance)
 239 {
 240     aAdvance = CEIL_TO_TWIPS(GetMetrics().maxAdvance);
 241     return NS_OK;
 242 }
 243
 244 NS_IMETHODIMP
 245 nsThebesFontMetrics::GetLanguage(nsIAtom** aLanguage)
 246 {
 247     *aLanguage = mLanguage;
 248     NS_IF_ADDREF(*aLanguage);
 249     return NS_OK;
 250 }
 251
 252 NS_IMETHODIMP
 253 nsThebesFontMetrics::GetFontHandle(nsFontHandle &aHandle)
 254 {
 255     return NS_ERROR_NOT_IMPLEMENTED;
 256 }
 257
 258 NS_IMETHODIMP
 259 nsThebesFontMetrics::GetAveCharWidth(nscoord& aAveCharWidth)
 260 {
 261     // Use CEIL instead of ROUND for consistency with GetMaxAdvance
 262     aAveCharWidth = CEIL_TO_TWIPS(GetMetrics().aveCharWidth);
 263     return NS_OK;
 264 }
 265
 266 NS_IMETHODIMP
 267 nsThebesFontMetrics::GetSpaceWidth(nscoord& aSpaceCharWidth)
 268 {
 269     aSpaceCharWidth = CEIL_TO_TWIPS(GetMetrics().spaceWidth);
 270     return NS_OK;
 271 }
 272
 273 PRInt32
 274 nsThebesFontMetrics::GetMaxStringLength()
 275 {
 276     const gfxFont::Metrics& m = GetMetrics();
 277     const double x = 32767.0 / m.maxAdvance;
 278     PRInt32 len = (PRInt32)floor(x);
 279     return PR_MAX(1, len);
 280 }
 281
 282 class StubPropertyProvider : public gfxTextRun::PropertyProvider {
 283 public:
 284     virtual void GetHyphenationBreaks(PRUint32 aStart, PRUint32 aLength,
 285                                       PRPackedBool* aBreakBefore) {
 286         NS_ERROR("This shouldn't be called because we never call BreakAndMeasureText");
 287     }
 288     virtual gfxFloat GetHyphenWidth() {
 289         NS_ERROR("This shouldn't be called because we never enable hyphens");
 290         return 0;
 291     }
 292     virtual void GetSpacing(PRUint32 aStart, PRUint32 aLength,
 293                             Spacing* aSpacing) {
 294         NS_ERROR("This shouldn't be called because we never enable spacing");
 295     }
 296 };
 297
 298 nsresult
 299 nsThebesFontMetrics::GetWidth(const char* aString, PRUint32 aLength, nscoord& aWidth,
 300                               nsThebesRenderingContext *aContext)
 301 {
 302     if (aLength == 0) {
 303         aWidth = 0;
 304         return NS_OK;
 305     }
 306
 307     // callers that hit this should not be so stupid
 308     if ((aLength == 1) && (aString[0] == ' '))
 309         return GetSpaceWidth(aWidth);
 310
 311     StubPropertyProvider provider;
 312     AutoTextRun textRun(this, aContext, aString, aLength);
 313     if (!textRun.get())
 314         return NS_ERROR_FAILURE;
 315
 316     aWidth = NSToCoordRound(textRun->GetAdvanceWidth(0, aLength, &provider));
 317
 318     return NS_OK;
 319 }
 320
 321 nsresult
 322 nsThebesFontMetrics::GetWidth(const PRUnichar* aString, PRUint32 aLength,
 323                               nscoord& aWidth, PRInt32 *aFontID,
 324                               nsThebesRenderingContext *aContext)
 325 {
 326     if (aLength == 0) {
 327         aWidth = 0;
 328         return NS_OK;
 329     }
 330
 331     // callers that hit this should not be so stupid
 332     if ((aLength == 1) && (aString[0] == ' '))
 333         return GetSpaceWidth(aWidth);
 334
 335     StubPropertyProvider provider;
 336     AutoTextRun textRun(this, aContext, aString, aLength);
 337     if (!textRun.get())
 338         return NS_ERROR_FAILURE;
 339
 340     aWidth = NSToCoordRound(textRun->GetAdvanceWidth(0, aLength, &provider));
 341
 342     return NS_OK;
 343 }
 344
 345 // Get the text dimensions for this string
 346 nsresult
 347 nsThebesFontMetrics::GetTextDimensions(const PRUnichar* aString,
 348                                     PRUint32 aLength,
 349                                     nsTextDimensions& aDimensions,
 350                                     PRInt32* aFontID)
 351 {
 352     return NS_OK;
 353 }
 354
 355 nsresult
 356 nsThebesFontMetrics::GetTextDimensions(const char*         aString,
 357                                    PRInt32             aLength,
 358                                    PRInt32             aAvailWidth,
 359                                    PRInt32*            aBreaks,
 360                                    PRInt32             aNumBreaks,
 361                                    nsTextDimensions&   aDimensions,
 362                                    PRInt32&            aNumCharsFit,
 363                                    nsTextDimensions&   aLastWordDimensions,
 364                                    PRInt32*            aFontID)
 365 {
 366     return NS_OK;
 367 }
 368 nsresult
 369 nsThebesFontMetrics::GetTextDimensions(const PRUnichar*    aString,
 370                                    PRInt32             aLength,
 371                                    PRInt32             aAvailWidth,
 372                                    PRInt32*            aBreaks,
 373                                    PRInt32             aNumBreaks,
 374                                    nsTextDimensions&   aDimensions,
 375                                    PRInt32&            aNumCharsFit,
 376                                    nsTextDimensions&   aLastWordDimensions,
 377                                    PRInt32*            aFontID)
 378 {
 379     return NS_OK;
 380 }
 381
 382 // Draw a string using this font handle on the surface passed in.
 383 nsresult
 384 nsThebesFontMetrics::DrawString(const char *aString, PRUint32 aLength,
 385                                 nscoord aX, nscoord aY,
 386                                 const nscoord* aSpacing,
 387                                 nsThebesRenderingContext *aContext)
 388 {
 389     if (aLength == 0)
 390         return NS_OK;
 391
 392     NS_ASSERTION(!aSpacing, "Spacing not supported here");
 393     StubPropertyProvider provider;
 394     AutoTextRun textRun(this, aContext, aString, aLength);
 395     if (!textRun.get())
 396         return NS_ERROR_FAILURE;
 397     gfxPoint pt(aX, aY);
 398     if (mTextRunRTL) {
 399         pt.x += textRun->GetAdvanceWidth(0, aLength, &provider);
 400     }
 401     textRun->Draw(aContext->ThebesContext(), pt, 0, aLength,
 402                   nsnull, &provider, nsnull);
 403     return NS_OK;
 404 }
 405
 406 nsresult
 407 nsThebesFontMetrics::DrawString(const PRUnichar* aString, PRUint32 aLength,
 408                                 nscoord aX, nscoord aY,
 409                                 PRInt32 aFontID,
 410                                 const nscoord* aSpacing,
 411                                 nsThebesRenderingContext *aContext)
 412 {
 413     if (aLength == 0)
 414         return NS_OK;
 415
 416     NS_ASSERTION(!aSpacing, "Spacing not supported here");
 417     StubPropertyProvider provider;
 418     AutoTextRun textRun(this, aContext, aString, aLength);
 419     if (!textRun.get())
 420         return NS_ERROR_FAILURE;
 421     gfxPoint pt(aX, aY);
 422     if (mTextRunRTL) {
 423         pt.x += textRun->GetAdvanceWidth(0, aLength, &provider);
 424     }
 425     textRun->Draw(aContext->ThebesContext(), pt, 0, aLength,
 426                   nsnull, &provider, nsnull);
 427     return NS_OK;
 428 }
 429
 430 #ifdef MOZ_MATHML
 431
 432 static void
 433 GetTextRunBoundingMetrics(gfxTextRun *aTextRun, PRUint32 aStart, PRUint32 aLength,
 434                           nsThebesRenderingContext *aContext,
 435                           nsBoundingMetrics &aBoundingMetrics)
 436 {
 437     StubPropertyProvider provider;
 438     gfxTextRun::Metrics theMetrics =
 439         aTextRun->MeasureText(aStart, aLength, gfxFont::TIGHT_HINTED_OUTLINE_EXTENTS,
 440                               aContext->ThebesContext(), &provider);
 441         // note that TIGHT_HINTED_OUTLINE_EXTENTS can be expensive (on Windows)
 442         // but this is only used for MathML positioning so it's not critical
 443
 444     aBoundingMetrics.leftBearing = NSToCoordFloor(theMetrics.mBoundingBox.X());
 445     aBoundingMetrics.rightBearing = NSToCoordCeil(theMetrics.mBoundingBox.XMost());
 446     aBoundingMetrics.width = NSToCoordRound(theMetrics.mAdvanceWidth);
 447     aBoundingMetrics.ascent = NSToCoordCeil(- theMetrics.mBoundingBox.Y());
 448     aBoundingMetrics.descent = NSToCoordCeil(theMetrics.mBoundingBox.YMost());
 449 }
 450
 451 nsresult
 452 nsThebesFontMetrics::GetBoundingMetrics(const char *aString, PRUint32 aLength,
 453                                         nsThebesRenderingContext *aContext,
 454                                         nsBoundingMetrics &aBoundingMetrics)
 455 {
 456     if (aLength == 0) {
 457         aBoundingMetrics.Clear();
 458         return NS_OK;
 459     }
 460
 461     AutoTextRun textRun(this, aContext, aString, aLength);
 462     if (!textRun.get())
 463         return NS_ERROR_FAILURE;
 464
 465     GetTextRunBoundingMetrics(textRun.get(), 0, aLength, aContext, aBoundingMetrics);
 466     return NS_OK;
 467 }
 468
 469 nsresult
 470 nsThebesFontMetrics::GetBoundingMetrics(const PRUnichar *aString, PRUint32 aLength,
 471                                         nsThebesRenderingContext *aContext,
 472                                         nsBoundingMetrics &aBoundingMetrics)
 473 {
 474     if (aLength == 0) {
 475         aBoundingMetrics.Clear();
 476         return NS_OK;
 477     }
 478
 479     AutoTextRun textRun(this, aContext, aString, aLength);
 480     if (!textRun.get())
 481         return NS_ERROR_FAILURE;
 482
 483     GetTextRunBoundingMetrics(textRun.get(), 0, aLength, aContext, aBoundingMetrics);
 484     return NS_OK;
 485 }
 486
 487 #endif /* MOZ_MATHML */
 488
 489 // Set the direction of the text rendering
 490 nsresult
 491 nsThebesFontMetrics::SetRightToLeftText(PRBool aIsRTL)
 492 {
 493     mIsRightToLeft = aIsRTL;
 494     return NS_OK;
 495 }
 496
 497 // Set the direction of the text rendering
 498 PRBool
 499 nsThebesFontMetrics::GetRightToLeftText()
 500 {
 501     return mIsRightToLeft;
 502 }
 503
 504 /* virtual */ gfxUserFontSet*
 505 nsThebesFontMetrics::GetUserFontSet()
 506 {
 507     return mFontGroup->GetUserFontSet();
 508 }