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
  13  * License.
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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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  28  * in which case the provisions of the GPL or the LGPL are applicable instead
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  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  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     delete mFontStyle;
  62     //delete mFontGroup;
  63 }
  64
  65 NS_IMETHODIMP
  66 nsThebesFontMetrics::Init(const nsFont& aFont, nsIAtom* aLangGroup,
  67                           nsIDeviceContext *aContext,
  68                           gfxUserFontSet *aUserFontSet)
  69 {
  70     mFont = aFont;
  71     mLangGroup = aLangGroup;
  72     mDeviceContext = (nsThebesDeviceContext*)aContext;
  73     mP2A = mDeviceContext->AppUnitsPerDevPixel();
  74     mIsRightToLeft = PR_FALSE;
  75     mTextRunRTL = PR_FALSE;
  76
  77     gfxFloat size = gfxFloat(aFont.size) / mP2A;
  78
  79     nsCString langGroup;
  80     if (aLangGroup) {
  81         const char* lg;
  82         mLangGroup->GetUTF8String(&lg);
  83         langGroup.Assign(lg);
  84     }
  85
  86     mFontStyle = new gfxFontStyle(aFont.style, aFont.weight, size, langGroup,
  87                                   aFont.sizeAdjust, aFont.systemFont,
  88                                   aFont.familyNameQuirks);
  89
  90     mFontGroup =
  91         gfxPlatform::GetPlatform()->CreateFontGroup(aFont.name, mFontStyle,
  92                                                     aUserFontSet);
  93
  94     return NS_OK;
  95 }
  96
  97 NS_IMETHODIMP
  98 nsThebesFontMetrics::Destroy()
  99 {
 100     return NS_OK;
 101 }
 102
 103 // XXXTODO get rid of this macro
 104 #define ROUND_TO_TWIPS(x) (nscoord)floor(((x) * mP2A) + 0.5)
 105 #define CEIL_TO_TWIPS(x) (nscoord)NS_ceil((x) * mP2A)
 106
 107 const gfxFont::Metrics& nsThebesFontMetrics::GetMetrics() const
 108 {
 109     return mFontGroup->GetFontAt(0)->GetMetrics();
 110 }
 111
 112 NS_IMETHODIMP
 113 nsThebesFontMetrics::GetXHeight(nscoord& aResult)
 114 {
 115     aResult = ROUND_TO_TWIPS(GetMetrics().xHeight);
 116     return NS_OK;
 117 }
 118
 119 NS_IMETHODIMP
 120 nsThebesFontMetrics::GetSuperscriptOffset(nscoord& aResult)
 121 {
 122     aResult = ROUND_TO_TWIPS(GetMetrics().superscriptOffset);
 123     return NS_OK;
 124 }
 125
 126 NS_IMETHODIMP
 127 nsThebesFontMetrics::GetSubscriptOffset(nscoord& aResult)
 128 {
 129     aResult = ROUND_TO_TWIPS(GetMetrics().subscriptOffset);
 130     return NS_OK;
 131 }
 132
 133 NS_IMETHODIMP
 134 nsThebesFontMetrics::GetStrikeout(nscoord& aOffset, nscoord& aSize)
 135 {
 136     aOffset = ROUND_TO_TWIPS(GetMetrics().strikeoutOffset);
 137     aSize = ROUND_TO_TWIPS(GetMetrics().strikeoutSize);
 138     return NS_OK;
 139 }
 140
 141 NS_IMETHODIMP
 142 nsThebesFontMetrics::GetUnderline(nscoord& aOffset, nscoord& aSize)
 143 {
 144     aOffset = ROUND_TO_TWIPS(mFontGroup->GetUnderlineOffset());
 145     aSize = ROUND_TO_TWIPS(GetMetrics().underlineSize);
 146
 147     return NS_OK;
 148 }
 149
 150 // GetHeight/GetMaxAscent/GetMaxDescent/GetMaxHeight must contain the
 151 // text-decoration lines drawable area. See bug 421353.
 152 // BE CAREFUL for rounding each values. The logic MUST be same as
 153 // nsCSSRendering::GetTextDecorationRectInternal's.
 154
 155 static gfxFloat ComputeMaxDescent(const gfxFont::Metrics& aMetrics,
 156                                   gfxFontGroup* aFontGroup)
 157 {
 158     gfxFloat offset = NS_floor(-aFontGroup->GetUnderlineOffset() + 0.5);
 159     gfxFloat size = NS_round(aMetrics.underlineSize);
 160     gfxFloat minDescent = NS_floor(offset + size + 0.5);
 161     return PR_MAX(minDescent, aMetrics.maxDescent);
 162 }
 163
 164 static gfxFloat ComputeMaxAscent(const gfxFont::Metrics& aMetrics)
 165 {
 166     return NS_floor(aMetrics.maxAscent + 0.5);
 167 }
 168
 169 NS_IMETHODIMP
 170 nsThebesFontMetrics::GetHeight(nscoord &aHeight)
 171 {
 172     aHeight = CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics())) +
 173         CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
 174     return NS_OK;
 175 }
 176
 177 NS_IMETHODIMP
 178 nsThebesFontMetrics::GetInternalLeading(nscoord &aLeading)
 179 {
 180     aLeading = ROUND_TO_TWIPS(GetMetrics().internalLeading);
 181     return NS_OK;
 182 }
 183
 184 NS_IMETHODIMP
 185 nsThebesFontMetrics::GetExternalLeading(nscoord &aLeading)
 186 {
 187     aLeading = ROUND_TO_TWIPS(GetMetrics().externalLeading);
 188     return NS_OK;
 189 }
 190
 191 NS_IMETHODIMP
 192 nsThebesFontMetrics::GetEmHeight(nscoord &aHeight)
 193 {
 194     aHeight = ROUND_TO_TWIPS(GetMetrics().emHeight);
 195     return NS_OK;
 196 }
 197
 198 NS_IMETHODIMP
 199 nsThebesFontMetrics::GetEmAscent(nscoord &aAscent)
 200 {
 201     aAscent = ROUND_TO_TWIPS(GetMetrics().emAscent);
 202     return NS_OK;
 203 }
 204
 205 NS_IMETHODIMP
 206 nsThebesFontMetrics::GetEmDescent(nscoord &aDescent)
 207 {
 208     aDescent = ROUND_TO_TWIPS(GetMetrics().emDescent);
 209     return NS_OK;
 210 }
 211
 212 NS_IMETHODIMP
 213 nsThebesFontMetrics::GetMaxHeight(nscoord &aHeight)
 214 {
 215     aHeight = CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics())) +
 216         CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
 217     return NS_OK;
 218 }
 219
 220 NS_IMETHODIMP
 221 nsThebesFontMetrics::GetMaxAscent(nscoord &aAscent)
 222 {
 223     aAscent = CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics()));
 224     return NS_OK;
 225 }
 226
 227 NS_IMETHODIMP
 228 nsThebesFontMetrics::GetMaxDescent(nscoord &aDescent)
 229 {
 230     aDescent = CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
 231     return NS_OK;
 232 }
 233
 234 NS_IMETHODIMP
 235 nsThebesFontMetrics::GetMaxAdvance(nscoord &aAdvance)
 236 {
 237     aAdvance = CEIL_TO_TWIPS(GetMetrics().maxAdvance);
 238     return NS_OK;
 239 }
 240
 241 NS_IMETHODIMP
 242 nsThebesFontMetrics::GetLangGroup(nsIAtom** aLangGroup)
 243 {
 244     *aLangGroup = mLangGroup;
 245     NS_IF_ADDREF(*aLangGroup);
 246     return NS_OK;
 247 }
 248
 249 NS_IMETHODIMP
 250 nsThebesFontMetrics::GetFontHandle(nsFontHandle &aHandle)
 251 {
 252     return NS_ERROR_NOT_IMPLEMENTED;
 253 }
 254
 255 NS_IMETHODIMP
 256 nsThebesFontMetrics::GetAveCharWidth(nscoord& aAveCharWidth)
 257 {
 258     // Use CEIL instead of ROUND for consistency with GetMaxAdvance
 259     aAveCharWidth = CEIL_TO_TWIPS(GetMetrics().aveCharWidth);
 260     return NS_OK;
 261 }
 262
 263 NS_IMETHODIMP
 264 nsThebesFontMetrics::GetSpaceWidth(nscoord& aSpaceCharWidth)
 265 {
 266     aSpaceCharWidth = CEIL_TO_TWIPS(GetMetrics().spaceWidth);
 267     return NS_OK;
 268 }
 269
 270 PRInt32
 271 nsThebesFontMetrics::GetMaxStringLength()
 272 {
 273     const gfxFont::Metrics& m = GetMetrics();
 274     const double x = 32767.0 / m.maxAdvance;
 275     PRInt32 len = (PRInt32)floor(x);
 276     return PR_MAX(1, len);
 277 }
 278
 279 class StubPropertyProvider : public gfxTextRun::PropertyProvider {
 280 public:
 281     virtual void GetHyphenationBreaks(PRUint32 aStart, PRUint32 aLength,
 282                                       PRPackedBool* aBreakBefore) {
 283         NS_ERROR("This shouldn't be called because we never call BreakAndMeasureText");
 284     }
 285     virtual gfxFloat GetHyphenWidth() {
 286         NS_ERROR("This shouldn't be called because we never enable hyphens");
 287         return 0;
 288     }
 289     virtual void GetSpacing(PRUint32 aStart, PRUint32 aLength,
 290                             Spacing* aSpacing) {
 291         NS_ERROR("This shouldn't be called because we never enable spacing");
 292     }
 293 };
 294
 295 nsresult
 296 nsThebesFontMetrics::GetWidth(const char* aString, PRUint32 aLength, nscoord& aWidth,
 297                               nsThebesRenderingContext *aContext)
 298 {
 299     if (aLength == 0) {
 300         aWidth = 0;
 301         return NS_OK;
 302     }
 303
 304     // callers that hit this should not be so stupid
 305     if ((aLength == 1) && (aString[0] == ' '))
 306         return GetSpaceWidth(aWidth);
 307
 308     StubPropertyProvider provider;
 309     AutoTextRun textRun(this, aContext, aString, aLength);
 310     if (!textRun.get())
 311         return NS_ERROR_FAILURE;
 312
 313     aWidth = NSToCoordRound(textRun->GetAdvanceWidth(0, aLength, &provider));
 314
 315     return NS_OK;
 316 }
 317
 318 nsresult
 319 nsThebesFontMetrics::GetWidth(const PRUnichar* aString, PRUint32 aLength,
 320                               nscoord& aWidth, PRInt32 *aFontID,
 321                               nsThebesRenderingContext *aContext)
 322 {
 323     if (aLength == 0) {
 324         aWidth = 0;
 325         return NS_OK;
 326     }
 327
 328     // callers that hit this should not be so stupid
 329     if ((aLength == 1) && (aString[0] == ' '))
 330         return GetSpaceWidth(aWidth);
 331
 332     StubPropertyProvider provider;
 333     AutoTextRun textRun(this, aContext, aString, aLength);
 334     if (!textRun.get())
 335         return NS_ERROR_FAILURE;
 336
 337     aWidth = NSToCoordRound(textRun->GetAdvanceWidth(0, aLength, &provider));
 338
 339     return NS_OK;
 340 }
 341
 342 // Get the text dimensions for this string
 343 nsresult
 344 nsThebesFontMetrics::GetTextDimensions(const PRUnichar* aString,
 345                                     PRUint32 aLength,
 346                                     nsTextDimensions& aDimensions,
 347                                     PRInt32* aFontID)
 348 {
 349     return NS_OK;
 350 }
 351
 352 nsresult
 353 nsThebesFontMetrics::GetTextDimensions(const char*         aString,
 354                                    PRInt32             aLength,
 355                                    PRInt32             aAvailWidth,
 356                                    PRInt32*            aBreaks,
 357                                    PRInt32             aNumBreaks,
 358                                    nsTextDimensions&   aDimensions,
 359                                    PRInt32&            aNumCharsFit,
 360                                    nsTextDimensions&   aLastWordDimensions,
 361                                    PRInt32*            aFontID)
 362 {
 363     return NS_OK;
 364 }
 365 nsresult
 366 nsThebesFontMetrics::GetTextDimensions(const PRUnichar*    aString,
 367                                    PRInt32             aLength,
 368                                    PRInt32             aAvailWidth,
 369                                    PRInt32*            aBreaks,
 370                                    PRInt32             aNumBreaks,
 371                                    nsTextDimensions&   aDimensions,
 372                                    PRInt32&            aNumCharsFit,
 373                                    nsTextDimensions&   aLastWordDimensions,
 374                                    PRInt32*            aFontID)
 375 {
 376     return NS_OK;
 377 }
 378
 379 // Draw a string using this font handle on the surface passed in.
 380 nsresult
 381 nsThebesFontMetrics::DrawString(const char *aString, PRUint32 aLength,
 382                                 nscoord aX, nscoord aY,
 383                                 const nscoord* aSpacing,
 384                                 nsThebesRenderingContext *aContext)
 385 {
 386     if (aLength == 0)
 387         return NS_OK;
 388
 389     NS_ASSERTION(!aSpacing, "Spacing not supported here");
 390     StubPropertyProvider provider;
 391     AutoTextRun textRun(this, aContext, aString, aLength);
 392     if (!textRun.get())
 393         return NS_ERROR_FAILURE;
 394     gfxPoint pt(aX, aY);
 395     if (mTextRunRTL) {
 396         pt.x += textRun->GetAdvanceWidth(0, aLength, &provider);
 397     }
 398     textRun->Draw(aContext->ThebesContext(), pt, 0, aLength,
 399                   nsnull, &provider, nsnull);
 400     return NS_OK;
 401 }
 402
 403 nsresult
 404 nsThebesFontMetrics::DrawString(const PRUnichar* aString, PRUint32 aLength,
 405                                 nscoord aX, nscoord aY,
 406                                 PRInt32 aFontID,
 407                                 const nscoord* aSpacing,
 408                                 nsThebesRenderingContext *aContext)
 409 {
 410     if (aLength == 0)
 411         return NS_OK;
 412
 413     NS_ASSERTION(!aSpacing, "Spacing not supported here");
 414     StubPropertyProvider provider;
 415     AutoTextRun textRun(this, aContext, aString, aLength);
 416     if (!textRun.get())
 417         return NS_ERROR_FAILURE;
 418     gfxPoint pt(aX, aY);
 419     if (mTextRunRTL) {
 420         pt.x += textRun->GetAdvanceWidth(0, aLength, &provider);
 421     }
 422     textRun->Draw(aContext->ThebesContext(), pt, 0, aLength,
 423                   nsnull, &provider, nsnull);
 424     return NS_OK;
 425 }
 426
 427 #ifdef MOZ_MATHML
 428
 429 static void
 430 GetTextRunBoundingMetrics(gfxTextRun *aTextRun, PRUint32 aStart, PRUint32 aLength,
 431                           nsThebesRenderingContext *aContext,
 432                           nsBoundingMetrics &aBoundingMetrics)
 433 {
 434     StubPropertyProvider provider;
 435     gfxTextRun::Metrics theMetrics =
 436         aTextRun->MeasureText(aStart, aLength, PR_TRUE, aContext->ThebesContext(), &provider);
 437
 438     aBoundingMetrics.leftBearing = NSToCoordFloor(theMetrics.mBoundingBox.X());
 439     aBoundingMetrics.rightBearing = NSToCoordCeil(theMetrics.mBoundingBox.XMost());
 440     aBoundingMetrics.width = NSToCoordRound(theMetrics.mAdvanceWidth);
 441     aBoundingMetrics.ascent = NSToCoordCeil(- theMetrics.mBoundingBox.Y());
 442     aBoundingMetrics.descent = NSToCoordCeil(theMetrics.mBoundingBox.YMost());
 443 }
 444
 445 nsresult
 446 nsThebesFontMetrics::GetBoundingMetrics(const char *aString, PRUint32 aLength,
 447                                         nsThebesRenderingContext *aContext,
 448                                         nsBoundingMetrics &aBoundingMetrics)
 449 {
 450     if (aLength == 0) {
 451         aBoundingMetrics.Clear();
 452         return NS_OK;
 453     }
 454
 455     AutoTextRun textRun(this, aContext, aString, aLength);
 456     if (!textRun.get())
 457         return NS_ERROR_FAILURE;
 458
 459     GetTextRunBoundingMetrics(textRun.get(), 0, aLength, aContext, aBoundingMetrics);
 460     return NS_OK;
 461 }
 462
 463 nsresult
 464 nsThebesFontMetrics::GetBoundingMetrics(const PRUnichar *aString, PRUint32 aLength,
 465                                         nsThebesRenderingContext *aContext,
 466                                         nsBoundingMetrics &aBoundingMetrics)
 467 {
 468     if (aLength == 0) {
 469         aBoundingMetrics.Clear();
 470         return NS_OK;
 471     }
 472
 473     AutoTextRun textRun(this, aContext, aString, aLength);
 474     if (!textRun.get())
 475         return NS_ERROR_FAILURE;
 476
 477     GetTextRunBoundingMetrics(textRun.get(), 0, aLength, aContext, aBoundingMetrics);
 478     return NS_OK;
 479 }
 480
 481 #endif /* MOZ_MATHML */
 482
 483 // Set the direction of the text rendering
 484 nsresult
 485 nsThebesFontMetrics::SetRightToLeftText(PRBool aIsRTL)
 486 {
 487     mIsRightToLeft = aIsRTL;
 488     return NS_OK;
 489 }
 490
 491 // Set the direction of the text rendering
 492 PRBool
 493 nsThebesFontMetrics::GetRightToLeftText()
 494 {
 495     return mIsRightToLeft;
 496 }