| File: | var/lib/jenkins/workspace/firefox-scan-build/layout/mathml/nsMathMLmmultiscriptsFrame.cpp |
| Warning: | line 470, column 9 Value stored to 'trySupScriptShift' is never read |
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| 1 | /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ |
| 2 | /* vim: set ts=8 sts=2 et sw=2 tw=80: */ |
| 3 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| 4 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| 5 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| 6 | |
| 7 | #include "nsMathMLmmultiscriptsFrame.h" |
| 8 | |
| 9 | #include "mozilla/dom/Document.h" |
| 10 | #include "mozilla/dom/Element.h" |
| 11 | #include "mozilla/PresShell.h" |
| 12 | #include "mozilla/StaticPrefs_mathml.h" |
| 13 | #include "nsLayoutUtils.h" |
| 14 | #include "nsPresContext.h" |
| 15 | #include <algorithm> |
| 16 | #include "gfxContext.h" |
| 17 | #include "gfxMathTable.h" |
| 18 | #include "gfxTextRun.h" |
| 19 | |
| 20 | using namespace mozilla; |
| 21 | |
| 22 | // |
| 23 | // <mmultiscripts> -- attach prescripts and tensor indices to a base - |
| 24 | // implementation <msub> -- attach a subscript to a base - implementation |
| 25 | // <msubsup> -- attach a subscript-superscript pair to a base - implementation |
| 26 | // <msup> -- attach a superscript to a base - implementation |
| 27 | // |
| 28 | |
| 29 | nsIFrame* NS_NewMathMLmmultiscriptsFrame(PresShell* aPresShell, |
| 30 | ComputedStyle* aStyle) { |
| 31 | return new (aPresShell) |
| 32 | nsMathMLmmultiscriptsFrame(aStyle, aPresShell->GetPresContext()); |
| 33 | } |
| 34 | |
| 35 | NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmmultiscriptsFrame)void* nsMathMLmmultiscriptsFrame ::operator new(size_t sz, mozilla ::PresShell * aShell) { return aShell->AllocateFrame(nsQueryFrame ::nsMathMLmmultiscriptsFrame_id, sz); } |
| 36 | |
| 37 | nsMathMLmmultiscriptsFrame::~nsMathMLmmultiscriptsFrame() = default; |
| 38 | |
| 39 | uint8_t nsMathMLmmultiscriptsFrame::ScriptIncrement(nsIFrame* aFrame) { |
| 40 | if (!aFrame) return 0; |
| 41 | if (mFrames.ContainsFrame(aFrame)) { |
| 42 | if (mFrames.FirstChild() == aFrame || |
| 43 | aFrame->GetContent()->IsMathMLElement(nsGkAtoms::mprescripts_)) { |
| 44 | return 0; // No script increment for base frames or prescript markers |
| 45 | } |
| 46 | return 1; |
| 47 | } |
| 48 | return 0; // not a child |
| 49 | } |
| 50 | |
| 51 | NS_IMETHODIMPnsresult |
| 52 | nsMathMLmmultiscriptsFrame::TransmitAutomaticData() { |
| 53 | // if our base is an embellished operator, let its state bubble to us |
| 54 | mPresentationData.baseFrame = mFrames.FirstChild(); |
| 55 | GetEmbellishDataFrom(mPresentationData.baseFrame, mEmbellishData); |
| 56 | |
| 57 | // The TeXbook (Ch 17. p.141) says the superscript inherits the compression |
| 58 | // while the subscript is compressed. So here we collect subscripts and set |
| 59 | // the compression flag in them. |
| 60 | |
| 61 | int32_t count = 0; |
| 62 | bool isSubScript = !mContent->IsMathMLElement(nsGkAtoms::msup_); |
| 63 | |
| 64 | AutoTArray<nsIFrame*, 8> subScriptFrames; |
| 65 | nsIFrame* childFrame = mFrames.FirstChild(); |
| 66 | while (childFrame) { |
| 67 | if (childFrame->GetContent()->IsMathMLElement(nsGkAtoms::mprescripts_)) { |
| 68 | // mprescripts frame |
| 69 | } else if (0 == count) { |
| 70 | // base frame |
| 71 | } else { |
| 72 | // super/subscript block |
| 73 | if (isSubScript) { |
| 74 | // subscript |
| 75 | subScriptFrames.AppendElement(childFrame); |
| 76 | } else { |
| 77 | // superscript |
| 78 | } |
| 79 | PropagateFrameFlagFor(childFrame, NS_FRAME_MATHML_SCRIPT_DESCENDANT); |
| 80 | isSubScript = !isSubScript; |
| 81 | } |
| 82 | count++; |
| 83 | childFrame = childFrame->GetNextSibling(); |
| 84 | } |
| 85 | for (int32_t i = subScriptFrames.Length() - 1; i >= 0; i--) { |
| 86 | childFrame = subScriptFrames[i]; |
| 87 | PropagatePresentationDataFor(childFrame, NS_MATHML_COMPRESSED0x00000002U, |
| 88 | NS_MATHML_COMPRESSED0x00000002U); |
| 89 | } |
| 90 | |
| 91 | return NS_OK; |
| 92 | } |
| 93 | |
| 94 | /* virtual */ |
| 95 | nsresult nsMathMLmmultiscriptsFrame::Place(DrawTarget* aDrawTarget, |
| 96 | bool aPlaceOrigin, |
| 97 | ReflowOutput& aDesiredSize) { |
| 98 | nscoord subScriptShift = 0; |
| 99 | nscoord supScriptShift = 0; |
| 100 | float fontSizeInflation = nsLayoutUtils::FontSizeInflationFor(this); |
| 101 | |
| 102 | return PlaceMultiScript(PresContext(), aDrawTarget, aPlaceOrigin, |
| 103 | aDesiredSize, this, subScriptShift, supScriptShift, |
| 104 | fontSizeInflation); |
| 105 | } |
| 106 | |
| 107 | // exported routine that both munderover and mmultiscripts share. |
| 108 | // munderover uses this when movablelimits is set. |
| 109 | nsresult nsMathMLmmultiscriptsFrame::PlaceMultiScript( |
| 110 | nsPresContext* aPresContext, DrawTarget* aDrawTarget, bool aPlaceOrigin, |
| 111 | ReflowOutput& aDesiredSize, nsMathMLContainerFrame* aFrame, |
| 112 | nscoord aUserSubScriptShift, nscoord aUserSupScriptShift, |
| 113 | float aFontSizeInflation) { |
| 114 | nsAtom* tag = aFrame->GetContent()->NodeInfo()->NameAtom(); |
| 115 | |
| 116 | // This function deals with both munderover etc. as well as msubsup etc. |
| 117 | // As the former behaves identically to the later, we treat it as such |
| 118 | // to avoid additional checks later. |
| 119 | if (aFrame->GetContent()->IsMathMLElement(nsGkAtoms::mover_)) |
| 120 | tag = nsGkAtoms::msup_; |
| 121 | else if (aFrame->GetContent()->IsMathMLElement(nsGkAtoms::munder_)) |
| 122 | tag = nsGkAtoms::msub_; |
| 123 | else if (aFrame->GetContent()->IsMathMLElement(nsGkAtoms::munderover_)) |
| 124 | tag = nsGkAtoms::msubsup_; |
| 125 | |
| 126 | nsBoundingMetrics bmFrame; |
| 127 | |
| 128 | nscoord minShiftFromXHeight, subDrop, supDrop; |
| 129 | |
| 130 | //////////////////////////////////////// |
| 131 | // Initialize super/sub shifts that |
| 132 | // depend only on the current font |
| 133 | //////////////////////////////////////// |
| 134 | |
| 135 | nsIFrame* baseFrame = aFrame->PrincipalChildList().FirstChild(); |
| 136 | |
| 137 | if (!baseFrame) { |
| 138 | if (tag == nsGkAtoms::mmultiscripts_) |
| 139 | aFrame->ReportErrorToConsole("NoBase"); |
| 140 | else |
| 141 | aFrame->ReportChildCountError(); |
| 142 | return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize); |
| 143 | } |
| 144 | |
| 145 | // get x-height (an ex) |
| 146 | const nsStyleFont* font = aFrame->StyleFont(); |
| 147 | RefPtr<nsFontMetrics> fm = |
| 148 | nsLayoutUtils::GetFontMetricsForFrame(baseFrame, aFontSizeInflation); |
| 149 | |
| 150 | nscoord xHeight = fm->XHeight(); |
| 151 | |
| 152 | nscoord oneDevPixel = fm->AppUnitsPerDevPixel(); |
| 153 | RefPtr<gfxFont> mathFont = fm->GetThebesFontGroup()->GetFirstMathFont(); |
| 154 | // scriptspace from TeX for extra spacing after sup/subscript |
| 155 | nscoord scriptSpace; |
| 156 | if (mathFont) { |
| 157 | scriptSpace = mathFont->MathTable()->Constant( |
| 158 | gfxMathTable::SpaceAfterScript, oneDevPixel); |
| 159 | } else { |
| 160 | // (0.5pt in plain TeX) |
| 161 | scriptSpace = nsPresContext::CSSPointsToAppUnits(0.5f); |
| 162 | } |
| 163 | |
| 164 | // Try and read sub and sup drops from the MATH table. |
| 165 | if (mathFont) { |
| 166 | subDrop = mathFont->MathTable()->Constant( |
| 167 | gfxMathTable::SubscriptBaselineDropMin, oneDevPixel); |
| 168 | supDrop = mathFont->MathTable()->Constant( |
| 169 | gfxMathTable::SuperscriptBaselineDropMax, oneDevPixel); |
| 170 | } |
| 171 | |
| 172 | // force the scriptSpace to be at least 1 pixel |
| 173 | nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1); |
| 174 | scriptSpace = std::max(onePixel, scriptSpace); |
| 175 | |
| 176 | ///////////////////////////////////// |
| 177 | // first the shift for the subscript |
| 178 | |
| 179 | nscoord subScriptShift; |
| 180 | if (mathFont) { |
| 181 | // Try and get the sub script shift from the MATH table. Note that contrary |
| 182 | // to TeX we only have one parameter. |
| 183 | subScriptShift = mathFont->MathTable()->Constant( |
| 184 | gfxMathTable::SubscriptShiftDown, oneDevPixel); |
| 185 | } else { |
| 186 | // subScriptShift{1,2} |
| 187 | // = minimum amount to shift the subscript down |
| 188 | // = sub{1,2} in TeXbook |
| 189 | // subScriptShift1 = subscriptshift attribute * x-height |
| 190 | nscoord subScriptShift1, subScriptShift2; |
| 191 | // Get subScriptShift{1,2} default from font |
| 192 | GetSubScriptShifts(fm, subScriptShift1, subScriptShift2); |
| 193 | if (tag == nsGkAtoms::msub_) { |
| 194 | subScriptShift = subScriptShift1; |
| 195 | } else { |
| 196 | subScriptShift = std::max(subScriptShift1, subScriptShift2); |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | if (0 < aUserSubScriptShift) { |
| 201 | // the user has set the subscriptshift attribute |
| 202 | subScriptShift = std::max(subScriptShift, aUserSubScriptShift); |
| 203 | } |
| 204 | |
| 205 | ///////////////////////////////////// |
| 206 | // next the shift for the superscript |
| 207 | |
| 208 | nscoord supScriptShift; |
| 209 | nsPresentationData presentationData; |
| 210 | aFrame->GetPresentationData(presentationData); |
| 211 | if (mathFont) { |
| 212 | // Try and get the super script shift from the MATH table. Note that |
| 213 | // contrary to TeX we only have two parameters. |
| 214 | supScriptShift = mathFont->MathTable()->Constant( |
| 215 | NS_MATHML_IS_COMPRESSED(presentationData.flags)(0x00000002U == ((presentationData.flags) & 0x00000002U)) |
| 216 | ? gfxMathTable::SuperscriptShiftUpCramped |
| 217 | : gfxMathTable::SuperscriptShiftUp, |
| 218 | oneDevPixel); |
| 219 | } else { |
| 220 | // supScriptShift{1,2,3} |
| 221 | // = minimum amount to shift the supscript up |
| 222 | // = sup{1,2,3} in TeX |
| 223 | // supScriptShift1 = superscriptshift attribute * x-height |
| 224 | // Note that there are THREE values for supscript shifts depending |
| 225 | // on the current style |
| 226 | nscoord supScriptShift1, supScriptShift2, supScriptShift3; |
| 227 | // Set supScriptShift{1,2,3} default from font |
| 228 | GetSupScriptShifts(fm, supScriptShift1, supScriptShift2, supScriptShift3); |
| 229 | |
| 230 | // get sup script shift depending on current script level and display style |
| 231 | // Rule 18c, App. G, TeXbook |
| 232 | if (font->mMathDepth == 0 && font->mMathStyle == StyleMathStyle::Normal && |
| 233 | !NS_MATHML_IS_COMPRESSED(presentationData.flags)(0x00000002U == ((presentationData.flags) & 0x00000002U))) { |
| 234 | // Style D in TeXbook |
| 235 | supScriptShift = supScriptShift1; |
| 236 | } else if (NS_MATHML_IS_COMPRESSED(presentationData.flags)(0x00000002U == ((presentationData.flags) & 0x00000002U))) { |
| 237 | // Style C' in TeXbook = D',T',S',SS' |
| 238 | supScriptShift = supScriptShift3; |
| 239 | } else { |
| 240 | // everything else = T,S,SS |
| 241 | supScriptShift = supScriptShift2; |
| 242 | } |
| 243 | } |
| 244 | |
| 245 | if (0 < aUserSupScriptShift) { |
| 246 | // the user has set the supscriptshift attribute |
| 247 | supScriptShift = std::max(supScriptShift, aUserSupScriptShift); |
| 248 | } |
| 249 | |
| 250 | //////////////////////////////////// |
| 251 | // Get the children's sizes |
| 252 | //////////////////////////////////// |
| 253 | |
| 254 | const WritingMode wm(aDesiredSize.GetWritingMode()); |
| 255 | nscoord width = 0, prescriptsWidth = 0, rightBearing = 0; |
| 256 | nscoord minSubScriptShift = 0, minSupScriptShift = 0; |
| 257 | nscoord trySubScriptShift = subScriptShift; |
| 258 | nscoord trySupScriptShift = supScriptShift; |
| 259 | nscoord maxSubScriptShift = subScriptShift; |
| 260 | nscoord maxSupScriptShift = supScriptShift; |
| 261 | ReflowOutput baseSize(wm); |
| 262 | ReflowOutput subScriptSize(wm); |
| 263 | ReflowOutput supScriptSize(wm); |
| 264 | ReflowOutput multiSubSize(wm), multiSupSize(wm); |
| 265 | baseFrame = nullptr; |
| 266 | nsIFrame* subScriptFrame = nullptr; |
| 267 | nsIFrame* supScriptFrame = nullptr; |
| 268 | nsIFrame* prescriptsFrame = nullptr; // frame of <mprescripts/>, if there. |
| 269 | |
| 270 | bool firstPrescriptsPair = false; |
| 271 | nsBoundingMetrics bmBase, bmSubScript, bmSupScript, bmMultiSub, bmMultiSup; |
| 272 | multiSubSize.SetBlockStartAscent(-0x7FFFFFFF); |
| 273 | multiSupSize.SetBlockStartAscent(-0x7FFFFFFF); |
| 274 | bmMultiSub.ascent = bmMultiSup.ascent = -0x7FFFFFFF; |
| 275 | bmMultiSub.descent = bmMultiSup.descent = -0x7FFFFFFF; |
| 276 | nscoord italicCorrection = 0; |
| 277 | |
| 278 | nsBoundingMetrics boundingMetrics; |
| 279 | boundingMetrics.width = 0; |
| 280 | boundingMetrics.ascent = boundingMetrics.descent = -0x7FFFFFFF; |
| 281 | aDesiredSize.Width() = aDesiredSize.Height() = 0; |
| 282 | |
| 283 | int32_t count = 0; |
| 284 | |
| 285 | // Boolean to determine whether the current child is a subscript. |
| 286 | // Note that only msup starts with a superscript. |
| 287 | bool isSubScript = (tag != nsGkAtoms::msup_); |
| 288 | |
| 289 | nsIFrame* childFrame = aFrame->PrincipalChildList().FirstChild(); |
| 290 | while (childFrame) { |
| 291 | if (childFrame->GetContent()->IsMathMLElement(nsGkAtoms::mprescripts_)) { |
| 292 | if (tag != nsGkAtoms::mmultiscripts_) { |
| 293 | if (aPlaceOrigin) { |
| 294 | aFrame->ReportInvalidChildError(nsGkAtoms::mprescripts_); |
| 295 | } |
| 296 | return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize); |
| 297 | } |
| 298 | if (prescriptsFrame) { |
| 299 | // duplicate <mprescripts/> found |
| 300 | // report an error, encourage people to get their markups in order |
| 301 | if (aPlaceOrigin) { |
| 302 | aFrame->ReportErrorToConsole("DuplicateMprescripts"); |
| 303 | } |
| 304 | return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize); |
| 305 | } |
| 306 | if (!isSubScript) { |
| 307 | if (aPlaceOrigin) { |
| 308 | aFrame->ReportErrorToConsole("SubSupMismatch"); |
| 309 | } |
| 310 | return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize); |
| 311 | } |
| 312 | |
| 313 | prescriptsFrame = childFrame; |
| 314 | firstPrescriptsPair = true; |
| 315 | } else if (0 == count) { |
| 316 | // base |
| 317 | baseFrame = childFrame; |
| 318 | GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase); |
| 319 | |
| 320 | if (tag != nsGkAtoms::msub_) { |
| 321 | // Apply italics correction if there is the potential for a |
| 322 | // postsupscript. |
| 323 | GetItalicCorrection(bmBase, italicCorrection); |
| 324 | // If italics correction is applied, we always add "a little to spare" |
| 325 | // (see TeXbook Ch.11, p.64), as we estimate the italic creation |
| 326 | // ourselves and it isn't the same as TeX. |
| 327 | italicCorrection += onePixel; |
| 328 | } |
| 329 | |
| 330 | // we update boundingMetrics.{ascent,descent} with that |
| 331 | // of the baseFrame only after processing all the sup/sub pairs |
| 332 | boundingMetrics.width = bmBase.width; |
| 333 | boundingMetrics.rightBearing = bmBase.rightBearing; |
| 334 | boundingMetrics.leftBearing = bmBase.leftBearing; // until overwritten |
| 335 | } else { |
| 336 | // super/subscript block |
| 337 | if (isSubScript) { |
| 338 | // subscript |
| 339 | subScriptFrame = childFrame; |
| 340 | GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, |
| 341 | bmSubScript); |
| 342 | if (!mathFont) { |
| 343 | // get the subdrop from the subscript font |
| 344 | GetSubDropFromChild(subScriptFrame, subDrop, aFontSizeInflation); |
| 345 | } |
| 346 | |
| 347 | // parameter v, Rule 18a, App. G, TeXbook |
| 348 | minSubScriptShift = bmBase.descent + subDrop; |
| 349 | trySubScriptShift = std::max(minSubScriptShift, subScriptShift); |
| 350 | multiSubSize.SetBlockStartAscent(std::max( |
| 351 | multiSubSize.BlockStartAscent(), subScriptSize.BlockStartAscent())); |
| 352 | bmMultiSub.ascent = std::max(bmMultiSub.ascent, bmSubScript.ascent); |
| 353 | bmMultiSub.descent = std::max(bmMultiSub.descent, bmSubScript.descent); |
| 354 | multiSubSize.Height() = |
| 355 | std::max(multiSubSize.Height(), |
| 356 | subScriptSize.Height() - subScriptSize.BlockStartAscent()); |
| 357 | if (bmSubScript.width) width = bmSubScript.width + scriptSpace; |
| 358 | rightBearing = bmSubScript.rightBearing; |
| 359 | |
| 360 | if (tag == nsGkAtoms::msub_) { |
| 361 | boundingMetrics.rightBearing = boundingMetrics.width + rightBearing; |
| 362 | boundingMetrics.width += width; |
| 363 | |
| 364 | nscoord subscriptTopMax; |
| 365 | if (mathFont) { |
| 366 | subscriptTopMax = mathFont->MathTable()->Constant( |
| 367 | gfxMathTable::SubscriptTopMax, oneDevPixel); |
| 368 | } else { |
| 369 | // get min subscript shift limit from x-height |
| 370 | // = h(x) - 4/5 * sigma_5, Rule 18b, App. G, TeXbook |
| 371 | subscriptTopMax = NSToCoordRound((4.0f / 5.0f) * xHeight); |
| 372 | } |
| 373 | nscoord minShiftFromXHeight = bmSubScript.ascent - subscriptTopMax; |
| 374 | maxSubScriptShift = std::max(trySubScriptShift, minShiftFromXHeight); |
| 375 | |
| 376 | maxSubScriptShift = std::max(maxSubScriptShift, trySubScriptShift); |
| 377 | trySubScriptShift = subScriptShift; |
| 378 | } |
| 379 | } else { |
| 380 | // supscript |
| 381 | supScriptFrame = childFrame; |
| 382 | GetReflowAndBoundingMetricsFor(supScriptFrame, supScriptSize, |
| 383 | bmSupScript); |
| 384 | if (!mathFont) { |
| 385 | // get the supdrop from the supscript font |
| 386 | GetSupDropFromChild(supScriptFrame, supDrop, aFontSizeInflation); |
| 387 | } |
| 388 | // parameter u, Rule 18a, App. G, TeXbook |
| 389 | minSupScriptShift = bmBase.ascent - supDrop; |
| 390 | nscoord superscriptBottomMin; |
| 391 | if (mathFont) { |
| 392 | superscriptBottomMin = mathFont->MathTable()->Constant( |
| 393 | gfxMathTable::SuperscriptBottomMin, oneDevPixel); |
| 394 | } else { |
| 395 | // get min supscript shift limit from x-height |
| 396 | // = d(x) + 1/4 * sigma_5, Rule 18c, App. G, TeXbook |
| 397 | superscriptBottomMin = NSToCoordRound((1.0f / 4.0f) * xHeight); |
| 398 | } |
| 399 | minShiftFromXHeight = bmSupScript.descent + superscriptBottomMin; |
| 400 | trySupScriptShift = std::max( |
| 401 | minSupScriptShift, std::max(minShiftFromXHeight, supScriptShift)); |
| 402 | multiSupSize.SetBlockStartAscent(std::max( |
| 403 | multiSupSize.BlockStartAscent(), supScriptSize.BlockStartAscent())); |
| 404 | bmMultiSup.ascent = std::max(bmMultiSup.ascent, bmSupScript.ascent); |
| 405 | bmMultiSup.descent = std::max(bmMultiSup.descent, bmSupScript.descent); |
| 406 | multiSupSize.Height() = |
| 407 | std::max(multiSupSize.Height(), |
| 408 | supScriptSize.Height() - supScriptSize.BlockStartAscent()); |
| 409 | |
| 410 | if (bmSupScript.width) |
| 411 | width = std::max(width, bmSupScript.width + scriptSpace); |
| 412 | |
| 413 | if (!prescriptsFrame) { // we are still looping over base & postscripts |
| 414 | rightBearing = std::max(rightBearing, |
| 415 | italicCorrection + bmSupScript.rightBearing); |
| 416 | boundingMetrics.rightBearing = boundingMetrics.width + rightBearing; |
| 417 | boundingMetrics.width += width; |
| 418 | } else { |
| 419 | prescriptsWidth += width; |
| 420 | if (firstPrescriptsPair) { |
| 421 | firstPrescriptsPair = false; |
| 422 | boundingMetrics.leftBearing = |
| 423 | std::min(bmSubScript.leftBearing, bmSupScript.leftBearing); |
| 424 | } |
| 425 | } |
| 426 | width = rightBearing = 0; |
| 427 | |
| 428 | // negotiate between the various shifts so that |
| 429 | // there is enough gap between the sup and subscripts |
| 430 | // Rule 18e, App. G, TeXbook |
| 431 | if (tag == nsGkAtoms::mmultiscripts_ || tag == nsGkAtoms::msubsup_) { |
| 432 | nscoord subSuperscriptGapMin; |
| 433 | if (mathFont) { |
| 434 | subSuperscriptGapMin = mathFont->MathTable()->Constant( |
| 435 | gfxMathTable::SubSuperscriptGapMin, oneDevPixel); |
| 436 | } else { |
| 437 | nscoord ruleSize; |
| 438 | GetRuleThickness(aDrawTarget, fm, ruleSize); |
| 439 | subSuperscriptGapMin = 4 * ruleSize; |
| 440 | } |
| 441 | nscoord gap = (trySupScriptShift - bmSupScript.descent) - |
| 442 | (bmSubScript.ascent - trySubScriptShift); |
| 443 | if (gap < subSuperscriptGapMin) { |
| 444 | // adjust trySubScriptShift to get a gap of subSuperscriptGapMin |
| 445 | trySubScriptShift += subSuperscriptGapMin - gap; |
| 446 | } |
| 447 | |
| 448 | // next we want to ensure that the bottom of the superscript |
| 449 | // will be > superscriptBottomMaxWithSubscript |
| 450 | nscoord superscriptBottomMaxWithSubscript; |
| 451 | if (mathFont) { |
| 452 | superscriptBottomMaxWithSubscript = mathFont->MathTable()->Constant( |
| 453 | gfxMathTable::SuperscriptBottomMaxWithSubscript, oneDevPixel); |
| 454 | } else { |
| 455 | superscriptBottomMaxWithSubscript = |
| 456 | NSToCoordRound((4.0f / 5.0f) * xHeight); |
| 457 | } |
| 458 | gap = superscriptBottomMaxWithSubscript - |
| 459 | (trySupScriptShift - bmSupScript.descent); |
| 460 | if (gap > 0) { |
| 461 | trySupScriptShift += gap; |
| 462 | trySubScriptShift -= gap; |
| 463 | } |
| 464 | } |
| 465 | |
| 466 | maxSubScriptShift = std::max(maxSubScriptShift, trySubScriptShift); |
| 467 | maxSupScriptShift = std::max(maxSupScriptShift, trySupScriptShift); |
| 468 | |
| 469 | trySubScriptShift = subScriptShift; |
| 470 | trySupScriptShift = supScriptShift; |
Value stored to 'trySupScriptShift' is never read | |
| 471 | } |
| 472 | |
| 473 | isSubScript = !isSubScript; |
| 474 | } |
| 475 | count++; |
| 476 | childFrame = childFrame->GetNextSibling(); |
| 477 | } |
| 478 | |
| 479 | // NoBase error may also have been reported above |
| 480 | if ((count != 2 && (tag == nsGkAtoms::msup_ || tag == nsGkAtoms::msub_)) || |
| 481 | (count != 3 && tag == nsGkAtoms::msubsup_) || !baseFrame || |
| 482 | (!isSubScript && tag == nsGkAtoms::mmultiscripts_)) { |
| 483 | // report an error, encourage people to get their markups in order |
| 484 | if (aPlaceOrigin) { |
| 485 | if ((count != 2 && |
| 486 | (tag == nsGkAtoms::msup_ || tag == nsGkAtoms::msub_)) || |
| 487 | (count != 3 && tag == nsGkAtoms::msubsup_)) { |
| 488 | aFrame->ReportChildCountError(); |
| 489 | } else if (!baseFrame) { |
| 490 | aFrame->ReportErrorToConsole("NoBase"); |
| 491 | } else { |
| 492 | aFrame->ReportErrorToConsole("SubSupMismatch"); |
| 493 | } |
| 494 | } |
| 495 | return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize); |
| 496 | } |
| 497 | |
| 498 | // we left out the width of prescripts, so ... |
| 499 | boundingMetrics.rightBearing += prescriptsWidth; |
| 500 | boundingMetrics.width += prescriptsWidth; |
| 501 | |
| 502 | // Zero out the shifts in where a frame isn't present to avoid the potential |
| 503 | // for overflow. |
| 504 | if (!subScriptFrame) maxSubScriptShift = 0; |
| 505 | if (!supScriptFrame) maxSupScriptShift = 0; |
| 506 | |
| 507 | // we left out the base during our bounding box updates, so ... |
| 508 | if (tag == nsGkAtoms::msub_) { |
| 509 | boundingMetrics.ascent = |
| 510 | std::max(bmBase.ascent, bmMultiSub.ascent - maxSubScriptShift); |
| 511 | } else { |
| 512 | boundingMetrics.ascent = |
| 513 | std::max(bmBase.ascent, (bmMultiSup.ascent + maxSupScriptShift)); |
| 514 | } |
| 515 | if (tag == nsGkAtoms::msup_) { |
| 516 | boundingMetrics.descent = |
| 517 | std::max(bmBase.descent, bmMultiSup.descent - maxSupScriptShift); |
| 518 | } else { |
| 519 | boundingMetrics.descent = |
| 520 | std::max(bmBase.descent, (bmMultiSub.descent + maxSubScriptShift)); |
| 521 | } |
| 522 | aFrame->SetBoundingMetrics(boundingMetrics); |
| 523 | |
| 524 | // get the reflow metrics ... |
| 525 | aDesiredSize.SetBlockStartAscent( |
| 526 | std::max(baseSize.BlockStartAscent(), |
| 527 | std::max(multiSubSize.BlockStartAscent() - maxSubScriptShift, |
| 528 | multiSupSize.BlockStartAscent() + maxSupScriptShift))); |
| 529 | aDesiredSize.Height() = |
| 530 | aDesiredSize.BlockStartAscent() + |
| 531 | std::max(baseSize.Height() - baseSize.BlockStartAscent(), |
| 532 | std::max(multiSubSize.Height() + maxSubScriptShift, |
| 533 | multiSupSize.Height() - maxSupScriptShift)); |
| 534 | aDesiredSize.Width() = boundingMetrics.width; |
| 535 | aDesiredSize.mBoundingMetrics = boundingMetrics; |
| 536 | |
| 537 | aFrame->SetReference(nsPoint(0, aDesiredSize.BlockStartAscent())); |
| 538 | |
| 539 | ////////////////// |
| 540 | // Place Children |
| 541 | |
| 542 | // Place prescripts, followed by base, and then postscripts. |
| 543 | // The list of frames is in the order: {base} {postscripts} {prescripts} |
| 544 | // We go over the list in a circular manner, starting at <prescripts/> |
| 545 | |
| 546 | if (aPlaceOrigin) { |
| 547 | nscoord dx = 0, dy = 0; |
| 548 | |
| 549 | // With msub and msup there is only one element and |
| 550 | // subscriptFrame/supScriptFrame have already been set above where |
| 551 | // relevant. In these cases we skip to the reflow part. |
| 552 | if (tag == nsGkAtoms::msub_ || tag == nsGkAtoms::msup_) |
| 553 | count = 1; |
| 554 | else |
| 555 | count = 0; |
| 556 | childFrame = prescriptsFrame; |
| 557 | bool isPreScript = true; |
| 558 | do { |
| 559 | if (!childFrame) { // end of prescripts, |
| 560 | isPreScript = false; |
| 561 | // place the base ... |
| 562 | childFrame = baseFrame; |
| 563 | dy = aDesiredSize.BlockStartAscent() - baseSize.BlockStartAscent(); |
| 564 | FinishReflowChild( |
| 565 | baseFrame, aPresContext, baseSize, nullptr, |
| 566 | aFrame->MirrorIfRTL(aDesiredSize.Width(), baseSize.Width(), dx), dy, |
| 567 | ReflowChildFlags::Default); |
| 568 | dx += bmBase.width; |
| 569 | } else if (prescriptsFrame == childFrame) { |
| 570 | // Clear reflow flags of prescripts frame. |
| 571 | prescriptsFrame->DidReflow(aPresContext, nullptr); |
| 572 | } else { |
| 573 | // process each sup/sub pair |
| 574 | if (0 == count) { |
| 575 | subScriptFrame = childFrame; |
| 576 | count = 1; |
| 577 | } else if (1 == count) { |
| 578 | if (tag != nsGkAtoms::msub_) supScriptFrame = childFrame; |
| 579 | count = 0; |
| 580 | |
| 581 | // get the ascent/descent of sup/subscripts stored in their rects |
| 582 | // rect.x = descent, rect.y = ascent |
| 583 | if (subScriptFrame) |
| 584 | GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, |
| 585 | bmSubScript); |
| 586 | if (supScriptFrame) |
| 587 | GetReflowAndBoundingMetricsFor(supScriptFrame, supScriptSize, |
| 588 | bmSupScript); |
| 589 | |
| 590 | width = std::max(subScriptSize.Width(), supScriptSize.Width()); |
| 591 | |
| 592 | if (subScriptFrame) { |
| 593 | nscoord x = dx; |
| 594 | // prescripts should be right aligned |
| 595 | // https://bugzilla.mozilla.org/show_bug.cgi?id=928675 |
| 596 | if (isPreScript) x += width - subScriptSize.Width(); |
| 597 | dy = aDesiredSize.BlockStartAscent() - |
| 598 | subScriptSize.BlockStartAscent() + maxSubScriptShift; |
| 599 | FinishReflowChild(subScriptFrame, aPresContext, subScriptSize, |
| 600 | nullptr, |
| 601 | aFrame->MirrorIfRTL(aDesiredSize.Width(), |
| 602 | subScriptSize.Width(), x), |
| 603 | dy, ReflowChildFlags::Default); |
| 604 | } |
| 605 | |
| 606 | if (supScriptFrame) { |
| 607 | nscoord x = dx; |
| 608 | if (isPreScript) { |
| 609 | x += width - supScriptSize.Width(); |
| 610 | } else { |
| 611 | // post superscripts are shifted by the italic correction value |
| 612 | x += italicCorrection; |
| 613 | } |
| 614 | dy = aDesiredSize.BlockStartAscent() - |
| 615 | supScriptSize.BlockStartAscent() - maxSupScriptShift; |
| 616 | FinishReflowChild(supScriptFrame, aPresContext, supScriptSize, |
| 617 | nullptr, |
| 618 | aFrame->MirrorIfRTL(aDesiredSize.Width(), |
| 619 | supScriptSize.Width(), x), |
| 620 | dy, ReflowChildFlags::Default); |
| 621 | } |
| 622 | dx += width + scriptSpace; |
| 623 | } |
| 624 | } |
| 625 | childFrame = childFrame->GetNextSibling(); |
| 626 | } while (prescriptsFrame != childFrame); |
| 627 | } |
| 628 | |
| 629 | return NS_OK; |
| 630 | } |