summaryrefslogtreecommitdiffstats
path: root/layout/mathml/nsMathMLmpaddedFrame.cpp
blob: 5b2e8282fa5d78e8d3b88e00dc3ad0736646f1d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */


#include "nsMathMLmpaddedFrame.h"
#include "nsMathMLElement.h"
#include "mozilla/gfx/2D.h"
#include <algorithm>

//
// <mpadded> -- adjust space around content - implementation
//

#define NS_MATHML_SIGN_INVALID           -1 // if the attribute is not there
#define NS_MATHML_SIGN_UNSPECIFIED        0
#define NS_MATHML_SIGN_MINUS              1
#define NS_MATHML_SIGN_PLUS               2

#define NS_MATHML_PSEUDO_UNIT_UNSPECIFIED 0
#define NS_MATHML_PSEUDO_UNIT_ITSELF      1 // special
#define NS_MATHML_PSEUDO_UNIT_WIDTH       2
#define NS_MATHML_PSEUDO_UNIT_HEIGHT      3
#define NS_MATHML_PSEUDO_UNIT_DEPTH       4
#define NS_MATHML_PSEUDO_UNIT_NAMEDSPACE  5

nsIFrame*
NS_NewMathMLmpaddedFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
  return new (aPresShell) nsMathMLmpaddedFrame(aContext);
}

NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmpaddedFrame)

nsMathMLmpaddedFrame::~nsMathMLmpaddedFrame()
{
}

NS_IMETHODIMP
nsMathMLmpaddedFrame::InheritAutomaticData(nsIFrame* aParent) 
{
  // let the base class get the default from our parent
  nsMathMLContainerFrame::InheritAutomaticData(aParent);

  mPresentationData.flags |= NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY;

  return NS_OK;
}

void
nsMathMLmpaddedFrame::ProcessAttributes()
{
  /*
  parse the attributes

  width  = [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | h-unit | namedspace)
  height = [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | v-unit | namedspace)
  depth  = [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | v-unit | namedspace)
  lspace = [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | h-unit | namedspace)
  voffset= [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | v-unit | namedspace)
  */

  nsAutoString value;

  // width
  mWidthSign = NS_MATHML_SIGN_INVALID;
  mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::width, value);
  if (!value.IsEmpty()) {
    if (!ParseAttribute(value, mWidthSign, mWidth, mWidthPseudoUnit)) {      
      ReportParseError(nsGkAtoms::width->GetUTF16String(), value.get());
    }
  }

  // height
  mHeightSign = NS_MATHML_SIGN_INVALID;
  mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::height, value);
  if (!value.IsEmpty()) {
    if (!ParseAttribute(value, mHeightSign, mHeight, mHeightPseudoUnit)) {
      ReportParseError(nsGkAtoms::height->GetUTF16String(), value.get());
    }
  }

  // depth
  mDepthSign = NS_MATHML_SIGN_INVALID;
  mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::depth_, value);
  if (!value.IsEmpty()) {
    if (!ParseAttribute(value, mDepthSign, mDepth, mDepthPseudoUnit)) {
      ReportParseError(nsGkAtoms::depth_->GetUTF16String(), value.get());
    }
  }

  // lspace
  mLeadingSpaceSign = NS_MATHML_SIGN_INVALID;
  mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::lspace_, value);
  if (!value.IsEmpty()) {
    if (!ParseAttribute(value, mLeadingSpaceSign, mLeadingSpace, 
                        mLeadingSpacePseudoUnit)) {
      ReportParseError(nsGkAtoms::lspace_->GetUTF16String(), value.get());
    }
  }

  // voffset
  mVerticalOffsetSign = NS_MATHML_SIGN_INVALID;
  mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::voffset_, value);
  if (!value.IsEmpty()) {
    if (!ParseAttribute(value, mVerticalOffsetSign, mVerticalOffset,
                        mVerticalOffsetPseudoUnit)) {
      ReportParseError(nsGkAtoms::voffset_->GetUTF16String(), value.get());
    }
  }
  
}

// parse an input string in the following format (see bug 148326 for testcases):
// [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | css-unit | namedspace)
bool
nsMathMLmpaddedFrame::ParseAttribute(nsString&   aString,
                                     int32_t&    aSign,
                                     nsCSSValue& aCSSValue,
                                     int32_t&    aPseudoUnit)
{
  aCSSValue.Reset();
  aSign = NS_MATHML_SIGN_INVALID;
  aPseudoUnit = NS_MATHML_PSEUDO_UNIT_UNSPECIFIED;
  aString.CompressWhitespace(); // aString is not a const in this code

  int32_t stringLength = aString.Length();
  if (!stringLength)
    return false;

  nsAutoString number, unit;

  //////////////////////
  // see if the sign is there

  int32_t i = 0;

  if (aString[0] == '+') {
    aSign = NS_MATHML_SIGN_PLUS;
    i++;
  }
  else if (aString[0] == '-') {
    aSign = NS_MATHML_SIGN_MINUS;
    i++;
  }
  else
    aSign = NS_MATHML_SIGN_UNSPECIFIED;

  // get the number
  bool gotDot = false, gotPercent = false;
  for (; i < stringLength; i++) {
    char16_t c = aString[i];
    if (gotDot && c == '.') {
      // error - two dots encountered
      aSign = NS_MATHML_SIGN_INVALID;
      return false;
    }

    if (c == '.')
      gotDot = true;
    else if (!nsCRT::IsAsciiDigit(c)) {
      break;
    }
    number.Append(c);
  }

  // catch error if we didn't enter the loop above... we could simply initialize
  // floatValue = 1, to cater for cases such as width="height", but that wouldn't
  // be in line with the spec which requires an explicit number
  if (number.IsEmpty()) {
    aSign = NS_MATHML_SIGN_INVALID;
    return false;
  }

  nsresult errorCode;
  float floatValue = number.ToFloat(&errorCode);
  if (NS_FAILED(errorCode)) {
    aSign = NS_MATHML_SIGN_INVALID;
    return false;
  }

  // see if this is a percentage-based value
  if (i < stringLength && aString[i] == '%') {
    i++;
    gotPercent = true;
  }

  // the remainder now should be a css-unit, or a pseudo-unit, or a named-space
  aString.Right(unit, stringLength - i);

  if (unit.IsEmpty()) {
    if (gotPercent) {
      // case ["+"|"-"] unsigned-number "%" 
      aCSSValue.SetPercentValue(floatValue / 100.0f);
      aPseudoUnit = NS_MATHML_PSEUDO_UNIT_ITSELF;
      return true;
    } else {
      // case ["+"|"-"] unsigned-number
      // XXXfredw: should we allow non-zero unitless values? See bug 757703.
      if (!floatValue) {
        aCSSValue.SetFloatValue(floatValue, eCSSUnit_Number);
        aPseudoUnit = NS_MATHML_PSEUDO_UNIT_ITSELF;
        return true;
      }
    }
  }
  else if (unit.EqualsLiteral("width"))  aPseudoUnit = NS_MATHML_PSEUDO_UNIT_WIDTH;
  else if (unit.EqualsLiteral("height")) aPseudoUnit = NS_MATHML_PSEUDO_UNIT_HEIGHT;
  else if (unit.EqualsLiteral("depth"))  aPseudoUnit = NS_MATHML_PSEUDO_UNIT_DEPTH;
  else if (!gotPercent) { // percentage can only apply to a pseudo-unit

    // see if the unit is a named-space
    if (nsMathMLElement::ParseNamedSpaceValue(unit, aCSSValue,
                                              nsMathMLElement::
                                              PARSE_ALLOW_NEGATIVE)) {
      // re-scale properly, and we know that the unit of the named-space is 'em'
      floatValue *= aCSSValue.GetFloatValue();
      aCSSValue.SetFloatValue(floatValue, eCSSUnit_EM);
      aPseudoUnit = NS_MATHML_PSEUDO_UNIT_NAMEDSPACE;
      return true;
    }

    // see if the input was just a CSS value
    // We are not supposed to have a unitless, percent, negative or namedspace
    // value here.
    number.Append(unit); // leave the sign out if it was there
    if (nsMathMLElement::ParseNumericValue(number, aCSSValue, 
                                           nsMathMLElement::
                                           PARSE_SUPPRESS_WARNINGS, nullptr))
      return true;
  }

  // if we enter here, we have a number that will act as a multiplier on a pseudo-unit
  if (aPseudoUnit != NS_MATHML_PSEUDO_UNIT_UNSPECIFIED) {
    if (gotPercent)
      aCSSValue.SetPercentValue(floatValue / 100.0f);
    else
      aCSSValue.SetFloatValue(floatValue, eCSSUnit_Number);

    return true;
  }


#ifdef DEBUG
  printf("mpadded: attribute with bad numeric value: %s\n",
          NS_LossyConvertUTF16toASCII(aString).get());
#endif
  // if we reach here, it means we encounter an unexpected input
  aSign = NS_MATHML_SIGN_INVALID;
  return false;
}

void
nsMathMLmpaddedFrame::UpdateValue(int32_t                  aSign,
                                  int32_t                  aPseudoUnit,
                                  const nsCSSValue&        aCSSValue,
                                  const ReflowOutput& aDesiredSize,
                                  nscoord&                 aValueToUpdate,
                                  float                aFontSizeInflation) const
{
  nsCSSUnit unit = aCSSValue.GetUnit();
  if (NS_MATHML_SIGN_INVALID != aSign && eCSSUnit_Null != unit) {
    nscoord scaler = 0, amount = 0;

    if (eCSSUnit_Percent == unit || eCSSUnit_Number == unit) {
      switch(aPseudoUnit) {
        case NS_MATHML_PSEUDO_UNIT_WIDTH:
             scaler = aDesiredSize.Width();
             break;

        case NS_MATHML_PSEUDO_UNIT_HEIGHT:
             scaler = aDesiredSize.BlockStartAscent();
             break;

        case NS_MATHML_PSEUDO_UNIT_DEPTH:
             scaler = aDesiredSize.Height() - aDesiredSize.BlockStartAscent();
             break;

        default:
          // if we ever reach here, it would mean something is wrong 
          // somewhere with the setup and/or the caller
          NS_ERROR("Unexpected Pseudo Unit");
          return;
      }
    }

    if (eCSSUnit_Number == unit)
      amount = NSToCoordRound(float(scaler) * aCSSValue.GetFloatValue());
    else if (eCSSUnit_Percent == unit)
      amount = NSToCoordRound(float(scaler) * aCSSValue.GetPercentValue());
    else
      amount = CalcLength(PresContext(), mStyleContext, aCSSValue,
                          aFontSizeInflation);

    if (NS_MATHML_SIGN_PLUS == aSign)
      aValueToUpdate += amount;
    else if (NS_MATHML_SIGN_MINUS == aSign)
      aValueToUpdate -= amount;
    else
      aValueToUpdate  = amount;
  }
}

void
nsMathMLmpaddedFrame::Reflow(nsPresContext*          aPresContext,
                             ReflowOutput&     aDesiredSize,
                             const ReflowInput& aReflowInput,
                             nsReflowStatus&          aStatus)
{
  mPresentationData.flags &= ~NS_MATHML_ERROR;
  ProcessAttributes();

  ///////////////
  // Let the base class format our content like an inferred mrow
  nsMathMLContainerFrame::Reflow(aPresContext, aDesiredSize,
                                 aReflowInput, aStatus);
  //NS_ASSERTION(NS_FRAME_IS_COMPLETE(aStatus), "bad status");
}

/* virtual */ nsresult
nsMathMLmpaddedFrame::Place(DrawTarget*          aDrawTarget,
                            bool                 aPlaceOrigin,
                            ReflowOutput& aDesiredSize)
{
  nsresult rv =
    nsMathMLContainerFrame::Place(aDrawTarget, false, aDesiredSize);
  if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
    DidReflowChildren(PrincipalChildList().FirstChild());
    return rv;
  }

  nscoord height = aDesiredSize.BlockStartAscent();
  nscoord depth  = aDesiredSize.Height() - aDesiredSize.BlockStartAscent();
  // The REC says:
  //
  // "The lspace attribute ('leading' space) specifies the horizontal location
  // of the positioning point of the child content with respect to the
  // positioning point of the mpadded element. By default they coincide, and
  // therefore absolute values for lspace have the same effect as relative
  // values."
  //
  // "MathML renderers should ensure that, except for the effects of the
  // attributes, the relative spacing between the contents of the mpadded
  // element and surrounding MathML elements would not be modified by replacing
  // an mpadded element with an mrow element with the same content, even if
  // linebreaking occurs within the mpadded element."
  //
  // (http://www.w3.org/TR/MathML/chapter3.html#presm.mpadded)
  // 
  // "In those discussions, the terms leading and trailing are used to specify
  // a side of an object when which side to use depends on the directionality;
  // ie. leading means left in LTR but right in RTL."
  // (http://www.w3.org/TR/MathML/chapter3.html#presm.bidi.math)
  nscoord lspace = 0;
  // In MathML3, "width" will be the bounding box width and "advancewidth" will
  // refer "to the horizontal distance between the positioning point of the
  // mpadded and the positioning point for the following content".  MathML2
  // doesn't make the distinction.
  nscoord width  = aDesiredSize.Width();
  nscoord voffset = 0;

  int32_t pseudoUnit;
  nscoord initialWidth = width;
  float fontSizeInflation = nsLayoutUtils::FontSizeInflationFor(this);

  // update width
  pseudoUnit = (mWidthPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
             ? NS_MATHML_PSEUDO_UNIT_WIDTH : mWidthPseudoUnit;
  UpdateValue(mWidthSign, pseudoUnit, mWidth,
              aDesiredSize, width, fontSizeInflation);
  width = std::max(0, width);

  // update "height" (this is the ascent in the terminology of the REC)
  pseudoUnit = (mHeightPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
             ? NS_MATHML_PSEUDO_UNIT_HEIGHT : mHeightPseudoUnit;
  UpdateValue(mHeightSign, pseudoUnit, mHeight,
              aDesiredSize, height, fontSizeInflation);
  height = std::max(0, height);

  // update "depth" (this is the descent in the terminology of the REC)
  pseudoUnit = (mDepthPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
             ? NS_MATHML_PSEUDO_UNIT_DEPTH : mDepthPseudoUnit;
  UpdateValue(mDepthSign, pseudoUnit, mDepth,
              aDesiredSize, depth, fontSizeInflation);
  depth = std::max(0, depth);

  // update lspace
  if (mLeadingSpacePseudoUnit != NS_MATHML_PSEUDO_UNIT_ITSELF) {
    pseudoUnit = mLeadingSpacePseudoUnit;
    UpdateValue(mLeadingSpaceSign, pseudoUnit, mLeadingSpace,
                aDesiredSize, lspace, fontSizeInflation);
  }

  // update voffset
  if (mVerticalOffsetPseudoUnit != NS_MATHML_PSEUDO_UNIT_ITSELF) {
    pseudoUnit = mVerticalOffsetPseudoUnit;
    UpdateValue(mVerticalOffsetSign, pseudoUnit, mVerticalOffset,
                aDesiredSize, voffset, fontSizeInflation);
  }
  // do the padding now that we have everything
  // The idea here is to maintain the invariant that <mpadded>...</mpadded> (i.e.,
  // with no attributes) looks the same as <mrow>...</mrow>. But when there are
  // attributes, tweak our metrics and move children to achieve the desired visual
  // effects.

  if ((StyleVisibility()->mDirection ?
       mWidthSign : mLeadingSpaceSign) != NS_MATHML_SIGN_INVALID) {
    // there was padding on the left. dismiss the left italic correction now
    // (so that our parent won't correct us)
    mBoundingMetrics.leftBearing = 0;
  }

  if ((StyleVisibility()->mDirection ?
       mLeadingSpaceSign : mWidthSign) != NS_MATHML_SIGN_INVALID) {
    // there was padding on the right. dismiss the right italic correction now
    // (so that our parent won't correct us)
    mBoundingMetrics.width = width;
    mBoundingMetrics.rightBearing = mBoundingMetrics.width;
  }

  nscoord dx = (StyleVisibility()->mDirection ?
                width - initialWidth - lspace : lspace);
    
  aDesiredSize.SetBlockStartAscent(height);
  aDesiredSize.Width() = mBoundingMetrics.width;
  aDesiredSize.Height() = depth + aDesiredSize.BlockStartAscent();
  mBoundingMetrics.ascent = height;
  mBoundingMetrics.descent = depth;
  aDesiredSize.mBoundingMetrics = mBoundingMetrics;

  mReference.x = 0;
  mReference.y = aDesiredSize.BlockStartAscent();

  if (aPlaceOrigin) {
    // Finish reflowing child frames, positioning their origins.
    PositionRowChildFrames(dx, aDesiredSize.BlockStartAscent() - voffset);
  }

  return NS_OK;
}

/* virtual */ nsresult
nsMathMLmpaddedFrame::MeasureForWidth(DrawTarget* aDrawTarget,
                                      ReflowOutput& aDesiredSize)
{
  ProcessAttributes();
  return Place(aDrawTarget, false, aDesiredSize);
}