summaryrefslogtreecommitdiff
path: root/dom/grid/GridLines.cpp
blob: 898885346449764d73e9f62432e9831e6f6bfd2d (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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "GridLines.h"

#include "GridDimension.h"
#include "GridLine.h"
#include "mozilla/dom/GridBinding.h"
#include "nsGridContainerFrame.h"

namespace mozilla {
namespace dom {

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GridLines, mParent, mLines)
NS_IMPL_CYCLE_COLLECTING_ADDREF(GridLines)
NS_IMPL_CYCLE_COLLECTING_RELEASE(GridLines)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GridLines)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

GridLines::GridLines(GridDimension* aParent)
  : mParent(aParent)
{
  MOZ_ASSERT(aParent,
    "Should never be instantiated with a null GridDimension");
}

GridLines::~GridLines()
{
}

JSObject*
GridLines::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
  return GridLinesBinding::Wrap(aCx, this, aGivenProto);
}

uint32_t
GridLines::Length() const
{
  return mLines.Length();
}

GridLine*
GridLines::Item(uint32_t aIndex)
{
  return mLines.SafeElementAt(aIndex);
}

GridLine*
GridLines::IndexedGetter(uint32_t aIndex,
                         bool& aFound)
{
  aFound = aIndex < mLines.Length();
  if (!aFound) {
    return nullptr;
  }
  return mLines[aIndex];
}

void
GridLines::SetLineInfo(const ComputedGridTrackInfo* aTrackInfo,
                       const ComputedGridLineInfo* aLineInfo,
                       const nsTArray<RefPtr<GridArea>>& aAreas,
                       bool aIsRow)
{
  MOZ_ASSERT(aLineInfo);
  mLines.Clear();

  if (!aTrackInfo) {
    return;
  }

  uint32_t trackCount = aTrackInfo->mEndFragmentTrack -
                        aTrackInfo->mStartFragmentTrack;

  // If there is at least one track, line count is one more
  // than the number of tracks.
  if (trackCount > 0) {
    nscoord lastTrackEdge = 0;
    nscoord startOfNextTrack;
    uint32_t repeatIndex = 0;
    uint32_t numRepeatTracks = aTrackInfo->mRemovedRepeatTracks.Length();
    uint32_t numAddedLines = 0;

    for (uint32_t i = aTrackInfo->mStartFragmentTrack;
         i < aTrackInfo->mEndFragmentTrack + 1;
         i++) {
      // Since line indexes are 1-based, calculate a 1-based value
      // for this track to simplify some calculations.
      const uint32_t line1Index = i + 1;

      startOfNextTrack = (i < aTrackInfo->mEndFragmentTrack) ?
                         aTrackInfo->mPositions[i] :
                         lastTrackEdge;

      nsTArray<nsString> lineNames;
      lineNames = aLineInfo->mNames.SafeElementAt(i, nsTArray<nsString>());

      // Add in names from grid areas where this line is used as a boundary.
      for (auto area : aAreas) {
        bool haveNameToAdd = false;
        nsAutoString nameToAdd;
        area->GetName(nameToAdd);
        if (aIsRow) {
          if (area->RowStart() == line1Index) {
            haveNameToAdd = true;
            nameToAdd.AppendLiteral("-start");
          } else if (area->RowEnd() == line1Index) {
            haveNameToAdd = true;
            nameToAdd.AppendLiteral("-end");
          }
        } else {
          if (area->ColumnStart() == line1Index) {
            haveNameToAdd = true;
            nameToAdd.AppendLiteral("-start");
          } else if (area->ColumnEnd() == line1Index) {
            haveNameToAdd = true;
            nameToAdd.AppendLiteral("-end");
          }
        }

        if (haveNameToAdd && !lineNames.Contains(nameToAdd)) {
          lineNames.AppendElement(nameToAdd);
        }
      }

      if (i >= (aTrackInfo->mRepeatFirstTrack +
                aTrackInfo->mNumLeadingImplicitTracks) &&
          repeatIndex < numRepeatTracks) {
        numAddedLines += AppendRemovedAutoFits(aTrackInfo,
                                               aLineInfo,
                                               lastTrackEdge,
                                               repeatIndex,
                                               numRepeatTracks,
                                               lineNames);
      }

      RefPtr<GridLine> line = new GridLine(this);
      mLines.AppendElement(line);
      MOZ_ASSERT(line1Index > 0, "line1Index must be positive.");
      bool isBeforeFirstExplicit =
        (line1Index <= aTrackInfo->mNumLeadingImplicitTracks);
      // Calculate an actionable line number for this line, that could be used
      // in a css grid property to align a grid item or area at that line.
      // For implicit lines that appear before line 1, report a number of 0.
      // We can't report negative indexes, because those have a different
      // meaning in the css grid spec (negative indexes are negative-1-based
      // from the end of the grid decreasing towards the front).
      uint32_t lineNumber = isBeforeFirstExplicit ? 0 :
        (line1Index - aTrackInfo->mNumLeadingImplicitTracks + numAddedLines);
      GridDeclaration lineType =
        (isBeforeFirstExplicit ||
         line1Index > (aTrackInfo->mNumLeadingImplicitTracks +
                       aTrackInfo->mNumExplicitTracks + 1))
         ? GridDeclaration::Implicit
         : GridDeclaration::Explicit;
      line->SetLineValues(
        lineNames,
        nsPresContext::AppUnitsToDoubleCSSPixels(lastTrackEdge),
        nsPresContext::AppUnitsToDoubleCSSPixels(startOfNextTrack -
                                                 lastTrackEdge),
        lineNumber,
        lineType
      );

      if (i < aTrackInfo->mEndFragmentTrack) {
        lastTrackEdge = aTrackInfo->mPositions[i] + aTrackInfo->mSizes[i];
      }
    }
  }
}

uint32_t
GridLines::AppendRemovedAutoFits(const ComputedGridTrackInfo* aTrackInfo,
                                 const ComputedGridLineInfo* aLineInfo,
                                 nscoord aLastTrackEdge,
                                 uint32_t& aRepeatIndex,
                                 uint32_t aNumRepeatTracks,
                                 nsTArray<nsString>& aLineNames)
{
  // Check to see if lineNames contains ALL of the before line names.
  bool alreadyHasBeforeLineNames = true;
  for (const auto& beforeName : aLineInfo->mNamesBefore) {
    if (!aLineNames.Contains(beforeName)) {
      alreadyHasBeforeLineNames = false;
      break;
    }
  }

  bool extractedExplicitLineNames = false;
  nsTArray<nsString> explicitLineNames;
  uint32_t linesAdded = 0;
  while (aRepeatIndex < aNumRepeatTracks &&
         aTrackInfo->mRemovedRepeatTracks[aRepeatIndex]) {
    // If this is not the very first call to this function, and if we
    // haven't already added a line this call, pull all the explicit
    // names to pass along to the next line that will be added after
    // this function completes.
    if (aRepeatIndex > 0 &&
        linesAdded == 0) {
      // Find the names that didn't match the before or after names,
      // and extract them.
      for (const auto& name : aLineNames) {
        if (!aLineInfo->mNamesBefore.Contains(name) &&
            !aLineInfo->mNamesAfter.Contains(name)) {
          explicitLineNames.AppendElement(name);
        }
      }
      for (const auto& extractedName : explicitLineNames) {
        aLineNames.RemoveElement(extractedName);
      }
      extractedExplicitLineNames = true;
    }

    // If this is the second or later time through, or didn't already
    // have before names, add them.
    if (linesAdded > 0 || !alreadyHasBeforeLineNames) {
      aLineNames.AppendElements(aLineInfo->mNamesBefore);
    }

    RefPtr<GridLine> line = new GridLine(this);
    mLines.AppendElement(line);
    uint32_t lineNumber = aTrackInfo->mRepeatFirstTrack +
                          aRepeatIndex + 1;
    line->SetLineValues(
      aLineNames,
      nsPresContext::AppUnitsToDoubleCSSPixels(aLastTrackEdge),
      nsPresContext::AppUnitsToDoubleCSSPixels(0),
      lineNumber,
      GridDeclaration::Explicit
    );

    // No matter what, the next line should have the after names associated
    // with it. If we go through the loop again, the before names will also
    // be added.
    aLineNames = aLineInfo->mNamesAfter;
    aRepeatIndex++;

    linesAdded++;
  }
  aRepeatIndex++;

  if (extractedExplicitLineNames) {
    // Pass on the explicit names we saved to the next explicit line.
    aLineNames.AppendElements(explicitLineNames);
  }

  if (alreadyHasBeforeLineNames && linesAdded > 0) {
    // If we started with before names, pass them on to the next explicit
    // line.
    aLineNames.AppendElements(aLineInfo->mNamesBefore);
  }
  return linesAdded;
}

} // namespace dom
} // namespace mozilla