third_party/WebKit/Source/core/layout/LayoutTable.h

   1 /*
   2  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
   3  *           (C) 1997 Torben Weis (weis@kde.org)
   4  *           (C) 1998 Waldo Bastian (bastian@kde.org)
   5  *           (C) 1999 Lars Knoll (knoll@kde.org)
   6  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
   7  * Copyright (C) 2003, 2004, 2005, 2006, 2009, 2010 Apple Inc. All rights reserved.
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Library General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Library General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Library General Public License
  20  * along with this library; see the file COPYING.LIB.  If not, write to
  21  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22  * Boston, MA 02110-1301, USA.
  23  */
  24
  25 #ifndef LayoutTable_h
  26 #define LayoutTable_h
  27
  28 #include "core/CSSPropertyNames.h"
  29 #include "core/CoreExport.h"
  30 #include "core/layout/LayoutBlock.h"
  31 #include "core/style/CollapsedBorderValue.h"
  32 #include "wtf/Vector.h"
  33
  34 namespace blink {
  35
  36 class LayoutTableCol;
  37 class LayoutTableCaption;
  38 class LayoutTableCell;
  39 class LayoutTableSection;
  40 class TableLayoutAlgorithm;
  41
  42 enum SkipEmptySectionsValue { DoNotSkipEmptySections, SkipEmptySections };
  43
  44 // LayoutTable is the LayoutObject associated with
  45 // display: table or inline-table.
  46 //
  47 // LayoutTable is the master coordinator for determining the overall table
  48 // structure. The reason is that LayoutTableSection children have a local
  49 // view over what their structure is but don't account for other
  50 // LayoutTableSection. Thus LayoutTable helps keep consistency across
  51 // LayoutTableSection. See e.g. m_column below.
  52 //
  53 // LayoutTable expects only 3 types of children:
  54 // - zero or more LayoutTableCol
  55 // - zero or more LayoutTableCaption
  56 // - zero or more LayoutTableSection
  57 // This is aligned with what HTML5 expects:
  58 // https://html.spec.whatwg.org/multipage/tables.html#the-table-element
  59 // with one difference: we allow more than one caption as we follow what
  60 // CSS expects (https://bugs.webkit.org/show_bug.cgi?id=69773).
  61 // Those expectations are enforced by LayoutTable::addChild, that wraps unknown
  62 // children into an anonymous LayoutTableSection. This is what the "generate
  63 // missing child wrapper" step in CSS mandates in
  64 // http://www.w3.org/TR/CSS21/tables.html#anonymous-boxes.
  65 //
  66 // TODO(jchaffraix): Explain more of the class structure.
  67 class CORE_EXPORT LayoutTable final : public LayoutBlock {
  68 public:
  69     explicit LayoutTable(Element*);
  70     ~LayoutTable() override;
  71
  72     // Per CSS 3 writing-mode: "The first and second values of the 'border-spacing' property represent spacing between columns
  73     // and rows respectively, not necessarily the horizontal and vertical spacing respectively".
  74     int hBorderSpacing() const { return m_hSpacing; }
  75     int vBorderSpacing() const { return m_vSpacing; }
  76
  77     bool collapseBorders() const { return style()->borderCollapse(); }
  78
  79     int borderStart() const override { return m_borderStart; }
  80     int borderEnd() const override { return m_borderEnd; }
  81     int borderBefore() const override;
  82     int borderAfter() const override;
  83
  84     int borderLeft() const override
  85     {
  86         if (style()->isHorizontalWritingMode())
  87             return style()->isLeftToRightDirection() ? borderStart() : borderEnd();
  88         return style()->isFlippedBlocksWritingMode() ? borderAfter() : borderBefore();
  89     }
  90
  91     int borderRight() const override
  92     {
  93         if (style()->isHorizontalWritingMode())
  94             return style()->isLeftToRightDirection() ? borderEnd() : borderStart();
  95         return style()->isFlippedBlocksWritingMode() ? borderBefore() : borderAfter();
  96     }
  97
  98     int borderTop() const override
  99     {
 100         if (style()->isHorizontalWritingMode())
 101             return style()->isFlippedBlocksWritingMode() ? borderAfter() : borderBefore();
 102         return style()->isLeftToRightDirection() ? borderStart() : borderEnd();
 103     }
 104
 105     int borderBottom() const override
 106     {
 107         if (style()->isHorizontalWritingMode())
 108             return style()->isFlippedBlocksWritingMode() ? borderBefore() : borderAfter();
 109         return style()->isLeftToRightDirection() ? borderEnd() : borderStart();
 110     }
 111
 112     int outerBorderBefore() const;
 113     int outerBorderAfter() const;
 114     int outerBorderStart() const;
 115     int outerBorderEnd() const;
 116
 117     int outerBorderLeft() const
 118     {
 119         if (style()->isHorizontalWritingMode())
 120             return style()->isLeftToRightDirection() ? outerBorderStart() : outerBorderEnd();
 121         return style()->isFlippedBlocksWritingMode() ? outerBorderAfter() : outerBorderBefore();
 122     }
 123
 124     int outerBorderRight() const
 125     {
 126         if (style()->isHorizontalWritingMode())
 127             return style()->isLeftToRightDirection() ? outerBorderEnd() : outerBorderStart();
 128         return style()->isFlippedBlocksWritingMode() ? outerBorderBefore() : outerBorderAfter();
 129     }
 130
 131     int outerBorderTop() const
 132     {
 133         if (style()->isHorizontalWritingMode())
 134             return style()->isFlippedBlocksWritingMode() ? outerBorderAfter() : outerBorderBefore();
 135         return style()->isLeftToRightDirection() ? outerBorderStart() : outerBorderEnd();
 136     }
 137
 138     int outerBorderBottom() const
 139     {
 140         if (style()->isHorizontalWritingMode())
 141             return style()->isFlippedBlocksWritingMode() ? outerBorderBefore() : outerBorderAfter();
 142         return style()->isLeftToRightDirection() ? outerBorderEnd() : outerBorderStart();
 143     }
 144
 145     int calcBorderStart() const;
 146     int calcBorderEnd() const;
 147     void recalcBordersInRowDirection();
 148
 149     void addChild(LayoutObject* child, LayoutObject* beforeChild = nullptr) override;
 150     void addChildIgnoringContinuation(LayoutObject* newChild, LayoutObject* beforeChild = nullptr) override;
 151
 152     struct ColumnStruct {
 153         ALLOW_ONLY_INLINE_ALLOCATION();
 154         explicit ColumnStruct(unsigned initialSpan = 1)
 155             : span(initialSpan)
 156         {
 157         }
 158
 159         unsigned span;
 160     };
 161
 162     void forceSectionsRecalc()
 163     {
 164         setNeedsSectionRecalc();
 165         recalcSections();
 166     }
 167
 168     const Vector<ColumnStruct>& columns() const { return m_columns; }
 169     const Vector<int>& columnPositions() const { return m_columnPos; }
 170     void setColumnPosition(unsigned index, int position)
 171     {
 172         // Note that if our horizontal border-spacing changed, our position will change but not
 173         // our column's width. In practice, horizontal border-spacing won't change often.
 174         m_columnLogicalWidthChanged |= m_columnPos[index] != position;
 175         m_columnPos[index] = position;
 176     }
 177
 178     LayoutTableSection* header() const { return m_head; }
 179     LayoutTableSection* footer() const { return m_foot; }
 180     LayoutTableSection* firstBody() const { return m_firstBody; }
 181
 182     // This function returns 0 if the table has no section.
 183     LayoutTableSection* topSection() const;
 184     LayoutTableSection* bottomSection() const;
 185
 186     // This function returns 0 if the table has no non-empty sections.
 187     LayoutTableSection* topNonEmptySection() const;
 188
 189     unsigned lastColumnIndex() const { return numEffCols() - 1; }
 190
 191     void splitColumn(unsigned position, unsigned firstSpan);
 192     void appendColumn(unsigned span);
 193     unsigned numEffCols() const { return m_columns.size(); }
 194     unsigned spanOfEffCol(unsigned effCol) const { return m_columns[effCol].span; }
 195
 196     unsigned colToEffCol(unsigned column) const
 197     {
 198         if (!m_hasCellColspanThatDeterminesTableWidth)
 199             return column;
 200
 201         unsigned effColumn = 0;
 202         unsigned numColumns = numEffCols();
 203         for (unsigned c = 0; effColumn < numColumns && c + m_columns[effColumn].span - 1 < column; ++effColumn)
 204             c += m_columns[effColumn].span;
 205         return effColumn;
 206     }
 207
 208     unsigned effColToCol(unsigned effCol) const
 209     {
 210         if (!m_hasCellColspanThatDeterminesTableWidth)
 211             return effCol;
 212
 213         unsigned c = 0;
 214         for (unsigned i = 0; i < effCol; i++)
 215             c += m_columns[i].span;
 216         return c;
 217     }
 218
 219     LayoutUnit borderSpacingInRowDirection() const
 220     {
 221         if (unsigned effectiveColumnCount = numEffCols())
 222             return static_cast<LayoutUnit>(effectiveColumnCount + 1) * hBorderSpacing();
 223
 224         return 0;
 225     }
 226
 227     // Override paddingStart/End to return pixel values to match behavor of LayoutTableCell.
 228     LayoutUnit paddingEnd() const override { return static_cast<int>(LayoutBlock::paddingEnd()); }
 229     LayoutUnit paddingStart() const override { return static_cast<int>(LayoutBlock::paddingStart()); }
 230
 231     LayoutUnit bordersPaddingAndSpacingInRowDirection() const
 232     {
 233         // 'border-spacing' only applies to separate borders (see 17.6.1 The separated borders model).
 234         return borderStart() + borderEnd() + (collapseBorders() ? LayoutUnit() : (paddingStart() + paddingEnd() + borderSpacingInRowDirection()));
 235     }
 236
 237     // Return the first column or column-group.
 238     LayoutTableCol* firstColumn() const;
 239
 240     LayoutTableCol* colElement(unsigned col, bool* startEdge = nullptr, bool* endEdge = nullptr) const
 241     {
 242         // The common case is to not have columns, make that case fast.
 243         if (!m_hasColElements)
 244             return nullptr;
 245         return slowColElement(col, startEdge, endEdge);
 246     }
 247
 248     bool needsSectionRecalc() const { return m_needsSectionRecalc; }
 249     void setNeedsSectionRecalc()
 250     {
 251         if (documentBeingDestroyed())
 252             return;
 253         m_needsSectionRecalc = true;
 254         setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::TableChanged);
 255     }
 256
 257     LayoutTableSection* sectionAbove(const LayoutTableSection*, SkipEmptySectionsValue = DoNotSkipEmptySections) const;
 258     LayoutTableSection* sectionBelow(const LayoutTableSection*, SkipEmptySectionsValue = DoNotSkipEmptySections) const;
 259
 260     LayoutTableCell* cellAbove(const LayoutTableCell*) const;
 261     LayoutTableCell* cellBelow(const LayoutTableCell*) const;
 262     LayoutTableCell* cellBefore(const LayoutTableCell*) const;
 263     LayoutTableCell* cellAfter(const LayoutTableCell*) const;
 264
 265     typedef Vector<CollapsedBorderValue> CollapsedBorderValues;
 266     void invalidateCollapsedBorders();
 267
 268     // FIXME: This method should be moved into TablePainter.
 269     const CollapsedBorderValue* currentBorderValue() const { return m_currentBorder; }
 270     void setCurrentBorderValue(const CollapsedBorderValue* val) { m_currentBorder = val; }
 271
 272     bool hasSections() const { return m_head || m_foot || m_firstBody; }
 273
 274     void recalcSectionsIfNeeded() const
 275     {
 276         if (m_needsSectionRecalc)
 277             recalcSections();
 278     }
 279
 280     static LayoutTable* createAnonymousWithParent(const LayoutObject*);
 281     LayoutBox* createAnonymousBoxWithSameTypeAs(const LayoutObject* parent) const override
 282     {
 283         return createAnonymousWithParent(parent);
 284     }
 285
 286     const BorderValue& tableStartBorderAdjoiningCell(const LayoutTableCell*) const;
 287     const BorderValue& tableEndBorderAdjoiningCell(const LayoutTableCell*) const;
 288
 289     void addCaption(const LayoutTableCaption*);
 290     void removeCaption(const LayoutTableCaption*);
 291     void addColumn(const LayoutTableCol*);
 292     void removeColumn(const LayoutTableCol*);
 293
 294     void paintBoxDecorationBackground(const PaintInfo&, const LayoutPoint&) final;
 295
 296     void paintMask(const PaintInfo&, const LayoutPoint&) final;
 297
 298     const CollapsedBorderValues& collapsedBorders()
 299     {
 300         ASSERT(m_collapsedBordersValid);
 301         return m_collapsedBorders;
 302     }
 303
 304     void subtractCaptionRect(LayoutRect&) const;
 305
 306     const char* name() const override { return "LayoutTable"; }
 307
 308 protected:
 309     void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override;
 310     void simplifiedNormalFlowLayout() override;
 311     PaintInvalidationReason invalidatePaintIfNeeded(PaintInvalidationState&, const LayoutBoxModelObject& paintInvalidationContainer) override;
 312     void invalidatePaintOfSubtreesIfNeeded(PaintInvalidationState&) override;
 313
 314 private:
 315     bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectTable || LayoutBlock::isOfType(type); }
 316
 317     void paintObject(const PaintInfo&, const LayoutPoint&) override;
 318     void layout() override;
 319     void computeIntrinsicLogicalWidths(LayoutUnit& minWidth, LayoutUnit& maxWidth) const override;
 320     void computePreferredLogicalWidths() override;
 321     bool nodeAtPoint(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) override;
 322
 323     int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const override;
 324     int firstLineBoxBaseline() const override;
 325     int inlineBlockBaseline(LineDirectionMode) const override;
 326
 327     LayoutTableCol* slowColElement(unsigned col, bool* startEdge, bool* endEdge) const;
 328
 329     void updateColumnCache() const;
 330     void invalidateCachedColumns();
 331
 332     void updateLogicalWidth() override;
 333
 334     LayoutUnit convertStyleLogicalWidthToComputedWidth(const Length& styleLogicalWidth, LayoutUnit availableWidth);
 335     LayoutUnit convertStyleLogicalHeightToComputedHeight(const Length& styleLogicalHeight);
 336
 337     LayoutRect overflowClipRect(const LayoutPoint& location, OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize) const override;
 338
 339     void addOverflowFromChildren() override;
 340
 341     void recalcSections() const;
 342     void layoutCaption(LayoutTableCaption&);
 343
 344     void distributeExtraLogicalHeight(int extraLogicalHeight);
 345
 346     void recalcCollapsedBordersIfNeeded();
 347
 348     mutable Vector<int> m_columnPos;
 349
 350     // This Vector holds the columns counts over the entire table.
 351     //
 352     // To save memory at the expense of massive code complexity, the code tries
 353     // to coalesce columns. This means that we try to the wider column grouping
 354     // seen over the LayoutTableSections.
 355     //
 356     // Note that this is also a defensive pattern as <td colspan="6666666666">
 357     // only allocates a single entry in this Vector. This argument is weak
 358     // though as we cap colspans in HTMLTableCellElement.
 359     //
 360     // The following example would have 2 ColumnStruct [ 3, 2 ]:
 361     // <table>
 362     //   <tr>
 363     //     <td colspan="3"></td>
 364     //     <td colspan="2"></td>
 365     //   </tr>
 366     // </table>
 367     //
 368     // Columns can be split if we add a row with a different colspan structure.
 369     // See splitColumn and appendColumn for operations over |m_columns|.
 370     //
 371     // See colToEffCol for converting an absolute column index into an
 372     // index into |m_columns|.
 373     mutable Vector<ColumnStruct> m_columns;
 374
 375     // The captions associated with this object.
 376     mutable Vector<LayoutTableCaption*> m_captions;
 377
 378     mutable Vector<LayoutTableCol*> m_columnLayoutObjects;
 379
 380     mutable LayoutTableSection* m_head;
 381     mutable LayoutTableSection* m_foot;
 382     mutable LayoutTableSection* m_firstBody;
 383
 384     // The layout algorithm used by this table.
 385     //
 386     // CSS 2.1 defines 2 types of table layouts toggled with 'table-layout':
 387     // fixed (TableLayoutAlgorithmFixed) and auto (TableLayoutAlgorithmAuto).
 388     // See http://www.w3.org/TR/CSS21/tables.html#width-layout.
 389     //
 390     // The layout algorithm is delegated to TableLayoutAlgorithm. This enables
 391     // changing 'table-layout' without having to reattach the <table>.
 392     //
 393     // As the algorithm is dependent on the style, this field is nullptr before
 394     // the first style is applied in styleDidChange().
 395     OwnPtr<TableLayoutAlgorithm> m_tableLayout;
 396
 397     // A sorted list of all unique border values that we want to paint.
 398     CollapsedBorderValues m_collapsedBorders;
 399     const CollapsedBorderValue* m_currentBorder;
 400     bool m_collapsedBordersValid : 1;
 401
 402     mutable bool m_hasColElements : 1;
 403     mutable bool m_needsSectionRecalc : 1;
 404
 405     bool m_columnLogicalWidthChanged : 1;
 406     mutable bool m_columnLayoutObjectsValid: 1;
 407     mutable bool m_hasCellColspanThatDeterminesTableWidth : 1;
 408     bool hasCellColspanThatDeterminesTableWidth() const
 409     {
 410         for (unsigned c = 0; c < numEffCols(); c++) {
 411             if (m_columns[c].span > 1)
 412                 return true;
 413         }
 414         return false;
 415     }
 416
 417     short m_hSpacing;
 418     short m_vSpacing;
 419     int m_borderStart;
 420     int m_borderEnd;
 421 };
 422
 423 inline LayoutTableSection* LayoutTable::topSection() const
 424 {
 425     ASSERT(!needsSectionRecalc());
 426     if (m_head)
 427         return m_head;
 428     if (m_firstBody)
 429         return m_firstBody;
 430     return m_foot;
 431 }
 432
 433 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutTable, isTable());
 434
 435 } // namespace blink
 436
 437 #endif // LayoutTable_h