layout/tables/celldata.h
author Matt Woodrow <mwoodrow@mozilla.com>
Wed, 20 Nov 2019 03:29:25 +0000
changeset 503066 e76dbab2aea8354660281221c1aa08356107881c
parent 451613 8ad209d77614e79e1a8cd2b9dc6ca9aab4469917
permissions -rw-r--r--
Bug 1597015 - Split DocumentChannelParent into two separate classes (DocumentLoadListener and DocumentChannelParent). r=mayhemer,jya Currently DocumentChannelParent serves two fairly separate functions. It acts as a logic controller for a connecting load (ultimately on behalf of a CanonicalBrowsingContext), that creates a channel and once it gets a response, figures out the right thing to do with it (send to the originating process, send to a new process, handle as a download etc). It's the parent-side IPDL actor for an nsIChannel implementation that we hold in the docshell as a placeholder while the above happens. This is largely a backwards compatibility hack since docshell expects to have a channel when a load has been initiated (but in the future we could do loads more directly through BrowsingContext and rewrite docshell to understand waiting on that). This patch splits this into two separate classes (and adds more documentation explaining exactly what each one does). It shouldn't affect any behaviour. Differential Revision: https://phabricator.services.mozilla.com/D53383

/* -*- 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/. */
#ifndef CellData_h__
#define CellData_h__

#include "nsISupports.h"
#include "nsITableCellLayout.h"  // for MAX_COLSPAN / MAX_ROWSPAN
#include "nsCoord.h"
#include "mozilla/gfx/Types.h"
#include "mozilla/WritingModes.h"
#include <stdint.h>

class nsTableCellFrame;
class nsCellMap;
class BCCellData;

/**
 * Data stored by nsCellMap to rationalize rowspan and colspan cells.
 */
class CellData {
 public:
  /** Initialize the mOrigCell pointer
   * @param aOrigCell  the table cell frame which will be stored in mOrigCell.
   */
  void Init(nsTableCellFrame* aCellFrame);

  /** does a cell originate from here
   * @return    is true if a cell corresponds to this cellmap entry
   */
  bool IsOrig() const;

  /** is the celldata valid
   * @return    is true if no cell originates and the cell is not spanned by
   *            a row- or colspan. mBits are 0 in this case and mOrigCell is
   *            nullptr
   */
  bool IsDead() const;

  /** is the entry spanned by row- or a colspan
   * @return    is true if the entry is spanned by a row- or colspan
   */
  bool IsSpan() const;

  /** is the entry spanned by rowspan
   * @return    is true if the entry is spanned by a rowspan
   */
  bool IsRowSpan() const;

  /** is the entry spanned by a zero rowspan
   * zero rowspans span all cells starting from the originating cell down to
   * the end of the rowgroup or a cell originating in the same column
   * @return    is true if the entry is spanned by a zero rowspan
   */
  bool IsZeroRowSpan() const;

  /** mark the current entry as spanned by a zero rowspan
   * @param aIsZero    if true mark the entry as covered by a zero rowspan
   */
  void SetZeroRowSpan(bool aIsZero);

  /** get the distance from the current entry to the corresponding origin of the
   * rowspan
   * @return    containing the distance in the column to the originating cell
   */
  uint32_t GetRowSpanOffset() const;

  /** set the distance from the current entry to the corresponding origin of
   * the rowspan
   * @param    the distance in the column to the originating cell
   */
  void SetRowSpanOffset(uint32_t aSpan);

  /** is the entry spanned by colspan
   * @return    is true if the entry is spanned by a colspan
   */
  bool IsColSpan() const;

  /** get the distance from the current entry to the corresponding origin of
   *  the colspan
   * @return    containing the distance in the row to the originating cell
   */
  uint32_t GetColSpanOffset() const;

  /** set the distance from the current entry to the corresponding origin of the
   * colspan
   * @param    the distance in the column to the originating cell
   */
  void SetColSpanOffset(uint32_t aSpan);

  /** is the entry spanned by a row- and a colspan
   * @return    is true if the entry is spanned by a row- and a colspan
   */
  bool IsOverlap() const;

  /** mark the current entry as spanned by a row- and a colspan
   * @param aOverlap    if true mark the entry as covered by a row- and
   *                    a colspan
   */
  void SetOverlap(bool aOverlap);

  /** get the table cell frame for this entry
   * @return    a pointer to the cellframe, this will be nullptr when the entry
   *            is only a spanned entry
   */
  nsTableCellFrame* GetCellFrame() const;

 private:
  friend class nsCellMap;
  friend class BCCellData;

  /**
   * Implemented in nsCellMap.cpp
   *
   * @param aOrigCell  the table cell frame which will be stored in mOrigCell.
   */
  explicit CellData(nsTableCellFrame* aOrigCell);

  ~CellData();  // implemented in nsCellMap.cpp

 protected:
  // this union relies on the assumption that an object (not primitive type)
  // does not start on an odd bit boundary. If mSpan is 0 then mOrigCell is in
  // effect and the data does not represent a span. If mSpan is 1, then mBits is
  // in effect and the data represents a span. mBits must match the size of
  // mOrigCell on both 32- and 64-bit platforms.
  union {
    nsTableCellFrame* mOrigCell;
    uintptr_t mBits;
  };
};

// Border Collapsing Cell Data
enum BCBorderOwner {
  eTableOwner = 0,
  eColGroupOwner = 1,
  eAjaColGroupOwner = 2,  // col group to the left
  eColOwner = 3,
  eAjaColOwner = 4,  // col to the left
  eRowGroupOwner = 5,
  eAjaRowGroupOwner = 6,  // row group above
  eRowOwner = 7,
  eAjaRowOwner = 8,  // row above
  eCellOwner = 9,
  eAjaCellOwner = 10  // cell to the top or to the left
};

// BCPixelSize is in device pixels.
typedef uint16_t BCPixelSize;

// These are the max sizes that are stored. If they are exceeded, then the max
// is stored and the actual value is computed when needed.
#define MAX_BORDER_WIDTH nscoord((1u << (sizeof(BCPixelSize) * 8)) - 1)

// The half of border on inline/block-axis start side
static inline BCPixelSize BC_BORDER_START_HALF(BCPixelSize px) {
  return px - px / 2;
}
// The half of border on inline/block-axis end side
static inline BCPixelSize BC_BORDER_END_HALF(BCPixelSize px) { return px / 2; }

static inline nscoord BC_BORDER_START_HALF_COORD(int32_t d2a, BCPixelSize px) {
  return BC_BORDER_START_HALF(px) * d2a;
}
static inline nscoord BC_BORDER_END_HALF_COORD(int32_t d2a, BCPixelSize px) {
  return BC_BORDER_END_HALF(px) * d2a;
}

// BCData stores the bstart and istart border info and the corner connecting the
// two.
class BCData {
 public:
  BCData();

  ~BCData();

  nscoord GetIStartEdge(BCBorderOwner& aOwner, bool& aStart) const;

  void SetIStartEdge(BCBorderOwner aOwner, nscoord aSize, bool aStart);

  nscoord GetBStartEdge(BCBorderOwner& aOwner, bool& aStart) const;

  void SetBStartEdge(BCBorderOwner aOwner, nscoord aSize, bool aStart);

  BCPixelSize GetCorner(mozilla::LogicalSide& aCornerOwner, bool& aBevel) const;

  void SetCorner(BCPixelSize aSubSize, mozilla::LogicalSide aOwner,
                 bool aBevel);

  inline bool IsIStartStart() const { return (bool)mIStartStart; }

  inline void SetIStartStart(bool aValue) { mIStartStart = aValue; }

  inline bool IsBStartStart() const { return (bool)mBStartStart; }

  inline void SetBStartStart(bool aValue) { mBStartStart = aValue; }

 protected:
  BCPixelSize mIStartSize;     // size in pixels of iStart border
  BCPixelSize mBStartSize;     // size in pixels of bStart border
  BCPixelSize mCornerSubSize;  // size of the largest border not in the
                               //   dominant plane (for example, if corner is
                               //   owned by the segment to its bStart or bEnd,
                               //   then the size is the max of the border
                               //   sizes of the segments to its iStart or iEnd.
  unsigned mIStartOwner : 4;   // owner of iStart border
  unsigned mBStartOwner : 4;   // owner of bStart border
  unsigned mIStartStart : 1;   // set if this is the start of a block-dir border
                               // segment
  unsigned mBStartStart : 1;   // set if this is the start of an inline-dir
                               // border segment
  unsigned mCornerSide : 2;    // LogicalSide of the owner of the bStart-iStart
                               // corner relative to the corner
  unsigned mCornerBevel : 1;   // is the corner beveled (only two segments,
                               // perpendicular, not dashed or dotted).
};

// BCCellData entries replace CellData entries in the cell map if the border
// collapsing model is in effect. BCData for a row and col entry contains the
// left and top borders of cell at that row and col and the corner connecting
// the two. The right borders of the cells in the last col and the bottom
// borders of the last row are stored in separate BCData entries in the cell
// map.
class BCCellData : public CellData {
 public:
  explicit BCCellData(nsTableCellFrame* aOrigCell);
  ~BCCellData();

  BCData mData;
};

// The layout of a celldata is as follows.  The top 10 bits are the colspan
// offset (which is enough to represent our allowed values 1-1000 for colspan).
// Then there are two bits of flags.
// XXXmats Then one unused bit that we should decide how to use in bug 862624.
// Then 16 bits of rowspan offset (which
// lets us represent numbers up to 65535.  Then another 3 bits of flags.

// num bits to shift right to get right aligned col span
#define COL_SPAN_SHIFT 22
// num bits to shift right to get right aligned row span
#define ROW_SPAN_SHIFT 3

// the col offset to the data containing the original cell.
#define COL_SPAN_OFFSET (0x3FF << COL_SPAN_SHIFT)
// the row offset to the data containing the original cell
#define ROW_SPAN_OFFSET (0xFFFF << ROW_SPAN_SHIFT)

// And the flags
#define SPAN 0x00000001                       // there a row or col span
#define ROW_SPAN 0x00000002                   // there is a row span
#define ROW_SPAN_0 0x00000004                 // the row span is 0
#define COL_SPAN (1 << (COL_SPAN_SHIFT - 2))  // there is a col span
#define OVERLAP \
  (1 << (COL_SPAN_SHIFT - 1))  // there is a row span and
                               // col span but not by
                               // same cell

inline nsTableCellFrame* CellData::GetCellFrame() const {
  if (SPAN != (SPAN & mBits)) {
    return mOrigCell;
  }
  return nullptr;
}

inline void CellData::Init(nsTableCellFrame* aCellFrame) {
  mOrigCell = aCellFrame;
}

inline bool CellData::IsOrig() const {
  return ((nullptr != mOrigCell) && (SPAN != (SPAN & mBits)));
}

inline bool CellData::IsDead() const { return (0 == mBits); }

inline bool CellData::IsSpan() const { return (SPAN == (SPAN & mBits)); }

inline bool CellData::IsRowSpan() const {
  return (SPAN == (SPAN & mBits)) && (ROW_SPAN == (ROW_SPAN & mBits));
}

inline bool CellData::IsZeroRowSpan() const {
  return (SPAN == (SPAN & mBits)) && (ROW_SPAN == (ROW_SPAN & mBits)) &&
         (ROW_SPAN_0 == (ROW_SPAN_0 & mBits));
}

inline void CellData::SetZeroRowSpan(bool aIsZeroSpan) {
  if (SPAN == (SPAN & mBits)) {
    if (aIsZeroSpan) {
      mBits |= ROW_SPAN_0;
    } else {
      mBits &= ~ROW_SPAN_0;
    }
  }
}

inline uint32_t CellData::GetRowSpanOffset() const {
  if ((SPAN == (SPAN & mBits)) && ((ROW_SPAN == (ROW_SPAN & mBits)))) {
    return (uint32_t)((mBits & ROW_SPAN_OFFSET) >> ROW_SPAN_SHIFT);
  }
  return 0;
}

inline void CellData::SetRowSpanOffset(uint32_t aSpan) {
  mBits &= ~ROW_SPAN_OFFSET;
  mBits |= (aSpan << ROW_SPAN_SHIFT);
  mBits |= SPAN;
  mBits |= ROW_SPAN;
}

inline bool CellData::IsColSpan() const {
  return (SPAN == (SPAN & mBits)) && (COL_SPAN == (COL_SPAN & mBits));
}

inline uint32_t CellData::GetColSpanOffset() const {
  if ((SPAN == (SPAN & mBits)) && ((COL_SPAN == (COL_SPAN & mBits)))) {
    return (uint32_t)((mBits & COL_SPAN_OFFSET) >> COL_SPAN_SHIFT);
  }
  return 0;
}

inline void CellData::SetColSpanOffset(uint32_t aSpan) {
  mBits &= ~COL_SPAN_OFFSET;
  mBits |= (aSpan << COL_SPAN_SHIFT);

  mBits |= SPAN;
  mBits |= COL_SPAN;
}

inline bool CellData::IsOverlap() const {
  return (SPAN == (SPAN & mBits)) && (OVERLAP == (OVERLAP & mBits));
}

inline void CellData::SetOverlap(bool aOverlap) {
  if (SPAN == (SPAN & mBits)) {
    if (aOverlap) {
      mBits |= OVERLAP;
    } else {
      mBits &= ~OVERLAP;
    }
  }
}

inline BCData::BCData() {
  mIStartOwner = mBStartOwner = eCellOwner;
  SetBStartStart(true);
  SetIStartStart(true);
  mIStartSize = mCornerSubSize = mBStartSize = 0;
  mCornerSide = mozilla::eLogicalSideBStart;
  mCornerBevel = false;
}

inline BCData::~BCData() {}

inline nscoord BCData::GetIStartEdge(BCBorderOwner& aOwner,
                                     bool& aStart) const {
  aOwner = (BCBorderOwner)mIStartOwner;
  aStart = IsIStartStart();

  return (nscoord)mIStartSize;
}

inline void BCData::SetIStartEdge(BCBorderOwner aOwner, nscoord aSize,
                                  bool aStart) {
  mIStartOwner = aOwner;
  mIStartSize = (aSize > MAX_BORDER_WIDTH) ? MAX_BORDER_WIDTH : aSize;
  SetIStartStart(aStart);
}

inline nscoord BCData::GetBStartEdge(BCBorderOwner& aOwner,
                                     bool& aStart) const {
  aOwner = (BCBorderOwner)mBStartOwner;
  aStart = IsBStartStart();

  return (nscoord)mBStartSize;
}

inline void BCData::SetBStartEdge(BCBorderOwner aOwner, nscoord aSize,
                                  bool aStart) {
  mBStartOwner = aOwner;
  mBStartSize = (aSize > MAX_BORDER_WIDTH) ? MAX_BORDER_WIDTH : aSize;
  SetBStartStart(aStart);
}

inline BCPixelSize BCData::GetCorner(mozilla::LogicalSide& aOwnerSide,
                                     bool& aBevel) const {
  aOwnerSide = mozilla::LogicalSide(mCornerSide);
  aBevel = (bool)mCornerBevel;
  return mCornerSubSize;
}

inline void BCData::SetCorner(BCPixelSize aSubSize,
                              mozilla::LogicalSide aOwnerSide, bool aBevel) {
  mCornerSubSize = aSubSize;
  mCornerSide = aOwnerSide;
  mCornerBevel = aBevel;
}

#endif