The Tor Browser: layout/tables/BasicTableLayoutStrategy.cpp@deefc01c0e14 (annotated)

layout/tables/BasicTableLayoutStrategy.cpp@deefc01c0e14 (annotated)

layout/tables/BasicTableLayoutStrategy.cpp

Thu, 15 Jan 2015 21:03:48 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 21:03:48 +0100
branch: TOR_BUG_9701
changeset 11: deefc01c0e14
permissions: -rw-r--r--

Integrate friendly tips from Tor colleagues to make (or not) 4.5 alpha 3;
This includes removal of overloaded (but unused) methods, and addition of
a overlooked call to DataStruct::SetData(nsISupports, uint32_t, bool.)

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 // vim:cindent:ts=4:et:sw=4:
 /* 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/. */
 /*
  * Web-compatible algorithms that determine column and table widths,
  * used for CSS2's 'table-layout: auto'.
  */
 #include "BasicTableLayoutStrategy.h"
 #include "nsTableFrame.h"
 #include "nsTableCellFrame.h"
 #include "nsLayoutUtils.h"
 #include "nsGkAtoms.h"
 #include "SpanningCellSorter.h"
 #include <algorithm>
 using namespace mozilla;
 using namespace mozilla::layout;
 namespace css = mozilla::css;
 #undef  DEBUG_TABLE_STRATEGY
 BasicTableLayoutStrategy::BasicTableLayoutStrategy(nsTableFrame *aTableFrame)
   : nsITableLayoutStrategy(nsITableLayoutStrategy::Auto)
   , mTableFrame(aTableFrame)
 {
     MarkIntrinsicWidthsDirty();
 }
 /* virtual */
 BasicTableLayoutStrategy::~BasicTableLayoutStrategy()
 {
 }
 /* virtual */ nscoord
 BasicTableLayoutStrategy::GetMinWidth(nsRenderingContext* aRenderingContext)
 {
     DISPLAY_MIN_WIDTH(mTableFrame, mMinWidth);
     if (mMinWidth == NS_INTRINSIC_WIDTH_UNKNOWN)
         ComputeIntrinsicWidths(aRenderingContext);
     return mMinWidth;
 }
 /* virtual */ nscoord
 BasicTableLayoutStrategy::GetPrefWidth(nsRenderingContext* aRenderingContext,
                                        bool aComputingSize)
 {
     DISPLAY_PREF_WIDTH(mTableFrame, mPrefWidth);
     NS_ASSERTION((mPrefWidth == NS_INTRINSIC_WIDTH_UNKNOWN) ==
                  (mPrefWidthPctExpand == NS_INTRINSIC_WIDTH_UNKNOWN),
                  "dirtyness out of sync");
     if (mPrefWidth == NS_INTRINSIC_WIDTH_UNKNOWN)
         ComputeIntrinsicWidths(aRenderingContext);
     return aComputingSize ? mPrefWidthPctExpand : mPrefWidth;
 }
 struct CellWidthInfo {
     CellWidthInfo(nscoord aMinCoord, nscoord aPrefCoord,
                   float aPrefPercent, bool aHasSpecifiedWidth)
         : hasSpecifiedWidth(aHasSpecifiedWidth)
         , minCoord(aMinCoord)
         , prefCoord(aPrefCoord)
         , prefPercent(aPrefPercent)
     {
     }
     bool hasSpecifiedWidth;
     nscoord minCoord;
     nscoord prefCoord;
     float prefPercent;
 };
 // Used for both column and cell calculations.  The parts needed only
 // for cells are skipped when aIsCell is false.
 static CellWidthInfo
 GetWidthInfo(nsRenderingContext *aRenderingContext,
              nsIFrame *aFrame, bool aIsCell)
 {
     nscoord minCoord, prefCoord;
     const nsStylePosition *stylePos = aFrame->StylePosition();
     bool isQuirks = aFrame->PresContext()->CompatibilityMode() ==
                     eCompatibility_NavQuirks;
     nscoord boxSizingToBorderEdge = 0;
     if (aIsCell) {
         // If aFrame is a container for font size inflation, then shrink
         // wrapping inside of it should not apply font size inflation.
         AutoMaybeDisableFontInflation an(aFrame);
         minCoord = aFrame->GetMinWidth(aRenderingContext);
         prefCoord = aFrame->GetPrefWidth(aRenderingContext);
         // Until almost the end of this function, minCoord and prefCoord
         // represent the box-sizing based width values (which mean they
         // should include horizontal padding and border width when
         // box-sizing is set to border-box).
         // Note that this function returns border-box width, we add the
         // outer edges near the end of this function.
         // XXX Should we ignore percentage padding?
         nsIFrame::IntrinsicWidthOffsetData offsets = aFrame->IntrinsicWidthOffsets(aRenderingContext);
         // In quirks mode, table cell width should be content-box,
         // but height should be border box.
         // Because of this historic anomaly, we do not use quirk.css.
         // (We can't specify one value of box-sizing for width and another
         // for height).
         // For this reason, we also do not use box-sizing for just one of
         // them, as this may be confusing.
         if (isQuirks) {
             boxSizingToBorderEdge = offsets.hPadding + offsets.hBorder;
         }
         else {
             switch (stylePos->mBoxSizing) {
                 case NS_STYLE_BOX_SIZING_CONTENT:
                     boxSizingToBorderEdge = offsets.hPadding + offsets.hBorder;
                     break;
                 case NS_STYLE_BOX_SIZING_PADDING:
                     minCoord += offsets.hPadding;
                     prefCoord += offsets.hPadding;
                     boxSizingToBorderEdge = offsets.hBorder;
                     break;
                 default:
                     // NS_STYLE_BOX_SIZING_BORDER
                     minCoord += offsets.hPadding + offsets.hBorder;
                     prefCoord += offsets.hPadding + offsets.hBorder;
                     break;
             }
         }
     } else {
         minCoord = 0;
         prefCoord = 0;
     }
     float prefPercent = 0.0f;
     bool hasSpecifiedWidth = false;
     const nsStyleCoord &width = stylePos->mWidth;
     nsStyleUnit unit = width.GetUnit();
     // NOTE: We're ignoring calc() units with percentages here, for lack of a
     // sensible idea for what to do with them.  This means calc() with
     // percentages is basically handled like 'auto' for table cells and
     // columns.
     if (width.ConvertsToLength()) {
         hasSpecifiedWidth = true;
         // Note: since ComputeWidthValue was designed to return content-box
         // width, it will (in some cases) subtract the box-sizing edges.
         // We prevent this unwanted behavior by calling it with
         // aContentEdgeToBoxSizing and aBoxSizingToMarginEdge set to 0.
         nscoord w = nsLayoutUtils::ComputeWidthValue(aRenderingContext,
                                                      aFrame, 0, 0, 0, width);
         // Quirk: A cell with "nowrap" set and a coord value for the
         // width which is bigger than the intrinsic minimum width uses
         // that coord value as the minimum width.
         // This is kept up-to-date with dynamic changes to nowrap by code in
         // nsTableCellFrame::AttributeChanged
         if (aIsCell && w > minCoord && isQuirks &&
             aFrame->GetContent()->HasAttr(kNameSpaceID_None,
                                           nsGkAtoms::nowrap)) {
             minCoord = w;
         }
         prefCoord = std::max(w, minCoord);
     } else if (unit == eStyleUnit_Percent) {
         prefPercent = width.GetPercentValue();
     } else if (unit == eStyleUnit_Enumerated && aIsCell) {
         switch (width.GetIntValue()) {
             case NS_STYLE_WIDTH_MAX_CONTENT:
                 // 'width' only affects pref width, not min
                 // width, so don't change anything
                 break;
             case NS_STYLE_WIDTH_MIN_CONTENT:
                 prefCoord = minCoord;
                 break;
             case NS_STYLE_WIDTH_FIT_CONTENT:
             case NS_STYLE_WIDTH_AVAILABLE:
                 // act just like 'width: auto'
                 break;
             default:
                 NS_NOTREACHED("unexpected enumerated value");
         }
     }
     nsStyleCoord maxWidth(stylePos->mMaxWidth);
     if (maxWidth.GetUnit() == eStyleUnit_Enumerated) {
         if (!aIsCell || maxWidth.GetIntValue() == NS_STYLE_WIDTH_AVAILABLE)
             maxWidth.SetNoneValue();
         else if (maxWidth.GetIntValue() == NS_STYLE_WIDTH_FIT_CONTENT)
             // for 'max-width', '-moz-fit-content' is like
             // '-moz-max-content'
             maxWidth.SetIntValue(NS_STYLE_WIDTH_MAX_CONTENT,
                                  eStyleUnit_Enumerated);
     }
     unit = maxWidth.GetUnit();
     // XXX To really implement 'max-width' well, we'd need to store
     // it separately on the columns.
     if (maxWidth.ConvertsToLength() || unit == eStyleUnit_Enumerated) {
         nscoord w =
             nsLayoutUtils::ComputeWidthValue(aRenderingContext, aFrame,
 , 0, 0, maxWidth);
         if (w < minCoord)
             minCoord = w;
         if (w < prefCoord)
             prefCoord = w;
     } else if (unit == eStyleUnit_Percent) {
         float p = stylePos->mMaxWidth.GetPercentValue();
         if (p < prefPercent)
             prefPercent = p;
     }
     // treat calc() with percentages on max-width just like 'none'.
     nsStyleCoord minWidth(stylePos->mMinWidth);
     if (minWidth.GetUnit() == eStyleUnit_Enumerated) {
         if (!aIsCell || minWidth.GetIntValue() == NS_STYLE_WIDTH_AVAILABLE)
             minWidth.SetCoordValue(0);
         else if (minWidth.GetIntValue() == NS_STYLE_WIDTH_FIT_CONTENT)
             // for 'min-width', '-moz-fit-content' is like
             // '-moz-min-content'
             minWidth.SetIntValue(NS_STYLE_WIDTH_MIN_CONTENT,
                                  eStyleUnit_Enumerated);
     }
     unit = minWidth.GetUnit();
     if (minWidth.ConvertsToLength() || unit == eStyleUnit_Enumerated) {
         nscoord w =
             nsLayoutUtils::ComputeWidthValue(aRenderingContext, aFrame,
 , 0, 0, minWidth);
         if (w > minCoord)
             minCoord = w;
         if (w > prefCoord)
             prefCoord = w;
     } else if (unit == eStyleUnit_Percent) {
         float p = stylePos->mMinWidth.GetPercentValue();
         if (p > prefPercent)
             prefPercent = p;
     }
     // treat calc() with percentages on min-width just like '0'.
     // XXX Should col frame have border/padding considered?
     if (aIsCell) {
         minCoord += boxSizingToBorderEdge;
         prefCoord = NSCoordSaturatingAdd(prefCoord, boxSizingToBorderEdge);
     }
     return CellWidthInfo(minCoord, prefCoord, prefPercent, hasSpecifiedWidth);
 }
 static inline CellWidthInfo
 GetCellWidthInfo(nsRenderingContext *aRenderingContext,
                  nsTableCellFrame *aCellFrame)
 {
     return GetWidthInfo(aRenderingContext, aCellFrame, true);
 }
 static inline CellWidthInfo
 GetColWidthInfo(nsRenderingContext *aRenderingContext,
                 nsIFrame *aFrame)
 {
     return GetWidthInfo(aRenderingContext, aFrame, false);
 }
 /**
  * The algorithm in this function, in addition to meeting the
  * requirements of Web-compatibility, is also invariant under reordering
  * of the rows within a table (something that most, but not all, other
  * browsers are).
  */
 void
 BasicTableLayoutStrategy::ComputeColumnIntrinsicWidths(nsRenderingContext* aRenderingContext)
 {
     nsTableFrame *tableFrame = mTableFrame;
     nsTableCellMap *cellMap = tableFrame->GetCellMap();
     mozilla::AutoStackArena arena;
     SpanningCellSorter spanningCells;
     // Loop over the columns to consider the columns and cells *without*
     // a colspan.
     int32_t col, col_end;
     for (col = 0, col_end = cellMap->GetColCount(); col < col_end; ++col) {
         nsTableColFrame *colFrame = tableFrame->GetColFrame(col);
         if (!colFrame) {
             NS_ERROR("column frames out of sync with cell map");
             continue;
         }
         colFrame->ResetIntrinsics();
         colFrame->ResetSpanIntrinsics();
         // Consider the widths on the column.
         CellWidthInfo colInfo = GetColWidthInfo(aRenderingContext, colFrame);
         colFrame->AddCoords(colInfo.minCoord, colInfo.prefCoord,
                             colInfo.hasSpecifiedWidth);
         colFrame->AddPrefPercent(colInfo.prefPercent);
         // Consider the widths on the column-group.  Note that we follow
         // what the HTML spec says here, and make the width apply to
         // each column in the group, not the group as a whole.
         // If column has width, column-group doesn't override width.
         if (colInfo.minCoord == 0 && colInfo.prefCoord == 0 &&
             colInfo.prefPercent == 0.0f) {
             NS_ASSERTION(colFrame->GetParent()->GetType() ==
                              nsGkAtoms::tableColGroupFrame,
                          "expected a column-group");
             colInfo = GetColWidthInfo(aRenderingContext, colFrame->GetParent());
             colFrame->AddCoords(colInfo.minCoord, colInfo.prefCoord,
                                 colInfo.hasSpecifiedWidth);
             colFrame->AddPrefPercent(colInfo.prefPercent);
         }
         // Consider the contents of and the widths on the cells without
         // colspans.
         nsCellMapColumnIterator columnIter(cellMap, col);
         int32_t row, colSpan;
         nsTableCellFrame* cellFrame;
         while ((cellFrame = columnIter.GetNextFrame(&row, &colSpan))) {
             if (colSpan > 1) {
                 spanningCells.AddCell(colSpan, row, col);
                 continue;
             }
             CellWidthInfo info = GetCellWidthInfo(aRenderingContext, cellFrame);
             colFrame->AddCoords(info.minCoord, info.prefCoord,
                                 info.hasSpecifiedWidth);
             colFrame->AddPrefPercent(info.prefPercent);
         }
 #ifdef DEBUG_dbaron_off
         printf("table %p col %d nonspan: min=%d pref=%d spec=%d pct=%f\n",
                mTableFrame, col, colFrame->GetMinCoord(),
                colFrame->GetPrefCoord(), colFrame->GetHasSpecifiedCoord(),
                colFrame->GetPrefPercent());
 #endif
     }
 #ifdef DEBUG_TABLE_STRATEGY
     printf("ComputeColumnIntrinsicWidths single\n");
     mTableFrame->Dump(false, true, false);
 #endif
     // Consider the cells with a colspan that we saved in the loop above
     // into the spanning cell sorter.  We consider these cells by seeing
     // if they require adding to the widths resulting only from cells
     // with a smaller colspan, and therefore we must process them sorted
     // in increasing order by colspan.  For each colspan group, we
     // accumulate new values to accumulate in the column frame's Span*
     // members.
     //
     // Considering things only relative to the widths resulting from
     // cells with smaller colspans (rather than incrementally including
     // the results from spanning cells, or doing spanning and
     // non-spanning cells in a single pass) means that layout remains
     // row-order-invariant and (except for percentage widths that add to
     // more than 100%) column-order invariant.
     //
     // Starting with smaller colspans makes it more likely that we
     // satisfy all the constraints given and don't distribute space to
     // columns where we don't need it.
     SpanningCellSorter::Item *item;
     int32_t colSpan;
     while ((item = spanningCells.GetNext(&colSpan))) {
         NS_ASSERTION(colSpan > 1,
                      "cell should not have been put in spanning cell sorter");
         do {
             int32_t row = item->row;
             col = item->col;
             CellData *cellData = cellMap->GetDataAt(row, col);
             NS_ASSERTION(cellData && cellData->IsOrig(),
                          "bogus result from spanning cell sorter");
             nsTableCellFrame *cellFrame = cellData->GetCellFrame();
             NS_ASSERTION(cellFrame, "bogus result from spanning cell sorter");
             CellWidthInfo info = GetCellWidthInfo(aRenderingContext, cellFrame);
             if (info.prefPercent > 0.0f) {
                 DistributePctWidthToColumns(info.prefPercent,
                                             col, colSpan);
             }
             DistributeWidthToColumns(info.minCoord, col, colSpan,
                                      BTLS_MIN_WIDTH, info.hasSpecifiedWidth);
             DistributeWidthToColumns(info.prefCoord, col, colSpan,
                                      BTLS_PREF_WIDTH, info.hasSpecifiedWidth);
         } while ((item = item->next));
         // Combine the results of the span analysis into the main results,
         // for each increment of colspan.
         for (col = 0, col_end = cellMap->GetColCount(); col < col_end; ++col) {
             nsTableColFrame *colFrame = tableFrame->GetColFrame(col);
             if (!colFrame) {
                 NS_ERROR("column frames out of sync with cell map");
                 continue;
             }
             colFrame->AccumulateSpanIntrinsics();
             colFrame->ResetSpanIntrinsics();
 #ifdef DEBUG_dbaron_off
             printf("table %p col %d span %d: min=%d pref=%d spec=%d pct=%f\n",
                    mTableFrame, col, colSpan, colFrame->GetMinCoord(),
                    colFrame->GetPrefCoord(), colFrame->GetHasSpecifiedCoord(),
                    colFrame->GetPrefPercent());
 #endif
         }
     }
     // Prevent percentages from adding to more than 100% by (to be
     // compatible with other browsers) treating any percentages that would
     // increase the total percentage to more than 100% as the number that
     // would increase it to only 100% (which is 0% if we've already hit
     // 100%).  This means layout depends on the order of columns.
     float pct_used = 0.0f;
     for (col = 0, col_end = cellMap->GetColCount(); col < col_end; ++col) {
         nsTableColFrame *colFrame = tableFrame->GetColFrame(col);
         if (!colFrame) {
             NS_ERROR("column frames out of sync with cell map");
             continue;
         }
         colFrame->AdjustPrefPercent(&pct_used);
     }
 #ifdef DEBUG_TABLE_STRATEGY
     printf("ComputeColumnIntrinsicWidths spanning\n");
     mTableFrame->Dump(false, true, false);
 #endif
 }
 void
 BasicTableLayoutStrategy::ComputeIntrinsicWidths(nsRenderingContext* aRenderingContext)
 {
     ComputeColumnIntrinsicWidths(aRenderingContext);
     nsTableCellMap *cellMap = mTableFrame->GetCellMap();
     nscoord min = 0, pref = 0, max_small_pct_pref = 0, nonpct_pref_total = 0;
     float pct_total = 0.0f; // always from 0.0f - 1.0f
     int32_t colCount = cellMap->GetColCount();
     nscoord spacing = mTableFrame->GetCellSpacingX();
     nscoord add = spacing; // add (colcount + 1) * spacing for columns
                            // where a cell originates
     for (int32_t col = 0; col < colCount; ++col) {
         nsTableColFrame *colFrame = mTableFrame->GetColFrame(col);
         if (!colFrame) {
             NS_ERROR("column frames out of sync with cell map");
             continue;
         }
         if (mTableFrame->ColumnHasCellSpacingBefore(col)) {
             add += spacing;
         }
         min += colFrame->GetMinCoord();
         pref = NSCoordSaturatingAdd(pref, colFrame->GetPrefCoord());
         // Percentages are of the table, so we have to reverse them for
         // intrinsic widths.
         float p = colFrame->GetPrefPercent();
         if (p > 0.0f) {
             nscoord colPref = colFrame->GetPrefCoord();
             nscoord new_small_pct_expand =
                 (colPref == nscoord_MAX ?
                  nscoord_MAX : nscoord(float(colPref) / p));
             if (new_small_pct_expand > max_small_pct_pref) {
                 max_small_pct_pref = new_small_pct_expand;
             }
             pct_total += p;
         } else {
             nonpct_pref_total = NSCoordSaturatingAdd(nonpct_pref_total,
                                                      colFrame->GetPrefCoord());
         }
     }
     nscoord pref_pct_expand = pref;
     // Account for small percentages expanding the preferred width of
     // *other* columns.
     if (max_small_pct_pref > pref_pct_expand) {
         pref_pct_expand = max_small_pct_pref;
     }
     // Account for large percentages expanding the preferred width of
     // themselves.  There's no need to iterate over the columns multiple
     // times, since when there is such a need, the small percentage
     // effect is bigger anyway.  (I think!)
     NS_ASSERTION(0.0f <= pct_total && pct_total <= 1.0f,
                  "column percentage widths not adjusted down to 100%");
     if (pct_total == 1.0f) {
         if (nonpct_pref_total > 0) {
             pref_pct_expand = nscoord_MAX;
             // XXX Or should I use some smaller value?  (Test this using
             // nested tables!)
         }
     } else {
         nscoord large_pct_pref =
             (nonpct_pref_total == nscoord_MAX ?
              nscoord_MAX :
              nscoord(float(nonpct_pref_total) / (1.0f - pct_total)));
         if (large_pct_pref > pref_pct_expand)
             pref_pct_expand = large_pct_pref;
     }
     // border-spacing isn't part of the basis for percentages
     if (colCount > 0) {
         min += add;
         pref = NSCoordSaturatingAdd(pref, add);
         pref_pct_expand = NSCoordSaturatingAdd(pref_pct_expand, add);
     }
     mMinWidth = min;
     mPrefWidth = pref;
     mPrefWidthPctExpand = pref_pct_expand;
 }
 /* virtual */ void
 BasicTableLayoutStrategy::MarkIntrinsicWidthsDirty()
 {
     mMinWidth = NS_INTRINSIC_WIDTH_UNKNOWN;
     mPrefWidth = NS_INTRINSIC_WIDTH_UNKNOWN;
     mPrefWidthPctExpand = NS_INTRINSIC_WIDTH_UNKNOWN;
     mLastCalcWidth = nscoord_MIN;
 }
 /* virtual */ void
 BasicTableLayoutStrategy::ComputeColumnWidths(const nsHTMLReflowState& aReflowState)
 {
     nscoord width = aReflowState.ComputedWidth();
     if (mLastCalcWidth == width)
         return;
     mLastCalcWidth = width;
     NS_ASSERTION((mMinWidth == NS_INTRINSIC_WIDTH_UNKNOWN) ==
                  (mPrefWidth == NS_INTRINSIC_WIDTH_UNKNOWN),
                  "dirtyness out of sync");
     NS_ASSERTION((mMinWidth == NS_INTRINSIC_WIDTH_UNKNOWN) ==
                  (mPrefWidthPctExpand == NS_INTRINSIC_WIDTH_UNKNOWN),
                  "dirtyness out of sync");
     // XXX Is this needed?
     if (mMinWidth == NS_INTRINSIC_WIDTH_UNKNOWN)
         ComputeIntrinsicWidths(aReflowState.rendContext);
     nsTableCellMap *cellMap = mTableFrame->GetCellMap();
     int32_t colCount = cellMap->GetColCount();
     if (colCount <= 0)
         return; // nothing to do
     DistributeWidthToColumns(width, 0, colCount, BTLS_FINAL_WIDTH, false);
 #ifdef DEBUG_TABLE_STRATEGY
     printf("ComputeColumnWidths final\n");
     mTableFrame->Dump(false, true, false);
 #endif
 }
 void
 BasicTableLayoutStrategy::DistributePctWidthToColumns(float aSpanPrefPct,
                                                       int32_t aFirstCol,
                                                       int32_t aColCount)
 {
     // First loop to determine:
     int32_t nonPctColCount = 0; // number of spanned columns without % width
     nscoord nonPctTotalPrefWidth = 0; // total pref width of those columns
     // and to reduce aSpanPrefPct by columns that already have % width
     int32_t scol, scol_end;
     nsTableCellMap *cellMap = mTableFrame->GetCellMap();
     for (scol = aFirstCol, scol_end = aFirstCol + aColCount;
          scol < scol_end; ++scol) {
         nsTableColFrame *scolFrame = mTableFrame->GetColFrame(scol);
         if (!scolFrame) {
             NS_ERROR("column frames out of sync with cell map");
             continue;
         }
         float scolPct = scolFrame->GetPrefPercent();
         if (scolPct == 0.0f) {
             nonPctTotalPrefWidth += scolFrame->GetPrefCoord();
             if (cellMap->GetNumCellsOriginatingInCol(scol) > 0) {
                 ++nonPctColCount;
             }
         } else {
             aSpanPrefPct -= scolPct;
         }
     }
     if (aSpanPrefPct <= 0.0f || nonPctColCount == 0) {
         // There's no %-width on the colspan left over to distribute,
         // or there are no columns to which we could distribute %-width
         return;
     }
     // Second loop, to distribute what remains of aSpanPrefPct
     // between the non-percent-width spanned columns
     const bool spanHasNonPctPref = nonPctTotalPrefWidth > 0; // Loop invariant
     for (scol = aFirstCol, scol_end = aFirstCol + aColCount;
          scol < scol_end; ++scol) {
         nsTableColFrame *scolFrame = mTableFrame->GetColFrame(scol);
         if (!scolFrame) {
             NS_ERROR("column frames out of sync with cell map");
             continue;
         }
         if (scolFrame->GetPrefPercent() == 0.0f) {
             NS_ASSERTION((!spanHasNonPctPref ||
                           nonPctTotalPrefWidth != 0) &&
                          nonPctColCount != 0,
                          "should not be zero if we haven't allocated "
                          "all pref percent");
             float allocatedPct; // % width to be given to this column
             if (spanHasNonPctPref) {
                 // Group so we're multiplying by 1.0f when we need
                 // to use up aSpanPrefPct.
                 allocatedPct = aSpanPrefPct *
                     (float(scolFrame->GetPrefCoord()) /
                      float(nonPctTotalPrefWidth));
             } else if (cellMap->GetNumCellsOriginatingInCol(scol) > 0) {
                 // distribute equally when all pref widths are 0
                 allocatedPct = aSpanPrefPct / float(nonPctColCount);
             } else {
                 allocatedPct = 0.0f;
             }
             // Allocate the percent
             scolFrame->AddSpanPrefPercent(allocatedPct);
             // To avoid accumulating rounding error from division,
             // subtract this column's values from the totals.
             aSpanPrefPct -= allocatedPct;
             nonPctTotalPrefWidth -= scolFrame->GetPrefCoord();
             if (cellMap->GetNumCellsOriginatingInCol(scol) > 0) {
                 --nonPctColCount;
             }
             if (!aSpanPrefPct) {
                 // No more span-percent-width to distribute --> we're done.
                 NS_ASSERTION(spanHasNonPctPref ?
                              nonPctTotalPrefWidth == 0 :
                              nonPctColCount == 0,
                              "No more pct width to distribute, but there are "
                              "still cols that need some.");
                 return;
             }
         }
     }
 }
 void
 BasicTableLayoutStrategy::DistributeWidthToColumns(nscoord aWidth,
                                                    int32_t aFirstCol,
                                                    int32_t aColCount,
                                                    BtlsWidthType aWidthType,
                                                    bool aSpanHasSpecifiedWidth)
 {
     NS_ASSERTION(aWidthType != BTLS_FINAL_WIDTH ||
                  (aFirstCol == 0 &&
                   aColCount == mTableFrame->GetCellMap()->GetColCount()),
             "Computing final column widths, but didn't get full column range");
     // border-spacing isn't part of the basis for percentages.
     nscoord spacing = mTableFrame->GetCellSpacingX();
     nscoord subtract = 0;
     // aWidth initially includes border-spacing for the boundaries in between
     // each of the columns. We start at aFirstCol + 1 because the first
     // in-between boundary would be at the left edge of column aFirstCol + 1
     for (int32_t col = aFirstCol + 1; col < aFirstCol + aColCount; ++col) {
         if (mTableFrame->ColumnHasCellSpacingBefore(col)) {
             subtract += spacing;
         }
     }
     if (aWidthType == BTLS_FINAL_WIDTH) {
         // If we're computing final col-width, then aWidth initially includes
         // border spacing on the table's far left + far right edge, too.  Need
         // to subtract those out, too.
         subtract += spacing * 2;
     }
     aWidth = NSCoordSaturatingSubtract(aWidth, subtract, nscoord_MAX);
     /*
      * The goal of this function is to distribute |aWidth| between the
      * columns by making an appropriate AddSpanCoords or SetFinalWidth
      * call for each column.  (We call AddSpanCoords if we're
      * distributing a column-spanning cell's minimum or preferred width
      * to its spanned columns.  We call SetFinalWidth if we're
      * distributing a table's final width to its columns.)
      *
      * The idea is to either assign one of the following sets of widths
      * or a weighted average of two adjacent sets of widths.  It is not
      * possible to assign values smaller than the smallest set of
      * widths.  However, see below for handling the case of assigning
      * values larger than the largest set of widths.  From smallest to
      * largest, these are:
      *
      * 1. [guess_min] Assign all columns their min width.
      *
      * 2. [guess_min_pct] Assign all columns with percentage widths
      * their percentage width, and all other columns their min width.
      *
      * 3. [guess_min_spec] Assign all columns with percentage widths
      * their percentage width, all columns with specified coordinate
      * widths their pref width (since it doesn't matter whether it's the
      * largest contributor to the pref width that was the specified
      * contributor), and all other columns their min width.
      *
      * 4. [guess_pref] Assign all columns with percentage widths their
      * specified width, and all other columns their pref width.
      *
      * If |aWidth| is *larger* than what we would assign in (4), then we
      * expand the columns:
      *
      *   a. if any columns without a specified coordinate width or
      *   percent width have nonzero pref width, in proportion to pref
      *   width [total_flex_pref]
      *
      *   b. otherwise, if any columns without a specified coordinate
      *   width or percent width, but with cells originating in them,
      *   have zero pref width, equally between these
      *   [numNonSpecZeroWidthCols]
      *
      *   c. otherwise, if any columns without percent width have nonzero
      *   pref width, in proportion to pref width [total_fixed_pref]
      *
      *   d. otherwise, if any columns have nonzero percentage widths, in
      *   proportion to the percentage widths [total_pct]
      *
      *   e. otherwise, equally.
      */
     // Loop #1 over the columns, to figure out the four values above so
     // we know which case we're dealing with.
     nscoord guess_min = 0,
             guess_min_pct = 0,
             guess_min_spec = 0,
             guess_pref = 0,
             total_flex_pref = 0,
             total_fixed_pref = 0;
     float total_pct = 0.0f; // 0.0f to 1.0f
     int32_t numInfiniteWidthCols = 0;
     int32_t numNonSpecZeroWidthCols = 0;
     int32_t col;
     nsTableCellMap *cellMap = mTableFrame->GetCellMap();
     for (col = aFirstCol; col < aFirstCol + aColCount; ++col) {
         nsTableColFrame *colFrame = mTableFrame->GetColFrame(col);
         if (!colFrame) {
             NS_ERROR("column frames out of sync with cell map");
             continue;
         }
         nscoord min_width = colFrame->GetMinCoord();
         guess_min += min_width;
         if (colFrame->GetPrefPercent() != 0.0f) {
             float pct = colFrame->GetPrefPercent();
             total_pct += pct;
             nscoord val = nscoord(float(aWidth) * pct);
             if (val < min_width)
                 val = min_width;
             guess_min_pct += val;
             guess_pref = NSCoordSaturatingAdd(guess_pref, val);
         } else {
             nscoord pref_width = colFrame->GetPrefCoord();
             if (pref_width == nscoord_MAX) {
                 ++numInfiniteWidthCols;
             }
             guess_pref = NSCoordSaturatingAdd(guess_pref, pref_width);
             guess_min_pct += min_width;
             if (colFrame->GetHasSpecifiedCoord()) {
                 // we'll add on the rest of guess_min_spec outside the
                 // loop
                 nscoord delta = NSCoordSaturatingSubtract(pref_width,
                                                           min_width, 0);
                 guess_min_spec = NSCoordSaturatingAdd(guess_min_spec, delta);
                 total_fixed_pref = NSCoordSaturatingAdd(total_fixed_pref,
                                                         pref_width);
             } else if (pref_width == 0) {
                 if (cellMap->GetNumCellsOriginatingInCol(col) > 0) {
                     ++numNonSpecZeroWidthCols;
                 }
             } else {
                 total_flex_pref = NSCoordSaturatingAdd(total_flex_pref,
                                                        pref_width);
             }
         }
     }
     guess_min_spec = NSCoordSaturatingAdd(guess_min_spec, guess_min_pct);
     // Determine what we're flexing:
     enum Loop2Type {
         FLEX_PCT_SMALL, // between (1) and (2) above
         FLEX_FIXED_SMALL, // between (2) and (3) above
         FLEX_FLEX_SMALL, // between (3) and (4) above
         FLEX_FLEX_LARGE, // greater than (4) above, case (a)
         FLEX_FLEX_LARGE_ZERO, // greater than (4) above, case (b)
         FLEX_FIXED_LARGE, // greater than (4) above, case (c)
         FLEX_PCT_LARGE, // greater than (4) above, case (d)
         FLEX_ALL_LARGE // greater than (4) above, case (e)
     };
     Loop2Type l2t;
     // These are constants (over columns) for each case's math.  We use
     // a pair of nscoords rather than a float so that we can subtract
     // each column's allocation so we avoid accumulating rounding error.
     nscoord space; // the amount of extra width to allocate
     union {
         nscoord c;
         float f;
     } basis; // the sum of the statistic over columns to divide it
     if (aWidth < guess_pref) {
         if (aWidthType != BTLS_FINAL_WIDTH && aWidth <= guess_min) {
             // Return early -- we don't have any extra space to distribute.
             return;
         }
         NS_ASSERTION(!(aWidthType == BTLS_FINAL_WIDTH && aWidth < guess_min),
                      "Table width is less than the "
                      "sum of its columns' min widths");
         if (aWidth < guess_min_pct) {
             l2t = FLEX_PCT_SMALL;
             space = aWidth - guess_min;
             basis.c = guess_min_pct - guess_min;
         } else if (aWidth < guess_min_spec) {
             l2t = FLEX_FIXED_SMALL;
             space = aWidth - guess_min_pct;
             basis.c = NSCoordSaturatingSubtract(guess_min_spec, guess_min_pct,
                                                 nscoord_MAX);
         } else {
             l2t = FLEX_FLEX_SMALL;
             space = aWidth - guess_min_spec;
             basis.c = NSCoordSaturatingSubtract(guess_pref, guess_min_spec,
                                                 nscoord_MAX);
         }
     } else {
         space = NSCoordSaturatingSubtract(aWidth, guess_pref, nscoord_MAX);
         if (total_flex_pref > 0) {
             l2t = FLEX_FLEX_LARGE;
             basis.c = total_flex_pref;
         } else if (numNonSpecZeroWidthCols > 0) {
             l2t = FLEX_FLEX_LARGE_ZERO;
             basis.c = numNonSpecZeroWidthCols;
         } else if (total_fixed_pref > 0) {
             l2t = FLEX_FIXED_LARGE;
             basis.c = total_fixed_pref;
         } else if (total_pct > 0.0f) {
             l2t = FLEX_PCT_LARGE;
             basis.f = total_pct;
         } else {
             l2t = FLEX_ALL_LARGE;
             basis.c = aColCount;
         }
     }
 #ifdef DEBUG_dbaron_off
     printf("ComputeColumnWidths: %d columns in width %d,\n"
            "  guesses=[%d,%d,%d,%d], totals=[%d,%d,%f],\n"
            "  l2t=%d, space=%d, basis.c=%d\n",
            aColCount, aWidth,
            guess_min, guess_min_pct, guess_min_spec, guess_pref,
            total_flex_pref, total_fixed_pref, total_pct,
            l2t, space, basis.c);
 #endif
     for (col = aFirstCol; col < aFirstCol + aColCount; ++col) {
         nsTableColFrame *colFrame = mTableFrame->GetColFrame(col);
         if (!colFrame) {
             NS_ERROR("column frames out of sync with cell map");
             continue;
         }
         nscoord col_width;
         float pct = colFrame->GetPrefPercent();
         if (pct != 0.0f) {
             col_width = nscoord(float(aWidth) * pct);
             nscoord col_min = colFrame->GetMinCoord();
             if (col_width < col_min)
                 col_width = col_min;
         } else {
             col_width = colFrame->GetPrefCoord();
         }
         nscoord col_width_before_adjust = col_width;
         switch (l2t) {
             case FLEX_PCT_SMALL:
                 col_width = col_width_before_adjust = colFrame->GetMinCoord();
                 if (pct != 0.0f) {
                     nscoord pct_minus_min =
                         nscoord(float(aWidth) * pct) - col_width;
                     if (pct_minus_min > 0) {
                         float c = float(space) / float(basis.c);
                         basis.c -= pct_minus_min;
                         col_width += NSToCoordRound(float(pct_minus_min) * c);
                     }
                 }
                 break;
             case FLEX_FIXED_SMALL:
                 if (pct == 0.0f) {
                     NS_ASSERTION(col_width == colFrame->GetPrefCoord(),
                                  "wrong width assigned");
                     if (colFrame->GetHasSpecifiedCoord()) {
                         nscoord col_min = colFrame->GetMinCoord();
                         nscoord pref_minus_min = col_width - col_min;
                         col_width = col_width_before_adjust = col_min;
                         if (pref_minus_min != 0) {
                             float c = float(space) / float(basis.c);
                             basis.c -= pref_minus_min;
                             col_width += NSToCoordRound(
                                 float(pref_minus_min) * c);
                         }
                     } else
                         col_width = col_width_before_adjust =
                             colFrame->GetMinCoord();
                 }
                 break;
             case FLEX_FLEX_SMALL:
                 if (pct == 0.0f &&
                     !colFrame->GetHasSpecifiedCoord()) {
                     NS_ASSERTION(col_width == colFrame->GetPrefCoord(),
                                  "wrong width assigned");
                     nscoord col_min = colFrame->GetMinCoord();
                     nscoord pref_minus_min =
                         NSCoordSaturatingSubtract(col_width, col_min, 0);
                     col_width = col_width_before_adjust = col_min;
                     if (pref_minus_min != 0) {
                         float c = float(space) / float(basis.c);
                         // If we have infinite-width cols, then the standard
                         // adjustment to col_width using 'c' won't work,
                         // because basis.c and pref_minus_min are both
                         // nscoord_MAX and will cancel each other out in the
                         // col_width adjustment (making us assign all the
                         // space to the first inf-width col).  To correct for
                         // this, we'll also divide by numInfiniteWidthCols to
                         // spread the space equally among the inf-width cols.
                         if (numInfiniteWidthCols) {
                             if (colFrame->GetPrefCoord() == nscoord_MAX) {
                                 c = c / float(numInfiniteWidthCols);
                                 --numInfiniteWidthCols;
                             } else {
                                 c = 0.0f;
                             }
                         }
                         basis.c = NSCoordSaturatingSubtract(basis.c,
                                                             pref_minus_min,
                                                             nscoord_MAX);
                         col_width += NSToCoordRound(
                             float(pref_minus_min) * c);
                     }
                 }
                 break;
             case FLEX_FLEX_LARGE:
                 if (pct == 0.0f &&
                     !colFrame->GetHasSpecifiedCoord()) {
                     NS_ASSERTION(col_width == colFrame->GetPrefCoord(),
                                  "wrong width assigned");
                     if (col_width != 0) {
                         if (space == nscoord_MAX) {
                             basis.c -= col_width;
                             col_width = nscoord_MAX;
                         } else {
                             float c = float(space) / float(basis.c);
                             basis.c -= col_width;
                             col_width += NSToCoordRound(float(col_width) * c);
                         }
                     }
                 }
                 break;
             case FLEX_FLEX_LARGE_ZERO:
                 if (pct == 0.0f &&
                     !colFrame->GetHasSpecifiedCoord() &&
                     cellMap->GetNumCellsOriginatingInCol(col) > 0) {
                     NS_ASSERTION(col_width == 0 &&
                                  colFrame->GetPrefCoord() == 0,
                                  "Since we're in FLEX_FLEX_LARGE_ZERO case, "
                                  "all auto-width cols should have zero pref "
                                  "width.");
                     float c = float(space) / float(basis.c);
                     col_width += NSToCoordRound(c);
                     --basis.c;
                 }
                 break;
             case FLEX_FIXED_LARGE:
                 if (pct == 0.0f) {
                     NS_ASSERTION(col_width == colFrame->GetPrefCoord(),
                                  "wrong width assigned");
                     NS_ASSERTION(colFrame->GetHasSpecifiedCoord() ||
                                  colFrame->GetPrefCoord() == 0,
                                  "wrong case");
                     if (col_width != 0) {
                         float c = float(space) / float(basis.c);
                         basis.c -= col_width;
                         col_width += NSToCoordRound(float(col_width) * c);
                     }
                 }
                 break;
             case FLEX_PCT_LARGE:
                 NS_ASSERTION(pct != 0.0f || colFrame->GetPrefCoord() == 0,
                              "wrong case");
                 if (pct != 0.0f) {
                     float c = float(space) / basis.f;
                     col_width += NSToCoordRound(pct * c);
                     basis.f -= pct;
                 }
                 break;
             case FLEX_ALL_LARGE:
                 {
                     float c = float(space) / float(basis.c);
                     col_width += NSToCoordRound(c);
                     --basis.c;
                 }
                 break;
         }
         // Only subtract from space if it's a real number.
         if (space != nscoord_MAX) {
             NS_ASSERTION(col_width != nscoord_MAX,
                  "How is col_width nscoord_MAX if space isn't?");
             NS_ASSERTION(col_width_before_adjust != nscoord_MAX,
                  "How is col_width_before_adjust nscoord_MAX if space isn't?");
             space -= col_width - col_width_before_adjust;
         }
         NS_ASSERTION(col_width >= colFrame->GetMinCoord(),
                      "assigned width smaller than min");
         // Apply the new width
         switch (aWidthType) {
             case BTLS_MIN_WIDTH:
                 {
                     // Note: AddSpanCoords requires both a min and pref width.
                     // For the pref width, we'll just pass in our computed
                     // min width, because the real pref width will be at least
                     // as big
                     colFrame->AddSpanCoords(col_width, col_width,
                                             aSpanHasSpecifiedWidth);
                 }
                 break;
             case BTLS_PREF_WIDTH:
                 {
                     // Note: AddSpanCoords requires both a min and pref width.
                     // For the min width, we'll just pass in 0, because
                     // the real min width will be at least 0
                     colFrame->AddSpanCoords(0, col_width,
                                             aSpanHasSpecifiedWidth);
                 }
                 break;
             case BTLS_FINAL_WIDTH:
                 {
                     nscoord old_final = colFrame->GetFinalWidth();
                     colFrame->SetFinalWidth(col_width);
                     if (old_final != col_width)
                         mTableFrame->DidResizeColumns();
                 }
                 break;
         }
     }
     NS_ASSERTION((space == 0 || space == nscoord_MAX) &&
                  ((l2t == FLEX_PCT_LARGE)
                     ? (-0.001f < basis.f && basis.f < 0.001f)
                     : (basis.c == 0 || basis.c == nscoord_MAX)),
                  "didn't subtract all that we added");
 }

The Tor Browser / annotate

layout/tables/BasicTableLayoutStrategy.cpp@deefc01c0e14 (annotated)

layout/tables/BasicTableLayoutStrategy.cpp