diff -r 000000000000 -r 6474c204b198 layout/tables/BasicTableLayoutStrategy.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/layout/tables/BasicTableLayoutStrategy.cpp Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,1058 @@ +/* -*- 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 + +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, 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, 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"); +}