Bug 505184. When 'deflation' of the background area is not required, paint table backgrounds using a dedicated nsDisplayBackground instead of the multipurpose nsDisplayTableBorderBackground. r=fantasai

gfx/public/nsMargin.h

@@ -104,6 +104,8 @@ struct nsMargin {
                                                  right -= aMargin.right;
                                                  bottom -= aMargin.bottom;
                                                  return *this;}
+
+  PRBool IsZero() { return !left && !top && !right && !bottom; }
 };
 
 struct nsIntMargin {
@@ -138,6 +140,8 @@ struct nsIntMargin {
     return nsIntMargin(left + aMargin.left, top + aMargin.top,
                     right + aMargin.right, bottom + aMargin.bottom);
   }
+
+  PRBool IsZero() { return !left && !top && !right && !bottom; }
 };
 
 #endif /* NSMARGIN_H */

layout/tables/nsTableFrame.cpp

@@ -1409,9 +1409,21 @@ nsTableFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 
   DO_GLOBAL_REFLOW_COUNT_DSP_COLOR("nsTableFrame", NS_RGB(255,128,255));
 
+  if (GetStyleVisibility()->IsVisible()) {
+    nsMargin deflate = GetDeflationForBackground(PresContext());
+    // If 'deflate' is (0,0,0,0) then we can paint the table background
+    // in its own display item, so do that to take advantage of
+    // opacity and visibility optimizations
+    if (deflate.IsZero()) {
+      nsresult rv = DisplayBackgroundUnconditional(aBuilder, aLists, PR_FALSE);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
   // This background is created regardless of whether this frame is
   // visible or not. Visibility decisions are delegated to the
-  // table background painter.
+  // table background painter. This handles borders and backgrounds
+  // for the table.
   nsDisplayTableItem* item = new (aBuilder) nsDisplayTableBorderBackground(this);
   nsresult rv = aLists.BorderBackground()->AppendNewToTop(item);
   NS_ENSURE_SUCCESS(rv, rv);
@@ -1419,6 +1431,16 @@ nsTableFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
   return DisplayGenericTablePart(aBuilder, this, aDirtyRect, aLists, item);
 }
 
+nsMargin
+nsTableFrame::GetDeflationForBackground(nsPresContext* aPresContext) const
+{
+  if (eCompatibility_NavQuirks != aPresContext->CompatibilityMode() ||
+      !IsBorderCollapse())
+    return nsMargin(0,0,0,0);
+
+  return GetOuterBCBorder();
+}
+
 // XXX We don't put the borders and backgrounds in tree order like we should.
 // That requires some major surgery which we aren't going to do right now.
 void
@@ -1431,30 +1453,11 @@ nsTableFrame::PaintTableBorderBackground(nsIRenderingContext& aRenderingContext,
   TableBackgroundPainter painter(this, TableBackgroundPainter::eOrigin_Table,
                                  presContext, aRenderingContext,
                                  aDirtyRect, aPt);
-  nsresult rv;
-  
-  if (eCompatibility_NavQuirks == presContext->CompatibilityMode()) {
-    nsMargin deflate(0,0,0,0);
-    if (IsBorderCollapse()) {
-      PRInt32 p2t = nsPresContext::AppUnitsPerCSSPixel();
-      BCPropertyData* propData =
-        (BCPropertyData*)nsTableFrame::GetProperty((nsIFrame*)this,
-                                                   nsGkAtoms::tableBCProperty,
-                                                   PR_FALSE);
-      if (propData) {
-        deflate.top    = BC_BORDER_TOP_HALF_COORD(p2t, propData->mTopBorderWidth);
-        deflate.right  = BC_BORDER_RIGHT_HALF_COORD(p2t, propData->mRightBorderWidth);
-        deflate.bottom = BC_BORDER_BOTTOM_HALF_COORD(p2t, propData->mBottomBorderWidth);
-        deflate.left   = BC_BORDER_LEFT_HALF_COORD(p2t, propData->mLeftBorderWidth);
-      }
-    }
-    rv = painter.PaintTable(this, &deflate);
-    if (NS_FAILED(rv)) return;
-  }
-  else {
-    rv = painter.PaintTable(this, nsnull);
-    if (NS_FAILED(rv)) return;
-  }
+  nsMargin deflate = GetDeflationForBackground(presContext);
+  // If 'deflate' is (0,0,0,0) then we'll paint the table background
+  // in a separate display item, so don't do it here.
+  nsresult rv = painter.PaintTable(this, deflate, !deflate.IsZero());
+  if (NS_FAILED(rv)) return;
 
   if (GetStyleVisibility()->IsVisible()) {
     const nsStyleBorder* border = GetStyleBorder();
@@ -2593,6 +2596,7 @@ nsTableFrame::GetExcludedOuterBCBorder() const
 {
   return GetOuterBCBorder() - GetIncludedOuterBCBorder();
 }
+
 static
 void GetSeparateModelBorderPadding(const nsHTMLReflowState* aReflowState,
                                    nsStyleContext&          aStyleContext,

layout/tables/nsTableFrame.h

@@ -298,6 +298,12 @@ public:
    */
   nsMargin GetExcludedOuterBCBorder() const;
 
+  /**
+   * In quirks mode, the size of the table background is reduced
+   * by the outer BC border. Compute the reduction needed.
+   */
+  nsMargin GetDeflationForBackground(nsPresContext* aPresContext) const;
+
   /** Get width of table + colgroup + col collapse: elements that
    *  continue along the length of the whole left side.
    *  see nsTablePainter about continuous borders

layout/tables/nsTablePainter.cpp

@@ -282,15 +282,13 @@ nsresult
 TableBackgroundPainter::PaintTableFrame(nsTableFrame*         aTableFrame,
                                         nsTableRowGroupFrame* aFirstRowGroup,
                                         nsTableRowGroupFrame* aLastRowGroup,
-                                        nsMargin*             aDeflate)
+                                        const nsMargin&       aDeflate)
 {
   NS_PRECONDITION(aTableFrame, "null frame");
   TableBackgroundData tableData;
   tableData.SetFull(aTableFrame);
   tableData.mRect.MoveTo(0,0); //using table's coords
-  if (aDeflate) {
-    tableData.mRect.Deflate(*aDeflate);
-  }
+  tableData.mRect.Deflate(aDeflate);
   if (mIsBorderCollapse && tableData.ShouldSetBCBorder()) {
     if (aFirstRowGroup && aLastRowGroup && mNumCols > 0) {
       //only handle non-degenerate tables; we need a more robust BC model
@@ -354,8 +352,9 @@ TableBackgroundPainter::TranslateContext(nscoord aDX,
 }
 
 nsresult
-TableBackgroundPainter::PaintTable(nsTableFrame* aTableFrame,
-                                   nsMargin*     aDeflate)
+TableBackgroundPainter::PaintTable(nsTableFrame*   aTableFrame,
+                                   const nsMargin& aDeflate,
+                                   PRBool          aPaintTableBackground)
 {
   NS_PRECONDITION(aTableFrame, "null table frame");
 
@@ -363,13 +362,17 @@ TableBackgroundPainter::PaintTable(nsTableFrame* aTableFrame,
   aTableFrame->OrderRowGroups(rowGroups);
 
   if (rowGroups.Length() < 1) { //degenerate case
-    PaintTableFrame(aTableFrame, nsnull, nsnull, nsnull);
+    if (aPaintTableBackground) {
+      PaintTableFrame(aTableFrame, nsnull, nsnull, nsMargin(0,0,0,0));
+    }
     /* No cells; nothing else to paint */
     return NS_OK;
   }
 
-  PaintTableFrame(aTableFrame, rowGroups[0], rowGroups[rowGroups.Length() - 1],
-                  aDeflate);
+  if (aPaintTableBackground) {
+    PaintTableFrame(aTableFrame, rowGroups[0], rowGroups[rowGroups.Length() - 1],
+                    aDeflate);
+  }
 
   /*Set up column background/border data*/
   if (mNumCols > 0) {

layout/tables/nsTablePainter.h

@@ -93,21 +93,26 @@ class TableBackgroundPainter
     /* ~*~ Using nsTablePainter Background Painting ~*~
 
        A call to PaintTable will normally paint all of the table's
-       elements (except the cells in non-BC). Elements with views
-       however, will be skipped and must create their own painter
-       to call the appropriate paint function in their ::Paint
+       elements (except for the table background, if aPaintTableBackground
+       is false).
+       Elements with views however, will be skipped and must create their
+       own painter to call the appropriate paint function in their ::Paint
        method (e.g. painter.PaintRow in nsTableRow::Paint)
     */
 
-    /** Paint background for the table frame and its children down through cells
+    /** Paint background for the table frame (if requested) and its children
+      * down through cells.
       * (Cells themselves will only be painted in border collapse)
       * Table must do a flagged TABLE_BG_PAINT ::Paint call on its
       * children afterwards
       * @param aTableFrame - the table frame
       * @param aDeflate    - deflation needed to bring table's mRect
       *                      to the outer grid lines in border-collapse
+      * @param aPaintTableBackground - if true, the table background
+      * is included, otherwise it isn't
       */
-    nsresult PaintTable(nsTableFrame* aTableFrame, nsMargin* aDeflate);
+    nsresult PaintTable(nsTableFrame* aTableFrame, const nsMargin& aDeflate,
+                        PRBool aPaintTableBackground);
 
     /** Paint background for the row group and its children down through cells
       * (Cells themselves will only be painted in border collapse)
@@ -143,7 +148,7 @@ class TableBackgroundPainter
     nsresult PaintTableFrame(nsTableFrame*         aTableFrame,
                              nsTableRowGroupFrame* aFirstRowGroup,
                              nsTableRowGroupFrame* aLastRowGroup,
-                             nsMargin*             aDeflate = nsnull);
+                             const nsMargin&       aDeflate);
 
     /* aPassThrough params indicate whether to paint the element or to just
      * pass through and paint underlying layers only