Bug 1109571 part 3 - Implement table caption specific code for ComputeAutoSize(), GetCorrectedParent() (for getting the style parent frame) and AccessibleType(). r=roc

layout/generic/nsBlockFrame.cpp

@@ -6442,6 +6442,10 @@ nsBlockFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 a11y::AccType
 nsBlockFrame::AccessibleType()
 {
+  if (IsTableCaption()) {
+    return GetRect().IsEmpty() ? a11y::eNoType : a11y::eHTMLCaptionType;
+  }
+
   // block frame may be for <hr>
   if (mContent->Tag() == nsGkAtoms::hr) {
     return a11y::eHTMLHRType;

layout/generic/nsContainerFrame.cpp

@@ -885,7 +885,7 @@ nsContainerFrame::DoInlineIntrinsicISize(nsRenderingContext *aRenderingContext,
 
 /* virtual */
 LogicalSize
-nsContainerFrame::ComputeAutoSize(nsRenderingContext *aRenderingContext,
+nsContainerFrame::ComputeAutoSize(nsRenderingContext* aRenderingContext,
                                   WritingMode aWM,
                                   const LogicalSize& aCBSize,
                                   nscoord aAvailableISize,
@@ -908,6 +908,33 @@ nsContainerFrame::ComputeAutoSize(nsRenderingContext *aRenderingContext,
   } else {
     result.ISize(aWM) = availBased;
   }
+
+  if (IsTableCaption()) {
+    // If we're a container for font size inflation, then shrink
+    // wrapping inside of us should not apply font size inflation.
+    AutoMaybeDisableFontInflation an(this);
+
+    // XXX todo: make this aware of vertical writing modes
+    uint8_t captionSide = StyleTableBorder()->mCaptionSide;
+    if (captionSide == NS_STYLE_CAPTION_SIDE_LEFT ||
+        captionSide == NS_STYLE_CAPTION_SIDE_RIGHT) {
+      result.ISize(aWM) = GetMinISize(aRenderingContext);
+    } else if (captionSide == NS_STYLE_CAPTION_SIDE_TOP ||
+               captionSide == NS_STYLE_CAPTION_SIDE_BOTTOM) {
+      // The outer frame constrains our available width to the width of
+      // the table.  Grow if our min-width is bigger than that, but not
+      // larger than the containing block width.  (It would really be nice
+      // to transmit that information another way, so we could grow up to
+      // the table's available width, but that's harder.)
+      nscoord min = GetMinISize(aRenderingContext);
+      if (min > aCBSize.ISize(aWM)) {
+        min = aCBSize.ISize(aWM);
+      }
+      if (min > result.ISize(aWM)) {
+        result.ISize(aWM) = min;
+      }
+    }
+  }
   return result;
 }
 

layout/generic/nsFrame.cpp

@@ -7080,6 +7080,9 @@ nsFrame::ChildIsDirty(nsIFrame* aChild)
 a11y::AccType
 nsFrame::AccessibleType()
 {
+  if (IsTableCaption() && !GetRect().IsEmpty()) {
+    return a11y::eHTMLCaptionType;
+  }
   return a11y::eNoType;
 }
 #endif
@@ -7748,11 +7751,20 @@ GetIBSplitSiblingForAnonymousBlock(const nsIFrame* aFrame)
 static nsIFrame*
 GetCorrectedParent(const nsIFrame* aFrame)
 {
-  nsIFrame *parent = aFrame->GetParent();
+  nsIFrame* parent = aFrame->GetParent();
   if (!parent) {
     return nullptr;
   }
 
+  // For a table caption we want the _inner_ table frame (unless it's anonymous)
+  // as the style parent.
+  if (aFrame->IsTableCaption()) {
+    nsIFrame* innerTable = parent->GetFirstPrincipalChild();
+    if (!innerTable->StyleContext()->GetPseudo()) {
+      return innerTable;
+    }
+  }
+
   // Outer tables are always anon boxes; if we're in here for an outer
   // table, that actually means its the _inner_ table that wants to
   // know its parent.  So get the pseudo of the inner in that case.

layout/generic/nsGfxScrollFrame.cpp

@@ -931,6 +931,10 @@ nsHTMLScrollFrame::GetFrameName(nsAString& aResult) const
 a11y::AccType
 nsHTMLScrollFrame::AccessibleType()
 {
+  if (IsTableCaption()) {
+    return GetRect().IsEmpty() ? a11y::eNoType : a11y::eHTMLCaptionType;
+  }
+
   // Create an accessible regardless of focusable state because the state can be
   // changed during frame life cycle without any notifications to accessibility.
   if (mContent->IsRootOfNativeAnonymousSubtree() ||