Bug 400057. Make nsBlockInFlowLineIterator useful for finding the line containing a frame, searching across block continuations and their overflow lines. Use it in various places, especially in textrun construction. r+sr=dbaron

layout/base/nsCaret.cpp

@@ -646,8 +646,9 @@ FindContainingLine(nsIFrame* aFrame)
     nsBlockFrame* blockParent;
     if (NS_SUCCEEDED(parent->QueryInterface(kBlockFrameCID, (void**)&blockParent)))
     {
-      nsBlockFrame::line_iterator line = blockParent->FindLineFor(aFrame);
-      return line != blockParent->end_lines() ? line.get() : nsnull;
+      PRBool isValid;
+      nsBlockInFlowLineIterator iter(blockParent, aFrame, &isValid);
+      return isValid ? iter.GetLine().get() : nsnull;
     }
     aFrame = parent;
   }

layout/generic/nsBlockFrame.cpp

@@ -1582,33 +1582,6 @@ nsBlockFrame::PrepareResizeReflow(nsBlockReflowState& aState)
 
 //----------------------------------------
 
-nsBlockFrame::line_iterator
-nsBlockFrame::FindLineFor(nsIFrame* aFrame)
-{
-  NS_PRECONDITION(aFrame, "why pass a null frame?");
-  line_iterator line = begin_lines(),
-                line_end = end_lines();
-  for ( ; line != line_end; ++line) {
-    // If the target frame is in-flow, and this line contains the it,
-    // then we've found our line.
-    if (line->Contains(aFrame))
-      return line;
-
-    // If the target frame is floated, and this line contains the
-    // float's placeholder, then we've found our line.
-    if (line->HasFloats()) {
-      for (nsFloatCache *fc = line->GetFirstFloat();
-           fc != nsnull;
-           fc = fc->Next()) {
-        if (aFrame == fc->mPlaceholder->GetOutOfFlowFrame())
-          return line;
-      }
-    }
-  }
-
-  return line_end;
-}
-
 /**
  * Propagate reflow "damage" from from earlier lines to the current
  * line.  The reflow damage comes from the following sources:
@@ -3597,9 +3570,10 @@ nsBlockFrame::ReflowInlineFrame(nsBlockReflowState& aState,
     aState.mReflowStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
     nsBlockFrame* ourNext = static_cast<nsBlockFrame*>(GetNextInFlow());
     if (ourNext && aFrame->GetNextInFlow()) {
-      line_iterator f = ourNext->FindLineFor(aFrame->GetNextInFlow());
-      if (f != ourNext->end_lines()) {
-        f->MarkDirty();
+      PRBool isValid;
+      nsBlockInFlowLineIterator iter(ourNext, aFrame->GetNextInFlow(), &isValid);
+      if (isValid) {
+        iter.GetLine()->MarkDirty();
       }
     }
   }
@@ -5161,6 +5135,51 @@ nsBlockInFlowLineIterator::nsBlockInFlowLineIterator(nsBlockFrame* aFrame,
   *aFoundValidLine = FindValidLine();
 }
 
+static nsIFrame*
+FindChildContaining(nsBlockFrame* aFrame, nsIFrame* aFindFrame)
+{
+  nsIFrame* child;
+  while (PR_TRUE) {
+    nsIFrame* block = aFrame;
+    while (PR_TRUE) {
+      child = nsLayoutUtils::FindChildContainingDescendant(block, aFindFrame);
+      if (child)
+        break;
+      block = block->GetNextContinuation();
+    }
+    if (!child)
+      return nsnull;
+    if (!(child->GetStateBits() & NS_FRAME_OUT_OF_FLOW))
+      break;
+    aFindFrame = aFrame->PresContext()->FrameManager()->GetPlaceholderFrameFor(child);
+  }
+
+  return child;
+}
+
+nsBlockInFlowLineIterator::nsBlockInFlowLineIterator(nsBlockFrame* aFrame,
+    nsIFrame* aFindFrame, PRBool* aFoundValidLine)
+  : mFrame(aFrame), mInOverflowLines(nsnull)
+{
+  mLine = aFrame->begin_lines();
+
+  *aFoundValidLine = PR_FALSE;
+
+  nsIFrame* child = FindChildContaining(aFrame, aFindFrame);
+  if (!child)
+    return;
+
+  if (!FindValidLine())
+    return;
+
+  do {
+    if (mLine->Contains(child)) {
+      *aFoundValidLine = PR_TRUE;
+      return;
+    }
+  } while (Next());
+}
+
 PRBool
 nsBlockInFlowLineIterator::IsLastLineInList()
 {
@@ -6244,9 +6263,10 @@ nsBlockFrame::ChildIsDirty(nsIFrame* aChild)
     // Mark the line containing the child frame dirty. We would rather do this
     // in MarkIntrinsicWidthsDirty but that currently won't tell us which
     // child is being dirtied.
-    line_iterator fline = FindLineFor(aChild);
-    if (fline != end_lines()) {
-      MarkLineDirty(fline);
+    PRBool isValid;
+    nsBlockInFlowLineIterator iter(this, aChild, &isValid);
+    if (isValid) {
+      MarkLineDirty(iter.GetLine());
     }
   }
 

layout/generic/nsBlockFrame.h

@@ -273,10 +273,6 @@ public:
     */
   nsIFrame* GetTopBlockChild(nsPresContext *aPresContext);
 
-  // Returns the line containing aFrame, or end_lines() if the frame
-  // isn't in the block.
-  line_iterator FindLineFor(nsIFrame* aFrame);
-
   static nsresult GetCurrentLine(nsBlockReflowState *aState, nsLineBox **aOutCurrentLine);
 
   // Create a contination for aPlaceholder and its out of flow frame and
@@ -692,8 +688,20 @@ class nsBlockInFlowLineIterator {
 public:
   typedef nsBlockFrame::line_iterator line_iterator;
   nsBlockInFlowLineIterator(nsBlockFrame* aFrame, line_iterator aLine, PRBool aInOverflow);
+  /**
+   * Set up the iterator to point to the first line found starting from
+   * aFrame. Sets aFoundValidLine to false if there is no such line.
+   */
   nsBlockInFlowLineIterator(nsBlockFrame* aFrame, PRBool* aFoundValidLine);
-  
+  /**
+   * Set up the iterator to point to the line that contains aFindFrame (either
+   * directly or indirectly).  If aFrame is out of flow, or contained in an
+   * out-of-flow, finds the line containing the out-of-flow's placeholder. If
+   * the frame is not found, sets aFoundValidLine to false.
+   */
+  nsBlockInFlowLineIterator(nsBlockFrame* aFrame, nsIFrame* aFindFrame,
+                            PRBool* aFoundValidLine);
+
   line_iterator GetLine() { return mLine; }
   PRBool IsLastLineInList();
   nsBlockFrame* GetContainer() { return mFrame; }

layout/generic/nsHTMLReflowState.cpp

@@ -936,11 +936,11 @@ nsHTMLReflowState::CalculateHypotheticalBox(nsPresContext*    aPresContext,
   nsBlockFrame* blockFrame;
   if (NS_SUCCEEDED(aContainingBlock->QueryInterface(kBlockFrameCID,
                                   reinterpret_cast<void**>(&blockFrame)))) {
-    // We need the immediate child of the block frame, and that may not be
-    // the placeholder frame
-    nsIFrame *blockChild =
-      nsLayoutUtils::FindChildContainingDescendant(blockFrame, aPlaceholderFrame);
-    nsBlockFrame::line_iterator lineBox = blockFrame->FindLineFor(blockChild);
+    PRBool isValid;
+    nsBlockInFlowLineIterator iter(blockFrame, aPlaceholderFrame, &isValid);
+    NS_ASSERTION(isValid, "Can't find placeholder!");
+    NS_ASSERTION(iter.GetContainer() == blockFrame, "Found placeholder in wrong block!");
+    nsBlockFrame::line_iterator lineBox = iter.GetLine();
 
     // How we determine the hypothetical box depends on whether the element
     // would have been inline-level or block-level

layout/generic/nsTextFrameThebes.cpp

@@ -838,6 +838,9 @@ static void
 BuildTextRuns(gfxContext* aContext, nsTextFrame* aForFrame,
               nsIFrame* aLineContainer, const nsLineList::iterator* aForFrameLine)
 {
+  NS_ASSERTION(aForFrame || aForFrameLine,
+               "One of aForFrame or aForFrameLine must be set!");
+  
   if (!aLineContainer) {
     aLineContainer = FindLineContainer(aForFrame);
   } else {
@@ -869,23 +872,18 @@ BuildTextRuns(gfxContext* aContext, nsTextFrame* aForFrame,
   }
 
   // Find the line containing aForFrame
-  nsBlockFrame::line_iterator startLine;
+
+  PRBool isValid = PR_TRUE;
+  nsBlockInFlowLineIterator backIterator(block, &isValid);
   if (aForFrameLine) {
-    startLine = *aForFrameLine;
+    backIterator = nsBlockInFlowLineIterator(block, *aForFrameLine, PR_FALSE);
   } else {
-    NS_ASSERTION(aForFrame, "One of aForFrame or aForFrameLine must be set!");
-    nsIFrame* immediateChild =
-      nsLayoutUtils::FindChildContainingDescendant(block, aForFrame);
-    // This may be a float e.g. for a floated first-letter
-    if (immediateChild->GetStateBits() & NS_FRAME_OUT_OF_FLOW) {
-      immediateChild =
-        nsLayoutUtils::FindChildContainingDescendant(block,
-          presContext->FrameManager()->GetPlaceholderFrameFor(immediateChild));
-    }
-    startLine = block->FindLineFor(immediateChild);
-    NS_ASSERTION(startLine != block->end_lines(),
-                 "Frame is not in the block!!!");
+    backIterator = nsBlockInFlowLineIterator(block, aForFrame, &isValid);
+    NS_ASSERTION(isValid, "aForFrame not found in block, someone lied to us");
+    NS_ASSERTION(backIterator.GetContainer() == block,
+                 "Someone lied to us about the block");
   }
+  nsBlockFrame::line_iterator startLine = backIterator.GetLine();
 
   // Find a line where we can start building text runs. We choose the last line
   // where:
@@ -900,17 +898,14 @@ BuildTextRuns(gfxContext* aContext, nsTextFrame* aForFrame,
   // but we discard them instead of assigning them to frames.
   // This is a little awkward because we traverse lines in the reverse direction
   // but we traverse the frames in each line in the forward direction.
-  nsBlockInFlowLineIterator backIterator(block, startLine, PR_FALSE);
+  nsBlockInFlowLineIterator forwardIterator = backIterator;
   nsTextFrame* stopAtFrame = aForFrame;
   nsTextFrame* nextLineFirstTextFrame = nsnull;
   PRBool seenTextRunBoundaryOnLaterLine = PR_FALSE;
   PRBool mayBeginInTextRun = PR_TRUE;
-  PRBool inOverflow = PR_FALSE;
-  nsBlockFrame::line_iterator line;
   while (PR_TRUE) {
-    line = backIterator.GetLine();
-    block = backIterator.GetContainer();
-    inOverflow = backIterator.GetInOverflow();
+    forwardIterator = backIterator;
+    nsBlockFrame::line_iterator line = backIterator.GetLine();
     if (!backIterator.Prev() || backIterator.GetLine()->IsBlock()) {
       mayBeginInTextRun = PR_FALSE;
       break;
@@ -954,11 +949,10 @@ BuildTextRuns(gfxContext* aContext, nsTextFrame* aForFrame,
   // text frames will be accumulated into textRunFrames as we go. When a
   // text run boundary is required we flush textRunFrames ((re)building their
   // gfxTextRuns as necessary).
-  nsBlockInFlowLineIterator forwardIterator(block, line, inOverflow);
   PRBool seenStartLine = PR_FALSE;
   PRUint32 linesAfterStartLine = 0;
   do {
-    line = forwardIterator.GetLine();
+    nsBlockFrame::line_iterator line = forwardIterator.GetLine();
     if (line->IsBlock())
       break;
     line->SetInvalidateTextRuns(PR_FALSE);