Bug 1416099 - part 7: Make HTMLEditRules::ReturnInParagraph() use start of selection to split parent block instead of receiving the point from arguments r=m_kato

Now, we know HTMLEditRules::ReturnInParagraph() always splits the parent block
at start of selection.  So, it doesn't need to receive the position from the
caller because the cost to get start of selection from first range of Selection
is really cheap.

MozReview-Commit-ID: EvNb6lUBLdt

--HG--
extra : rebase_source : 448fcb4e3a3c6df777825e8747839d6cd9ee2d56

editor/libeditor/HTMLEditRules.cpp

@@ -1802,11 +1802,7 @@ HTMLEditRules::WillInsertBreak(Selection& aSelection,
       (separator != ParagraphSeparator::br &&
        blockParent->IsAnyOfHTMLElements(nsGkAtoms::p, nsGkAtoms::div))) {
     // Paragraphs: special rules to look for <br>s
-    EditActionResult result =
-      ReturnInParagraph(aSelection, *blockParent,
-                        atStartOfSelection.Container(),
-                        atStartOfSelection.Offset(),
-                        atStartOfSelection.GetChildAtOffset());
+    EditActionResult result = ReturnInParagraph(aSelection, *blockParent);
     if (NS_WARN_IF(result.Failed())) {
       return result.Rv();
     }
@@ -6734,21 +6730,24 @@ HTMLEditRules::ReturnInHeader(Selection& aSelection,
 
 EditActionResult
 HTMLEditRules::ReturnInParagraph(Selection& aSelection,
-                                 nsINode& aParentDivOrP,
-                                 nsINode* aNode,
-                                 int32_t aOffset,
-                                 nsIContent* aChildAtOffset)
+                                 nsINode& aParentDivOrP)
 {
   if (NS_WARN_IF(!mHTMLEditor)) {
     return EditActionResult(NS_ERROR_NOT_AVAILABLE);
   }
 
-  nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
-  if (!node) {
-    return EditActionResult(NS_ERROR_NULL_POINTER);
+  RefPtr<HTMLEditor> htmlEditor = mHTMLEditor;
+
+  nsRange* firstRange = aSelection.GetRangeAt(0);
+  if (NS_WARN_IF(!firstRange)) {
+    return EditActionResult(NS_ERROR_FAILURE);
   }
 
-  RefPtr<HTMLEditor> htmlEditor = mHTMLEditor;
+  EditorDOMPoint atStartOfSelection(firstRange->StartRef());
+  if (NS_WARN_IF(!atStartOfSelection.IsSet())) {
+    return EditActionResult(NS_ERROR_FAILURE);
+  }
+  MOZ_ASSERT(atStartOfSelection.IsSetAndValid());
 
   bool doesCRCreateNewP = htmlEditor->GetReturnInParagraphCreatesNewParagraph();
 
@@ -6757,39 +6756,41 @@ HTMLEditRules::ReturnInParagraph(Selection& aSelection,
 
   // Point to split aParentDivOrP.
   // XXX If we don't need to use nsIDOMNode here, we should use EditorDOMPoint.
-  nsCOMPtr<nsIDOMNode> containerAtSplitPoint = GetAsDOMNode(aNode);
-  int32_t offsetAtSplitPoint = aOffset;
+  nsCOMPtr<nsIDOMNode> containerAtSplitPoint =
+    GetAsDOMNode(atStartOfSelection.Container());
+  int32_t offsetAtSplitPoint = atStartOfSelection.Offset();
 
   EditorRawDOMPoint pointToInsertBR;
-  if (aNode == &aParentDivOrP && doesCRCreateNewP) {
-    // We are at the edges of the block, we don't need to create new <br>.
+  if (doesCRCreateNewP &&
+      atStartOfSelection.Container() == &aParentDivOrP) {
+    // We are at the edges of the block, so, we don't need to create new <br>.
     brNode = nullptr;
-  } else if (EditorBase::IsTextNode(aNode)) {
+  } else if (EditorBase::IsTextNode(atStartOfSelection.Container())) {
     // at beginning of text node?
-    if (!aOffset) {
+    if (atStartOfSelection.IsStartOfContainer()) {
       // is there a BR prior to it?
-      brNode = htmlEditor->GetPriorHTMLSibling(node);
+      brNode = htmlEditor->GetPriorHTMLSibling(atStartOfSelection.Container());
       if (!brNode ||
           !htmlEditor->IsVisibleBRElement(brNode) ||
           TextEditUtils::HasMozAttr(GetAsDOMNode(brNode))) {
-        pointToInsertBR.Set(node);
+        pointToInsertBR.Set(atStartOfSelection.Container());
         brNode = nullptr;
       }
-    } else if (aOffset == static_cast<int32_t>(node->Length())) {
+    } else if (atStartOfSelection.IsEndOfContainer()) {
       // we're at the end of text node...
       // is there a BR after to it?
-      brNode = htmlEditor->GetNextHTMLSibling(node);
+      brNode = htmlEditor->GetNextHTMLSibling(atStartOfSelection.Container());
       if (!brNode ||
           !htmlEditor->IsVisibleBRElement(brNode) ||
           TextEditUtils::HasMozAttr(GetAsDOMNode(brNode))) {
-        pointToInsertBR.Set(node);
+        pointToInsertBR.Set(atStartOfSelection.Container());
         DebugOnly<bool> advanced = pointToInsertBR.AdvanceOffset();
         NS_WARNING_ASSERTION(advanced,
-          "Failed to advance offset to after the container");
+          "Failed to advance offset to after the container of selection start");
         brNode = nullptr;
       }
     } else {
-      nsCOMPtr<nsINode> leftNode = node;
+      nsCOMPtr<nsINode> leftNode = atStartOfSelection.Container();
 
       if (doesCRCreateNewP) {
         nsCOMPtr<nsIDOMNode> leftDOMNode;
@@ -6808,25 +6809,22 @@ HTMLEditRules::ReturnInParagraph(Selection& aSelection,
       pointToInsertBR.Set(leftNode);
       DebugOnly<bool> advanced = pointToInsertBR.AdvanceOffset();
       NS_WARNING_ASSERTION(advanced,
-        "Failed to advance offset to after the container");
+        "Failed to advance offset to after the container of selection start");
     }
   } else {
     // not in a text node.
     // is there a BR prior to it?
     nsCOMPtr<nsIContent> nearNode;
-    nearNode = htmlEditor->GetPreviousEditableHTMLNode(
-                             EditorRawDOMPoint(node, aChildAtOffset, aOffset));
+    nearNode =
+      htmlEditor->GetPreviousEditableHTMLNode(atStartOfSelection.AsRaw());
     if (!nearNode || !htmlEditor->IsVisibleBRElement(nearNode) ||
         TextEditUtils::HasMozAttr(GetAsDOMNode(nearNode))) {
       // is there a BR after it?
       nearNode =
-        htmlEditor->GetNextEditableHTMLNode(
-                      EditorRawDOMPoint(node, aChildAtOffset, aOffset));
+        htmlEditor->GetNextEditableHTMLNode(atStartOfSelection.AsRaw());
       if (!nearNode || !htmlEditor->IsVisibleBRElement(nearNode) ||
           TextEditUtils::HasMozAttr(GetAsDOMNode(nearNode))) {
-        pointToInsertBR.Set(node, aOffset);
-        NS_WARNING_ASSERTION(pointToInsertBR.IsSetAndValid(),
-          "Failed to set point to insert <br> to given node");
+        pointToInsertBR = atStartOfSelection;
         splitAfterNewBR = true;
       }
     }

editor/libeditor/HTMLEditRules.h

@@ -297,22 +297,19 @@ protected:
 
   /**
    * ReturnInParagraph() does the right thing for Enter key press or
-   * 'insertParagraph' command in aParentDivOrP.
+   * 'insertParagraph' command in aParentDivOrP.  aParentDivOrP will be
+   * split at start of first selection range.
    *
-   * @param aSelection      The selection
+   * @param aSelection      The selection.  aParentDivOrP will be split at
+   *                        start of the first selection range.
    * @param aParentDivOrP   The parent block.  This must be <p> or <div>
    *                        element.
-   * @param aTextNode
-   * @param aOffset
-   * @param aChildAtOffset
    * @return                Returns with NS_OK if this doesn't meat any
    *                        unexpected situation.  If this method tries to
    *                        split the paragraph, marked as handled.
    */
   EditActionResult ReturnInParagraph(Selection& aSelection,
-                                     nsINode& aParentDivOrP,
-                                     nsINode* aTextNode, int32_t aOffset,
-                                     nsIContent* aChildAtOffset);
+                                     nsINode& aParentDivOrP);
 
   /**
    * SplitParagraph() splits the parent block, aPara, at aSelNode - aOffset.