Bug 1484128 - part 1: Create HTMLEditor::GetFirstSelectedTableCellEle…

…ment() for internal use of HTMLEditor::GetFirstSelectedCell() r=m_kato

HTMLEditor::GetFirstSelectedCell() is an XPCOM method, but used internally a
lot.  Therefore, we should create a non-virtual method for internal use.

This patch creates HTMLEditor::GetFirstSelectedTableCellElement(), and it
won't return NS_SUCCESS_EDITOR_ELEMENT_NOT_FOUND since nobody needs the
value.  It's enough to check whether the result is nullptr without error for
any callers.

Differential Revision: https://phabricator.services.mozilla.com/D4060

editor/libeditor/HTMLEditRules.cpp

@@ -2350,18 +2350,21 @@ HTMLEditRules::WillDeleteSelection(nsIEditor::EDirection aAction,
   }
 
   // First check for table selection mode.  If so, hand off to table editor.
-  RefPtr<Element> cell;
-  nsresult rv =
-    HTMLEditorRef().GetFirstSelectedCell(nullptr, getter_AddRefs(cell));
-  if (NS_SUCCEEDED(rv) && cell) {
-    rv = HTMLEditorRef().DeleteTableCellContents();
+  ErrorResult error;
+  RefPtr<Element> cellElement =
+    HTMLEditorRef().GetFirstSelectedTableCellElement(SelectionRef(),
+                                                     error);
+  if (cellElement) {
+    error.SuppressException();
+    nsresult rv = HTMLEditorRef().DeleteTableCellContents();
     if (NS_WARN_IF(!CanHandleEditAction())) {
       return NS_ERROR_EDITOR_DESTROYED;
     }
     *aHandled = true;
     return rv;
   }
-  cell = nullptr;
+  nsresult rv = error.StealNSResult();
+  cellElement = nullptr;
 
   // origCollapsed is used later to determine whether we should join blocks. We
   // don't really care about bCollapsed because it will be modified by
@@ -2443,7 +2446,8 @@ HTMLEditRules::WillDeleteSelection(nsIEditor::EDirection aAction,
     if (!visNode) {
       // Can't find anything to delete!
       *aCancel = true;
-      // XXX This is the result of HTMLEditorRef().GetFirstSelectedCell().
+      // XXX This is the result of
+      //     HTMLEditorRef().GetFirstSelectedTableCellElement().
       //     The value could be both an error and NS_OK.
       return rv;
     }

editor/libeditor/HTMLEditor.cpp

@@ -3003,18 +3003,31 @@ HTMLEditor::SetHTMLBackgroundColorWithTransaction(const nsAString& aColor)
   RefPtr<nsAtom> bgColorAtom = NS_Atomize("bgcolor");
   if (element) {
     if (selectedCount > 0) {
-      // Traverse all selected cells
-      RefPtr<Element> cell;
-      rv = GetFirstSelectedCell(nullptr, getter_AddRefs(cell));
-      if (NS_SUCCEEDED(rv) && cell) {
-        while (cell) {
-          rv = setColor ?
-                 SetAttributeWithTransaction(*cell, *bgColorAtom, aColor) :
-                 RemoveAttributeWithTransaction(*cell, *bgColorAtom);
+      RefPtr<Selection> selection = GetSelection();
+      if (NS_WARN_IF(!selection)) {
+        return NS_ERROR_FAILURE;
+      }
+      IgnoredErrorResult ignoredError;
+      RefPtr<Element> cellElement =
+        GetFirstSelectedTableCellElement(*selection, ignoredError);
+      if (cellElement) {
+        if (setColor) {
+          while (cellElement) {
+            rv =
+              SetAttributeWithTransaction(*cellElement, *bgColorAtom, aColor);
+            if (NS_WARN_IF(NS_FAILED(rv))) {
+              return rv;
+            }
+            GetNextSelectedCell(nullptr, getter_AddRefs(cellElement));
+          }
+          return NS_OK;
+        }
+        while (cellElement) {
+          rv = RemoveAttributeWithTransaction(*cellElement, *bgColorAtom);
           if (NS_FAILED(rv)) {
             return rv;
           }
-          GetNextSelectedCell(nullptr, getter_AddRefs(cell));
+          GetNextSelectedCell(nullptr, getter_AddRefs(cellElement));
         }
         return NS_OK;
       }

editor/libeditor/HTMLEditor.h

@@ -530,6 +530,28 @@ class HTMLEditor final : public TextEditor
    */
   Element* GetSelectionContainerElement(Selection& aSelection) const;
 
+  /**
+   * GetFirstSelectedTableCellElement() returns a <td> or <th> element if
+   * first range of Selection (i.e., result of Selection::GetRangeAt(0))
+   * selects a <td> element or <th> element.  Even if Selection is in
+   * a cell element, this returns nullptr.  And even if 2nd or later
+   * range of Selection selects a cell element, also returns nullptr.
+   * Note that when this looks for a cell element, this resets the internal
+   * index of ranges of Selection.  When you call GetNextSelectedCell() after
+   * a call of this, it'll return 2nd selected cell if there is.
+   *
+   * @param aSelection          Selection for this editor.
+   * @param aRv                 Returns error if there is no selection or
+   *                            first range of Selection is unexpected.
+   * @return                    A <td> or <th> element is selected by first
+   *                            range of Selection.  Note that the range must
+   *                            be: startContaienr and endContainer are same
+   *                            <tr> element, startOffset + 1 equals endOffset.
+   */
+  already_AddRefed<Element>
+  GetFirstSelectedTableCellElement(Selection& aSelection,
+                                   ErrorResult& aRv) const;
+
   void IsNextCharInNodeWhitespace(nsIContent* aContent,
                                   int32_t aOffset,
                                   bool* outIsSpace,
@@ -1214,7 +1236,7 @@ class HTMLEditor final : public TextEditor
   nsresult GetLastCellInRow(nsINode* aRowNode,
                             nsINode** aCellNode);
 
-  nsresult GetCellFromRange(nsRange* aRange, Element** aCell);
+  static nsresult GetCellFromRange(nsRange* aRange, Element** aCell);
 
   /**
    * This sets background on the appropriate container element (table, cell,)
@@ -1855,8 +1877,9 @@ class HTMLEditor final : public TextEditor
   bool mCSSAware;
   UniquePtr<CSSEditUtils> mCSSEditUtils;
 
-  // Used by GetFirstSelectedCell and GetNextSelectedCell
-  int32_t  mSelectedCellIndex;
+  // mSelectedCellIndex is reset by GetFirstSelectedTableCellElement(),
+  // then, it'll be referred and incremented by GetNextSelectedCell().
+  mutable int32_t mSelectedCellIndex;
 
   nsString mLastStyleSheetURL;
   nsString mLastOverrideStyleSheetURL;

editor/libeditor/HTMLEditorDataTransfer.cpp

@@ -203,7 +203,9 @@ HTMLEditor::DoInsertHTMLWithContext(const nsAString& aInputString,
 
   // Get selection
   RefPtr<Selection> selection = GetSelection();
-  NS_ENSURE_STATE(selection);
+  if (NS_WARN_IF(!selection)) {
+    return NS_ERROR_FAILURE;
+  }
 
   // create a dom document fragment that represents the structure to paste
   nsCOMPtr<nsINode> fragmentAsNode, streamStartParent, streamEndParent;
@@ -282,9 +284,10 @@ HTMLEditor::DoInsertHTMLWithContext(const nsAString& aInputString,
   // Are there any table elements in the list?
   // check for table cell selection mode
   bool cellSelectionMode = false;
-  RefPtr<Element> cell;
-  rv = GetFirstSelectedCell(nullptr, getter_AddRefs(cell));
-  if (NS_SUCCEEDED(rv) && cell) {
+  IgnoredErrorResult ignoredError;
+  RefPtr<Element> cellElement =
+    GetFirstSelectedTableCellElement(*selection, ignoredError);
+  if (cellElement) {
     cellSelectionMode = true;
   }