Bug 1730088 part 7: Move CharAt to HyperTextAccessibleBase. r=eeejay

Differential Revision: https://phabricator.services.mozilla.com/D127212

accessible/basetypes/HyperTextAccessibleBase.cpp

@@ -140,4 +140,24 @@ void HyperTextAccessibleBase::TextSubstring(int32_t aStartOffset,
   endChild->AppendTextTo(aText, 0, endOffset - endChildOffset);
 }
 
+bool HyperTextAccessibleBase::CharAt(int32_t aOffset, nsAString& aChar,
+              int32_t* aStartOffset, int32_t* aEndOffset) {
+  MOZ_ASSERT(!aStartOffset == !aEndOffset,
+                 "Offsets should be both defined or both undefined!");
+
+  int32_t childIdx = GetChildIndexAtOffset(aOffset);
+  if (childIdx == -1) {
+    return false;
+  }
+
+  Accessible* child = Acc()->ChildAt(childIdx);
+  child->AppendTextTo(aChar, aOffset - GetChildOffset(childIdx), 1);
+
+  if (aStartOffset && aEndOffset) {
+    *aStartOffset = aOffset;
+    *aEndOffset = aOffset + aChar.Length();
+  }
+  return true;
+}
+
 }  // namespace mozilla::a11y

accessible/basetypes/HyperTextAccessibleBase.h

@@ -87,6 +87,12 @@ class HyperTextAccessibleBase {
   virtual void TextSubstring(int32_t aStartOffset, int32_t aEndOffset,
                              nsAString& aText) const;
 
+  /**
+   * Get a character at the given offset (don't support magic offsets).
+   */
+  bool CharAt(int32_t aOffset, nsAString& aChar,
+              int32_t* aStartOffset = nullptr, int32_t* aEndOffset = nullptr);
+
  protected:
   virtual const Accessible* Acc() const = 0;
   Accessible* Acc() {

accessible/generic/HyperTextAccessible.h

@@ -144,26 +144,7 @@ class HyperTextAccessible : public HyperTextAccessibleBase,
   //////////////////////////////////////////////////////////////////////////////
   // TextAccessible
 
-  /**
-   * Get a character at the given offset (don't support magic offsets).
-   */
-  bool CharAt(int32_t aOffset, nsAString& aChar,
-              int32_t* aStartOffset = nullptr, int32_t* aEndOffset = nullptr) {
-    NS_ASSERTION(!aStartOffset == !aEndOffset,
-                 "Offsets should be both defined or both undefined!");
-
-    int32_t childIdx = GetChildIndexAtOffset(aOffset);
-    if (childIdx == -1) return false;
-
-    LocalAccessible* child = LocalChildAt(childIdx);
-    child->AppendTextTo(aChar, aOffset - GetChildOffset(childIdx), 1);
-
-    if (aStartOffset && aEndOffset) {
-      *aStartOffset = aOffset;
-      *aEndOffset = aOffset + aChar.Length();
-    }
-    return true;
-  }
+  using HyperTextAccessibleBase::CharAt;
 
   char16_t CharAt(int32_t aOffset) {
     nsAutoString charAtOffset;