Bug 1746104 - part 6-1: Make `IMENotification::SelectionChangeDataBase` and `WidgetQueryContentEvent::Reply` have `AnchorOffset` and `FocusOffset` r=m_kato,geckoview-reviewers

`StartOffset` and `EndOffset` of `IMENotification::SelectionChangeDataBase`
depend on whether the range is reversed or not.  Therefore, their actual
meaning is "anchor offset" and "focus offset" in the DOM selection terms.

Similarly, `SelectionStartOffset` and `SelectionEndOffset` of
`WidgetQueryContentEvent::Reply` are exactly same ones.

Therefore, they should be renamed to `AnchorOffset` and `FocusOffset` for
making what they return clearer.

Differential Revision: https://phabricator.services.mozilla.com/D137427

dom/events/TextComposition.cpp

@@ -489,7 +489,7 @@ uint32_t TextComposition::GetSelectionStartOffset() {
   if (NS_WARN_IF(querySelectedTextEvent.DidNotFindSelection())) {
     return 0;  // XXX Is this okay?
   }
-  return querySelectedTextEvent.mReply->SelectionStartOffset();
+  return querySelectedTextEvent.mReply->AnchorOffset();
 }
 
 void TextComposition::OnCompositionEventDispatched(

widget/IMEData.h

@@ -767,11 +767,11 @@ struct IMENotification final {
     void SetWritingMode(const WritingMode& aWritingMode);
     WritingMode GetWritingMode() const;
 
-    uint32_t StartOffset() const {
+    uint32_t AnchorOffset() const {
       MOZ_ASSERT(mHasRange);
       return mOffset + (mReversed ? Length() : 0);
     }
-    uint32_t EndOffset() const {
+    uint32_t FocusOffset() const {
       MOZ_ASSERT(mHasRange);
       return mOffset + (mReversed ? 0 : Length());
     }

widget/TextEvents.h

@@ -1203,13 +1203,13 @@ class WidgetQueryContentEvent : public WidgetGUIEvent {
                  mEventMessage == eQuerySelectedText);
       return mOffsetAndData.isSome() ? mOffsetAndData->Length() : 0;
     }
-    MOZ_NEVER_INLINE_DEBUG uint32_t SelectionStartOffset() const {
+    MOZ_NEVER_INLINE_DEBUG uint32_t AnchorOffset() const {
       MOZ_ASSERT(mEventMessage == eQuerySelectedText);
       MOZ_ASSERT(mOffsetAndData.isSome());
       return StartOffset() + (mReversed ? DataLength() : 0);
     }
 
-    MOZ_NEVER_INLINE_DEBUG uint32_t SelectionEndOffset() const {
+    MOZ_NEVER_INLINE_DEBUG uint32_t FocusOffset() const {
       MOZ_ASSERT(mEventMessage == eQuerySelectedText);
       MOZ_ASSERT(mOffsetAndData.isSome());
       return StartOffset() + (mReversed ? 0 : DataLength());

widget/android/GeckoEditableSupport.cpp

@@ -701,10 +701,10 @@ void GeckoEditableSupport::FlushIMEChanges(FlushChangesFlag aFlags) {
         return;
       }
 
-      selStart = static_cast<int32_t>(
-          querySelectedTextEvent.mReply->SelectionStartOffset());
-      selEnd = static_cast<int32_t>(
-          querySelectedTextEvent.mReply->SelectionEndOffset());
+      selStart =
+          static_cast<int32_t>(querySelectedTextEvent.mReply->AnchorOffset());
+      selEnd =
+          static_cast<int32_t>(querySelectedTextEvent.mReply->FocusOffset());
     }
 
     if (aFlags == FLUSH_FLAG_RECOVER && textTransaction.IsValid()) {
@@ -1342,10 +1342,10 @@ nsresult GeckoEditableSupport::NotifyIME(
               ToString(aNotification.mSelectionChangeData).c_str());
 
       if (aNotification.mSelectionChangeData.HasRange()) {
-        mCachedSelection.mStartOffset =
-            aNotification.mSelectionChangeData.StartOffset();
-        mCachedSelection.mEndOffset =
-            aNotification.mSelectionChangeData.EndOffset();
+        mCachedSelection.mStartOffset = static_cast<int32_t>(
+            aNotification.mSelectionChangeData.AnchorOffset());
+        mCachedSelection.mEndOffset = static_cast<int32_t>(
+            aNotification.mSelectionChangeData.FocusOffset());
       } else {
         mCachedSelection.Reset();
       }