Bug 1343037 part 9. Simplify the setup around the editor state's GetSelectionDirection function. r=ehsan

Really, there are only two cases we need to worry about.  Either
IsSelectionCached(), and then our SelectionProperties has the data we want, or
not and then we have a non-null mSelCon which has the data we want.

MozReview-Commit-ID: AEW9D1zG6sM

dom/html/HTMLInputElement.cpp

@@ -6571,29 +6571,15 @@ HTMLInputElement::GetSelectionDirection(nsAString& aDirection, ErrorResult& aRv)
     return;
   }
 
-  nsIFormControlFrame* formControlFrame = GetFormControlFrame(true);
   nsTextEditorState* state = GetEditorState();
-  if (!state) {
-    aRv.Throw(NS_ERROR_FAILURE);
+  MOZ_ASSERT(state, "SupportsTextSelection came back true!");
+  nsITextControlFrame::SelectionDirection dir =
+    state->GetSelectionDirection(aRv);
+  if (aRv.Failed()) {
     return;
   }
-
-  nsresult rv = NS_ERROR_FAILURE;
-  if (formControlFrame) {
-    nsITextControlFrame::SelectionDirection dir;
-    rv = state->GetSelectionDirection(&dir);
-    if (NS_SUCCEEDED(rv)) {
-      DirectionToName(dir, aDirection);
-      return;
-    }
-  }
   
-  if (state->IsSelectionCached()) {
-    DirectionToName(state->GetSelectionProperties().GetDirection(), aDirection);
-    return;
-  }
-
-  aRv.Throw(rv);
+  DirectionToName(dir, aDirection);
 }
 
 void

dom/html/HTMLTextAreaElement.cpp

@@ -807,23 +807,12 @@ DirectionToName(nsITextControlFrame::SelectionDirection dir, nsAString& aDirecti
 void
 HTMLTextAreaElement::GetSelectionDirection(nsAString& aDirection, ErrorResult& aError)
 {
-  nsresult rv = NS_ERROR_FAILURE;
-  nsIFormControlFrame* formControlFrame = GetFormControlFrame(true);
-  if (formControlFrame) {
-    nsITextControlFrame::SelectionDirection dir;
-    rv = mState.GetSelectionDirection(&dir);
-    if (NS_SUCCEEDED(rv)) {
-      DirectionToName(dir, aDirection);
-      return;
-    }
-  }
-
-  if (mState.IsSelectionCached()) {
-    DirectionToName(mState.GetSelectionProperties().GetDirection(), aDirection);
+  nsITextControlFrame::SelectionDirection dir =
+    mState.GetSelectionDirection(aError);
+  if (aError.Failed()) {
     return;
   }
-
-  aError.Throw(rv);
+  DirectionToName(dir, aDirection);
 }
 
 void

dom/html/nsTextEditorState.cpp

@@ -1608,39 +1608,41 @@ nsTextEditorState::GetSelectionRange(int32_t* aSelectionStart,
                                             *aSelectionStart, *aSelectionEnd);
 }
 
-nsresult
-nsTextEditorState::GetSelectionDirection(nsITextControlFrame::SelectionDirection* aDirection)
+nsITextControlFrame::SelectionDirection
+nsTextEditorState::GetSelectionDirection(ErrorResult& aRv)
 {
-  MOZ_ASSERT(mBoundFrame,
-             "Caller didn't flush out frames and check for a frame?");
-  MOZ_ASSERT(aDirection);
+  MOZ_ASSERT(IsSelectionCached() || GetSelectionController(),
+             "How can we not have a cached selection if we have no selection "
+             "controller?");
 
-  // It's not clear that all the checks here are needed, but the previous
-  // version of this code in nsTextControlFrame was doing them, so we keep them
-  // for now.
-
-  nsresult rv = mBoundFrame->EnsureEditorInitialized();
-  NS_ENSURE_SUCCESS(rv, rv);
+  // Note that we may have both IsSelectionCached() _and_
+  // GetSelectionController() if we haven't initialized our editor yet.
+  if (IsSelectionCached()) {
+    return GetSelectionProperties().GetDirection();
+  }
 
   nsISelectionController* selCon = GetSelectionController();
-  NS_ENSURE_TRUE(selCon, NS_ERROR_FAILURE);
 
   nsCOMPtr<nsISelection> selection;
-  rv = selCon->GetSelection(nsISelectionController::SELECTION_NORMAL,
-                            getter_AddRefs(selection));
-  NS_ENSURE_SUCCESS(rv, rv);
-  NS_ENSURE_TRUE(selection, NS_ERROR_FAILURE);
+  nsresult rv = selCon->GetSelection(nsISelectionController::SELECTION_NORMAL,
+                                     getter_AddRefs(selection));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    aRv.Throw(rv);
+    return nsITextControlFrame::eForward; // Doesn't really matter
+  }
+  if (NS_WARN_IF(!selection)) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nsITextControlFrame::eForward; // Doesn't really matter
+  }
 
   dom::Selection* sel = selection->AsSelection();
   nsDirection direction = sel->GetSelectionDirection();
   if (direction == eDirNext) {
-    *aDirection = nsITextControlFrame::eForward;
-  } else if (direction == eDirPrevious) {
-    *aDirection = nsITextControlFrame::eBackward;
-  } else {
-    NS_NOTREACHED("Invalid nsDirection enum value");
+    return nsITextControlFrame::eForward;
   }
-  return NS_OK;
+
+  MOZ_ASSERT(direction == eDirPrevious);
+  return nsITextControlFrame::eBackward;
 }
 
 HTMLInputElement*
@@ -1721,11 +1723,13 @@ nsTextEditorState::UnbindFromFrame(nsTextControlFrame* aFrame)
   if (!IsSelectionCached()) {
     // Go ahead and cache it now.
     int32_t start = 0, end = 0;
-    nsITextControlFrame::SelectionDirection direction =
-      nsITextControlFrame::eForward;
     IgnoredErrorResult rangeRv;
     GetSelectionRange(&start, &end, rangeRv);
-    GetSelectionDirection(&direction);
+
+    IgnoredErrorResult dirRv;
+    nsITextControlFrame::SelectionDirection direction =
+      GetSelectionDirection(dirRv);
+
     MOZ_ASSERT(aFrame == mBoundFrame);
     SelectionProperties& props = GetSelectionProperties();
     props.SetStart(start);

dom/html/nsTextEditorState.h

@@ -278,7 +278,8 @@ public:
                          mozilla::ErrorResult& aRv);
 
   // Get the selection direction
-  nsresult GetSelectionDirection(nsITextControlFrame::SelectionDirection* aDirection);
+  nsITextControlFrame::SelectionDirection
+    GetSelectionDirection(mozilla::ErrorResult& aRv);
 
   void UpdateEditableState(bool aNotify) {
     if (mRootNode) {