From c97142b02986232cb5d42860c7645ffa7bdd103c Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@mit.edu>
Date: Thu, 9 Mar 2017 14:44:06 -0500
Subject: [PATCH] Bug 1343037 part 14.  Implement
 nsTextEditorState::SetSelectionDirection. r=ehsan

This introduces two behavior changes:

1)  In cached mode, we used to treat unknown selection directions as "none".
    Now we treat it like "forward", consistently with the "have an editor" mode.
2)  Before this change, in cached mode, we did not fire "select" events on
    selectionDirection changes.

MozReview-Commit-ID: 4nBCAm3mAiz
---
 dom/html/HTMLInputElement.cpp    | 18 ++----------------
 dom/html/HTMLTextAreaElement.cpp | 22 +---------------------
 dom/html/nsTextEditorState.cpp   | 32 ++++++++++++++++++++++++++++++++
 dom/html/nsTextEditorState.h     |  6 ++++++
 4 files changed, 41 insertions(+), 37 deletions(-)

diff --git a/dom/html/HTMLInputElement.cpp b/dom/html/HTMLInputElement.cpp
index b69e73bfabdf..eb234c061bdf 100644
--- a/dom/html/HTMLInputElement.cpp
+++ b/dom/html/HTMLInputElement.cpp
@@ -6539,22 +6539,8 @@ HTMLInputElement::SetSelectionDirection(const nsAString& aDirection, ErrorResult
   }
 
   nsTextEditorState* state = GetEditorState();
-  if (state && state->IsSelectionCached()) {
-    nsITextControlFrame::SelectionDirection dir = nsITextControlFrame::eNone;
-    if (aDirection.EqualsLiteral("forward")) {
-      dir = nsITextControlFrame::eForward;
-    } else if (aDirection.EqualsLiteral("backward")) {
-      dir = nsITextControlFrame::eBackward;
-    }
-    state->GetSelectionProperties().SetDirection(dir);
-    return;
-  }
-
-  int32_t start, end;
-  GetSelectionRange(&start, &end, aRv);
-  if (!aRv.Failed()) {
-    aRv = SetSelectionRange(start, end, aDirection);
-  }
+  MOZ_ASSERT(state, "SupportsTextSelection came back true!");
+  state->SetSelectionDirection(aDirection, aRv);
 }
 
 NS_IMETHODIMP
diff --git a/dom/html/HTMLTextAreaElement.cpp b/dom/html/HTMLTextAreaElement.cpp
index 8584c5355139..c00d3507f63d 100644
--- a/dom/html/HTMLTextAreaElement.cpp
+++ b/dom/html/HTMLTextAreaElement.cpp
@@ -765,27 +765,7 @@ void
 HTMLTextAreaElement::SetSelectionDirection(const nsAString& aDirection,
                                            ErrorResult& aError)
 {
-  if (mState.IsSelectionCached()) {
-    nsITextControlFrame::SelectionDirection dir = nsITextControlFrame::eNone;
-    if (aDirection.EqualsLiteral("forward")) {
-      dir = nsITextControlFrame::eForward;
-    } else if (aDirection.EqualsLiteral("backward")) {
-      dir = nsITextControlFrame::eBackward;
-    }
-    mState.GetSelectionProperties().SetDirection(dir);
-    return;
-  }
-
-  int32_t start, end;
-  GetSelectionRange(&start, &end, aError);
-  if (aError.Failed()) {
-    return;
-  }
-
-  nsresult rv = SetSelectionRange(start, end, aDirection);
-  if (NS_FAILED(rv)) {
-    aError.Throw(rv);
-  }
+  mState.SetSelectionDirection(aDirection, aError);
 }
 
 NS_IMETHODIMP
diff --git a/dom/html/nsTextEditorState.cpp b/dom/html/nsTextEditorState.cpp
index 8bad91001b57..6bbd2e0c12bd 100644
--- a/dom/html/nsTextEditorState.cpp
+++ b/dom/html/nsTextEditorState.cpp
@@ -1762,6 +1762,38 @@ nsTextEditorState::SetSelectionEnd(const mozilla::dom::Nullable<uint32_t>& aEnd,
   SetSelectionRange(start, end, dir, aRv);
 }
 
+static nsITextControlFrame::SelectionDirection
+DirectionStringToSelectionDirection(const nsAString& aDirection)
+{
+  if (aDirection.EqualsLiteral("backward")) {
+    return nsITextControlFrame::eBackward;
+  }
+
+  // We don't support directionless selections.
+  return nsITextControlFrame::eForward;
+}
+
+void
+nsTextEditorState::SetSelectionDirection(const nsAString& aDirection,
+                                         ErrorResult& aRv)
+{
+  nsITextControlFrame::SelectionDirection dir =
+    DirectionStringToSelectionDirection(aDirection);
+
+  if (IsSelectionCached()) {
+    GetSelectionProperties().SetDirection(dir);
+    return;
+  }
+
+  int32_t start, end;
+  GetSelectionRange(&start, &end, aRv);
+  if (aRv.Failed()) {
+    return;
+  }
+
+  SetSelectionRange(start, end, dir, aRv);
+}
+
 HTMLInputElement*
 nsTextEditorState::GetParentNumberControl(nsFrame* aFrame) const
 {
diff --git a/dom/html/nsTextEditorState.h b/dom/html/nsTextEditorState.h
index dbbc8494f945..0dd36458ff16 100644
--- a/dom/html/nsTextEditorState.h
+++ b/dom/html/nsTextEditorState.h
@@ -310,6 +310,12 @@ public:
   void SetSelectionEnd(const mozilla::dom::Nullable<uint32_t>& aEnd,
                        mozilla::ErrorResult& aRv);
 
+  // Set the selection direction.  This basically implements the
+  // https://html.spec.whatwg.org/multipage/forms.html#dom-textarea/input-selectiondirection
+  // setter.
+  void SetSelectionDirection(const nsAString& aDirection,
+                             mozilla::ErrorResult& aRv);
+
   void UpdateEditableState(bool aNotify) {
     if (mRootNode) {
       mRootNode->UpdateEditableState(aNotify);