Merge 117307 - Avoid jumpscroll when entering new text in a multi-line editor.

Source/WebCore/editing/Editor.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 926 matching lines @@
 }
 
 bool Editor::insertLineBreak()
 {
     if (!canEdit())
         return false;
 
     if (!shouldInsertText("\n", m_frame->selection()->toNormalizedRange().get(), EditorInsertActionTyped))
         return true;
 
+    VisiblePosition caret = m_frame->selection()->selection().visibleStart();
+    bool alignToEdge = isEndOfDocument(caret);
     bool autocorrectionIsApplied = m_alternativeTextController->applyAutocorrectionBeforeTypingIfAppropriate();
     TypingCommand::insertLineBreak(m_frame->document(), autocorrectionIsApplied ? TypingCommand::RetainAutocorrectionIndicator : 0);
-    revealSelectionAfterEditingOperation();
+    revealSelectionAfterEditingOperation(alignToEdge ? ScrollAlignment::alignToEdgeIfNeeded : ScrollAlignment::alignCenterIfNeeded);
 
     return true;
 }
 
 bool Editor::insertParagraphSeparator()
 {
     if (!canEdit())
         return false;
 
     if (!canEditRichly())
         return insertLineBreak();
 
     if (!shouldInsertText("\n", m_frame->selection()->toNormalizedRange().get(), EditorInsertActionTyped))
         return true;
 
+    VisiblePosition caret = m_frame->selection()->selection().visibleStart();
+    bool alignToEdge = isEndOfDocument(caret);
     bool autocorrectionIsApplied = m_alternativeTextController->applyAutocorrectionBeforeTypingIfAppropriate();
     TypingCommand::insertParagraphSeparator(m_frame->document(), autocorrectionIsApplied ? TypingCommand::RetainAutocorrectionIndicator : 0);
-    revealSelectionAfterEditingOperation();
+    revealSelectionAfterEditingOperation(alignToEdge ? ScrollAlignment::alignToEdgeIfNeeded : ScrollAlignment::alignCenterIfNeeded);
 
     return true;
 }
 
 void Editor::cut()
 {
     if (tryDHTMLCut())
         return; // DHTML did the whole operation
     if (!canCut()) {
         systemBeep();
@@ skipping 1297 matching lines @@
     Frame* frame = document->frame();
     ASSERT(frame);
     FrameView* frameView = frame->view();
     if (!frameView)
         return 0;
     IntPoint framePoint = frameView->windowToContents(windowPoint);
     VisibleSelection selection(frame->visiblePositionForPoint(framePoint));
     return avoidIntersectionWithNode(selection.toNormalizedRange().get(), m_deleteButtonController->containerElement());
 }
 
-void Editor::revealSelectionAfterEditingOperation()
+void Editor::revealSelectionAfterEditingOperation(const ScrollAlignment& alignment)
 {
     if (m_ignoreCompositionSelectionChange)
         return;
 
-    m_frame->selection()->revealSelection(ScrollAlignment::alignCenterIfNeeded);
+    m_frame->selection()->revealSelection(alignment);
 }
 
 void Editor::setIgnoreCompositionSelectionChange(bool ignore)
 {
     if (m_ignoreCompositionSelectionChange == ignore)
         return;
 
     m_ignoreCompositionSelectionChange = ignore;
     if (!ignore)
         revealSelectionAfterEditingOperation();
@@ skipping 752 matching lines @@
 {
     m_deleteButtonController->deviceScaleFactorChanged();
 }
 
 bool Editor::unifiedTextCheckerEnabled() const
 {
     return WebCore::unifiedTextCheckerEnabled(m_frame);
 }
 
 } // namespace WebCore