diff -r 000000000000 -r 6474c204b198 dom/events/ContentEventHandler.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/events/ContentEventHandler.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,130 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ContentEventHandler_h_
+#define mozilla_ContentEventHandler_h_
+
+#include "mozilla/EventForwards.h"
+#include "nsCOMPtr.h"
+#include "nsISelection.h"
+#include "nsRange.h"
+
+class nsPresContext;
+
+struct nsRect;
+
+namespace mozilla {
+
+enum LineBreakType
+{
+  LINE_BREAK_TYPE_NATIVE,
+  LINE_BREAK_TYPE_XP
+};
+
+/*
+ * Query Content Event Handler
+ *   ContentEventHandler is a helper class for EventStateManager.
+ *   The platforms request some content informations, e.g., the selected text,
+ *   the offset of the selected text and the text for specified range.
+ *   This class answers to NS_QUERY_* events from actual contents.
+ */
+
+class MOZ_STACK_CLASS ContentEventHandler
+{
+public:
+  ContentEventHandler(nsPresContext* aPresContext);
+
+  // NS_QUERY_SELECTED_TEXT event handler
+  nsresult OnQuerySelectedText(WidgetQueryContentEvent* aEvent);
+  // NS_QUERY_TEXT_CONTENT event handler
+  nsresult OnQueryTextContent(WidgetQueryContentEvent* aEvent);
+  // NS_QUERY_CARET_RECT event handler
+  nsresult OnQueryCaretRect(WidgetQueryContentEvent* aEvent);
+  // NS_QUERY_TEXT_RECT event handler
+  nsresult OnQueryTextRect(WidgetQueryContentEvent* aEvent);
+  // NS_QUERY_EDITOR_RECT event handler
+  nsresult OnQueryEditorRect(WidgetQueryContentEvent* aEvent);
+  // NS_QUERY_CONTENT_STATE event handler
+  nsresult OnQueryContentState(WidgetQueryContentEvent* aEvent);
+  // NS_QUERY_SELECTION_AS_TRANSFERABLE event handler
+  nsresult OnQuerySelectionAsTransferable(WidgetQueryContentEvent* aEvent);
+  // NS_QUERY_CHARACTER_AT_POINT event handler
+  nsresult OnQueryCharacterAtPoint(WidgetQueryContentEvent* aEvent);
+  // NS_QUERY_DOM_WIDGET_HITTEST event handler
+  nsresult OnQueryDOMWidgetHittest(WidgetQueryContentEvent* aEvent);
+
+  // NS_SELECTION_* event
+  nsresult OnSelectionEvent(WidgetSelectionEvent* aEvent);
+
+protected:
+  nsPresContext* mPresContext;
+  nsCOMPtr<nsIPresShell> mPresShell;
+  nsCOMPtr<nsISelection> mSelection;
+  nsRefPtr<nsRange> mFirstSelectedRange;
+  nsCOMPtr<nsIContent> mRootContent;
+
+  nsresult Init(WidgetQueryContentEvent* aEvent);
+  nsresult Init(WidgetSelectionEvent* aEvent);
+
+  nsresult InitBasic();
+  nsresult InitCommon();
+
+public:
+  // FlatText means the text that is generated from DOM tree. The BR elements
+  // are replaced to native linefeeds. Other elements are ignored.
+
+  // Get the offset in FlatText of the range. (also used by IMEContentObserver)
+  static nsresult GetFlatTextOffsetOfRange(nsIContent* aRootContent,
+                                           nsINode* aNode,
+                                           int32_t aNodeOffset,
+                                           uint32_t* aOffset,
+                                           LineBreakType aLineBreakType);
+  static nsresult GetFlatTextOffsetOfRange(nsIContent* aRootContent,
+                                           nsRange* aRange,
+                                           uint32_t* aOffset,
+                                           LineBreakType aLineBreakType);
+  // Get the native text length of a content node excluding any children
+  static uint32_t GetNativeTextLength(nsIContent* aContent,
+                                      uint32_t aMaxLength = UINT32_MAX);
+protected:
+  static uint32_t GetTextLength(nsIContent* aContent,
+                                LineBreakType aLineBreakType,
+                                uint32_t aMaxLength = UINT32_MAX);
+  static LineBreakType GetLineBreakType(WidgetQueryContentEvent* aEvent);
+  static LineBreakType GetLineBreakType(WidgetSelectionEvent* aEvent);
+  static LineBreakType GetLineBreakType(bool aUseNativeLineBreak);
+  // Returns focused content (including its descendant documents).
+  nsIContent* GetFocusedContent();
+  // Returns true if the content is a plugin host.
+  bool IsPlugin(nsIContent* aContent);
+  // QueryContentRect() sets the rect of aContent's frame(s) to aEvent.
+  nsresult QueryContentRect(nsIContent* aContent,
+                            WidgetQueryContentEvent* aEvent);
+  // Make the DOM range from the offset of FlatText and the text length.
+  // If aExpandToClusterBoundaries is true, the start offset and the end one are
+  // expanded to nearest cluster boundaries.
+  nsresult SetRangeFromFlatTextOffset(nsRange* aRange,
+                                      uint32_t aOffset,
+                                      uint32_t aLength,
+                                      LineBreakType aLineBreakType,
+                                      bool aExpandToClusterBoundaries,
+                                      uint32_t* aNewOffset = nullptr);
+  // Find the first textframe for the range, and get the start offset in
+  // the frame.
+  nsresult GetStartFrameAndOffset(nsRange* aRange,
+                                  nsIFrame** aFrame,
+                                  int32_t* aOffsetInFrame);
+  // Convert the frame relative offset to the root view relative offset.
+  nsresult ConvertToRootViewRelativeOffset(nsIFrame* aFrame,
+                                           nsRect& aRect);
+  // Expand aXPOffset to the nearest offset in cluster boundary. aForward is
+  // true, it is expanded to forward.
+  nsresult ExpandToClusterBoundary(nsIContent* aContent, bool aForward,
+                                   uint32_t* aXPOffset);
+};
+
+} // namespace mozilla
+
+#endif // mozilla_ContentEventHandler_h_