dom/base/nsDOMCaretPosition.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef nsDOMCaretPosition_h
   8 #define nsDOMCaretPosition_h
   9
  10 #include "nsCycleCollectionParticipant.h"
  11 #include "nsCOMPtr.h"
  12 #include "nsINode.h"
  13 #include "nsWrapperCache.h"
  14
  15 namespace mozilla {
  16 namespace dom {
  17 class DOMRect;
  18 }  // namespace dom
  19 }  // namespace mozilla
  20
  21 /**
  22  * Implementation of a DOM Caret Position, which is a node and offset within
  23  * that node, in the DOM tree.
  24  *
  25  * http://www.w3.org/TR/cssom-view/#dom-documentview-caretrangefrompoint
  26  *
  27  * @see Document::caretPositionFromPoint(float x, float y)
  28  */
  29 class nsDOMCaretPosition : public nsISupports, public nsWrapperCache {
  30   typedef mozilla::dom::DOMRect DOMRect;
  31
  32  public:
  33   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  34   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsDOMCaretPosition)
  35
  36   nsDOMCaretPosition(nsINode* aNode, uint32_t aOffset);
  37
  38   /**
  39    * Retrieve the offset (character position within the DOM node) of the
  40    * CaretPosition.
  41    *
  42    * @returns The offset within the DOM node.
  43    */
  44   uint32_t Offset() const { return mOffset; }
  45
  46   /**
  47    * Retrieve the DOM node with which this CaretPosition was established.
  48    * Normally, this will be created from a point, so it will be the DOM
  49    * node that lies at the point specified.
  50    *
  51    * @returns The DOM node of the CaretPosition.
  52    *
  53    * @see Document::caretPositionFromPoint(float x, float y)
  54    */
  55   nsINode* GetOffsetNode() const;
  56
  57   /**
  58    * Retrieve the bounding rectangle of this CaretPosition object.
  59    *
  60    * @returns An nsClientRect representing the bounding rectangle of this
  61    *          CaretPosition, if one can be successfully determined, otherwise
  62    *          nullptr.
  63    */
  64   already_AddRefed<DOMRect> GetClientRect() const;
  65
  66   /**
  67    * Set the anonymous content node that is the actual parent of this
  68    * CaretPosition object. In situations where the DOM node for a CaretPosition
  69    * actually lies within an anonymous content node (e.g. a textarea), the
  70    * actual parent is not set as the offset node. This is used to get the
  71    * correct bounding box of a CaretPosition object that lies within a textarea
  72    * or input element.
  73    *
  74    * @param aNode A pointer to an nsINode object that is the actual element
  75    *        within which this CaretPosition lies, but is an anonymous content
  76    *        node.
  77    */
  78   void SetAnonymousContentNode(nsINode* aNode) {
  79     mAnonymousContentNode = aNode;
  80   }
  81
  82   nsISupports* GetParentObject() const { return GetOffsetNode(); }
  83
  84   JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) final;
  85
  86  protected:
  87   virtual ~nsDOMCaretPosition();
  88
  89   uint32_t mOffset;
  90   nsCOMPtr<nsINode> mOffsetNode;
  91   nsCOMPtr<nsINode> mAnonymousContentNode;
  92 };
  93 #endif