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::dom {
  16 class DOMRect;
  17 }  // namespace mozilla::dom
  18
  19 /**
  20  * Implementation of a DOM Caret Position, which is a node and offset within
  21  * that node, in the DOM tree.
  22  *
  23  * http://www.w3.org/TR/cssom-view/#dom-documentview-caretrangefrompoint
  24  *
  25  * @see Document::caretPositionFromPoint(float x, float y)
  26  */
  27 class nsDOMCaretPosition : public nsISupports, public nsWrapperCache {
  28   using DOMRect = mozilla::dom::DOMRect;
  29
  30  public:
  31   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  32   NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(nsDOMCaretPosition)
  33
  34   nsDOMCaretPosition(nsINode* aNode, uint32_t aOffset);
  35
  36   /**
  37    * Retrieve the offset (character position within the DOM node) of the
  38    * CaretPosition.
  39    *
  40    * @returns The offset within the DOM node.
  41    */
  42   uint32_t Offset() const { return mOffset; }
  43
  44   /**
  45    * Retrieve the DOM node with which this CaretPosition was established.
  46    * Normally, this will be created from a point, so it will be the DOM
  47    * node that lies at the point specified.
  48    *
  49    * @returns The DOM node of the CaretPosition.
  50    *
  51    * @see Document::caretPositionFromPoint(float x, float y)
  52    */
  53   nsINode* GetOffsetNode() const;
  54
  55   /**
  56    * Retrieve the bounding rectangle of this CaretPosition object.
  57    *
  58    * @returns An nsClientRect representing the bounding rectangle of this
  59    *          CaretPosition, if one can be successfully determined, otherwise
  60    *          nullptr.
  61    */
  62   already_AddRefed<DOMRect> GetClientRect() const;
  63
  64   /**
  65    * Set the anonymous content node that is the actual parent of this
  66    * CaretPosition object. In situations where the DOM node for a CaretPosition
  67    * actually lies within an anonymous content node (e.g. a textarea), the
  68    * actual parent is not set as the offset node. This is used to get the
  69    * correct bounding box of a CaretPosition object that lies within a textarea
  70    * or input element.
  71    *
  72    * @param aNode A pointer to an nsINode object that is the actual element
  73    *        within which this CaretPosition lies, but is an anonymous content
  74    *        node.
  75    */
  76   void SetAnonymousContentNode(nsINode* aNode) {
  77     mAnonymousContentNode = aNode;
  78   }
  79
  80   nsISupports* GetParentObject() const { return GetOffsetNode(); }
  81
  82   JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) final;
  83
  84  protected:
  85   virtual ~nsDOMCaretPosition();
  86
  87   uint32_t mOffset;
  88   nsCOMPtr<nsINode> mOffsetNode;
  89   nsCOMPtr<nsINode> mAnonymousContentNode;
  90 };
  91 #endif