layout/generic/nsIAnonymousContentCreator.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 /*
   8  * interface for rendering objects that manually create subtrees of
   9  * anonymous content
  10  */
  11
  12 #ifndef nsIAnonymousContentCreator_h___
  13 #define nsIAnonymousContentCreator_h___
  14
  15 #include "mozilla/AnonymousContentKey.h"
  16
  17 #include "nsQueryFrame.h"
  18 #include "nsTArrayForwardDeclare.h"
  19 #include "X11UndefineNone.h"
  20
  21 class nsIContent;
  22
  23 /**
  24  * Any source for anonymous content can implement this interface to provide it.
  25  * HTML frames like nsFileControlFrame currently use this.
  26  *
  27  * @see nsCSSFrameConstructor
  28  */
  29 class nsIAnonymousContentCreator {
  30  public:
  31   NS_DECL_QUERYFRAME_TARGET(nsIAnonymousContentCreator)
  32
  33   struct ContentInfo {
  34     explicit ContentInfo(
  35         nsIContent* aContent,
  36         mozilla::AnonymousContentKey aKey = mozilla::AnonymousContentKey::None)
  37         : mContent(aContent), mKey(aKey) {}
  38
  39     nsIContent* mContent;
  40     mozilla::AnonymousContentKey mKey;
  41   };
  42
  43   /**
  44    * Creates "native" anonymous content and adds the created content to
  45    * the aElements array. None of the returned elements can be nullptr.
  46    *
  47    * If the anonymous content creator sets the editable flag on some
  48    * of the elements that it creates, the flag will be applied to the node
  49    * upon being bound to the document.
  50    *
  51    * @note The returned elements are owned by this object. This object is
  52    *       responsible for calling UnbindFromTree on the elements it returned
  53    *       from CreateAnonymousContent when appropriate (i.e. before releasing
  54    *       them).
  55    */
  56   virtual nsresult CreateAnonymousContent(nsTArray<ContentInfo>& aElements) = 0;
  57
  58   /**
  59    * Appends "native" anonymous children created by CreateAnonymousContent()
  60    * to the given content list depending on the filter.
  61    *
  62    * @see nsIContent::GetChildren for set of values used for filter.  Currently,
  63    *   eSkipPlaceholderContent is the only flag that any implementation of
  64    *   this method heeds.
  65    */
  66   virtual void AppendAnonymousContentTo(nsTArray<nsIContent*>& aElements,
  67                                         uint32_t aFilter) = 0;
  68 };
  69
  70 #endif