parser/htmlparser/nsIContentSink.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5 #ifndef nsIContentSink_h___
   6 #define nsIContentSink_h___
   7
   8 /**
   9  * MODULE NOTES:
  10  * @update  gess 4/1/98
  11  *
  12  * This pure virtual interface is used as the "glue" that connects the parsing
  13  * process to the content model construction process.
  14  *
  15  * The icontentsink interface is a very lightweight wrapper that represents the
  16  * content-sink model building process. There is another one that you may care
  17  * about more, which is the IHTMLContentSink interface. (See that file for
  18  * details).
  19  */
  20 #include "nsISupports.h"
  21 #include "nsString.h"
  22 #include "mozilla/FlushType.h"
  23 #include "mozilla/NotNull.h"
  24 #include "nsIDTD.h"
  25
  26 class nsParserBase;
  27 namespace mozilla {
  28 class Encoding;
  29 }
  30
  31 #define NS_ICONTENT_SINK_IID                         \
  32   {                                                  \
  33     0xcf9a7cbb, 0xfcbc, 0x4e13, {                    \
  34       0x8e, 0xf5, 0x18, 0xef, 0x2d, 0x3d, 0x58, 0x29 \
  35     }                                                \
  36   }
  37
  38 class nsIContentSink : public nsISupports {
  39  protected:
  40   using Encoding = mozilla::Encoding;
  41   template <typename T>
  42   using NotNull = mozilla::NotNull<T>;
  43
  44  public:
  45   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ICONTENT_SINK_IID)
  46
  47   /**
  48    * This method is called by the parser when it is entered from
  49    * the event loop. The content sink wants to know how long the
  50    * parser has been active since we last processed events on the
  51    * main event loop and this call calibrates that measurement.
  52    */
  53   NS_IMETHOD WillParse(void) = 0;
  54
  55   /**
  56    * This method gets called when the parser begins the process
  57    * of building the content model via the content sink.
  58    *
  59    * Default implementation provided since the sink should have the option of
  60    * doing nothing in response to this call.
  61    *
  62    * @update 5/7/98 gess
  63    */
  64   NS_IMETHOD WillBuildModel(nsDTDMode aDTDMode) { return NS_OK; }
  65
  66   /**
  67    * This method gets called when the parser concludes the process
  68    * of building the content model via the content sink.
  69    *
  70    * Default implementation provided since the sink should have the option of
  71    * doing nothing in response to this call.
  72    *
  73    * @update 5/7/98 gess
  74    */
  75   NS_IMETHOD DidBuildModel(bool aTerminated) { return NS_OK; }
  76
  77   /**
  78    * This method gets called when the parser gets i/o blocked,
  79    * and wants to notify the sink that it may be a while before
  80    * more data is available.
  81    *
  82    * @update 5/7/98 gess
  83    */
  84   NS_IMETHOD WillInterrupt(void) = 0;
  85
  86   /**
  87    * This method gets called when the parser i/o gets unblocked,
  88    * and we're about to start dumping content again to the sink.
  89    */
  90   virtual void WillResume() = 0;
  91
  92   /**
  93    * This method returns nullptr unless `this` can
  94    * be cast as nsHtml5TreeOpExecutor.
  95    */
  96   virtual nsIContentSink* AsExecutor() { return nullptr; }
  97
  98   /**
  99    * This method gets called by the parser so that the content
 100    * sink can retain a reference to the parser. The expectation
 101    * is that the content sink will drop the reference when it
 102    * gets the DidBuildModel notification i.e. when parsing is done.
 103    */
 104   NS_IMETHOD SetParser(nsParserBase* aParser) = 0;
 105
 106   /**
 107    * Flush content so that the content model is in sync with the state
 108    * of the sink.
 109    *
 110    * @param aType the type of flush to perform
 111    */
 112   virtual void FlushPendingNotifications(mozilla::FlushType aType) = 0;
 113
 114   /**
 115    * Set the document character set. This should be passed on to the
 116    * document itself.
 117    */
 118   virtual void SetDocumentCharset(NotNull<const Encoding*> aEncoding) = 0;
 119
 120   /**
 121    * Returns the target object (often a document object) into which
 122    * the content built by this content sink is being added, if any
 123    * (IOW, may return null).
 124    */
 125   virtual nsISupports* GetTarget() = 0;
 126
 127   /**
 128    * Returns true if there's currently script executing that we need to hold
 129    * parsing for.
 130    */
 131   virtual bool IsScriptExecuting() { return false; }
 132
 133   /**
 134    * Posts a runnable that continues parsing.
 135    */
 136   virtual void ContinueInterruptedParsingAsync() {}
 137
 138   virtual void InitialTranslationCompleted() {}
 139 };
 140
 141 NS_DEFINE_STATIC_IID_ACCESSOR(nsIContentSink, NS_ICONTENT_SINK_IID)
 142
 143 #endif /* nsIContentSink_h___ */