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 * License.
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 * The Original Code is Mozilla Communicator client code.
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 * The Initial Developer of the Original Code is 
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#ifndef nsIContentSink_h___
#define nsIContentSink_h___

/**
 * MODULE NOTES:
 * @update  gess 4/1/98
 * 
 * This pure virtual interface is used as the "glue" that connects the parsing 
 * process to the content model construction process.
 *
 * The icontentsink interface is a very lightweight wrapper that represents the
 * content-sink model building process. There is another one that you may care 
 * about more, which is the IHTMLContentSink interface. (See that file for details).
 */
#include "nsISupports.h"
#include "nsString.h"

class nsIParser;

#define NS_ICONTENT_SINK_IID \
{0x7f459e15, 0xd559, 0x4c50, {0x91, 0x30, 0x3a, 0xe7, 0x31, 0x46, 0x67, 0xa9}}
// The base value for the content ID counter.
// Values greater than or equal to this base value are used
// by each of the content sinks to assign unique values
// to the content objects created by them.
#define NS_CONTENT_ID_COUNTER_BASE 10000

class nsIContentSink : public nsISupports {
public:

  NS_DEFINE_STATIC_IID_ACCESSOR(NS_ICONTENT_SINK_IID)

  /**
   * This method gets called when the parser begins the process
   * of building the content model via the content sink.
   *
   * @update 5/7/98 gess
   */     
  NS_IMETHOD WillBuildModel(void)=0;

  /**
   * This method gets called when the parser concludes the process
   * of building the content model via the content sink.
   *
   * @update 5/7/98 gess
   */     
  NS_IMETHOD DidBuildModel()=0;

  /**
   * This method gets called when the parser gets i/o blocked,
   * and wants to notify the sink that it may be a while before
   * more data is available.
   *
   * @update 5/7/98 gess
   */     
  NS_IMETHOD WillInterrupt(void)=0;

  /**
   * This method gets called when the parser i/o gets unblocked,
   * and we're about to start dumping content again to the sink.
   *
   * @update 5/7/98 gess
   */     
  NS_IMETHOD WillResume(void)=0;

  /**
   * This method gets called by the parser so that the content
   * sink can retain a reference to the parser. The expectation
   * is that the content sink will drop the reference when it
   * gets the DidBuildModel notification i.e. when parsing is done.
   */
  NS_IMETHOD SetParser(nsIParser* aParser)=0;

  /**
   * Flush all pending notifications so that the content model
   * is in sync with the state of the sink.
   */
  NS_IMETHOD FlushPendingNotifications()=0;

  /**
   * Set the document character set. This should be passed on to the
   * document itself.
   */
  NS_IMETHOD SetDocumentCharset(nsACString& aCharset)=0;

  /**
   * Returns the target object (often a document object) into which
   * the content built by this content sink is being added, if any
   * (IOW, may return null).
   */
  virtual nsISupports *GetTarget()=0;
};

#endif /* nsIContentSink_h___ */
