netwerk/streamconv/converters/nsTXTToHTMLConv.h

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  20  * the Initial Developer. All Rights Reserved.
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  37
  38 #ifndef ____nstxttohtmlconv___h___
  39 #define ____nstxttohtmlconv___h___
  40
  41 #include "nsITXTToHTMLConv.h"
  42 #include "nsCOMPtr.h"
  43 #include "nsVoidArray.h"
  44 #include "nsIFactory.h"
  45 #include "nsString.h"
  46
  47 #define NS_NSTXTTOHTMLCONVERTER_CID                         \
  48 { /* 9ef9fa14-1dd1-11b2-9d65-d72d6d1f025e */ \
  49     0x9ef9fa14, \
  50     0x1dd1, \
  51     0x11b2, \
  52     {0x9d, 0x65, 0xd7, 0x2d, 0x6d, 0x1f, 0x02, 0x5e} \
  53 }
  54
  55 // Internal representation of a "token"
  56 typedef struct convToken {
  57     nsString token;     // the actual string (i.e. "http://")
  58     nsString modText;   // replacement text or href prepend text.
  59     PRBool   prepend;   // flag indicating how the modText should be used.
  60 } convToken;
  61
  62 /**
  63  * Convert plain text to HTML.
  64  *
  65  * OVERVIEW OF HOW THIS CLASS WORKS:
  66  *
  67  * This class stores an array of tokens that should be replaced by something,
  68  * or something that should be prepended.
  69  * The "token" member of convToken is the text to search for. This is a
  70  * substring of the desired token. Tokens are delimited by TOKEN_DELIMITERS.
  71  * That entire token will be replaced by modText (if prepend is false); or it
  72  * will be linkified and modText will be prepended to the token if prepend is
  73  * true.
  74  *
  75  * Note that all of the text will be in a preformatted block, so there is no
  76  * need to emit line-end tags, or set the font face to monospace.
  77  *
  78  * This works as a stream converter, so data will arrive by
  79  * OnStartRequest/OnDataAvailable/OnStopRequest calls.
  80  *
  81  * OStopR will possibly process a remaining token.
  82  *
  83  * If the data of one pass contains a part of a token, that part will be stored
  84  * in mBuffer. The rest of the data will be sent to the next listener.
  85  *
  86  * XXX this seems suboptimal. this means that this design will only work for
  87  * links. and it is impossible to append anything to the token. this means that,
  88  * for example, making *foo* bold is not possible.
  89  */
  90 class nsTXTToHTMLConv : public nsITXTToHTMLConv {
  91 public:
  92     NS_DECL_ISUPPORTS
  93     NS_DECL_NSISTREAMCONVERTER
  94     NS_DECL_NSITXTTOHTMLCONV
  95     NS_DECL_NSIREQUESTOBSERVER
  96     NS_DECL_NSISTREAMLISTENER
  97
  98     nsTXTToHTMLConv();
  99     virtual ~nsTXTToHTMLConv();
 100     nsresult Init();
 101
 102     // For factory creation.
 103     static NS_METHOD
 104     Create(nsISupports *aOuter, REFNSIID aIID, void **aResult) {
 105         nsresult rv;
 106         if (aOuter)
 107             return NS_ERROR_NO_AGGREGATION;
 108
 109         nsTXTToHTMLConv* _s = new nsTXTToHTMLConv();
 110         if (_s == nsnull)
 111             return NS_ERROR_OUT_OF_MEMORY;
 112         NS_ADDREF(_s);
 113         rv = _s->Init();
 114         if (NS_FAILED(rv)) {
 115             delete _s;
 116             return rv;
 117         }
 118         rv = _s->QueryInterface(aIID, aResult);
 119         NS_RELEASE(_s);
 120         return rv;
 121     }
 122
 123
 124 protected:
 125     // return the token and it's location in the underlying buffer.
 126     PRInt32 FindToken(PRInt32 cursor, convToken* *_retval);
 127
 128     // return the cursor location after munging HTML into the
 129     // underlying buffer, according to mToken
 130     PRInt32 CatHTML(PRInt32 front, PRInt32 back);
 131
 132     nsCOMPtr<nsIStreamListener>     mListener; // final listener (consumer)
 133     nsString                        mBuffer;   // any carry over data
 134     nsVoidArray                     mTokens;   // list of tokens to search for
 135     convToken                       *mToken;   // current token (if any)
 136     nsString                        mPageTitle; // Page title
 137     PRBool                          mPreFormatHTML; // Whether to use <pre> tags
 138 };
 139
 140 #endif // ____nstxttohtmlconv___h___
 141