sw/source/core/inc/SwPortionHandler.hxx

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   9  * This file incorporates work covered by the following license notice:
  10  *
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  12  *   contributor license agreements. See the NOTICE file distributed
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  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
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  19
  20 #ifndef INCLUDED_SW_SOURCE_CORE_INC_SWPORTIONHANDLER_HXX
  21 #define INCLUDED_SW_SOURCE_CORE_INC_SWPORTIONHANDLER_HXX
  22
  23 #include <swdllapi.h>
  24 #include <rtl/ustring.hxx>
  25 #include "TextFrameIndex.hxx"
  26
  27 class SwFont;
  28 enum class PortionType;
  29
  30 /** The SwPortionHandler interface implements a visitor for the layout
  31  * engine's text portions. This can be used to gather information of
  32  * the on-screen representation of a single paragraph.
  33  *
  34  * For each text portion, one of the methods text(...) or special(...)
  35  * is called, depending on whether it is a 'normal' run of text, or
  36  * any other portion. Additionally, the linebreak() method is called
  37  * once at the end of every on-screen line.
  38  *
  39  * All parameters relate to the 'view string', which is the text string
  40  * held by the sequence of all corresponding SwTextFrames.
  41  *
  42  * The SwPortionHandler can be used with the
  43  * SwTextFrame::VisitPortions(...) method.
  44  */
  45 class SW_DLLPUBLIC SwPortionHandler
  46 {
  47 public:
  48
  49     virtual ~SwPortionHandler() {}  /// (empty) destructor
  50
  51     /** text portion. A run of nLength characters from the view
  52      * string, that contains no special characters like embedded
  53      * fields, etc. Thus, the on-screen text of this portion
  54      * corresponds exactly to the corresponding characters in the
  55      * view string.
  56      */
  57     virtual void Text(
  58         TextFrameIndex nLength, ///< length of this portion in the view string
  59         PortionType nType       /// type of this portion
  60         ) = 0;
  61
  62     /** special portion. This method is called for every non-text
  63      * portion. The parameters describe the length of the
  64      * corresponding characters in the view string (often 0 or 1),
  65      * the text which is displayed, and the type of the portion.
  66      */
  67     virtual void Special(
  68         TextFrameIndex nLength, ///< length of this portion in the view string
  69         const OUString& rText, /// text which is painted on-screen
  70         PortionType nType         /// type of this portion
  71         ) = 0;
  72
  73     /** line break. This method is called whenever a line break in the
  74      * layout occurs.
  75      */
  76     virtual void LineBreak() = 0;
  77
  78     /** skip characters. The SwTextFrame may only display partially
  79      * display a certain paragraph (e.g. when the paragraph is split
  80      * across multiple pages). In this case, the Skip() method must be
  81      * called to inform the portion handler to ignore a certain run of
  82      * characters in the 'view string'. Skip(), if used at all, must
  83      * be called before any of the other methods is called. Calling
  84      * Skip() between portions is not allowed.
  85      */
  86     virtual void Skip(
  87         TextFrameIndex nLength   /// number of 'view string' characters to be skipped
  88         ) = 0;
  89
  90     /** end of paragraph. This method is to be called when all the
  91      * paragraph's portions have been processed.
  92      */
  93     virtual void Finish() = 0;
  94 };
  95
  96 #endif
  97
  98 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */