File indexing completed on 2024-05-12 04:02:16

 /*
     SPDX-FileCopyrightText: 2016 Volker Krause <vkrause@kde.org>
 
     SPDX-License-Identifier: MIT
 */
 
 #ifndef KSYNTAXHIGHLIGHTING_ABSTRACTHIGHLIGHTERM_H
 #define KSYNTAXHIGHLIGHTING_ABSTRACTHIGHLIGHTERM_H
 
 #include "definition.h"
 #include "ksyntaxhighlighting_export.h"
 
 #include <QObject>
 #include <QStringView>
 
 namespace KSyntaxHighlighting
 {
 class AbstractHighlighterPrivate;
 class FoldingRegion;
 class Format;
 class State;
 class Theme;
 
 /**
  * Abstract base class for highlighters.
  *
  * @section abshl_intro Introduction
  *
  * The AbstractHighlighter provides an interface to highlight text.
  *
  * The SyntaxHighlighting framework already ships with one implementation,
  * namely the SyntaxHighlighter, which also derives from QSyntaxHighlighter,
  * meaning that it can be used to highlight a QTextDocument or a QML TextEdit.
  * In order to use the SyntaxHighlighter, just call setDefinition() and
  * setTheme(), and the associated documents will automatically be highlighted.
  *
  * However, if you want to use the SyntaxHighlighting framework to implement
  * your own syntax highlighter, you need to sublcass from AbstractHighlighter.
  *
  * @section abshl_impl Implementing your own Syntax Highlighter
  *
  * In order to implement your own syntax highlighter, you need to inherit from
  * AbstractHighlighter. Then, pass each text line that needs to be highlighted
  * in order to highlightLine(). Internally, highlightLine() uses the Definition
  * initially set through setDefinition() and the State of the previous text line
  * to parse and highlight the given text line. For each visual highlighting
  * change, highlightLine() will call applyFormat(). Therefore, reimplement
  * applyFormat() to get notified of the Format that is valid in the range
  * starting at the given offset with the specified length. Similarly, for each
  * text part that starts or ends a code folding region, highlightLine() will
  * call applyFolding(). Therefore, if you are interested in code folding,
  * reimplement applyFolding() to get notified of the starting and ending code
  * folding regions, again specified in the range starting at the given offset
  * with the given length.
  *
  * The Format class itself depends on the current Theme. A theme must be
  * initially set once such that the Format%s instances can be queried for
  * concrete colors.
  *
  * Optionally, you can also reimplement setTheme() and setDefinition() to get
  * notified whenever the Definition or the Theme changes.
  *
  * @see SyntaxHighlighter
  * @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT AbstractHighlighter
 {
 public:
     virtual ~AbstractHighlighter();
 
     /**
      * Returns the syntax definition used for highlighting.
      *
      * @see setDefinition()
      */
     Definition definition() const;
 
     /**
      * Sets the syntax definition used for highlighting.
      *
      * Subclasses can re-implement this method to e.g. trigger
      * re-highlighting or clear internal data structures if needed.
      */
     virtual void setDefinition(const Definition &def);
 
     /**
      * Returns the currently selected theme for highlighting.
      *
      * @note If no Theme was set through setTheme(), the returned Theme will be
      *       invalid, see Theme::isValid().
      */
     Theme theme() const;
 
     /**
      * Sets the theme used for highlighting.
      *
      * Subclasses can re-implement this method to e.g. trigger
      * re-highlighing or to do general palette color setup.
      */
     virtual void setTheme(const Theme &theme);
 
 protected:
     AbstractHighlighter();
     KSYNTAXHIGHLIGHTING_NO_EXPORT explicit AbstractHighlighter(AbstractHighlighterPrivate *dd);
 
     /**
      * Highlight the given line. Call this from your derived class
      * where appropriate. This will result in any number of applyFormat()
      * and applyFolding() calls as a result.
      * @param text A string containing the text of the line to highlight.
      * @param state The highlighting state handle returned by the call
      *        to highlightLine() for the previous line. For the very first line,
      *        just pass a default constructed State().
      * @returns The state of the highlighting engine after processing the
      *        given line. This needs to passed into highlightLine() for the
      *        next line. You can store the state for efficient partial
      *        re-highlighting for example during editing.
      *
      * @see applyFormat(), applyFolding()
      */
     State highlightLine(QStringView text, const State &state);
 
     /**
      * Reimplement this to apply formats to your output. The provided @p format
      * is valid for the interval [@p offset, @p offset + @p length).
      *
      * @param offset The start column of the interval for which @p format matches
      * @param length The length of the matching text
      * @param format The Format that applies to the range [offset, offset + length)
      *
      * @note Make sure to set a valid Definition, otherwise the parameter
      *       @p format is invalid for the entire line passed to highlightLine()
      *       (cf. Format::isValid()).
      *
      * @see applyFolding(), highlightLine()
      */
     virtual void applyFormat(int offset, int length, const Format &format) = 0;
 
     /**
      * Reimplement this to apply folding to your output. The provided
      * FoldingRegion @p region either stars or ends a code folding region in the
      * interval [@p offset, @p offset + @p length).
      *
      * @param offset The start column of the FoldingRegion
      * @param length The length of the matching text that starts / ends a
      *       folding region
      * @param region The FoldingRegion that applies to the range [offset, offset + length)
      *
      * @note The FoldingRegion @p region is @e always either of type
      *       FoldingRegion::Type::Begin or FoldingRegion::Type::End.
      *
      * @see applyFormat(), highlightLine(), FoldingRegion
      */
     virtual void applyFolding(int offset, int length, FoldingRegion region);
 
 protected:
     AbstractHighlighterPrivate *d_ptr;
 
 private:
     Q_DECLARE_PRIVATE(AbstractHighlighter)
     Q_DISABLE_COPY(AbstractHighlighter)
 };
 }
 
 QT_BEGIN_NAMESPACE
 Q_DECLARE_INTERFACE(KSyntaxHighlighting::AbstractHighlighter, "org.kde.SyntaxHighlighting.AbstractHighlighter")
 QT_END_NAMESPACE
 
 #endif // KSYNTAXHIGHLIGHTING_ABSTRACTHIGHLIGHTERM_H