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    41 

    42 #include "q3syntaxhighlighter.h"

    43 #include "q3syntaxhighlighter_p.h"

    44 

    45 #ifndef QT_NO_SYNTAXHIGHLIGHTER

    46 #include "q3textedit.h"

    47 #include "qtimer.h"

    48 

    49 QT_BEGIN_NAMESPACE

    50 

    51 /*!

    52     \class Q3SyntaxHighlighter

    53     \brief The Q3SyntaxHighlighter class is a base class for

    54     implementing Q3TextEdit syntax highlighters.

    55 

    56     \compat

    57 

    58     A syntax highligher automatically highlights parts of the text in

    59     a Q3TextEdit. Syntax highlighters are often used when the user is

    60     entering text in a specific format (for example, source code) and

    61     help the user to read the text and identify syntax errors.

    62 

    63     To provide your own syntax highlighting for Q3TextEdit, you must

    64     subclass Q3SyntaxHighlighter and reimplement highlightParagraph().

    65 

    66     When you create an instance of your Q3SyntaxHighlighter subclass,

    67     pass it the Q3TextEdit that you want the syntax highlighting to be

    68     applied to. After this your highlightParagraph() function will be

    69     called automatically whenever necessary. Use your

    70     highlightParagraph() function to apply formatting (e.g. setting

    71     the font and color) to the text that is passed to it.

    72 */

    73 

    74 /*!

    75     Constructs the Q3SyntaxHighlighter and installs it on \a textEdit.

    76     Ownership of the Q3SyntaxHighlighter is transferred to the \a

    77     textEdit

    78 */

    79 

    80 Q3SyntaxHighlighter::Q3SyntaxHighlighter(Q3TextEdit *textEdit)

    81     : para(0), edit(textEdit), d(new Q3SyntaxHighlighterPrivate)

    82 {

    83     textEdit->document()->setPreProcessor(new Q3SyntaxHighlighterInternal(this));

    84     textEdit->document()->invalidate();

    85     QTimer::singleShot(0, textEdit->viewport(), SLOT(update()));

    86 }

    87 

    88 /*!

    89     Destructor. Uninstalls this syntax highlighter from the textEdit()

    90 */

    91 

    92 Q3SyntaxHighlighter::~Q3SyntaxHighlighter()

    93 {

    94     delete d;

    95     textEdit()->document()->setPreProcessor(0);

    96 }

    97 

    98 /*!

    99     \fn int Q3SyntaxHighlighter::highlightParagraph(const QString &text, int endStateOfLastPara)

   100 

   101     This function is called when necessary by the rich text engine,

   102     i.e. on paragraphs which have changed.

   103 

   104     In your reimplementation you should parse the paragraph's \a text

   105     and call setFormat() as often as necessary to apply any font and

   106     color changes that you require. Your function must return a value

   107     which indicates the paragraph's end state: see below.

   108 

   109     Some syntaxes can have constructs that span paragraphs. For

   110     example, a C++ syntax highlighter should be able to cope with

   111     \c{/}\c{*...*}\c{/} comments that span paragraphs. To deal

   112     with these cases it is necessary to know the end state of the

   113     previous paragraph (e.g. "in comment").

   114 

   115     If your syntax does not have paragraph spanning constructs, simply

   116     ignore the \a endStateOfLastPara parameter and always return 0.

   117 

   118     Whenever highlightParagraph() is called it is passed a value for

   119     \a endStateOfLastPara. For the very first paragraph this value is

   120     always -2. For any other paragraph the value is the value returned

   121     by the most recent highlightParagraph() call that applied to the

   122     preceding paragraph.

   123 

   124     The value you return is up to you. We recommend only returning 0

   125     (to signify that this paragraph's syntax highlighting does not

   126     affect the following paragraph), or a positive integer (to signify

   127     that this paragraph has ended in the middle of a paragraph

   128     spanning construct).

   129 

   130     To find out which paragraph is highlighted, call

   131     currentParagraph().

   132 

   133     For example, if you're writing a simple C++ syntax highlighter,

   134     you might designate 1 to signify "in comment". For a paragraph

   135     that ended in the middle of a comment you'd return 1, and for

   136     other paragraphs you'd return 0. In your parsing code if \a

   137     endStateOfLastPara was 1, you would highlight the text as a C++

   138     comment until you reached the closing \c{*}\c{/}.

   139 */

   140 

   141 /*!

   142     This function is applied to the syntax highlighter's current

   143     paragraph (the text of which is passed to the highlightParagraph()

   144     function).

   145 

   146     The specified \a font and \a color are applied to the text from

   147     position \a start for \a count characters. (If \a count is 0,

   148     nothing is done.)

   149 */

   150 

   151 void Q3SyntaxHighlighter::setFormat(int start, int count, const QFont &font, const QColor &color)

   152 {

   153     if (!para || count <= 0)

   154         return;

   155     Q3TextFormat *f = 0;

   156     f = para->document()->formatCollection()->format(font, color);

   157     para->setFormat(start, count, f);

   158     f->removeRef();

   159 }

   160 

   161 /*! \overload */

   162 

   163 void Q3SyntaxHighlighter::setFormat(int start, int count, const QColor &color)

   164 {

   165     if (!para || count <= 0)

   166         return;

   167     Q3TextFormat *f = 0;

   168     QFont fnt = textEdit()->QWidget::font();

   169     f = para->document()->formatCollection()->format(fnt, color);

   170     para->setFormat(start, count, f);

   171     f->removeRef();

   172 }

   173 

   174 /*! \overload */

   175 

   176 void Q3SyntaxHighlighter::setFormat(int start, int count, const QFont &font)

   177 {

   178     if (!para || count <= 0)

   179         return;

   180     Q3TextFormat *f = 0;

   181     QColor c = textEdit()->viewport()->palette().color(textEdit()->viewport()->foregroundRole());

   182     f = para->document()->formatCollection()->format(font, c);

   183     para->setFormat(start, count, f);

   184     f->removeRef();

   185 }

   186 

   187 /*!

   188     \fn Q3TextEdit *Q3SyntaxHighlighter::textEdit() const

   189 

   190     Returns the Q3TextEdit on which this syntax highlighter is

   191     installed

   192 */

   193 

   194 /*!  Redoes the highlighting of the whole document.

   195 */

   196 

   197 void Q3SyntaxHighlighter::rehighlight()

   198 {

   199     Q3TextParagraph *s = edit->document()->firstParagraph();

   200     while (s) {

   201         s->invalidate(0);

   202         s->state = -1;

   203         s->needPreProcess = true;

   204         s = s->next();

   205     }

   206     edit->repaintContents();

   207 }

   208 

   209 /*!

   210     Returns the id of the paragraph which is highlighted, or -1 of no

   211     paragraph is currently highlighted.

   212 

   213     Usually this function is called from within highlightParagraph().

   214 */

   215 

   216 int Q3SyntaxHighlighter::currentParagraph() const

   217 {

   218     return d->currentParagraph;

   219 }

   220 

   221 QT_END_NAMESPACE

   222 

   223 #endif