bundles/winterwell.markdown/src/winterwell/markdown/editors/HeaderWithUnderlineRule.java

   1 /**
   2  * @author Telmo Brugnara
   3  * 10 Feb 2014
   4  */
   5 package winterwell.markdown.editors;
   6
   7 import org.eclipse.jface.text.rules.ICharacterScanner;
   8 import org.eclipse.jface.text.rules.IRule;
   9 import org.eclipse.jface.text.rules.IToken;
  10 import org.eclipse.jface.text.rules.Token;
  11
  12 public class HeaderWithUnderlineRule implements IRule {
  13
  14         IToken successToken = null;
  15
  16         public HeaderWithUnderlineRule(IToken token) {
  17                 successToken = token;
  18         }
  19
  20         public IToken evaluate(ICharacterScanner scanner) {
  21                 int c = -1;
  22                 int scanCount = 0;
  23                 if (scanner.getColumn()==0) {
  24                         do {
  25                                 c = scanner.read();
  26                                 scanCount++;
  27                         } while (!isNewLine((char) c) && c != ICharacterScanner.EOF);
  28                         if(c == ICharacterScanner.EOF) {
  29                                 // is not a header
  30                                 for(int i=0;i<scanCount;i++) { scanner.unread(); }
  31                                 return Token.UNDEFINED;
  32                         }
  33                         c = scanner.read();
  34                         scanCount++;
  35                         if(c == '\r') {
  36                                 c = scanner.read();
  37                                 scanCount++;
  38                         }
  39                         if(!isUnderline((char) c)) {
  40                                 // is not a header
  41                                 for(int i=0;i<scanCount;i++) { scanner.unread(); }
  42                                 return Token.UNDEFINED;
  43                         }
  44                         do {
  45                                 c = scanner.read();
  46                                 scanCount++;
  47                                 if(isNewLine((char) c) || c == ICharacterScanner.EOF) {
  48                                         //scanner.unread();
  49                                         return successToken;
  50                                 }
  51                                 if(!isUnderline((char) c) && !isWhitespace((char) c) && c != '\r') {
  52                                         // is not a header
  53                                         for(int i=0;i<scanCount;i++) { scanner.unread(); }
  54                                         return Token.UNDEFINED;
  55                                 }
  56                         } while (true);
  57                 }
  58
  59                 return Token.UNDEFINED;
  60         }
  61
  62         boolean isNewLine(char c) {
  63                 return c == '\n';
  64         }
  65
  66         boolean isUnderline(char c) {
  67                 return c == '=' || c == '-';
  68         }
  69
  70         boolean isWhitespace(char c) {
  71                 return c == ' ' || c == '\t';
  72         }
  73 }