attributed_string.m

- (NSMutableAttributedString *)attributedStringFromMarkup:(NSString *)markup {

  NSMutableAttributedString * mutableAttrString = [[[NSMutableAttributedString alloc] initWithString:@""] autorelease];
  NSString  * nextTextChunk = nil;
  NSString  * defaultFont = @"Georgia";
  NSString  * boldFont = @"Georgia-Bold";
  NSString  * headingFont = @"Gill-Sans";
  
  CGFloat   defaultFontSize = 18.0;
  CGFloat   headingFontSize = 22.0;
  
  CGFloat     fontSize = 0.0;
  NSString  * fontFace = nil;
  
  NSScanner * markupScanner = [NSScanner scannerWithString:markup];
  [markupScanner setCharactersToBeSkipped:nil];
  
  while (![markupScanner isAtEnd]) {
    [markupScanner scanUpToString:@"<" intoString:&nextTextChunk];
    [markupScanner scanString:@"<" intoString:NULL];
    
    if ([nextTextChunk length] > 0) {
      CTFontRef currentFont = CTFontCreateWithName((CFStringRef)(fontFace ? fontFace : defaultFont), 
                                                   (fontSize != 0.0 ? fontSize : defaultFontSize), NULL);
      UIColor   * color = [UIColor blackColor];
      NSDictionary  * attrs = [NSDictionary dictionaryWithObjectsAndKeys:
                                            (id)color.CGColor, kCTForegroundColorAttributeName,
                                            (id)currentFont, kCTFontAttributeName,
                                            nil];
      NSAttributedString  * newPiece = [[[NSAttributedString alloc] initWithString:nextTextChunk attributes:attrs] autorelease];
      [mutableAttrString appendAttributedString:newPiece];
      CFRelease(currentFont);
      
      nextTextChunk = nil;
    }
    
    NSString * elementData = nil;
    [markupScanner scanUpToString:@">" intoString:&elementData];
    [markupScanner scanString:@">" intoString:NULL];
    
    if (elementData) {
      if ([elementData length] == 1) {
        // Opening Tag
        if ([elementData caseInsensitiveCompare:@"b"] == NSOrderedSame) {
          fontFace = boldFont;
          fontSize = defaultFontSize;
        } else if ([elementData caseInsensitiveCompare:@"h"] == NSOrderedSame) {
          fontFace = headingFont;
          fontSize = headingFontSize;
        } else {
          fontFace = nil;
          fontSize = 0.0;
        }
      } else {
        // Closing Tag
        fontSize = 0.0;
        fontFace = nil;
      }
    }
  }
  
  return mutableAttrString;
}