iOS7 TextKit

iosText.m

// Useful TextKit functions
// from Apple's Advanced Text Layouts and Effects with Text Kit
// https://developer.apple.com/wwdc/videos/


//Finding the last character

- (CGPoint) lastcharacter
{
 NSLayoutManager *layoutManager = textView.layoutManager;
 NSUInteger characterIndex = textView.textStorage.length - 1;
 NSUInteger glyphIndex;
 CGRect rect;
 CGPoint glyphLocation;
 glyphIndex = [layoutManager glyphIndexForCharacterIndex:characterIndex];
 rect = [layoutManager lineFragmentRectForGlyphAtIndex:glyphIndex
                                        effectiveRange:NULL];
 glyphLocation = [layoutManager locationForGlyphAtIndex:glyphIndex];
 glyphLocation.x += CGRectGetMinX(rect);
 glyphLocation.y += CGRectGetMinY(rect);

  return glyphLocation;
}

// Finding the word under a touch
- (void) getWordAt: (CGPoint) location 
{
  NSLayoutManager *layoutManager = textView.layoutManager;
  CGPoint location = [touch locationInView:textView];
  NSUInteger characterIndex;
  characterIndex = [layoutManager characterIndexForPoint:location inTextContainer:textView.textContainer fractionOfDistanceBetweenInsertionPoints:NULL];
  if (characterIndex < textView.textStorage.length) 
  {
    // valid index 
    // Find the word range here
    // using -enumerateSubstringsInRange:options:usingBlock:
  }
}

//Counting the number of visual lines
- (NSUInteger) linesInText (UITextView *) textView
{
  NSLayoutManager *layoutManager = textView.layoutManager;
  NSTextContainer *textContainer = textView.textContainer;
  NSRange glyphRange, lineRange = NSMakeRange(0, 0);
  NSRect rect;
  CGFloat lastOriginY = -1.0;
  NSUInteger numberOfLines = 0;
  glyphRange = [layoutManager glyphRangeForTextContainer:textContainer];
  while (lineRange.location < NSMaxRange(glyphRange)) 
  {
   rect = [layoutManager lineFragmentRectForGlyphAtIndex:lineRange.location effectiveRange:&lineRange];
   if (CGRectMinY(rect) > lastOriginY) ++numberOfLines;
   lastOriginY = CGRectMinY(rect);
   lineRange.location = NSMaxRange(lineRange);
  }
  return numberOfLines;
}