iphone -Objective C get tap position in UITextView

 

I find some code about getting position from UITextView, but the guy didn't 

give the full code,  I fill up the missing code(the "while loop"), now I can get the position 

in text view, but this is my first version of this method, might have some bugs.

 

 

-(CGPoint)getPositionInTextView:(UITextView*) textView{

CGPoint origin = textView.frame.origin;

NSString* head = [textView.text substringToIndex:textView.selectedRange.location];

CGSize initialSize = [head sizeWithFont:textView.font constrainedToSize:textView.contentSize lineBreakMode:UILineBreakModeWordWrap];

NSUInteger startOfLine = [head length];

while (startOfLine > 0) {

  startOfLine--;

  NSString* reduction=[head substringToIndex:startOfLine];

  CGSize reductionSize = [reduction sizeWithFont:textView.font constrainedToSize:textView.contentSize        lineBreakMode:UILineBreakModeWordWrap];

  if(reductionSize.height<initialSize.height)

    break;  

}

NSString* tail = [head substringFromIndex:startOfLine];

CGSize lineSize = [tail sizeWithFont:textView.font forWidth:textView.contentSize.width lineBreakMode:UILineBreakModeWordWrap];

CGPoint cursor = origin;

cursor.x += lineSize.width;

cursor.y += initialSize.height - lineSize.height;

return cursor;

}