Quickies for NSTextView

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General

• Appending to the end of a textview [permalink]
  

      NSRange range;
      range = NSMakeRange ([[textView string] length], 0);
  
      [textView replaceCharactersInRange: range withString: string];

  And Peter Hosey provided a one-liner that may suit your needs better:

      [[[textView textStorage] mutableString] appendString: string];
  

• Deleting the selected text [permalink]
  [textView delete: nil]

• Determining the paragraph style at a particular point [permalink]
  

  - (NSParagraphStyle *) paragraphStyleInTextView: (NSTextView *) textView
                                          atIndex: (int) index
  {
      NSTextStorage *storage = [textView textStorage];
  
      NSDictionary *attributes;
      NSRange effectiveRange;
      attributes = [storage attributesAtIndex: index
                            effectiveRange: &effectiveRange];
  
      NSParagraphStyle *style;
      style = [attributes valueForKey: NSParagraphStyleAttributeName];
  
      return (style);
  
  } // paragraphStyleInTextView

• Finding the span of a paragraph [permalink]
  The NSString paragraphRangeForRange: method gives you the span of a paragraph. If you're using the text architecture, you need to get the string from the text storage. This chunklet shows the paragraph span for the current selection:

      NSRange selectedRange = [textview selectedRange];
      NSTextStorage *storage = [textview textStorage];
      effectiveRange = [[storage string] paragraphRangeForRange: selectedRange];

• Forcing validation of pending text field entries [permalink]
  [window makeFirstResponder: window]

• Moving insertion point to the end [permalink]
  NSRange range = { [[textView string] length], 0 };
[textView setSelectedRange: range];

• Moving insertion point to the start [permalink]
  NSRange zeroRange = { 0, 0 };
[textView setSelectedRange: zeroRange];

• Replacing NSTextView's contents with an attributed string [permalink]
  

          [[textView textStorage] setAttributedString: theNewString];

• Restricting typed in text to just digits [permalink]
  Create a subclass of NSNumberFormatter, add this method, and hook up the formatter to your text fields.

  - (BOOL) isPartialStringValid: (NSString **) partialStringPtr
          proposedSelectedRange: (NSRangePointer) proposedSelRangePtr
                 originalString: (NSString *) origString
          originalSelectedRange: (NSRange) origSelRange
               errorDescription: (NSString **) error
  {
      NSCharacterSet *nonDigits;
      NSRange newStuff;
      NSString *newStuffString;
  
      nonDigits = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
      newStuff = NSMakeRange(origSelRange.location,
                             proposedSelRangePtr->location
                             - origSelRange.location);
      newStuffString = [*partialStringPtr substringWithRange: newStuff];
  
      if ([newStuffString rangeOfCharacterFromSet: nonDigits
              options: NSLiteralSearch].location != NSNotFound) {
          *error = @"Input is not an integer";
          return (NO);
      } else {
          *error = nil;
          return (YES);
      }
  
  } // isPartialStringValid

• Scrolling to the end of a textview [permalink]
  

      NSRange range;
      range = NSMakeRange ([[textView string] length], 0);
  
      [textView scrollRangeToVisible: range];

  I've heard that scrollRangeToVisible is O(N) for the length of the text. So be on the lookout if you have lots of text involved.

• Show NSTextField text in gray if the field is disabled [permalink]
  NSTextField doesn't change its text color if the field is enabled or disabled (?) Even more bizarre, using NSColor's disabledControlTextColor won't draw the text in the disabled color. You need to use the secondarySelectedControlColor, which supposedly is for active controls that don't have focus. Go figure.

  To do it yourself, subclass NSTextField and override setEnabled: to change the color:

  - (void) setEnabled: (BOOL) flag
  {
      [super setEnabled: flag];
  
      if (flag == NO) {
          [self setTextColor: [NSColor secondarySelectedControlColor]];
      } else {
          [self setTextColor: [NSColor controlTextColor]];
      }
  
  } // setEnabled

  This actually kind of a gross workaround for a Cocoa bug - the disabled color is getting made darker rather than lighter. The secondarySelectedControlColor ends up looking disabled by a happy coincidence that it starts out lighter before being darkened. (or something like this. UberDude Dave MacLachlan has done the legwork to figure out the underlying problem.)

• Truncating text in the middle of a string [permalink]
  Sometimes you see text that is of the form "Some Gro...eral Fish", with the middle truncated but the ends still readable. You can get this effect yourself with:

  [[textfield cell] setLineBreakMode: NSLineBreakByTruncatingMiddle]
  

  (Thanks to Daniel Jalkut for this one)

• scrolling to the beginning of a textview [permalink]
  NSRange zeroRange = { 0, 0 };
[textView scrollRangeToVisible: zeroRange];

NSString

• Getting the contents of a TextView as an NSString [permalink]
  

  NSString *commitMessage;
  commitMessage = [[commitTextView textStorage] string];

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