Cbv: Added categories

2006-04-21T15:47:12Z

Added categories

Cbv: Moved from Snippets

2005-09-05T13:42:50Z

Moved from Snippets

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NSTextField displays text a user can select or edit and sends its action message to its target when the user presses the Return key while editing.

== Code chunks ==

=== Testing ''chars'' entered by users in ''NSTextField'' ===
When the contents of a NSTextField are changed by the user, it is possible to check whether or not to accept the changes.

1. Subclass NSTextField

2. In your subclass implement the
- (BOOL) textView: (NSTextView*) textView
shouldChangeTextInRange: (NSRange) range
replacementString: (NSString*) replacementString
method.

3. Within this method you can access to the ''replacementString'' as an NSString, or as ''char'' with the following line:
char c = *([replacementString cString] + 0);

4. You should return YES or NO depending on whether you accept the replacement string.

=== Limiting text input length in ''NSTextField'' ===
(based on Alexander Malmberg's snippet)

1. Subclass NSTextField

2. In your subclass implement the
- (BOOL) textView: (NSTextView*) textView
shouldChangeTextInRange: (NSRange) range
replacementString: (NSString*) replacementString
method.

3. Also create an instance variable setting method:
- (void) setMaxLength: (int) ml
{
maxLength = ml;
}

4. Then fill your implementation of textView:shouldChangeTextInRange:replacementString: with the following code:
int newLength;
/* The exact change isn't known. Disallow the change to be safe. */
if (range.location == NSNotFound)
return NO;
newLength=[[textView textStorage] length]+[replacementString length]-range.length;
if (newLength>maxLength)
return YES; //allowing
else
return NO; // not allowing

← Older revision		Revision as of 15:47, 21 April 2006
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	else		else
	return NO; // not allowing		return NO; // not allowing
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NSTextField - Revision history

Cbv: Added categories

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