Custom NSFormatter classes
Custom NSFormatter classes
- Subject: Custom NSFormatter classes
- From: Henri Häkkinen <email@hidden>
- Date: Sun, 3 Jan 2010 02:47:00 +0200
Hello.
I have an array of custom Foo objects which I would need to display in an NSTableView object. I implement the data source delegate like this:
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView {
return [arrayOfFoos count];
}
- (id)tableView:(NSTableView *)tableView objectValueForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger) row {
return [arrayOfFoos objectAtIndex:row];
}
Then I have NSFormatter subclass FooFormatter which takes in a Foo object and converts it to a string. This formatter object is attached to the formatter property of the TextFieldCell class in the NSTableView's table column. The FooFormatter is like this:
@implementation FooFormatter
- (NSString *)stringForObjectValue:(id)anObject {
if ([anObject isKindOfClass:[Foo class]] == NO) {
[NSException raise:NSInvalidArgumentException format:@"Wrong object"];
}
Foo *foo = (Foo *)anObject;
NSString *string;
// ... convert foo into string ...
return string;
}
@end
I am assuming here that the object returned by the data source objectValueForTableColumn: is passed to the formatter's stringForObjectValue: before it is displayed in the text field cell -- this seems not to be the case. I would like to keep formatting of Foo objects separate from the data source (if possible) since I intend to implement multiple different FooFormatter derived classes suited for different situations.
The Cocoa docs seem to be a little low on details on how these NSFormatter objects are supposed to work. Can anybody give me any insight? Would be appreciated. Thanks.
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden