Using NSValueTransformer to convert NSImage to NSData
Using NSValueTransformer to convert NSImage to NSData
- Subject: Using NSValueTransformer to convert NSImage to NSData
- From: Peter Zegelin <email@hidden>
- Date: Tue, 24 Mar 2009 23:39:33 +1100
I am trying to bind an NSImageView to my shared user defaults so that
when a user drops an image onto the control it is automatically scaled
and saved to the users preferences file. I have made a subclass of
NSValueTransformer to convert NSImage <> NSData for saving to the
defaults but am having no luck getting any further. When an image is
dropped my reverseTransformedValue is called but I have no idea what
to do next. I can't even figure out what 'value' is:
- (id)reverseTransformedValue:(id)value
[value description] gives just a string <................> with
nothing obvious in it.
So how do I transform whatever value is into an NSData object for
archiving?
My class is as follows:
@implementation ImageScalingAndArchivingTransformer // subclass of
NSValueTransformer
+ (Class)transformedValueClass { return [NSImage class]; }
+ (BOOL)allowsReverseTransformation { return YES; }
- (id)reverseTransformedValue:(id)value {
// what to do here to scale an image to icon size and convert it to
NSData?
}
- (id)transformedValue:(id)value {
// I am just returning the value here for now as it is currently
0x00 anyway.
return value;
}
thanks for any insights!
Peter
_______________________________________________
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