====== drag and drop onto program icon ======
===== configure the target =====
  * in Xcode, Get Info on the desired target
  * in the "Properties" tab, add a new document type
    * give the item a name, such as: Tiff Image
    * give the item a UTI, such as: public.tiff
    * set the Store Type to Binary
    * set the Role to Viewer
  * this alone should make an image file dragged onto the program icon appear to work, but nothing will happen yet

===== establish an application delegate =====
In IB (Interface Builder) set a delegate for "File's Owner", such as MyAppController

===== write the method to handle the drag and drop =====
Add this to the delegate of "File's Owner"
<code>
- (BOOL)application:(NSApplication *)theApplication openFile:(NSString *)filename
{
	NSFileManager *fm = [NSFileManager defaultManager];
	if([fm isReadableFileAtPath:filename]){
		[self openLocation:filename];
		return YES;
	}
	return NO;
}
</code>

===== write the method to handle the file =====
- (void)openLocation:(NSString *)newLocation
{
	if([fileManager fileExistsAtPath:newLocation]){
		// do something
	}
}


===== External Links =====
  * [[http://developer.apple.com/documentation/Carbon/Conceptual/understanding_utis/index.html|Uniform Type Identifiers Overview (Apple)]] 
  * http://en.wikipedia.org/wiki/Uniform_Type_Identifier