I actually just learned it the hard way. Look at Skim's SKSnapshotTableView : SKThumbnailTableView.
If this class would call [[self superclass] instancesRespondToSelector:@selector (validateMenuItem:)] inside the implementation of -validateMenuItem: in SKThumbnailTableView (which is called indirectly) it checks its superclass *at run time*, which is SKThumbnailTableView. So this check returns YES, and happily calls [super validateMenuItem:]. However this happens in SKThumbnailTableView's implementation, so it calls its superclass *at compile time* (which is what super does), which is NSTableView. The main point is: it sends the message to super, and the class for super is determined at compile time, so it also better check the class determined at compile time, and not at run time. Christiaan On 5 Aug 2007, at 6:59 PM, Adam R. Maxwell wrote: > Can you give a concrete example of when this would fail? I'm not sure > I see the problem. > > thanks, > adam > > On Aug 5, 2007, at 09:36, [EMAIL PROTECTED] wrote: > >> Revision: 10884 >> http://bibdesk.svn.sourceforge.net/bibdesk/? >> rev=10884&view=rev >> Author: hofman >> Date: 2007-08-05 09:36:16 -0700 (Sun, 05 Aug 2007) >> >> Log Message: >> ----------- >> Hard code the superclass for checking wether super responds to a >> selector, as the class of super is implicitly also hard coded. >> Otherwise it may check the wrong (sub)class. >> >> Modified Paths: >> -------------- >> trunk/bibdesk/BDSKFileMatcher.m >> trunk/bibdesk/BDSKPreferenceController.m >> trunk/bibdesk/BDSKZoomableScrollView.m >> trunk/bibdesk/BibDocument.m >> trunk/bibdesk/BibPersonController.m >> >> Modified: trunk/bibdesk/BDSKFileMatcher.m >> =================================================================== >> --- trunk/bibdesk/BDSKFileMatcher.m 2007-08-05 13:29:04 UTC (rev >> 10883) >> +++ trunk/bibdesk/BDSKFileMatcher.m 2007-08-05 16:36:16 UTC (rev >> 10884) >> @@ -740,7 +740,7 @@ >> >> - (void)awakeFromNib >> { >> - if ([[self superclass] instancesRespondToSelector:_cmd]) >> + if ([NSWindowController instancesRespondToSelector:_cmd]) >> [super awakeFromNib]; >> >> // colors similar to Spotlight's window: darker blue at bottom, >> lighter at top >> >> Modified: trunk/bibdesk/BDSKPreferenceController.m >> =================================================================== >> --- trunk/bibdesk/BDSKPreferenceController.m 2007-08-05 13:29:04 UTC >> (rev 10883) >> +++ trunk/bibdesk/BDSKPreferenceController.m 2007-08-05 16:36:16 UTC >> (rev 10884) >> @@ -103,7 +103,7 @@ >> - (void)awakeFromNib; >> { >> // OAPreferenceController may implement this in future >> - if ([[self superclass] instancesRespondToSelector:_cmd]) >> + if ([OAPreferenceController instancesRespondToSelector:_cmd]) >> [super awakeFromNib]; >> >> NSWindow *theWindow = [self window]; >> >> Modified: trunk/bibdesk/BDSKZoomableScrollView.m >> =================================================================== >> --- trunk/bibdesk/BDSKZoomableScrollView.m 2007-08-05 13:29:04 UTC >> (rev 10883) >> +++ trunk/bibdesk/BDSKZoomableScrollView.m 2007-08-05 16:36:16 UTC >> (rev 10884) >> @@ -237,7 +237,7 @@ >> return [self canZoomOut]; >> else if([menuItem action] == @selector(zoomToActualSize:)) >> return [self canZoomToActualSize]; >> - else if ([[self superclass] instancesRespondToSelector:_cmd]) >> + else if ([NSScrollView instancesRespondToSelector:_cmd]) >> return [super validateMenuItem:menuItem]; >> return YES; >> } >> >> Modified: trunk/bibdesk/BibDocument.m >> =================================================================== >> --- trunk/bibdesk/BibDocument.m 2007-08-05 13:29:04 UTC (rev 10883) >> +++ trunk/bibdesk/BibDocument.m 2007-08-05 16:36:16 UTC (rev 10884) >> @@ -802,7 +802,7 @@ >> NSSet *typesWithEncoding = [NSSet >> setWithObjects:BDSKBibTeXDocumentType, BDSKRISDocumentType, >> BDSKMinimalBibTeXDocumentType, BDSKLTBDocumentType, nil]; >> NSString *selectedType = [[sender selectedItem] >> representedObject]; >> [saveTextEncodingPopupButton setEnabled:[typesWithEncoding >> containsObject:selectedType]]; >> - if ([[self superclass] >> instancesRespondToSelector:@selector(changeSaveType:)]) >> + if ([NSDocument >> instancesRespondToSelector:@selector(changeSaveType:)]) >> [super changeSaveType:sender]; >> } >> >> >> Modified: trunk/bibdesk/BibPersonController.m >> =================================================================== >> --- trunk/bibdesk/BibPersonController.m 2007-08-05 13:29:04 UTC (rev >> 10883) >> +++ trunk/bibdesk/BibPersonController.m 2007-08-05 16:36:16 UTC (rev >> 10884) >> @@ -86,7 +86,7 @@ >> } >> >> - (void)awakeFromNib{ >> - if ([[self superclass] >> instancesRespondToSelector:@selector(awakeFromNib)]){ >> + if ([NSWindowController >> instancesRespondToSelector:@selector(awakeFromNib)]){ >> [super awakeFromNib]; >> } >> >> >> >> This was sent by the SourceForge.net collaborative development >> platform, the world's largest Open Source development site. >> >> --------------------------------------------------------------------- >> ---- >> This SF.net email is sponsored by: Splunk Inc. >> Still grepping through log files to find problems? Stop. >> Now Search log events and configuration files using AJAX and a >> browser. >> Download your FREE copy of Splunk now >> http://get.splunk.com/ >> _______________________________________________ >> Bibdesk-commit mailing list >> [EMAIL PROTECTED] >> https://lists.sourceforge.net/lists/listinfo/bibdesk-commit > > > ---------------------------------------------------------------------- > --- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a > browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Bibdesk-develop mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/bibdesk-develop ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Bibdesk-develop mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bibdesk-develop
