{"id":273,"date":"2008-01-09T13:09:17","date_gmt":"2008-01-09T21:09:17","guid":{"rendered":"http:\/\/www.corbinstreehouse.com\/blog\/?p=273"},"modified":"2018-10-31T10:15:16","modified_gmt":"2018-10-31T17:15:16","slug":"cocoa-willdisplaycell-delegate-method-of-nstableview-nscell-settextcolor-and-source-lists","status":"publish","type":"post","link":"https:\/\/www.corbinstreehouse.com\/blog\/2008\/01\/cocoa-willdisplaycell-delegate-method-of-nstableview-nscell-settextcolor-and-source-lists\/","title":{"rendered":"Cocoa: willDisplayCell delegate method of NSTableView, [NSCell setTextColor], and “source lists”"},"content":{"rendered":"

\n

Mac OS 10.5 added a “source list” highlighting style to NSTableView, with the API below for your reference:<\/p>\n

enum {<\/span><\/p>\n

NSTableViewSelectionHighlightStyleRegular<\/span> =<\/span> 0<\/span>,<\/span><\/p>\n

NSTableViewSelectionHighlightStyleSourceList<\/span> =<\/span> 1<\/span>,<\/span><\/p>\n

};<\/p>\n

typedef<\/span> NSInteger NSTableViewSelectionHighlightStyle;<\/span><\/p>\n

<\/p>\n

– (<\/span>NSTableViewSelectionHighlightStyle)selectionHighlightStyle;<\/span><\/p>\n

– (void<\/span>)setSelectionHighlightStyle:(NSTableViewSelectionHighlightStyle<\/span>)selectionHighlightStyle;<\/p>\n


<\/span><\/p>\n

Source lists should have bold text when the item is selected, and NSTableView attempts to auto-format the cell’s contents to automatically do this for you, as seen in this screen shot for the selected item in the open panel source list:<\/p>\n

<\/p>\n

However, the code that does this formatting does so by converting the ‘stringValue’ of the cell to an attributedStringValue that has the bold text. This is done *before* calling the delegate with “willDisplayCell”. The delegate gets the final say of how it looks in “willDisplayCell”, but this can cause unexpected results if you want to do something like this:<\/p>\n

– (<\/span>void<\/span>)tableView:(NSTableView<\/span> *)tableView willDisplayCell:(id<\/span>)cell forTableColumn:(NSTableColumn<\/span> *)tableColumn row:(NSInteger<\/span>)row {<\/p>\n

if<\/span>(row == 0<\/span>) {<\/p>\n

[cell setTextColor<\/span>: [NSColor<\/span> redColor<\/span>]];<\/p>\n

} else<\/span> {<\/p>\n

[cell<\/span> setTextColor: [<\/span>NSColor<\/span> blackColor]];<\/span><\/p>\n

}<\/p>\n

}<\/p>\n

The problem with the above code is that it is *too late* for the coloring to be correctly applied to the cell if it is selected. The work around is easy; you need to color the cell text earlier, and a perfect place to do that is in the new 10.5 delegate method “dataCellForTableColumn:”<\/p>\n

– (NSCell<\/span> *)tableView:(NSTableView<\/span> *)tableView dataCellForTableColumn:(NSTableColumn<\/span> *)tableColumn row:(NSInteger<\/span>)row {<\/p>\n

NSTextFieldCell<\/span> *cell = [tableColumn dataCell<\/span>];<\/p>\n

if<\/span>(row == 0<\/span>) {<\/p>\n

[cell setTextColor<\/span>: [NSColor<\/span> redColor<\/span>]];<\/p>\n

} else<\/span> {<\/p>\n

[cell<\/span> setTextColor: [<\/span>NSColor<\/span> blackColor]];<\/span><\/p>\n

}<\/p>\n

return<\/span> cell;<\/p>\n

}<\/p>\n

Cool. Have fun.<\/p>\n","protected":false},"excerpt":{"rendered":"

Mac OS 10.5 added a “source list” highlighting style to NSTableView, with the API below for your reference: enum { NSTableViewSelectionHighlightStyleRegular = 0, NSTableViewSelectionHighlightStyleSourceList = 1, }; typedef NSInteger NSTableViewSelectionHighlightStyle; – (NSTableViewSelectionHighlightStyle)selectionHighlightStyle; – (void)setSelectionHighlightStyle:(NSTableViewSelectionHighlightStyle)selectionHighlightStyle; Source… [read more]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4,6,86],"tags":[63,130,72],"class_list":["post-273","post","type-post","status-publish","format-standard","hentry","category-apple","category-cocoa","category-coding","tag-cocoa","tag-objc","tag-programming"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/posts\/273","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/comments?post=273"}],"version-history":[{"count":1,"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/posts\/273\/revisions"}],"predecessor-version":[{"id":5178,"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/posts\/273\/revisions\/5178"}],"wp:attachment":[{"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/media?parent=273"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/categories?post=273"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.corbinstreehouse.com\/blog\/wp-json\/wp\/v2\/tags?post=273"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}