In general, a user’s changes to a Cocoa NSTextField are saved when they finish editing (by tabbing or clicking to another field) or press return. This is fine, and it works 95% of the time. But on occasion we may find good reason to saved a user’s changes regardless of whether they’ve performed one of these completing actions.<\/p>\n
\nFor example, in the “Send to iTunes” feature I’m working on for FlexTime, I decided it was quite possible that a user would fine-tune an activity’s details, say change the text of a “Speak Text” cue, and then immediately select “Send to iTunes.” What should happen in this case? Certainly the user’s changes should be committed and included in the exported audio. The user hasn’t “finished editing” in a conventional way, but by choosing to export the routine, they’ve let me know they are expecting to hear what they’ve just typed.\n<\/p>\n
\nThe cleanest way to end editing for a particular window was explained to me a few years ago by Erik Buck, who kindly explained on a mailing list that it’s best to first ask the window to become firstResponder (thus taking firstReponder away from the focused field), and if that failed, to resort to the crude “endEditingFor:” method on NSWindow.\n<\/p>\n
\nThis works! But it has the side-effect of causing there to no longer be<\/em> a reasonable first responder for the window. In the scenario I’m dealing with, I want to:\n<\/p>\n \nI figured if I could be responsible for taking first responder status away from some field in my window, I could just give it back after I was done. But things don’t work out so easily in a world where the mysterious field editor is always being injected into the view hierarchy. My first naive solution resulted in my essentially saving and restoring the field editor<\/em> as the first responder for the window. But after the editing has ended, the field editor isn’t even on the screen anymore. So setting it to first responder just causes a weird focus-free situation that you can’t even tab out of.\n<\/p>\n \nThe solution, I realized, was to detect the field editor being the first responder and, in that situation, treat its delegate<\/em> as the responder that needs to be restored after editing. Now, I’m pretty sure that the delegate of a field editor will always be an NSResponder, but just to be sure, I do some runtime checking. The resulting code for “commit edits while saving and restoring the first responder” looks something like this:\n<\/p>\n \nThis works perfectly for my needs and hopefully it will at least put you on the right path towards making your app work perfectly, too.<\/p>\n","protected":false},"excerpt":{"rendered":" In general, a user’s changes to a Cocoa NSTextField are saved when they finish editing (by tabbing or clicking to another field) or press return. This is fine, and it works 95% of the time. But on occasion we may find good reason to saved a user’s changes regardless of whether they’ve performed one of […]<\/p>\n","protected":false},"author":10,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,15],"tags":[],"class_list":["post-229","post","type-post","status-publish","format-standard","hentry","category-cocoa","category-programming"],"_links":{"self":[{"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/posts\/229","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/comments?post=229"}],"version-history":[{"count":0,"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/posts\/229\/revisions"}],"wp:attachment":[{"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/media?parent=229"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/categories?post=229"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/redsweater.com\/blog\/wp-json\/wp\/v2\/tags?post=229"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n
\n\n\/\/ Save the current first responder, respecting the fact\n\/\/ that it might conceptually be the delegate of the \n\/\/ field editor that is \"first responder.\"\nid oldFirstResponder = [oMainDocumentWindow firstResponder];\nif ((oldFirstResponder != nil) &&\n [oldFirstResponder isKindOfClass:[NSTextView class]] &&\n [(NSTextView*)oldFirstResponder isFieldEditor])\n{ \n \/\/ A field editor's delegate is the view we're editing\n oldFirstResponder = [oldFirstResponder delegate];\n if ([oldFirstResponder isKindOfClass:[NSResponder class]] == NO)\n {\n \/\/ Eh ... we'd better back off if \n \/\/ this thing isn't a responder at all\n oldFirstResponder = nil;\n }\n} \n\n\/\/ Gracefully end all editing in our window (from Erik Buck).\n\/\/ This will cause the user's changes to be committed.\nif([oMainDocumentWindow makeFirstResponder:oMainDocumentWindow])\n{\n \/\/ All editing is now ended and delegate messages sent etc.\n}\nelse\n{\n \/\/ For some reason the text object being edited will\n \/\/ not resign first responder status so force an \n \/\/\/ end to editing anyway\n [oMainDocumentWindow endEditingFor:nil];\n}\n\n\/\/ If we had a first responder before, restore it\nif (oldFirstResponder != nil)\n{\n [oMainDocumentWindow makeFirstResponder:oldFirstResponder];\n}\n<\/font><\/pre>\n<\/p>\n