Comments on: A Stroke Of Luck

By: Jean-Daniel

Jean-Daniel — Mon, 12 Apr 2010 21:17:11 +0000

“So how long is ‘just long enough’ to open one new document but not more?”

You can change this setting in Keyboard system preferences.

About the default value, I don’t know how Apple determined it though.

By: James Ramsey

James Ramsey — Mon, 12 Apr 2010 03:34:53 +0000

David,
The delay is customizable. The Keyboard pane in System Preferences will allow you to control how the duration of the pause before it starts repeating, and then how quickly it repeats.

By: David Bennett Ecards

David Bennett Ecards — Sun, 11 Apr 2010 18:05:21 +0000

Daniel – Thank you for the reply, and yes, I see that it happens with Safari. I should have tried that first.

So how long is ‘just long enough’ to open one new document but not more?

Are these published figures?

Is there a lab with engineers measuring how long the slowest person in a sample takes before they lift their finger from the ‘n’ key?

By: Daniel Jalkut

Daniel Jalkut — Sun, 11 Apr 2010 14:54:50 +0000

Robby – I don’t know. It’s hard to speculate what lucky break you will get and where it will lead the mind. I definitely think the tool of AppleScript for automating and formalizing what I was testing helped me to think about the program more narrowly.

By: Robby Grossman

Robby Grossman — Sun, 11 Apr 2010 13:36:48 +0000

Good story and nice write-up. Do you think you ever would have thought to try the asymmetric key releasing if not for staring at the AppleScript code?

By: Daniel Jalkut

Daniel Jalkut — Sun, 11 Apr 2010 00:23:28 +0000

BooneJS – about the unit testing question, I’m not really an expert but generally speaking I would say that the particulars of the keyboard events and the scripting that led me to track down this bug are too large of scope to be permanently committed as unit tests. They are the particular details that led to an underlying bug in my application’s code. SO the underlying bug is what, philosophically, should have unit test alterations made to.

By: Doug Adams

Doug Adams — Sun, 11 Apr 2010 00:21:16 +0000

Try debugging an AppleScript app with AppleScript like that! Arrgghh! Loved the story though–been there.

By: Daniel Jalkut

Daniel Jalkut — Sat, 10 Apr 2010 22:09:13 +0000

Cameron – the problem is I don’t know how I would have guessed to consider the events themselves, until after I had already solved the problem. It’s one of those things where, sure in retrospecting knowing the order and types of events the user was sending would lead to the solution, but I was convinced it was some other reason he was seeing the bug and I wasn’t.

By: Cameron Hayne

Cameron Hayne — Sat, 10 Apr 2010 22:04:39 +0000

It seems to me that this would have been easier to track down if there was an input event logging facility built into your app. Then you could have asked the user to enable this logging facility, reproduce the bug, then email you the log.
Maybe it’s worth it to implement such a facility for all future apps?

By: Daniel Jalkut

Daniel Jalkut — Sat, 10 Apr 2010 17:30:47 +0000

David – the article is slightly fictionalized because I don’t want to share specifics that might give away details of a product I’m working on.

That said, the “rapid fire new windows” behavior you observed is standard behavior for any app that creates new documents. Try it in Safari, for example. It’s a behavior of the system to auto-repeat a keystroke if you hold down the key for a certain duration.

When I describe in the post the command key being lifted after the letter key, I’m still talking about a process that takes a fraction of a second, so it’s still short enough that you don’t get the key repeat.