Archive for the ‘intuitive’ Category

Apple’s TextEdit App. Can Erase Your Files

Tuesday, May 12th, 2009

Icon of the TextEdit Application.Apple’s TextEdit application has a massive design flaw that could potentially erase other files on your computer. Weird, right? Ironically, it’s TextEdit’s safeguard against loss of data that is the culprit of the defect. And the corruption of files isn’t a randomly occurring glitch either — it is caused by a shortcoming of the algorithm used in the Autosave feature.

The Autosave Flaw

When editing a document in TextEdit, a copy of your work is automatically saved every 30 seconds to the hard drive*. This behavior is common in software as it provides a convenient means to recover some of your work should the application unexpectedly quit or crash.

Unfortunately, the means by which TextEdit saves a copy of your work is awfully rudimentary. It simply writes your data to a regular file and gives it the same name as your TextEdit document but with “ (Autosaved)” appended as a suffix (without an extension). And since no verification is performed to see if a file with that particular name already exists, it will overwrite anything that gets in its way with no confirmation or warning!


To better illustrate this flaw, take the following scenario. Suppose, for whatever reason, that I have a file named Craziness (Autosaved) and I create a text document called Craziness.txt in the same directory. In the screenshot below Craziness (Autosaved) is an image file (with the extension removed in order to illustrate my point):

Screenshot of my 2 original files.

When I start editing my Craziness.txt file in TextEdit, the application autosaves my work (as it should), but since my image document has the same name as what TextEdit would call its autosaved file, my image file is overwritten:

Screenshot of TextEdit's autosaved file.

When I’m done editing my Craziness.txt document, TextEdit removes the autosaved copy (as one would expect). However, now my original image file is gone with no real way to recover it (since it’s not moved to the Trash but actually overwritten):

Screenshot showing loss of data caused by TextEdit.


Accounting for this file naming issue is so programmatically simple that it’s astounding the defect even exists. The simplest improvement would be to prefix the filename with a period (as in .Craziness (Autosaved)) in order to hide it from the Finder since the chances of having a naming conflict with a hidden file are greatly reduced.

But hiding the file from the user still allows for potential name collisions and as Mac OS X’s default text editor, TextEdit’s naming convention should be even more robust. To start, TextEdit could include either a timestamp or a sequence of random numbers to help make its autosaved filename unique. Most importantly, however, should be to verify if a file would be overwritten and if so, generate a different random number or append an incremental counter. Heck, even my Page Capture widget won’t overwrite files since it uses the same naming convention as Apple’s screencapturing application (File 1, File 2, File 3, etc.)

The Rant

One might argue that the possibility of having a file end with “ (Autosaved)” and not have an extension is pretty slim. So what? My argument is that the possibility of an application deleting other files blindly is a completely unacceptable use case scenario, no matter how rarely it may occur. I think it is more reasonable to expect that a corporation as large as Apple Inc. would produce software that doesn’t delete unrelated files from my hard drive without my knowledge. Especially since OS X is — as Apple claims — the “most advanced operating system in the world.”

*30 seconds is the default. The time interval is configurable and the user is allowed to disable the Autosave feature entirely.

A More Intuitive iPod Shuffle Switch

Wednesday, October 1st, 2008

The iPod Shuffle is a wonderful little product and in my opinion is by far the best mp3 player that doesn’t display information about what is playing. But there is an element of its design that I consider to be flawed and which I attribute to Apple’s consistent choice to sacrifice options for the sake of simplicity.

iPod Shuffle Close Up

One of the two switches on the iPod Shuffle chooses the play mode: either Continuous Playback or Shuffle. The former will repeatedly loop through all the songs in the order that they were added to the iPod from iTunes. The Shuffle mode will obviously play through them randomly, but will it stop playing after all the songs have been played through once? Are Shuffle and Continuous Playback mutually exclusive?

Different Shuffle Symbol Suggestions for the iPod ShuffleThis conflict seems minor, but there might be a major design flaw here. A switch is a user interface element that chooses between two possibilities. Ideally, neither choice implies the other (or else a different user interface element would be used…more about this later). But in the case of the iPod Shuffle, the Shuffle mode implies continuous playback as well. And I agree that it should—it’s intuitive to me that Shuffle would also continuously loop through all the songs. But with the current setup (Default Shuffle Symbol), however, moving the switch from Continuous Playback to Shuffle is contradictory. I would have at least made the symbol something like: Alternate Shuffle Symbol Suggestion 1 or Alternate Shuffle Symbol Suggestion 2.

You might now be saying to yourself: “That’s all fine and dandy because the current symbols on either side of the switch are simply graphical representations of two preset modes: one that continuously loops through the songs in order and another that continuously loops through the songs but in a random order.” Well, let’s not be so quick to make that assumption because as much as I’d agree with you, that’s not the way iTunes does it. iTunes uses buttons to select the mode allowing the user to turn both Shuffle and Continuous Playback on at the same time.

Playback choices in iTunesAnd let’s not kid ourselves that it is ok to have iTunes do something different than all the iPods out there. Apple’s success with their line of mp3 players (as well as their other products) is almost entirely attributable the almost necessary connection between their hardware and software components.