Brent Caswell wrote a post called "Rethinking the Lockscreen". Unfortunately he opened his post by heartily bashing iOS. This caused the comments to degrade into a flame war that buried any constructive discussion of the ideas Brent presented. This article is my critique of his ideas.

The lock screen's purpose

The lock screen's core function is to serve as the user interface (UI) for two related functions; preventing accidental input (e.g. butt-dialing), and preventing unauthorized access to user data. The lock screen is *not* a place for random information to be displayed. (More on that later.)

Background tasks and the lock screen

Currently, anything not directly related to the lock screen's core functionality has to do with notifying the user about things happening on the device *while the device is locked.*

These notifications take two forms. The first is a standard push notification. The second form is closely tied with Apple's background/multitasking APIs and is where the actual room for improvement is found.

Currently there are seven background APIs available to developers: audio, location, VoIP, Newsstand content, and three related to Bluetooth accessories/communication.

Let's look at each of them individually.

Audio

Double tapping the home button while the device is locked replaces the date with simple audio controls and current artist/album/song information. The wallpaper is replaced by the album art.

Third party apps that take advantage of background audio (e.g. Pandora) already have access to this UI so not only has this problem been solved, but the solution serves as a template for the lock screen interfaces of other apps that utilize background services. Basically, all Apple needs to do is make their custom lock screen controls accessible to third party apps that perform the same function.

Location

Apple's built-in Maps app has a custom lock screen UI that is shown when the app is giving turn-by turn directions. It follows the same pattern; text labels showing the next turn replacing the time/date at the top of the screen and the app's map view replacing the background wallpaper.

VoIP

VoIP apps like Skype could be similarly integrated into the existing "receiving call" UI. Again, all Apple has to do is provide hooks into existing labels and buttons for use by third-party VoIP apps.

Newsstand content

Newsstand apps have the ability to download new issues in the background. Standard notifications are sufficient in alerting user to the availability of new data and no custom lock screen UI is needed.

Bluetooth accessories

This is a unique use case. The majority of third party Bluetooth devices perform functions related to audio, a use case that has already been solved. Apple could perhaps work on an individual basis with the few device manufacturers who make peripherals not related to audio. For example, Apple has already worked with Nike to deeply integrate Nike+ with Apple devices, so they could maybe work together to bring that integration to the lock screen.

Fixing the lock screen

Brent says that he "set out to make the lockscreen flexible and open to the apps on your device". The problem here isn't that apps in general don't have enough access to the lock screen. In some cases they have too much access.

The real issue is that apps that use the background location, VoIP, and certain Bluetooth APIs have yet to be appropriately integrated into the lock screen.

None of the above require any *new* UI. Again, the general design pattern for custom lock screen controls is to replace the date/time bar with appropriate labels and replace the wallpaper with a non-interactive (though possibly dynamic) graphic. This is enough to provide almost any multitasking app (including Nike+) with a really great, generally consistent, lock screen experience.

The problem with "grabbers"

Brent also proposed expanding the lock screen's camera "grabber" functionality to other apps. This strikes me as another bad idea.

First of all, launching apps is the job of the home screen, not the lock screen. The problem of quick access to relevant data from the lock screen was solved when Apple added the ability to swipe a notification to go directly to that app.

Secondly, expanding the grabber functionality to other apps isn't necessary because the time constraint (the whole reason instant camera access was added to the lock screen in the first place) isn't present. Seconds can matter when you're trying to capture that fleeting moment of joy on your child's face, but seconds aren't nearly as crucial when writing a tweet, checking into an establishment, or taking a stylized photo of your food.

Additionally, the grabber itself is flawed. It contradicts the swipe left-to-right motion that is is embedded into every iPhone users muscle memory. By the time I remember I can swipe *up* from the *right* to access the camera I've already unlocked the device the normal way.

A better solution might be to add an option to have a permanent camera "notification" that looks and acts like a standard lock screen notification. Swipe left-to-right on the camera icon to go directly to the app. It could be located on the top half of the screen below the date/time bar and would be far enough away from the regular unlock control on the bottom so as to prevent it from being accidentally triggered.

This would be more consistent with how people dismiss the lock screen and have the added benefit of being less visually disruptive to the lock screen's aesthetic balance.

Conclusion

The lock and home screens are not supposed to be interactive beyond their core functionality. Their focus and simplicity is key to their usability. Adding things like widgets and live icons are the ingredients for an unusable mess of unrelated data.

When designing something it is extremely important to thoroughly define exactly what that something is. It's no coincidence that when you look up "indefinite" in a thesaurus you'll find words like "confused", "obscure", and "unclear". Designing involves making hundreds of little decisions and having a clear definition of what that thing you're making is can help you make good decisions and thus, a good product.

Like Lukas Mathis, I am ambivalent about unsolicited redesigns. Just because a design looks good doesn't mean it has been well thought out. As a great man once said, "Design is not just what it looks like and feels like. Design is how it works."

(posted by @gravityoptional - cybermoai.com)