This post is continuing my earlier article on
harmonizing touch screen gestures.
Look closely at recent apps and mobile operating systems. Swiping over the screen edge to trigger navigation related action, is becoming increasingly popular. No wonder, as edge gestures are fast and comfortable way to interact with your mobile app or device. They have a huge potential in them, but only a fraction of it has been put into use.
It's not all unicorns, rainbows and marshmallows, though. These hidden gestures come with major drawback in discoverability and variation in use. Here's few tricks how to improve the way edge gestures can be put to use.
1. Keep it simple, consistent and fit for one hand.
I can't stress this enough. The less there's to memorize, the faster it's to master. Eliminate exceptions and special conditions when an edge gesture is not working, or does something completely different. Focus on a robust gesture recognition, and let the physical repetition do the work for you. It's like training in any sport, so make sure those training conditions are obvious to the user. Interfaces are just tools, and a good
tool needs to be simple.
2. Think edges as physical buttons.
Edge gestures work especially well in controlling an operating system. A single edge gesture can be harnessed to perform similar kind of actions. For example, one edge can do things related to the power key (turn off screen, change profiles etc), while another one controls application window (minimize, close, windowed mode). Like in majority of other devices, notifications and whatnot could reside in another one.
So, with only three edges, an extremely competitive and simple interface can be built. If more than one action starts from the same edge, use absolute care in fine-tuning the feedback for it. The finger movement needs to feel different for your brain to associate them to their corresponding actions. Traveled distance, change in direction, speed or physical location, are all your usual suspects for separating them. Keep it simple, and prioritize the most used action.
The relation to hardware buttons helps people understand the idea behind it much better. Memorizing actions becomes faster and more natural, when there's a familiar relation between them. The reason for some actions not being available becomes more obvious that way. Take application window controls as an example. They are only available when there's an application window on the foreground.
3. The edge feedback is everything.
Just like with any other interactive elements, when user interacts with the edge, there should be an appropriate feedback on it. This is important for many users not familiar with interactive edges. Gestures in general can be performed so fast, that it's a good idea to keep the interacted edge highligted even after the gesture has been succesfully completed.
If your design uses gestures to control the application content, having different transitions for edge gestures and application content gestures is an advisable idea. It's a valuable difference to tell the two appart. After all, if edge gestures control the system level navigation, the feedback should be different than the application level navigation. Let's look at the hint animation for unlocking a smartphone as an example.
If you want to use edge gesture to unlock, you should direct attention to the interaction area. If everything moves (right side example), it implies parallel navigation (like going through images in gallery) instead. If you have plans for any lock screen controls (phone call controls, maps, flashlight, audio playback), you most likely should reserve that center screen flick for such actions.
4. Edge notifications and toggles.
This kind of edge indication can be used in several different ways to draw user attention to it. It can be indication of new content, or simply a reminder for a new user, that an edge gesture exist. The catch is that it doesn't introduce a tappable object on top of a keyboard or other interactive elements.
Since user is not able to control when someone sends a message to them (or when the system decides to emit one), it's annoying when a banner appears on top of link, only milliseconds before user touches it.
However, if the notification access is tied to the edge interaction, your tap will be registered by whatever it was intended for. The duration can also be shorter to avoid banners loitering on your screen for too long. You anyway know where to check those notifications.
Finally, if you want your edge to function as a toggle, the edge indication should also behave as one. This means that subsequent swipes across that edge turn the edge indication "on" and "off" again. Just like tapping on a regular toggle switch would.
The cool thing with edge toggles is in the effortless way to control it, compared to traditional notification panels. Those you need to close with the an opposite edge gesture, which require considerable thumb mobility to perform with a single hand.
With these tips, you should be able to considerably increase edge gesture benefits, while avoiding the common gesture pitfalls that plague major operating systems and applications.
Thanks for reading and see you in the next post. In the meantime, agree or disagree, debate or shout. Bring it on and spread the word.