For the most part, app icons on your smartphone are just that; flat artwork that just sits there on your home screen. With the release of Android O, Google hopes to put some life into those app logos on the display with the introduction of what the company is calling adaptive icons.
While this feature isn’t really available to users in the first O developer preview, Google says that this new feature will allow app developers to create icons that will have different shapes for different devices. For example, a Facebook app icon may have a square shape on a Google Pixel XL but a circular (or squircle) shape when it is displayed on a Samsung Galaxy S8. Google says that with Android O, each device can provide a mask for that icon, which the OS can use to render all icons with the same shape. This will likely be embraced by OEMs who would like to have some unique looking home screens and app icons without having to create their own unique UX.
Adaptive icons can be used with app shortcuts, inside the Settings app, sharing dialogs and in the overview screen
The adaptive icons can be used with app shortcuts, and they can also be set up inside the Settings app, along with sharing dialogs and the overview screen. They can also support a number of visual effects when a person interacts with an icon. In order for this new feature to work, Android O developers must create the launcher icons at 108 x 108 dp for both layers (the foreground and the background). Previous versions of Android supported just one layer for the app icon, and it was smaller at 48 x 48 dp.
In addition to the new animated icons, Android O will also support apps that will be able to take advantage of devices that have a wide-gamut color capable display. Android O apps will need to enable a flag in their manifest and load bitmaps with an embedded wide color profile. Google indicated it will support AdobeRGB, Pro Photo RGB, and DCI-P formats, among others.
Finally, the new version of Android will be able to use fonts as a fully supported resource type, which means that app developers will be able to use use fonts in XML layouts, along with the ability to define font families in XML. App developers can find out a lot more about how to use these new font resources on the Android O dev site.
All in all, it sounds like the new OS will offer developers a wider variety of UI and icon designs.