At the Google I/O conference 2018 to happen in the coming months, we expect to witness the announcement of the Android P Developer Preview. So far, little is known about the features of the next iteration of Android OS. The two biggest features those are rumored about Android P are the support for atypical display types including the display notch and an overhauled Material Design interface.
Now, a report by XDA Developers hints that Android P will add the Bluetooth HID device profile service to your smartphone. It is said that the smartphone can be doubled as a Bluetooth mouse or keyboard with this new OS version.
The report confirms that Bluetooth HID profile was added recently. The relevant APIs for developers seem to be unhidden from the developers, hinting that they can take advantage of this functionality on those devices that run Android P. It goes without saying that Google Pixel and Pixel 2 smartphones will be the first ones to be announced with Android P.
With Bluetooth Profiles support enabled, your smartphone can function as a HFP (Hands-Free Profile) and A2DP (Advanced Audio Distribution Profile). These are used for voice calls and music streaming over Bluetooth. With the implementation of HID (Human Interface Device) Bluetooth Profile, it is possible for Android devices to be used as input devices such as mouse, keyboard, joystick, etc.
Notably, Android does not support the implementation of HID in Bluetooth stack by default. Apparently, app developers cannot create apps those make use of the service to double your smartphone as a basic keyboard or mouse for input. Until then, if you want to get this functionality from your smartphone, you can download root-enabled apps available on the Google Play Store such as True Mouse/KB or Bluetooth+ on your smartphone to use it as an input device.
The native support for Bluetooth HID in AOSP means that all the Android P devices can function as input devices over Bluetooth. Samsung and Huawei are two companies that are already trying their hands at this kind of a feature. Samsung's recent flagship models - the Galaxy S9 and Galaxy S9+ have come up with the DeX Pad accessory, which will double the device as a trackpad. Huawei also supported this kind of feature in its own PC mode.