What does PROPERTY_OFFLOAD_SUPPORTED mean?

Question

WatchFaceService has a method public void onPropertiesChanged(Bundle properties) which returns a bundle of properties. One of them has a key PROPERTY_OFFLOAD_SUPPORTED.

Here are all properties that are available in WatchFaceService:

public static final String PROPERTY_BURN_IN_PROTECTION = "burn_in_protection";
public static final String PROPERTY_LOW_BIT_AMBIENT = "low_bit_ambient"; 
public static final String PROPERTY_IN_RETAIL_MODE = "in_retail_mode"; 
public static final String PROPERTY_OFFLOAD_SUPPORTED = "offload_supported";
public static final String PROPERTY_PHYSICAL_HANDS = "physical_hands";

They are not there in the docs but can be accessed from Android Studio.

What does PROPERTY_OFFLOAD_SUPPORTED property represent, and how it should be used?

Answer 1

PROPERTY_OFFLOAD_SUPPORTED is related to WatchFaceDecomposition. This is a feature that's available on certain devices (built on the Qualcomm 3100 platform), where the ambient mode drawing of the watch face is handed over to a separate (very energy-efficient) piece of hardware.

There are a lot of restrictions for what you can and can't do in this mode. It also offers a few new opportunities such as more color options and having a second hand(!).

The feature is unfortunately not very well-documented but there are a few articles out there that talk about how to build watch faces that supports it:

1. http://turndapage.com/2018/12/07/implementing-the-new-ambient-second-hand-for-wear-os-with-watch-face-decompositions
2. https://www.programmersought.com/article/49454594831/