There are two types of multi-window. One is 'Split view', and the other is 'Freeform window'. In non-foldable devices, Split view can hold two apps at the same time. In addition to this, our foldable device supports 3 split view to manipulate a big display. The big display also enhances usability of freeform window. Thus, it's important to utilize multi-window while concurrent multiple app running in order to make the best use of foldable devices.

Split View Freeform window
What is multi-resume ?

An app that is running in multi-window will be paused when not active in the previous Android versions.

With Android P (Pie), it provides a multi-resume functionality for all visible top activities if the app and OEM (Original Equipment Manufacturer) opts in.

Multi-resume is expected to become a mandatory behavior in Android Q.

Figure 3 Multi-resume current behavior Figure 3. The current behavior and the expected behavior with multi-resume

How can I make the app run in multi-resume?

Set the manifest flag to keep the app in a resumed state. This will allow the app to have resumed state even when it is not the topmost app.

Code Block 1 Manifest flag

    android:value=”true” />
  <activity ... />

Caution with singletons storing the resumed activity, including in frameworks you depend on