Add Small Window feature

[Korb]

The Small Window (aka picture-in-picture mode) feature allows you to display a window overlaying other apps and pin it to the edge of the screen as an always-on small label. The label can be freely moved along the side edges of the screen.

This mode in the case of a reading application is convenient because it allows you to place a sticker on the screen with data that you need constant access to while working with another application. At the same time, unlike Split-screen, this mode does not significantly reduce the size of the main application, but prevents it from being unloaded from memory without having to disable memory optimization for this application.

More details: Android Developers / Develop / Core areas / UI / Guides / Support multi-window mode

[WhitespaceQ]

You can force this through developer options by enabling (1) Force activities to be resizable and (2) Enable non-resizable in multi windows. If you're in tablet you can also enable (*) Enable freeform windows

You may need to restart the device after toggling the settings

[Korb]

You can force this through developer options by enabling (1) Force activities to be resizable

I don't have this setting.

and (2) Enable non-resizable in multi windows.

This setting in my case is called

Enable non-resizable in multi-window (allow non-resizable apps to be displayed in multi-window mode)

and it is enabled. Two dozen applications from the installed ones can be displayed in PiP mode. Librera Reader is not.

OS version: Funtouch OS 14
Model: Vivo T1 (4G, V2153)
Hardware version: MP_0.1
Build number: PD22010F_EX_A_14.2.9.0.W20
Baseband version: .HA.1.1.c2-00054-DIVAR_GENSP_PACK-1.29062.107
Kernel version: 4.19.157-perf+, 1 Sat Oct 12 11:14:50 CST 2024
Compile time: 12 Oct 2024 06:06:30
Android security update: 1 October 2024
Google Play system update: 1 October 2024
Software parameter update: 29 October 2024