I made an app that displays some data. When connecting a HDMI display to the android device, so data is displayed on it, its working fine. But if powerline is gone, the HDMI diplay is turning off, so data displays on device's screen. It is not a big problem, as I just need the data to be displayed on HDMI display when powerline will be connected again. Now, when connecting powerline again, HDMI display is not turning on and data continues displaying on device's screen. Can I do something about this?
Android has no concept of HDMI. You would have to contact the manufacturer of your specific device for questions about that device's support of HDMI.