Description

Turn ON/OFF the display of your Android phone, like scrcpy, using ADB Shell or Root.

Check Reddit Tasker for Tasker users.

Termux users can continue to the next section.

Building

You can follow these steps to build it in Termux.

yes | pkg upgrade -y

 

pkg install -y wget openjdk-21 dx android-tools

 

wget -O ~/android.jar "https://github.com/Sable/android-platforms/blob/master/android-35/android.jar?raw=true"

 

nano DisplayToggle.java

Now copy paste this:-

import android.os.Build;
import android.os.IBinder;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;

public class DisplayToggle {

	private static final Class<?> SURFACE_CONTROL_CLASS;
	private static final Class<?> DISPLAY_CONTROL_CLASS;

	static {
		try {
			SURFACE_CONTROL_CLASS = Class.forName("android.view.SurfaceControl");
			if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
				Class<?> classLoaderFactoryClass = Class.forName("com.android.internal.os.ClassLoaderFactory");
				Method createClassLoaderMethod = classLoaderFactoryClass.getDeclaredMethod("createClassLoader",
						String.class, String.class, String.class, ClassLoader.class, int.class, boolean.class, String.class);
				ClassLoader classLoader = (ClassLoader) createClassLoaderMethod.invoke(null,
						"/system/framework/services.jar", null, null, ClassLoader.getSystemClassLoader(), 0, true, null);
				DISPLAY_CONTROL_CLASS = classLoader.loadClass("com.android.server.display.DisplayControl");

				Method loadLibraryMethod = Runtime.class.getDeclaredMethod("loadLibrary0", Class.class, String.class);
				loadLibraryMethod.setAccessible(true);
				loadLibraryMethod.invoke(Runtime.getRuntime(), DISPLAY_CONTROL_CLASS, "android_servers");
			} else {
				DISPLAY_CONTROL_CLASS = null;
			}
		} catch (Exception e) {
			throw new AssertionError(e);
		}
	}

	public static void main(String... args) {
		System.out.println("Display mode: " + args[0]);
		int mode = Integer.parseInt(args[0]);

		try {
			if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE && DISPLAY_CONTROL_CLASS != null) {
				Method getPhysicalDisplayIdsMethod = DISPLAY_CONTROL_CLASS.getMethod("getPhysicalDisplayIds");
				Method getPhysicalDisplayTokenMethod = DISPLAY_CONTROL_CLASS.getMethod("getPhysicalDisplayToken", long.class);

				long[] displayIds = (long[]) getPhysicalDisplayIdsMethod.invoke(null);
				if (displayIds != null) {
					for (long displayId : displayIds) {
						IBinder token = (IBinder) getPhysicalDisplayTokenMethod.invoke(null, displayId);
						setDisplayPowerMode(token, mode);
					}
				}
			} else {
				setDisplayPowerMode(getBuiltInDisplay(), mode);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			System.exit(0);
		}
	}

	private static IBinder getBuiltInDisplay() throws Exception {
		Method method;
		if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
			method = SURFACE_CONTROL_CLASS.getMethod("getBuiltInDisplay", int.class);
			return (IBinder) method.invoke(null, 0);
		} else {
			method = SURFACE_CONTROL_CLASS.getMethod("getInternalDisplayToken");
			return (IBinder) method.invoke(null);
		}
	}

	private static void setDisplayPowerMode(IBinder displayToken, int mode) throws Exception {
		Method method = SURFACE_CONTROL_CLASS.getMethod("setDisplayPowerMode", IBinder.class, int.class);
		method.invoke(null, displayToken, mode);
	}
}

Then press CTRL+X+Y+ENTER and save it.

And then create its Java CLASS file:-

javac -Xlint:none -source 1.8 -target 1.8 -cp ~/android.jar DisplayToggle.java

Then DEX it using:-

dx --dex --output DisplayToggle.dex DisplayToggle.class

You have compiled the DisplayToggle.dex file (around 2.5kb).

Now copy it to internal storage to use it later.

termux-setup-storage

 

cp -f DisplayToggle.dex /storage/emulated/0

How To Use It

In an ADB Shell (from Termux or PC):-

To Turn Display OFF

adb shell CLASSPATH=/storage/emulated/0/DisplayToggle.dex app_process / DisplayToggle 0

To Turn Display ON

adb shell CLASSPATH=/storage/emulated/0/DisplayToggle.dex app_process / DisplayToggle 2

Note:-

In Termux if you are rooted, you can just replace every adb shell with su -c.

Credits

rom1v - Method to make java code executable

CheerfulPianissimo - Base Java code to make this possible