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Increase or Decrease Brightness in Android using Jetpack Compose

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Screen brightness is adjusted in many android applications while interacting with the screens. In the application, if we are displaying a QR code in that case we have to increase the screen brightness so that the QR code will be properly visible to the scanner. In this article, we will take a look at How to programmatically increase/decrease the brightness of our android device from our android application using Jetpack Compose

Step by Step Implementation

Step 1: Create a New Project in Android Studio

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. While choosing the template, select Empty Compose Activity. If you do not find this template, try upgrading the Android Studio to the latest version. We demonstrated the application in Kotlin, so make sure you select Kotlin as the primary language while creating a New Project.

Step 2: Working with the MainActivity.kt file

Go to the MainActivity.kt file and refer to the following code. Below is the code for the MainActivity.kt file. Comments are added inside the code to understand the code in more detail.

Kotlin




package com.example.newcanaryproject
  
import android.content.Context
import android.content.Context.BATTERY_SERVICE
import android.content.Intent
import android.os.BatteryManager
import android.os.Build
import android.os.Bundle
import android.provider.Settings
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.annotation.RequiresApi
import androidx.compose.foundation.layout.*
import androidx.compose.material.*
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import com.example.newcanaryproject.ui.theme.NewCanaryProjectTheme
import com.example.newcanaryproject.ui.theme.greenColor
import com.github.skydoves.colorpicker.compose.*
  
class MainActivity : ComponentActivity() {
  
    @RequiresApi(Build.VERSION_CODES.M)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            NewCanaryProjectTheme {
                // on below line we are specifying background color for our application
                Surface(
                    // on below line we are specifying modifier and color for our app
                    modifier = Modifier.fillMaxSize(), color = MaterialTheme.colors.background
                ) {
  
                    // on the below line we are specifying 
                    // the theme as the scaffold.
                    Scaffold(
  
                        // in scaffold we are specifying the top bar.
                        topBar = {
  
                            // inside the top bar we are 
                            // specifying background color.
                            TopAppBar(backgroundColor = greenColor,
  
                                // along with that we are specifying
                                // title for our top bar.
                                title = {
  
                                    // in the top bar we are specifying
                                    // tile as a text
                                    Text(
                                        // on the below line we are specifying
                                        // text to display in top app bar.
                                        text = "GFG",
  
                                        // on below line we are specifying
                                        // modifier to fill max width.
                                        modifier = Modifier.fillMaxWidth(),
  
                                        // on below line we are specifying
                                        // text alignment.
                                        textAlign = TextAlign.Center,
  
                                        // on below line we are specifying
                                        // color for our text.
                                        color = Color.White
                                    )
                                })
                        }) {
                        // on the below line we are calling control 
                        // battery status method to control battery status
                        ControlBrightNess(LocalContext.current)
                    }
                }
            }
        }
    }
}
  
@RequiresApi(Build.VERSION_CODES.M)
@Composable
fun ControlBrightNess(context: Context) {
    // on the below line we are creating a column,
    Column(
        // on the below line we are adding a modifier to it,
        modifier = Modifier
            .fillMaxSize()
             // on the below line we are adding padding.
            .padding(all = 30.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center,
    ) {
        // on below line we are creating 
        // button to maximize the brightness.
        Button(onClick = {
            // Check whether has the write settings permission or not.
            val settingsCanWrite = hasWriteSettingsPermission(context)
  
            // If do not have then open the Can 
            // modify system settings panel.
            if (!settingsCanWrite) {
                changeWriteSettingsPermission(context)
            } else {
                // on below line we are changing screen brightness. 
                changeScreenBrightness(context, 1)
            }
        }) {
            // on below line we are adding a text for a button. 
            Text(
                // on below line we are specifying text 
                text = "Minimize BrightNess",
                // on below line we are specifying
                // text color, font size and font weight
                color = Color.White,
                fontSize = 20.sp,
                fontWeight = FontWeight.Bold
            )
        }
  
        // on below line creating a spacer
        Spacer(modifier = Modifier.height(20.dp))
  
        // on below line we are creating button to minimize the brightness.
        Button(onClick = {
            // Check whether has the write settings permission or not.
            val settingsCanWrite = hasWriteSettingsPermission(context)
  
            // If do not have then open the Can 
            // modify system settings panel.
            if (!settingsCanWrite) {
                changeWriteSettingsPermission(context)
            } else {
                // on below line we are updating screen brightness. 
                changeScreenBrightness(context, 3500)
            }
        }) {
            // on below line we are adding a text for our button. 
            Text(
                // on below line we are adding a text message
                text = "Maximize BrightNess",
                // on below line we are adding a text color, 
                // font size and font weight for text
                color = Color.White,
                fontSize = 20.sp,
                fontWeight = FontWeight.Bold
            )
  
        }
    }
}
  
// Check whether this app has android 
// write settings permission.
@RequiresApi(Build.VERSION_CODES.M)
fun hasWriteSettingsPermission(context: Context): Boolean {
    var ret = true
    // Get the result from below code.
    ret = Settings.System.canWrite(context)
    return ret
}
  
// Start can modify system settings 
// panel to let user change the write
// settings permission.
fun changeWriteSettingsPermission(context: Context) {
    val intent = Intent(Settings.ACTION_MANAGE_WRITE_SETTINGS)
    context.startActivity(intent)
}
  
// This function only take effect
// in real physical android device,
// it can not take effect in android emulator.
fun changeScreenBrightness(
    context: Context,
    screenBrightnessValue: Int
) {   // Change the screen brightness
      // change mode to manual.
    Settings.System.putInt(
        context.contentResolver,
        Settings.System.SCREEN_BRIGHTNESS_MODE,
        Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL
    )
    // Apply the screen brightness value to the system, this will change
    // the value in Settings ---> Display ---> Brightness level.
    // It will also change the screen brightness for the device.
    Settings.System.putInt(
        context.contentResolver, Settings.System.SCREEN_BRIGHTNESS, screenBrightnessValue
    )
}


Now run your project to see the output of it. 

Output: 



Last Updated : 25 Aug, 2022
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