Determine Current Dock Type using Android Jetpack Compose

An android device is docked when it is connected to a charging cable or connected to a car charging. Dock state of an android device is related to charging. In this article, we will be building a simple application in which we will take a look at How to determine the current dock type in android 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: Adding a new color in the Color.kt file

Navigate to app > java > your app’s package name > ui.theme > Color.kt file and add the below code to it. Comments are added in the code to get to know it in detail.

Kotlin

package com.example.newcanaryproject.ui.theme

import androidx.compose.ui.graphics.Color

val Purple200 = Color(0xFF0F9D58)
val Purple500 = Color(0xFF0F9D58)
val Purple700 = Color(0xFF3700B3)
val Teal200 = Color(0xFF03DAC5)

// on below line we are adding different colors.
val greenColor = Color(0xFF0F9D58)

Step 3: 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.Intent
import android.content.IntentFilter
import android.os.Build
import android.os.Bundle
import android.text.style.TextAppearanceSpan
import android.util.Log
import android.view.View
import android.widget.TextView
import android.widget.Toast
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.runtime.mutableStateOf
import androidx.compose.runtime.remember
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.font.Typeface
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import androidx.core.content.res.ResourcesCompat
import com.example.newcanaryproject.ui.theme.NewCanaryProjectTheme
import com.example.newcanaryproject.ui.theme.greenColor
import org.w3c.dom.Text

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 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
                                    // title as a text
                                    Text(
                                        // on 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 below line we are calling method to display UI
                        dockState(context = LocalContext.current)
                    }
                }
            }
        }
    }
}

// on below line creating a method
// to send whatsapp message.
@RequiresApi(Build.VERSION_CODES.M)
@Composable
fun dockState(context: Context) {

    // on below line creating
    // a variable for dock state
    val dockValue = remember {
        mutableStateOf("")
    }

    // on below line we are creating a column,
    Column(
        // on below line we are
        // adding a modifier to it,
        modifier = Modifier
            .fillMaxSize()
            // on below line we are adding a padding.
            .padding(all = 30.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center,
    ) {
        // on below line we are adding a text for heading.
        Text(
            // on below line we are specifying text
            text = "Current Dock State in Android",
            // on below line we are
            // specifying text color,
            // font size and font weight
            color = greenColor,
            fontSize = 20.sp,
            fontWeight = FontWeight.Bold
        )

        // on below line we are adding a spacer.
        Spacer(modifier = Modifier.height(10.dp))

        // The dock-state details are included as an extra in a sticky broadcast of
        // the ACTION_DOCK_EVENT action. Because it's sticky, you can simply call
        // registerReceiver(), passing in null as the broadcast receiver.
        val dockStatus: Intent? = IntentFilter(Intent.ACTION_DOCK_EVENT).let { ifilter ->
            context.registerReceiver(null, ifilter)
        }

        // dockState is an Integer value received when intent is passed
        val dockState: Int = dockStatus?.getIntExtra(Intent.EXTRA_DOCK_STATE, -1) ?: -1

        // isDocked is a Boolean value which if true indicates
        // the device is in dock state and vice-versa
        val isDocked: Boolean = dockState != Intent.EXTRA_DOCK_STATE_UNDOCKED

        // isCar and isDesk are a Boolean values,
        // either of which if true indicates
        // the device is in a particular dock
        val isCar: Boolean = dockState == Intent.EXTRA_DOCK_STATE_CAR
        val isDesk: Boolean = dockState == Intent.EXTRA_DOCK_STATE_DESK
                || dockState == Intent.EXTRA_DOCK_STATE_LE_DESK
                || dockState == Intent.EXTRA_DOCK_STATE_HE_DESK

        // Output Cases
        when {
            isCar -> dockValue.value = "Dock Car"
            isDesk -> dockValue.value = "Dock Desk"
            !isDocked -> dockValue.value = "Not Docked"
        }

        // on below line we are adding
        // a text for dock state.
        Text(
            // on below line we are specifying text
            text = dockValue.value,
            // on below line we are
            // specifying text color,
            // font size and font weight
            color = greenColor,
            fontSize = 20.sp,
            fontWeight = FontWeight.Bold
        )
    }
}

Now run your application to see the output of it. 

Output: