Hello Readers! In this post, we are going to learn about how to use android tabHost in kotlin in any android application. We will also go through different attributes of TabHost widget that can be used to customise it.

Output

Tutorialwing Android TabHost Output

Getting Started

TabHost widget can be defined as below –

TabHost is a container for the tabbed window view.

TabHost contains two children. They are –
(a) A set of tab labels that user clicks to select a specific tab.
(b) A FrameLayout object that displays the selected tab views.

Attributes of Android TabHost Widget

Some of the popular attributes of android TabHost widget inherited from FrameLayout are –

Some of the popular attributes of android TabHost widget inherited from ViewGroup are –

Some of the popular attributes of android TabHost widget inherited from View are –

Example of Android TabHost In Kotlin

At first, we will create android application. Then, we will use TabHost widget in this application.

1. Creating New Project in Kotlin

Follow steps below to create new project. Please ignore the steps if you have already created the project.

2. Modify Values folder

Open res/values/strings.xml file. Then, add below code into it.

<resources>
	<string name="app_name">TabHost</string>
	<string name="presented_by">Presented by Tutorialwing.com</string>
	<string name="no_image">No Image</string>
	<string name="profile">Profile</string>
	<string name="recent">Recent</string>
	<string name="home">Home</string>
</resources>

3. Create Pages for Each Tab in TabHost

In this tutorial, we are going to show three tabs in the application. So, we will create three pages for tab. Their name would be as follows –
(a) HomeActivity.kt and xml file (activity_main.xml)
(b) RecentActivity.kt and xml file (activity_recent.xml)
(c) ProfileActivity.kt and xml file (activity_profile.xml)

3.1 Create First Page(Home Page) of TabHost

Create a new kotlin file, HomeActivity.kt, in main/java/com.tutorialwing.tabhost folder. Then, add below code into it.

package com.tutorialwing.tabhost

import android.os.Bundle
import android.support.v7.app.AppCompatActivity

class HomeActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_home)
    }
}

Now, create xml file for this activity class in res/layout folder and name it activity_home.xml. Then, add below code into it.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:background="@android:color/holo_blue_dark"
	android:gravity="center"
	android:orientation="vertical">

	<TextView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginBottom="20dp"
		android:text="@string/presented_by"
		android:textColor="@android:color/white"
		android:textSize="18sp"
		android:textStyle="bold"/>

	<ImageView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginBottom="20dp"
		android:contentDescription="@string/no_image"
		android:src="@mipmap/ic_launcher"/>

	<TextView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:text="@string/home"
		android:textColor="@android:color/white"
		android:textSize="17sp"/>

</LinearLayout>

3.2 Create Second Page(Recent Page) Of TabHost

Create a new kotlin file, RecentActivity.kt, in main/java/com.tutorialwing.tabhost folder. Then, add below code into it.

package com.tutorialwing.tabhost

import android.os.Bundle
import android.support.v7.app.AppCompatActivity

class RecentActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_recent)
    }
}

Now, create xml file for this activity class in res/layout folder and name it activity_recent.xml. Then, add below code into it.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:background="@android:color/holo_red_dark"
	android:gravity="center"
	android:orientation="vertical">

	<TextView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginBottom="20dp"
		android:text="@string/presented_by"
		android:textColor="@android:color/white"
		android:textSize="18sp"
		android:textStyle="bold"/>

	<ImageView
		android:id="@+id/imageView"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginBottom="20dp"
		android:contentDescription="@string/no_image"
		android:src="@mipmap/ic_launcher"/>

	<TextView
		android:id="@+id/txtMain"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:text="@string/recent"
		android:textColor="@android:color/white"
		android:textSize="17sp"/>

</LinearLayout>

3.3 Create Third Page(Profile Page) Of TabHost

Create a new kotlin file, ProfileActivity.kt, in main/java/com.tutorialwing.tabhost folder. Then, add below code into it.

package com.tutorialwing.tabhost

import android.os.Bundle
import android.support.v7.app.AppCompatActivity

class ProfileActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_profile)
    }
}

Now, create xml file for this activity class in res/layout folder and name it activity_profile.xml. Then, add below code into it.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:background="@android:color/holo_green_dark"
	android:gravity="center"
	android:orientation="vertical">

	<TextView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginBottom="20dp"
		android:text="@string/presented_by"
		android:textColor="@android:color/white"
		android:textSize="18sp"
		android:textStyle="bold"/>

	<ImageView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_marginBottom="20dp"
		android:contentDescription="@string/no_image"
		android:src="@mipmap/ic_launcher"/>

	<TextView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:text="@string/profile"
		android:textColor="@android:color/white"
		android:textSize="17sp"/>

</LinearLayout>

4. Use TabHost Widget in xml file

Open res/layout/activity_main.xml file. Then, add below code into it.

<?xml version="1.0" encoding="utf-8"?>
<TabHost
	android:id="@android:id/tabhost"
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="match_parent"
	android:layout_height="match_parent">

	<RelativeLayout
		android:layout_width="match_parent"
		android:layout_height="match_parent"
		android:orientation="vertical">

		<TabWidget
			android:id="@android:id/tabs"
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:layout_alignParentBottom="true">

		</TabWidget>

		<FrameLayout
			android:id="@android:id/tabcontent"
			android:layout_width="match_parent"
			android:layout_height="match_parent"
			android:layout_above="@android:id/tabs">

		</FrameLayout>

	</RelativeLayout>

</TabHost>

In activity_main.xml file, we have defined tabHost. Inside tabHost, we have tabWidget, that shows tab labels, and frameLayout that shows views for selected tab. In our case, we will show a separate activity for each page whenever any tab is selected. Now, we will access this tabHost in kotlin file and perform some operations on it.

5. Access TabHost in Kotlin file

Open src/main/java/com.tutorialwing.tabhost/MainActivity.kt file. Then, add below code into it.

package com.tutorialwing.tabhost

import android.app.TabActivity
import android.content.Intent
import android.os.Bundle
import android.widget.TabHost
import android.widget.Toast

class MainActivity : TabActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val tabHost = findViewById<TabHost>(android.R.id.tabhost)
        if (tabHost != null) {
            addTab(tabHost, getString(R.string.home), getString(R.string.home), HomeActivity::class.java)
            addTab(tabHost, getString(R.string.recent), getString(R.string.recent), RecentActivity::class.java)
            addTab(tabHost, getString(R.string.profile), getString(R.string.profile), ProfileActivity::class.java)

            tabHost.currentTab = 1
            tabHost.setOnTabChangedListener { tabId -> Toast.makeText(applicationContext, tabId, Toast.LENGTH_SHORT).show() }
        }
    }

    private fun addTab(tabHost: TabHost, name: String, indicator: String, className: Class<*>) {
        val tabSpec = tabHost.newTabSpec(name)
        tabSpec.setIndicator(indicator)
        val intent = Intent(this, className)
        tabSpec.setContent(intent)
        tabHost.addTab(tabSpec)
    }
}

We have accessed tabHost in kotlin file ( i.e. in MainActivity.kt file). Then, we have added three tab to tabHost. After that, we have defined tab change listener that displays currently selected tab.

Since AndroidManifest.xml file is very important in any android application, we are also going to see the content inside this file.

AndroidManifest.xml

Code inside src/main/AndroidManifest.xml file is as below –

<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.tutorialwing.tabhost"
		  xmlns:android="http://schemas.android.com/apk/res/android">

	<application
		android:allowBackup="true"
		android:icon="@mipmap/ic_launcher"
		android:label="@string/app_name"
		android:roundIcon="@mipmap/ic_launcher_round"
		android:supportsRtl="true"
		android:theme="@style/AppTheme">
		<activity android:name=".MainActivity">
			<intent-filter>
				<action android:name="android.intent.action.MAIN"/>

				<category android:name="android.intent.category.LAUNCHER"/>
			</intent-filter>
		</activity>
		<activity
			android:name=".RecentActivity"
			android:label="@string/recent">
		</activity>
		<activity
			android:name=".HomeActivity"
			android:label="@string/home">
		</activity>
		<activity
			android:name=".ProfileActivity"
			android:label="@string/profile">
		</activity>
	</application>

</manifest>

When we run the program, we will get output as shown above.

That’s end of tutorial on Android TabHost in Kotlin.