Kotlin toolbar back button

fmedlin / Toolbar.kotlin

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// (1) Defer to the support actionbar

// Set the toolbar to be the support actionbar of an AppCompatActivity

// .

setSupportActionBar(find(R.id.toolbar))

with(supportActionBar!!)

setDisplayHomeAsUpEnabled(true)

setDisplayShowHomeEnabled(true)

>

// .

// Handle the backpress with one of these methods:

// (a) With the v7 toolbar, override in AppCompatActivity

// .

override fun onSupportNavigateUp(): Boolean

onBackPressed()

return true

>

// .

// (b) Respond to options item selection

// .

override fun onOptionsItemSelected(item: MenuItem): Boolean

return when(item.itemId)

android.R.id.home ->

finish()

true

>

else -> super.onOptionsItemSelected(item)

>

>

// .

// (2) For standalone toolbars (when it is not set as the support actionbar)

// Add a navigation icon to the standalone tool bar by one of these:

// (a) In the toolbar layout

// .

android:id=»@+id/toolbar»

android:layout_width=»match_parent»

android:layout_height=»?attr/actionBarSize»

app:navigationIcon=»?attr/homeAsUpIndicator»/>

// .

// (b) Programmatically

// .

toolbar.setNavigationIcon(R.drawable.explicit-nav-icon)

// .

// Listen for the tap event directly on the toolbar

toolbar.setNavigationOnClickListener

onBackPressed()

>

// .

Источник

How to Add a Back Button to a Toolbar in Kotlin: A Step-by-Step Guide

Learn how to improve user experience in Android apps by adding a back button to a toolbar in Kotlin. Our comprehensive guide covers setting up the toolbar, showing the back button, different methods for adding the button, customizing its appearance, and other considerations.

In Android app development, the toolbar is an important component of the user interface. It provides users with easy access to app features and navigation options. One essential feature that should be included in a toolbar is a back button, which allows users to return to the previous screen or activity. In this article, we will provide you with a step-by-step guide on how to add a back button to a toolbar in Kotlin, a popular programming language for Android app development.

Setting up the toolbar as the support action bar

Before we can add a back button to the toolbar, we need to set it up as the support action bar. The support action bar is a version of the action bar that is backwards compatible with older versions of Android. It is included in the Android Support Library and provides a consistent look and feel across different Android devices.

To set up the toolbar as the support action bar, follow these steps:

val toolbar = findViewById(R.id.toolbar) 

setSupportActionBar(toolbar) 

Showing the back button

Now that we have set up the toolbar as the support action bar, we can show the back button. The back button is represented by an arrow icon that is displayed on the left side of the toolbar. To show the back button, we need to call the setDisplayHomeAsUpEnabled(true) function.

Here’s how to show the back button in Kotlin:

1. In the activity’s onCreate() method, call the supportActionBar?.setDisplayHomeAsUpEnabled(true) function.

override fun onCreate(savedInstanceState: Bundle?) < super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) val toolbar = findViewById(R.id.toolbar) setSupportActionBar(toolbar) supportActionBar?.setDisplayHomeAsUpEnabled(true) > 

override fun onOptionsItemSelected(item: MenuItem?): Boolean < when (item?.itemId) < android.R.id.home -> < onBackPressed() return true >> return super.onOptionsItemSelected(item) > 

[ KOTLIN ] BACK BUTTON IN ACTION BAR/ TOOLBAR

Web 28/09/2019 · SOURCE CODE — https://visualandroidblog.blogspot.com/2018/03/implement-up- button -in-any-activity.html?m=1How to …

Different methods for adding a back button to a toolbar

There are several methods available for adding a back button to a toolbar. One popular method is to use Android Asset Studio to create the arrow icon. Android Asset Studio is a web-based tool that allows you to create icons, colors, and other resources for your Android app.

Here are some methods for adding a back button to a toolbar:

• Use Android Asset Studio to create the arrow icon.
• Use a vector drawable for the arrow icon.
• Use a PNG image for the arrow icon.

Each method has its advantages and disadvantages. For example, using a vector drawable allows you to scale the arrow icon without losing quality, while using a PNG image may result in pixelation at higher resolutions.

Customizing the appearance of the back button

In addition to adding the back button to the toolbar, you may also want to customize its appearance. One way to do this is to use the setBackgroundResource() method to change the button background programmatically.

Here’s how to customize the appearance of the back button in Kotlin:

val backButton = findViewById(android.R.id.home) 

backButton.setBackgroundResource(R.drawable.back_button_background) 

You can also use other methods to customize the appearance of the back button, such as setImageDrawable() to set a custom image for the button.

How to implement back button on ActionBar/Toolbar

Web 20/03/2018 · This tutorial is about how to add back button in ActionBar/ Toolbar and go to previous activity on pressed.We will create a …

Other considerations for using the back button in Kotlin

When using the back button in Kotlin, there are some other considerations to keep in mind. For example, if you are using fragments in your app, you may need to override the onOptionsItemSelected() method in each fragment to handle the back button click event.

Here are some other considerations for using the back button in Kotlin:

• Handle the Home/up button in fragments by calling the onOptionsItemSelected() method in the parent activity.
• Enable the back button by specifying a parent activity in the AndroidManifest.xml file.
• Follow best practices for implementing buttons and navigation in Android apps, such as using icons that are clear and easy to understand.

By following these considerations, you can ensure that your back button is functioning properly and that your app provides a smooth and intuitive user experience.

Other helpful code examples for setting up a back button on a toolbar in Kotlin

mActionBar.setNavigationIcon(getResources().getDrawable(R.drawable.ic_action_back)); mActionBar.setNavigationOnClickListener(new View.OnClickListener() < @Override public void onClick(View v) < //What to do on back clicked >>);

In kotlin, how to setup a back button on a toolbar kotlin code example

Toolbar toolbar = (Toolbar) findViewById(R.id.my_awesome_toolbar); setSupportActionBar(toolbar);

getSupportActionBar().setDisplayHomeAsUpEnabled(true); getSupportActionBar().setDisplayShowHomeEnabled(true);

Conclusion

In this article, we have provided you with a step-by-step guide on how to add a back button to a toolbar in Kotlin. We have explained the importance of adding a back button to a toolbar and how it can improve user experience in Android apps. We have also covered various methods for adding a back button to a toolbar, customizing its appearance, and other considerations for using the back button in Kotlin. By following these tips and best practices, you can create an app that provides a seamless and enjoyable user experience.

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