What is constraint layout in Android? How does it compare to LinearLayout and RelativeLayout? In this blog post, we will answer all of these questions and more.
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Constraint layout is a relatively new layout type that was introduced with Android Studio 3.0. It offers many advantages over other layout types, including increased flexibility and performance. We will also show you how to use constraint layout in your own projects!
What is Constraint Layout in Android?
So, what exactly is constraint layout? Constraint layout is a type of layout that allows you to position and size widgets in a flexible way. Unlike LinearLayout and RelativeLayout, which are both restricted to two dimensions, constraint layout can be used in three dimensions. This means that you can create complex layouts with ease!
One of the biggest advantages of constraint layout is its performance. Because it doesn’t have to rely on nested view groups, it can often avoid the common performance issues that plague other layouts. In addition, constraint layout is much more flexible than other types of layouts. This flexibility comes at a cost though; because it’s so flexible, constraint layout can be more difficult to use than other layouts. Nevertheless, we think it’s worth the effort!
If you’re ready to learn more about constraint layout, then head on over to our tutorial on how to use constraint layout in Android Studio. We’ll show you everything you need to know, from creating a basic layout to adding constraints and making your layout responsive. Trust us, once you get the hang of it, you’ll never want to go back to using anything else!
How to Use Constraint Layout in Android
Now that we’ve talked about what constraint layout is, let’s learn how to use it in Android Studio. Constraint layout is a powerful tool, but it can be tricky to use if you’re not familiar with it. That’s why we’ve put together this tutorial on using constraintlayout in Android Studio.
We’ll walk you through everything from creating a basic layout to adding constraints and making your layout responsive. By the end of this tutorial, you’ll be an expert at using constraintlayout! So let’s get started.
Creating a New Project in Android Studio
First, open Android Studio and create a new project. We’ll call our project “ConstraintLayoutExample“. Once you’ve created your project, open the activity_main.xml file and delete the default TextView. We won’t be needing it for this example.
Next, drag a Button widget from the Palette into the design editor. Position it in the center of the screen and give it a label like “Click me!”. Your layout should now look something like this:
Adding Constraints
Now that we’ve talked about what constraint layout is and how it compares to other layouts, let’s learn how to use it in Android Studio! First, add the following dependency to your build.gradle file:
dependencies {
implementation 'com.android.support.constraint:constraint-layout:x.y.z' // Replace with the latest version!
}Next, open your activity_main.xml file and add the following code
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<Button
android:id="@+id/button"
android:text="Sample button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</androidx.constraintlayout.widget.ConstraintLayout>
Now that we’ve added the constraint layout, let’s add some constraints to our Button! We want our Button to be horizontally and vertically centered in the screen, so we’ll add constraints for both the left and right sides of the Button, as well as the top and bottom.
To do this, select your Button in the design editor. Then, click on the “Infer Constraints” button in the toolbar. This will automatically generate constraints for your view. Alternatively, you can also hold down the “Shift” key while dragging from one side of the view to another to create constraints.
Once you’ve added your constraints, your layout should look something like this:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sample button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
If everything looks good, go ahead and run your app! You should see your Button appear in the center of the screen. Congratulations, you’ve just created your first constraint layout!
Making Your Layout Responsive
One of the great things about constraint layout is that it makes it easy to create responsive layouts. To see how this works, let’s add another view to our layout.
This time, we’ll add an ImageView and position it below our Button. We want the ImageView to be horizontally centered and have a margin of 16dp from the top and bottom of the screen.
Adding Constraints
To add constraints to our ImageView, select it in the design editor and click on the “Infer Constraints” button in the toolbar. Then, add a margin of 16dp from the top and bottom of the screen. Your layout should now look something like this:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sample button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="@+id/imageView"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginTop="16dp"
android:src="@drawable/ic_launcher_background"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/button" />
</androidx.constraintlayout.widget.ConstraintLayout>
If you run your app on a device with a large screen, you’ll see that the ImageView is centered in the middle of the screen. However, if you run your app on a device with a smaller screen, you’ll see that the ImageView is moved to the top of the screen and centered there. This is because we’ve added constraints for the top and bottom of the ImageView, so when there’s not enough space to display both views side by side, Android will move the ImageView above the Button.
Adding Constraints for Orientation Changes
Now let’s say we want our Button to be below our ImageView when we change the orientation of our device. To do this, we need to add a constraint for the left side of the Button and remove the constraint for the top side.
Adding Constraints
If you run your app on a device with a large screen, you’ll see that the Button is still centered in the middle of the screen. However, if you change the orientation of your device to portrait mode, you’ll see that the Button is now below the ImageView.
This is because we’ve added a constraint for the left side of the Button, so when there’s not enough space to display both views side by side in landscape mode, Android will move the Button below the ImageView.
Constraint Layout vs Linear Layout in Android
Now that we’ve talked about what constraint layout is, let’s compare it to another popular layout type: LinearLayout. LinearLayout is the most basic type of layout in Android, and it arranges its children in a single column or row. This can be useful for simple layouts, but it quickly becomes limiting as your layout becomes more complex.
In contrast, constraint layout gives you much more control over how your widgets are arranged. With constraintlayout, you can position widgets anywhere on the screen, not just in a single column or row. You can also specify constraints between widgets, so that they resize and move together as the user resizes the screen. This is perfect for creating responsive layouts!
So which one should you use? If you need a simple layout, then LinearLayout is probably all you need. But if you want more control over your layout, or if you need to create a responsive layout, then constraintlayout is the way to go.
Constraint Layout vs Relative Layout in Android
Another popular layout type is RelativeLayout. RelativeLayout lets you position widgets relative to one another, or to the parent layout. This can be useful for certain types of layouts, but it can also be confusing and difficult to get right.
In contrast, constraintlayout gives you much more control over how your widgets are arranged. With constraintlayout, you can specify constraints between widgets, so that they resize and move together as the user resizes the screen. This is perfect for creating responsive layouts!
So which one should you use? If you need a simple layout, then LinearLayout or RelativeLayout might be all you need. But if you want more control over your layout, or if you need to create a responsive layout, then constraintlayout is the way to go.
Constraint Layout vs Other Layout Types in Android
There are many other types of layouts in Android, but constraintlayout is definitely one of the most popular. This is because constraintlayout gives you much more control over how your widgets are arranged. With constraintlayout, you can specify constraints between widgets, so that they resize and move together as the user resizes the screen. This is perfect for creating responsive layouts!
So if you need a layout that is flexible and easy to use, then constraintlayout is definitely the way to go.
And that’s it! You now know how to use constraint layout to create responsive layouts for your Android app. For more information on constraint layout, be sure to check out the official documentation. Thanks for reading!
I hope this helped you understand Constraint Layout a little better.
Learn more about Constraint layout from link here
Please leave any questions in the comments section below and I’ll do my best to answer them.
Happy coding!
