Android, MotionLayout, Animations, Tutorial, Electro4u

A Detailed Tutorial On How To Use MotionLayout In Android

MotionLayout is a powerful design tool in Android Studio that enables developers to easily create stunning animations. It is based on the ConstraintLayout, which allows for the creation of complex layouts with smooth transitions between states. In this tutorial, we will be taking a look at how to use MotionLayout in Android so that you can start creating great animations for your apps.

Set Up A MotionLayout Project

To get started, you will need to create a new project in your IDE of choice. Once you have done this, you will need to add the MotionLayout library as a dependency in your app's build.gradle file:

dependencies {
  implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta5'
  implementation 'androidx.constraintlayout:constraintlayout-motion:2.0.0-beta5'
}

Next, you will need to create your layout file. This should be based on a ConstraintLayout and must have an id of “@+id/motion_layout”. This will tell MotionLayout that this is the file it needs to work with.

Creating Transitions

Once your layout has been set up, you can start to create transitions between different states. This is done by creating a MotionScene file. You can do this by right clicking on the res folder, going to New -> XML -> MotionScene. You will then need to declare the start and end states of the transition in the MotionScene file:

<MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
             xmlns:app="http://schemas.android.com/apk/res-auto">
    <Transition
        app:constraintSetStart="@+id/start"
        app:constraintSetEnd="@+id/end">
    </Transition>

    <ConstraintSet android:id="@+id/start">
        <!-- add your start state constraints here -->
    </ConstraintSet>

    <ConstraintSet android:id="@+id/end">
        <!-- add your end state constraints here -->
    </ConstraintSet>
</MotionScene>

You will then need to add the transition you have just declared to your MotionLayout. This can be done by adding the following code to your layout file:

<androidx.constraintlayout.motion.widget.MotionLayout
    android:id="@+id/motion_layout"
    app:layoutDescription="@xml/motion_scene"
    ...>
    <!-- Your view here -->
</androidx.constraintlayout.motion.widget.MotionLayout>

Here, the app:layoutDescription attribute is used to reference the MotionScene file that we have just created.

Animating With MotionLayout

Now that you have created your transitions, you can start animating them! MotionLayout comes with a few built-in animation types such as fade, rotate, and translate. You can apply these animations to your views within your layout by adding the following code:

<androidx.constraintlayout.motion.widget.MotionLayout
    android:id="@+id/motion_layout"
    app:layoutDescription="@xml/motion_scene"
    app:animateLayoutChanges="true">

    <Button
        android:id="@+id/button"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:motionProgress="0.5"
        app:transitionEasing="linear"
        app:transitionPathRotate="90" />

</androidx.constraintlayout.motion.widget.MotionLayout>

Here, we are using the motionProgress attribute to indicate where the animation should be at a certain point in time, and the transitionEasing and transitionPathRotate attributes to control the animation's behavior. By playing around with these attributes, you can create animations that really bring your app to life.

Conclusion

In this tutorial, we have taken a look at how to use MotionLayout in Android. We have seen how to set up a MotionLayout project, how to create transitions between different states, and how to animate those transitions. Hopefully, this has given you a better understanding of how to use MotionLayout and how to create great animations for your applications!