Android Material Stepper Library Tutorial and Source Code

Steppers convey progress through numbered steps. Steppers display progress through a sequence of logical and numbered steps. They may also be used for navigation. Steppers may display a transient feedback message after a step is saved.

This library allows to use Material steppers inside Android applications. Steppers display progress through a sequence by breaking it up into multiple logical and numbered steps.

Types of Steps:
- Editable
- Non-editable
- Mobile
- Optional

Types of Steppers:
- Horizontal
- Vertical
- Linear
- Non-linear

Related:
Android AppIntro Slider Example
Android XML Animations Examples
Android Push Notification Tutorial Using Firebase

Supported features:

Color customisation of individual widgets inside of the stepper via View attributes or a style from a theme
Custom texts of individual widgets inside of the stepper via View attributes or a style from a theme
Embedding the stepper anywhere in the view hierarchy and changing the stepper type for various device configurations, e.g. phone/tablet, portrait/landscape
Step validation
Use with Fragments or Views

Getting started

Android Dependencies:

compile 'com.stepstone.stepper:material-stepper:2.2.0'

Create layout in XML

<?xml version="1.0" encoding="utf-8"?>
<com.stepstone.stepper.StepperLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/stepperLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    app:ms_stepperType="progress_bar" />


Create step Fragment(s)

Step fragments must extend android.support.v4.app.Fragment and implement com.stepstone.stepper.Step

public class StepFragmentSample extends Fragment implements Step {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.step, container, false);

        //initialize your UI

        return v;
    }

    @Override
    public VerificationError verifyStep() {
        //return null if the user can go to the next step, create a new VerificationError instance otherwise
        return null;
    }

    @Override
    public void onSelected() {
        //update UI when selected
    }

    @Override
    public void onError(@NonNull VerificationError error) {
        //handle error inside of the fragment, e.g. show error on EditText
    }

}

Extend AbstractFragmentStepAdapter

AbstractFragmentStepAdapter extends FragmentPagerAdapter but instead of overriding the method getItem(int) you must override the createStep(int) method.

public static class MyStepperAdapter extends AbstractFragmentStepAdapter {

    public MyStepperAdapter(FragmentManager fm, Context context) {
        super(fm, context);
    }

    @Override
    public Fragment createStep(int position) {
        final StepFragmentSample step = new StepFragmentSample();
        Bundle b = new Bundle();
        b.putInt(CURRENT_STEP_POSITION_KEY, position);
        step.setArguments(b);
        return step;
    }

    @Override
    public int getCount() {
        return 3;
    }

    @NonNull
    @Override
    public StepViewModel getViewModel(@IntRange(from = 0) int position) {
        //Override this method to set Step title for the Tabs, not necessary for other stepper types
        return new StepViewModel.Builder(context)
                .setTitle(R.string.tab_title) //can be a CharSequence instead
                .create();
    }
}

Set adapter in Activity

public class StepperActivity extends AppCompatActivity {

    private StepperLayout mStepperLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mStepperLayout = (StepperLayout) findViewById(R.id.stepperLayout);
        mStepperLayout.setAdapter(new MyStepperAdapter(getSupportFragmentManager(), this));
    }
}

Add a StepperListener in the Activity (optional)

public class StepperActivity extends AppCompatActivity implements StepperLayout.StepperListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        //...
        mStepperLayout.setListener(this);
    }

    @Override
    public void onCompleted(View completeButton) {
        Toast.makeText(this, "onCompleted!", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onError(VerificationError verificationError) {
        Toast.makeText(this, "onError! -> " + verificationError.getErrorMessage(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onStepSelected(int newStepPosition) {
        Toast.makeText(this, "onStepSelected! -> " + newStepPosition, Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onReturn() {
        finish();
    }

}

Change Next/Complete button's text color when going to the next step should be disabled (optional)

It is possible to change the Next/Complete button's text color (together with right chevron's color) when all the criteria to go to the next step are not met. This color should indicate that the user cannot go to next step yet and look as if disabled. Clicking on the button will still perform the regular step verification. There is a custom state added since setting android:state_enabled to false in a color selector would disable the clicks and we want to have them so that we can show an info message for the user. In order to set that color:

Create a new color selector in res/color

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto">
    <item app:state_verification_failed="true" android:color="#30BDBDBD"/>
    <item android:color="@color/ms_white"/>
</selector>

Change button's (text) color in layout file

<?xml version="1.0" encoding="utf-8"?>
<com.stepstone.stepper.StepperLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/stepperLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:ms_stepperType="dots"
    app:ms_nextButtonColor="@color/ms_custom_button_text_color"
    app:ms_completeButtonColor="@color/ms_custom_button_text_color" />

Toggle the state in code

mStepperLayout.setNextButtonVerificationFailed(!enabled);
mStepperLayout.setCompleteButtonVerificationFailed(!enabled);
Make an IO operation before going to the next step (optional)

If the user wants to e.g. save something in the database or make a network call on a separate Thread after clicking on the Next button he can perform these operations and then invoke the goToNextStep() method of the StepperLayout.OnNextClickedCallback in the current Step. While operations are performed, and the user would like to go back you can cancel them and then invoke onBackClicked() method of the StepperLayout.OnBackClickedCallback.

The fragment must implement BlockingStep instead of Step. Also, make sure that goToNextStep() gets called on the main thread. Note: the onNextClicked(StepperLayout.OnNextClickedCallback) method gets invoked after step verification. E.g.:

public class DelayedTransitionStepFragmentSample extends Fragment implements BlockingStep {

    //...

    @Override
    @UiThread
    public void onNextClicked(final StepperLayout.OnNextClickedCallback callback) {
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                callback.goToNextStep();
            }
        }, 2000L);
    }

    @Override
    @UiThread
    public void onBackClicked(StepperLayout.OnBackClickedCallback callback) {
        Toast.makeText(this.getContext(), "Your custom back action. Here you should cancel currently running operations", Toast.LENGTH_SHORT).show();
        callback.goToPrevStep();
     }

}

Changing Back/Next button labels per step

Sometimes you might want to have different labels on the Next and/or Back navigation buttons on different steps e.g. use the default labels on the first few steps, but display 'Summary' just before the last page.


In such case you need to override the getViewModel(int) method from the StepAdapter e.g.

    @NonNull
    @Override
    public StepViewModel getViewModel(@IntRange(from = 0) int position) {
        StepViewModel.Builder builder = new StepViewModel.Builder(context)
                .setTitle(R.string.tab_title);
        switch (position) {
            case 0:
                builder
                        .setNextButtonLabel("This way")
                        .setBackButtonLabel("Go to first");
                break;
            case 1:
                builder
                        .setNextButtonLabel(R.string.go_to_summary)
                        .setBackButtonLabel("Go to first");
                break;
            case 2:
                builder.setBackButtonLabel("Go back");
                break;
            default:
                throw new IllegalArgumentException("Unsupported position: " + position);
        }
        return builder.create();
    }

Using the same stepper styling across the application

If you have many steppers in your application in different activities/fragments you might want to set a common style in a theme. To do so, you need to set the ms_stepperStyle attribute in the theme, e.g.

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        ...

        <item name="ms_stepperStyle">@style/DotStepperStyle</item>
    </style>

and declare that style in the XML you keep your styles at, e.g.

    <style name="DotStepperStyle">
        <item name="ms_stepperType">dots</item>
        <item name="ms_activeStepColor">#FFFFFF</item>
        <item name="ms_inactiveStepColor">#006867</item>
        <item name="ms_bottomNavigationBackground">?attr/colorAccent</item>
    </style>

Showing a Back button on first step

By default if the user is on the first step then the Back button in the bottom navigation is hidden. This behaviour can be changed by setting ms_showBackButtonOnFirstStep to true, e.g.

    <?xml version="1.0" encoding="utf-8"?>
    <com.stepstone.stepper.StepperLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/stepperLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:ms_showBackButtonOnFirstStep="true"
        app:ms_stepperType="dots" />

To get a callback when this button was pressed you need set a StepperListener and write your own custom return logic in the onReturn() method to e.g. close the Activity.

Using with Views instead of Fragments

It is possible to use this library without the need to rely on Fragments. To do so you need to use AbstractStepAdapter instead of AbstractFragmentStepAdapter. For an example of how to use it with views please see the sample app.

Custom styling

Basic styling can be done by choosing the active and inactive step colors. There are some additional properties which can be changed directly from StepperLayout's attributes e.g. the background of bottom navigation buttons (see StepperLayout attributes) For advanced styling you can use ms_stepperLayoutTheme StepperLayout's attribute and provide your custom style to be used. See 'Custom StepperLayout theme' in the sample app for an example.

Advanced usage

For other examples, e.g. persisting state on rotation, displaying errors, changing whether the user can go to the next step, etc. check out the sample app.

Download Complete Source Code

Github: https://github.com/stepstone-tech/android-material-stepper