Android Material Stepper

This library allows to use Material steppers inside Android applications.

Quoting the documentation:

Steppers display progress through a sequence by breaking it up into multiple logical and numbered steps.

All of the code & features mentioned in Getting started and Advanced usage are showcased in the sample app. Moreover, you can find there other examples, e.g. how to persist state on rotation, display errors, change whether the user can go to the next step, etc. So please have a look!

Jump to section

• Supported steppers
• Supported features
• Getting started
• Advanced usage
  • Making extra operations before going to the next step
  • Changing button labels & compound drawables per step
  • Subtitles in tabs
  • Custom styling
  • Using same stepper styling across the application
  • Showing a Back button on first step
  • Using Views instead of Fragments as Steps
  • Showing an error on tabs if step verification failed
  • Stepper feedback
  • Changing button text color when going to the next step should be disabled
  • Hiding bottom navigation bar
• StepperLayout attributes
  • View attributes
  • StepperLayout style attributes
• Changelog
• Espresso tests
• Contributing
• License

Supported steppers

Mobile stepper with dots

Mobile stepper with progress bar

Mobile stepper without a progress indicator

Horizontal stepper

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
• showing errors in tabs
• showing stepper feedback for ongoing operations (see Stepper feedback)

Getting started

Download (from JCenter)

compile 'com.stepstone.stepper:material-stepper:4.3.1'

Note: This library adds a transitive dependency to AppCompat 25.4.0 which is the minimum Android Support library version compatible with the Stepper library.

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"
    app:ms_stepperType="progress_bar" />

For a complete list of StepperLayout attributes see [StepperLayout attributes](#StepperLayout attributes).

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 Step 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();
    }

}

Advanced usage

Making extra operations before going to the next step

After clicking on the Next button if the user wants to e.g.:

• save something in the database
• make a network call on a separate Thread
• simply save the data from the current step to some other component or parent Activity (see 'Passing data between steps' in the sample app for more details)

he can perform these operations and then invoke the goToNextStep() method of the StepperLayout.OnNextClickedCallback in the current Step. If the user wants to perform these operations on the final step, when clicking on the Complete button, he needs to invoke the complete() method of the StepperLayout.OnCompleteClickedCallback. 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.

To do so the fragment/view must implement BlockingStep instead of Step. Also, make sure that goToNextStep() and/or complete() get called on the main thread. Note: onNextClicked(StepperLayout.OnNextClickedCallback) and onCompleteClicked(StepperLayout.OnCompleteClickedCallback) methods get 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 onCompleteClicked(final StepperLayout.OnCompleteClickedCallback callback) {
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                callback.complete();
            }
        }, 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 button labels & compound drawables per step

Sometimes you might want to have different labels on the Next/Complete 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. You might also want to use your custom icons instead of the default navigation button compound drawables or not show the compound drawables for some of the buttons.

    @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
                    .setEndButtonLabel("This way")
                    .setBackButtonLabel("Cancel")
                    .setNextButtonEndDrawableResId(R.drawable.ms_forward_arrow)
                    .setBackButtonStartDrawableResId(StepViewModel.NULL_DRAWABLE);
                break;
            case 1:
                builder
                    .setEndButtonLabel(R.string.go_to_summary)
                    .setBackButtonLabel("Go to first")
                    .setBackButtonStartDrawableResId(R.drawable.ms_back_arrow);
                break;
            case 2:
                builder
                    .setBackButtonLabel("Go back")
                    .setEndButtonLabel("I'm done!");
                break;
            default:
                throw new IllegalArgumentException("Unsupported position: " + position);
        }
        return builder.create();
    }

It is also possible to hide Back/Next/Complete buttons on each step if needed. To do so you need to call setBackButtonVisible(false) and/or setEndButtonVisible(false) on StepViewModel.Builder in your adapter.

Subtitles in tabs

You can set a subtitle for each step in stepper with tabs, e.g. to mark a step as optional. To do so you need to set the subtitle by calling StepViewModel.Builder#setSubtitle(int) or StepViewModel.Builder#setSubtitle(CharSequence) in your adapter's getViewModel method.

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.

Using 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 Views instead of Fragments as Steps

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.

Showing an error on tabs if step verification failed

To show an error in the tabbed stepper if step verification fails you need to set ms_showErrorStateEnabled attribute to true.

If you want to keep the error displayed when going back to the previous step you need to also set ms_showErrorStateOnBackEnabled to true. If you want display an error message below the step title you need to set ms_showErrorMessageEnabled to true. The message set in VerificationError will be then displayed.

Stepper feedback

It is possible to show stepper feedback for ongoing operations (see Stepper feedback). To do so you firstly need to set ms_stepperFeedbackType to one or more of:

• tabs - shows a progress message instead of the tabs during operation.
• content_progress - shows a progress bar on top of the steps' content.
• content_fade - partially fades the content out during operation (should not be used together with content_overlay). You can change the default fade amount with ms_stepperFeedback_contentFadeAlpha attribute.
• content_overlay - shows a dimmed overlay over the content during the operation (should not be used together with content_fade). You can change the overlay background with ms_stepperFeedback_contentOverlayBackground attribute.
• disabled_bottom_navigation - disables the buttons in the bottom navigation during operation. In order to see that the buttons are disabled on the bottom navigation bar, make sure that the button colors are assigned using color selectors with a disabled state (see the sample app).
• disabled_content_interaction - intercepts touch events on the steps' content and ignores them during operation.

The default is none which does nothing. It is possible to use multiple flags together.

After setting this to show the feedback you need to call StepperLayout#showProgress(@NonNull String progressMessage) and do hide the progress indicator you need to call StepperLayout#hideProgress().

E.g. In layout:

    <?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_backButtonColor="@color/ms_disabling_button_text_color_selector"
        app:ms_nextButtonColor="@color/ms_disabling_button_text_color_selector"
        app:ms_completeButtonColor="@color/ms_disabling_button_text_color_selector"
        app:ms_stepperType="tabs"
        app:ms_stepperFeedbackType="tabs|content|disabled_bottom_navigation" />

and in BlockingStep:

public class StepperFeedbackStepFragment extends Fragment implements BlockingStep {

    //...

    @Override
    @UiThread
    public void onNextClicked(final StepperLayout.OnNextClickedCallback callback) {
        callback.getStepperLayout().showProgress("Operation in progress, please wait...");
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                callback.goToNextStep();
                callback.getStepperLayout().hideProgress();
            }
        }, 2000L);
    }

    //...

Changing button text color when going to the next step should be disabled

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:

1. 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>

2. 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" />

3. Toggle the state in code

    mStepperLayout.setNextButtonVerificationFailed(!enabled);
    mStepperLayout.setCompleteButtonVerificationFailed(!enabled);

Hiding bottom navigation bar

Bottom navigation bar is shown by default. If in your UI you would like to hide the bottom navigation bar you can do that by either setting the ms_showBottomNavigation attribute in XML to false or by setting it programmatically by calling StepperLayout#setShowBottomNavigation(boolean) with false.

StepperLayout attributes

View attributes

A list of base StepperLayout attributes used for behaviour configuration & base UI configuration. For advanced styling please see StepperLayout style attributes.

StepperLayout style attributes

A list of ms_stepperLayoutTheme attributes responsible for styling of StepperLayout's child views.

Changelog

See changelog

Espresso tests

If you wish to run Espresso tests on a screen containing a StepperLayout you might want to use espresso-material-stepper which contains useful Espresso actions and matchers such as clicking on navigation buttons & tabs. To do so add a Gradle dependency:

    androidTestCompile 'com.stepstone.stepper:espresso-material-stepper:X.X.X'

Please see the sample app which uses it in instrumentation tests for more details.

Contributing

All contributions are welcome and encouraged!

If you wish to contribute please create an issue first explaining the proposed changes.

Project is built on Circle CI on which we run static code analysis as well as unit & instrumentation tests to ensure that the latest changes don't break anything. To check if your changes pass execute:

./gradlew checkWithUiTests

Or on a device below Marshmallow:

./gradlew checkWithUiTests -Ptest.integration.options.adbInstallOptions=-r

License

Copyright 2016 StepStone Services

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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