Introduction

FragmentStepper is a library that aims to make the process of creating steps screen (wizards) based on fragments more easy. The library handles internally:

Fragments state by using FragmentStatePagerAdapter so your fragment are restored even when you navigate back and forth with a good memory management
Animations for the transition between steps
Back and forth Navigation so you won't having to face the deadly deal of back stack management. Even Jake Wharton argues against the fragment back stack: https://youtu.be/arch-talk

Add it to your project

In your project root build.gradle with:

allprojects {
    repositories {
        maven { url "https://jitpack.io" }
    }
}

and in the app or module build.gradle:

dependencies {
    implementation 'com.github.Rygelouv:FragmentStepper:v0.0.3'
}

How to use

Step 1: add it to your layout

<com.rygelouv.fragmentstepper.FragmentStepper
        android:layout_weight="1"
        android:id="@+id/stepper"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        />

Step 2: let your activity inherit from `StepsManager` and implements methods

class MainActivity : AppCompatActivity(), StepsManager{
    ...
    
    override fun getCount(): Int {
            return 3
        }
    
    override fun getStep(position: Int): Fragment {
        return when(position){
            0 -> FirstFragment()
            1 -> SecondFragment()
            2 -> ThirdFragment.newInstance("Boom", "Baam")
            else -> FirstFragment()
        }
    }
}

Step 3: configure stepper

stepper = findViewById(R.id.stepper)
stepper.setParentActivity(this)
stepper.stepsChangeListener = object : FragmentStepper.StepChangeListener {
    override fun onStepChanged(stepNumber: Int) {
        Toast.makeText(this@MainActivity, "Page changed", Toast.LENGTH_SHORT).show()
        // Do whatever you want here
    }
}

Step 4: configure backstack in order to handle navigation

In your activity, override the onBackPressed() method and add this code

override fun onBackPressed() {
    if (stepper.isLastStep()) super.onBackPressed() else stepper.goToPreviousStep()
}

Step 5: there is no step 5. That's it you're all set

TODO

Handle animations for transition
Improve the way of handling backstack
Profile for memory management

How it's done ?

FragmentStepper library is based on ViewPager but with some customization an adaptation to make fit for the specific need of steps/wizards flows.

Credits

Author: Rygel Louv https://medium.com/@rygel

License

Copyright 2017 Rygelouv.

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.

rygelouv/FragmentStepper