<io.github.iamvaliyev.multitabmenu.MultiTabMenu
    android:id="@+id/multiTabMenu"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"/>

multiTabMenu = (MultiTabMenu) findViewById(R.id.multiTabMenu);
multiTabMenu.getSelectedCategory(); // return Category
multiTabMenu.getSelectedSubCategory(); // return Object
multiTabMenu.getSelectedCategoryPosition(); // return int
multiTabMenu.getSelectedSubCategoryPosition(); // return int

multiTabMenu.setupSubCategories(new CategoryAdapter(getApplicationContext(), list));

multiTabMenu.setOnCategorySelectedListener(new MultiTabMenu.OnCategorySelectedListener() {
           @Override
           public void onCategorySelected(Category category) {
               ....
           }

           @Override
           public void OnSubCategorySelected(Object object) {
               ....
           }
       });

public class CategoryAdapter extends ParentAdapter {

    List<Cat> list;

    public CategoryAdapter(Context context, List<Cat> list) {
        super(context, list);
        .......
    }

    @Override
    public View getSectionView(int position, View view, ViewGroup parent) {
        .......
    }

    @Override
    public View getChildView(int position, int childPosition, View view, ViewGroup parent) {
        .......
    }
}

public class YourCategoryModel implements Category<YourSubCategoryModel> {

    String title;
    List<YourSubCategoryModel> list = new ArrayList<>();

    public Cat(String title) {
        this.title = title;
    }

    @Override
    public List getChildItems() {
        return list;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public List<YourSubCategoryModel> getList() {
        return list;
    }

    public void setList(List<YourSubCategoryModel> list) {
        this.list = list;
    }

    public void add(SubCat subCat){
        list.add(subCat);
    }
}

    app:categoriesBackground="@color/colorPrimaryDark"
    app:subCategoriesBackground="@color/colorPrimary"
    app:triangleBackground="@color/colorAccent"

Copyright 2016 Emil Valiyev

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.