AgileAdapter

Develop faster list view components for Android.

You've probably used in adapters of Android applications. Have you noticed the amount of repetitive code at the time of working with them again and again? You've probably worked homogeneous and heterogeneous views with many problems, among them validate the type of view to use in a huge control structure such as a 'switch' or a 'if', you've probably experienced bad practices such as adding listeners inside the model pattern (Holder pattern) or making api calls inside the custom adapter.

The AgileAdapters are a component that helps the developer to use in a more efficient manner an adapter. Reducing the problems of architecture and facilitating the maintenance from android applications with simple views like an image and a title for example until complex views with several elements on each item view.

For this we are going to work with 3 new objects:

• ViewResolvers

The ViewResolvers objects are responsible exclusively to define the view to use.

• Populators

The populators populators objects are responsible exclusively to assign content to our components of vista.

• Interactors

The Interactors are responsible exclusively objects add interactions to our components of vista.

• AgileAdapterDTO

This object works as encapsulator of the 3 above mentioned components.

• AgileAdapter

Our main object AgileAdapter, receives in the constructor 2 parameters:

• A reference of an object that implements the interface
• A reference to an object AgileAdapterDTO.

How to?

In order to start working with this component, first we need to define our view to work with, our ViewResolver:

You must create a class, for example:

public class ItemViewResolver{

}

Now create your holder pattern class (If you want, you can create an inner class if that makes you feel confortable) or can create a package like ui.adapters.holders and create your holder pattern class that must extends HolderRecycler

public class ItemViewResolver{

    /**
    * The type Item holder.
    */
    public static final class ItemHolder extends HolderRecycler {
    
        private TextView titleView;
    
        /**
        * Instantiates a new Item holder.
        *
        * @param itemView the item view
        */
        public ItemHolder(View itemView) {
            super(itemView);
            this.titleView = (TextView) itemView.findViewById(R.id.item_title);
        }
    
        /**
        * Gets title view.
        *
        * @return the title view
        */
        public TextView getTitleView() {
            return titleView;
        }
    }
}

Now you can start creating your holder.

In order to create an association with our item layout, our view resolver class must extends ViewResolver

ViewResolver is an abstract class. That´s why now you need to implement the next two methods:

public class ItemViewResolver extends ViewResolver{
 
    /**
    * Creates a holder instance.
    *
    * @param convertView the convert view
    * @return the holder instance
    */
    @Override
    protected HolderRecycler getHolder(View convertView) {
        return new ItemHolder(convertView);
    }
    
    /**
    * Gets layout resource.
    *
    * @return the layout resource
    */
    @Override
    protected int getLayoutResource() {
        return R.layout.list_item_layout;
    }
}

Now our class looks like this:

public class ItemViewResolver extends ViewResolver {

    /**
     * Creates a holder instance.
     *
     * @param convertView the convert view
     * @return the holder instance
     */
    @Override
    protected HolderRecycler getHolder(View convertView) {
        return new ItemHolder(convertView);
    }

    /**
     * Gets layout resource.
     *
     * @return the layout resource
     */
    @Override
    protected int getLayoutResource() {
        return R.layout.list_item_layout;
    }

    /**
     * The type Item holder.
     */
    public static final class ItemHolder extends HolderRecycler {

        private TextView titleView;

        /**
         * Instantiates a new Item holder.
         *
         * @param itemView the item view
         */
        public ItemHolder(View itemView) {
            super(itemView);
            this.titleView = (TextView) itemView.findViewById(R.id.item_title);
        }

        /**
         * Gets title view.
         *
         * @return the title view
         */
        public TextView getTitleView() {
            return titleView;
        }
    }
}