EpoxyModelWithView.java

package com.airbnb.epoxy;

import android.support.annotation.LayoutRes;
import android.view.View;
import android.view.ViewGroup;

/**
 * A model that allows its view to be built programmatically instead of by inflating a layout
 * resource. Just implement {@link #buildView} so the adapter can create a new view for this model
 * when needed.
 * <p>
 * {@link #getViewType()} is used by the adapter to know how to reuse views for this model. This
 * means that all models that return the same type should be able to share the same view, and the
 * view won't be shared with models of any other type.
 * <p>
 * If it is left unimplemented then at runtime a unique view type will be created to use for all
 * models of that class. The generated view type will be negative so that it cannot collide with
 * values from resource files, which are used in normal Epoxy models. If you would like to share
 * the same view between models of different classes you can have those classes return the same view
 * type. A good way to manually create a view type value is by creating an R.id. value in an ids
 * resource file.
 */
public abstract class EpoxyModelWithView<T extends View> extends EpoxyModel<T> {

  /**
   * Get the view type associated with this model's view. Any models with the same view type will
   * have views recycled between them.
   *
   * @see android.support.v7.widget.RecyclerView.Adapter#getItemViewType(int)
   */
  @Override
  protected int getViewType() {
    return 0;
  }

  /**
   * Create and return a new instance of a view for this model. If no layout params are set on the
   * returned view then default layout params will be used.
   *
   * @param parent The parent ViewGroup that the returned view will be added to.
   */
  @Override
  protected abstract T buildView(ViewGroup parent);

  @Override
  protected final int getDefaultLayout() {
    throw new UnsupportedOperationException(
        "Layout resources are unsupported. Views must be created with `buildView`");
  }

  @Override
  public EpoxyModel<T> layout(@LayoutRes int layoutRes) {
    throw new UnsupportedOperationException(
        "Layout resources are unsupported. Views must be created with `buildView`");
  }
}