ViewContainer.java

package ru.ltst.u2020mvp.ui;

import android.app.Activity;
import android.view.ViewGroup;

import static butterknife.ButterKnife.findById;

/**
 * An indirection which allows controlling the root container used for each activity.
 */
public interface ViewContainer {
    /**
     * The root {@link android.view.ViewGroup} into which the activity should place its contents.
     */
    ViewGroup forActivity(Activity activity);

    /**
     * An {@link ViewContainer} which returns the normal activity content view.
     */
    ViewContainer DEFAULT = activity -> findById(activity, android.R.id.content);
}