Options in Java. Probably a terrible idea.

AdViewManager.java

package net.rdrei.android.scdl2.ui;

import android.view.InflateException;
import android.view.View;
import android.view.ViewGroup;

import com.crashlytics.android.Crashlytics;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.google.inject.Inject;
import com.google.inject.Provider;

import net.rdrei.android.option.Option;
import net.rdrei.android.scdl2.ApplicationPreferences;
import net.rdrei.android.scdl2.R;
import net.rdrei.android.scdl2.guice.ActivityLayoutInflater;

import roboguice.util.Ln;

/**
 * Loads and injects an AdView if required into an existing layout.
 *
 * @author pascal
 */
public class AdViewManager {
	private Provider<ApplicationPreferences> mPreferencesProvider;
	private ActivityLayoutInflater mInflater;

	@Inject
	public AdViewManager(Provider<ApplicationPreferences> preferencesProvider,
			ActivityLayoutInflater inflater) {
		this.mPreferencesProvider = preferencesProvider;
		this.mInflater = inflater;
	}

	private Option<View> getAdView(final ViewGroup baseView) {
		try {
			return Option.some(mInflater.inflate(R.layout.adview, baseView, false));
		} catch (InflateException exc) {
			Ln.e(exc);
			Crashlytics.logException(exc);
		}

		return Option.none();
	}

	private Option<View> setupView(final View view) {
		AdView adView;

		try {
			adView = (AdView) view;
		} catch (ClassCastException err) {
			adView = null;
			Crashlytics.logException(err);
		}

		if (adView != null) {
			final AdRequest adRequest = new AdRequest.Builder()
					.addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
					.build();
			adView.loadAd(adRequest);
			return Option.some(adView);
		}

		return Option.none();
	}

	/**
	 * Add the AdView to the given baseView.
	 *
	 * @param baseView The layout element to add the view to.
	 */
	public void addToView(final ViewGroup baseView) {
		final Option<View> adView = getAdView(baseView);
		adView
			.flatMap(this::setupView)
			.call(baseView::addView);
	}

	/**
	 * Add to the given baseView, but only if the application is non-adfree.
	 *
	 * @param baseView The view you want to see your ads in.
	 * @return True if added to layout, false if not.
	 */
	public boolean addToViewIfRequired(final ViewGroup baseView) {
		final boolean showAds = !mPreferencesProvider.get().isAdFree();
		if (showAds) {
			addToView(baseView);
		}

		return showAds;
	}
}

Consumer1.java

package net.rdrei.android.option;

public interface Consumer1<A> {
	void accept(A a);
}

Func1.java

package net.rdrei.android.option;

public interface Func1<A1, R> {
	R apply(A1 arg1);
}

None.java

package net.rdrei.android.option;

import java.util.NoSuchElementException;

public class None<A> extends Option<A> {

	None() {
	}

	@Override
	public <B> Option<B> map(Func1<A, B> f) {
		return NONE;
	}

	@Override
	public Option<A> call(Consumer1<A> f) {
		return this;
	}

	@Override
	public <B> Option<B> flatMap(Func1<A, Option<B>> f) {
		return NONE;
	}

	@Override
	public Option<A> filter(Predicate<? super A> predicate) {
		return NONE;
	}

	@Override
	public A getOrElse(A def) {
		return def;
	}

	@Override
	public boolean isEmpty() {
		return true;
	}

	@Override
	public A get() {
		throw new NoSuchElementException();
	}
}

Option.java

package net.rdrei.android.option;


public abstract class Option<A> {

	public static final None NONE = new None();

	public abstract <B> Option<B> map(Func1<A, B> f);

	public abstract Option<A> call(Consumer1<A> f);

	public abstract <B> Option<B> flatMap(Func1<A, Option<B>> f);

	public abstract Option<A> filter(Predicate<? super A> predicate);

	public abstract A getOrElse(A def);

	public abstract boolean isEmpty();

	public abstract A get();

	@SuppressWarnings("unchecked")
	public static <A> Some<A> some(A value) {
		return new Some(value);
	}

	@SuppressWarnings("unchecked")
	public static <A> None<A> none() {
		return NONE;
	}

	public static <A> Option<A> asOption(A value) {
		if (value == null) return none();
		else return some(value);
	}

}

Predicate.java

package net.rdrei.android.option;

public interface Predicate<T> {
	boolean test(T t);
}

Some.java

package net.rdrei.android.option;

public class Some<A> extends Option<A> {

	private final A value;

	Some(A value) {
		this.value = value;
	}

	@Override
	public <B> Option<B> map(Func1<A, B> f) {
		return some(f.apply(value));
	}

	@Override
	public Option<A> call(Consumer1<A> f) {
		f.accept(value);
		return this;
	}

	@Override
	public <B> Option<B> flatMap(Func1<A, Option<B>> f) {
		return f.apply(value);
	}

	@SuppressWarnings("unchecked")
	@Override
	public Option<A> filter(Predicate<? super A> predicate) {
		if (predicate.test(value)) {
			return this;
		} else {
			return None.NONE;
		}
	}

	@Override
	public A getOrElse(A def) {
		return value;
	}

	@Override
	public boolean isEmpty() {
		return false;
	}

	@Override
	public A get() {
		return value;
	}
}