add initial support for fragments

Fragments are not added to the View hierarchy yet. Only the lifecycle
callbacks are implemented

src/api-impl/android/app/Activity.java

@@ -23,6 +23,8 @@ import java.io.InputStream;
 import java.io.StringReader;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
+import java.util.List;
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserFactory;
 
@@ -36,6 +38,7 @@ public class Activity extends Context {
 	private int pendingRequestCode;
 	private int pendingResultCode;
 	private Intent pendingData;
+	List<Fragment> fragments = new ArrayList<>();
 
 	/**
 	 * Helper function to be called from native code to construct main activity
@@ -110,6 +113,10 @@ public class Activity extends Context {
 		System.out.println("- onCreate - yay!");
 		new ViewGroup(this).setId(R.id.content);
 
+		for (Fragment fragment : fragments) {
+			fragment.onCreate(savedInstanceState);
+		}
+
 		return;
 	}
 
@@ -118,6 +125,10 @@ public class Activity extends Context {
 		if (window.contentView != null)
 			window.setContentView(window.contentView);
 
+		for (Fragment fragment : fragments) {
+			fragment.onStart();
+		}
+
 		return;
 	}
 
@@ -134,24 +145,40 @@ public class Activity extends Context {
 			pendingData = null;
 		}
 
+		for (Fragment fragment : fragments) {
+			fragment.onResume();
+		}
+
 		return;
 	}
 
 	protected void onPause() {
 		System.out.println("- onPause - yay!");
 
+		for (Fragment fragment : fragments) {
+			fragment.onPause();
+		}
+
 		return;
 	}
 
 	protected void onStop() {
 		System.out.println("- onStop - yay!");
 
+		for (Fragment fragment : fragments) {
+			fragment.onStop();
+		}
+
 		return;
 	}
 
 	protected void onDestroy() {
 		System.out.println("- onDestroy - yay!");
 
+		for (Fragment fragment : fragments) {
+			fragment.onDestroy();
+		}
+
 		return;
 	}
 
@@ -291,7 +318,7 @@ public class Activity extends Context {
 	}
 
 	public FragmentManager getFragmentManager() {
-		return new FragmentManager();
+		return new FragmentManager(this);
 	}
 
 	public LayoutInflater getLayoutInflater() {

src/api-impl/android/app/Fragment.java

@@ -1,5 +1,31 @@
 package android.app;
 
+import android.os.Bundle;
+
 public class Fragment {
-	
+
+	Activity activity;
+
+	public void onCreate(Bundle savedInstanceState) {
+	}
+
+	public void onStart() {
+	}
+
+	public void onResume() {
+	}
+
+	public void onPause() {
+	}
+
+	public void onStop() {
+	}
+
+	public void onDestroy() {
+	}
+
+	public Activity getActivity() {
+		return activity;
+	}
+
 }

src/api-impl/android/app/FragmentManager.java

@@ -1,13 +1,19 @@
 package android.app;
 
 public class FragmentManager {
+
+	private Activity activity;
+
+	public FragmentManager(Activity activity) {
+		this.activity = activity;
+	}
 	
 	public Fragment findFragmentByTag(String tag) {
 		return null;
 	}
 
 	public FragmentTransaction beginTransaction() {
-		return new FragmentTransaction();
+		return new FragmentTransaction(activity);
 	}
 
 	public boolean executePendingTransactions() {

src/api-impl/android/app/FragmentTransaction.java

@@ -1,8 +1,16 @@
 package android.app;
 
 public class FragmentTransaction {
+
+	private Activity activity;
+
+	public FragmentTransaction(Activity activity) {
+		this.activity = activity;
+	}
 	
 	public FragmentTransaction add(Fragment fragment, String string) {
+		fragment.activity = activity;
+		activity.fragments.add(fragment);
 		return this;
 	}