Add a controller for contact selection lists

briar-android/src/org/briarproject/android/contactselection/ContactSelectorActivity.java

@@ -0,0 +1,91 @@
+package org.briarproject.android.contactselection;
+
+import android.os.Bundle;
+import android.support.annotation.CallSuper;
+import android.support.annotation.UiThread;
+
+import org.briarproject.R;
+import org.briarproject.android.BriarActivity;
+import org.briarproject.android.fragment.BaseFragment.BaseFragmentListener;
+import org.briarproject.api.contact.ContactId;
+import org.briarproject.api.sync.GroupId;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+public abstract class ContactSelectorActivity<I extends SelectableContactItem>
+		extends BriarActivity
+		implements BaseFragmentListener, ContactSelectorListener<I> {
+
+	final static String CONTACTS = "contacts";
+
+	// Subclasses may initialise the group ID in different places
+	protected GroupId groupId;
+	protected Collection<ContactId> contacts;
+
+	@Override
+	public void onCreate(Bundle bundle) {
+		super.onCreate(bundle);
+
+		setContentView(R.layout.activity_fragment_container);
+
+		if (bundle != null) {
+			// restore group ID if it was saved
+			byte[] groupBytes = bundle.getByteArray(GROUP_ID);
+			if (groupBytes != null) groupId = new GroupId(groupBytes);
+			// restore selected contacts if a selection was saved
+			ArrayList<Integer> intContacts =
+					bundle.getIntegerArrayList(CONTACTS);
+			if (intContacts != null) {
+				contacts = getContactsFromIntegers(intContacts);
+			}
+		}
+	}
+
+	@Override
+	public void onSaveInstanceState(Bundle outState) {
+		super.onSaveInstanceState(outState);
+		if (groupId != null) {
+			// save the group ID here regardless of how subclasses initialize it
+			outState.putByteArray(GROUP_ID, groupId.getBytes());
+		}
+		if (contacts != null) {
+			outState.putIntegerArrayList(CONTACTS,
+					getContactsFromIds(contacts));
+		}
+	}
+
+	@CallSuper
+	@UiThread
+	@Override
+	public void contactsSelected(Collection<ContactId> contacts) {
+		this.contacts = contacts;
+	}
+
+	static ArrayList<Integer> getContactsFromIds(
+			Collection<ContactId> contacts) {
+		// transform ContactIds to Integers so they can be added to a bundle
+		ArrayList<Integer> intContacts = new ArrayList<>(contacts.size());
+		for (ContactId contactId : contacts) {
+			intContacts.add(contactId.getInt());
+		}
+		return intContacts;
+	}
+
+	static Collection<ContactId> getContactsFromIntegers(
+			ArrayList<Integer> intContacts) {
+		// turn contact integers from a bundle back to ContactIds
+		List<ContactId> contacts = new ArrayList<>(intContacts.size());
+		for (Integer c : intContacts) {
+			contacts.add(new ContactId(c));
+		}
+		return contacts;
+	}
+
+	@Override
+	public void onFragmentCreated(String tag) {
+
+	}
+
+}