briar/briar-android/src/org/briarproject/android/sharing/InvitationActivity.java

package org.briarproject.android.sharing;

import android.content.Context;
import android.os.Bundle;
import android.support.annotation.StringRes;
import android.support.v7.widget.LinearLayoutManager;
import android.widget.Toast;

import org.briarproject.R;
import org.briarproject.android.BriarActivity;
import org.briarproject.android.controller.handler.UiResultExceptionHandler;
import org.briarproject.android.sharing.InvitationController.InvitationListener;
import org.briarproject.android.view.BriarRecyclerView;
import org.briarproject.api.db.DbException;
import org.briarproject.api.sharing.InvitationItem;

import java.util.Collection;
import java.util.logging.Logger;

import static android.widget.Toast.LENGTH_SHORT;
import static org.briarproject.android.sharing.InvitationAdapter.InvitationClickListener;

public abstract class InvitationActivity<I extends InvitationItem>
		extends BriarActivity
		implements InvitationListener, InvitationClickListener<I> {

	protected static final Logger LOG =
			Logger.getLogger(InvitationActivity.class.getName());

	private InvitationAdapter<I, ?> adapter;
	private BriarRecyclerView list;

	@Override
	public void onCreate(Bundle state) {
		super.onCreate(state);

		setContentView(R.layout.list);

		adapter = getAdapter(this, this);
		list = (BriarRecyclerView) findViewById(R.id.list);
		if (list != null) {
			list.setLayoutManager(new LinearLayoutManager(this));
			list.setAdapter(adapter);
		}
	}

	abstract protected InvitationAdapter<I, ?> getAdapter(Context ctx,
			InvitationClickListener<I> listener);

	@Override
	public void onStart() {
		super.onStart();
		loadInvitations(false);
	}

	@Override
	public void onStop() {
		super.onStop();
		adapter.clear();
		list.showProgressBar();
	}

	@Override
	public void onItemClick(I item, boolean accept) {
		respondToInvitation(item, accept);

		// show toast
		int res = getDeclineRes();
		if (accept) res = getAcceptRes();
		Toast.makeText(this, res, LENGTH_SHORT).show();

		// remove item and finish if it was the last
		adapter.incrementRevision();
		adapter.remove(item);
		if (adapter.getItemCount() == 0) {
			supportFinishAfterTransition();
		}
	}

	@Override
	public void loadInvitations(final boolean clear) {
		final int revision = adapter.getRevision();
		getController().loadInvitations(clear,
				new UiResultExceptionHandler<Collection<I>, DbException>(
						this) {
					@Override
					public void onResultUi(Collection<I> items) {
						displayInvitations(revision, items, clear);
					}

					@Override
					public void onExceptionUi(DbException exception) {
						// TODO proper error handling
						finish();
					}
				});
	}

	abstract protected InvitationController<I> getController();

	protected void respondToInvitation(final I item,
			final boolean accept) {
		getController().respondToInvitation(item, accept,
				new UiResultExceptionHandler<Void, DbException>(this) {
					@Override
					public void onResultUi(Void result) {

					}

					@Override
					public void onExceptionUi(DbException exception) {
						// TODO proper error handling
						finish();
					}
				});
	}

	@StringRes
	abstract protected int getAcceptRes();

	@StringRes
	abstract protected int getDeclineRes();

	protected void displayInvitations(final int revision,
			final Collection<I> invitations, final boolean clear) {
		runOnUiThreadUnlessDestroyed(new Runnable() {
			@Override
			public void run() {
				if (invitations.isEmpty()) {
					LOG.info("No more invitations available, finishing");
					supportFinishAfterTransition();
				} else if (revision == adapter.getRevision()) {
					adapter.incrementRevision();
					if (clear) adapter.setItems(invitations);
					else adapter.addAll(invitations);
				} else {
					LOG.info("Concurrent update, reloading");
					loadInvitations(clear);
				}
			}
		});
	}

}