TreeSampleActivity.java

/*
 * Copyright 2016 Square Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package flow.sample.tree;

import android.content.Context;
import android.support.annotation.LayoutRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import flow.Direction;
import flow.Flow;
import flow.KeyChanger;
import flow.KeyDispatcher;
import flow.State;
import flow.TraversalCallback;
import flow.sample.tree.ui.contacts.edit.EditEmailScreen;
import flow.sample.tree.ui.contacts.edit.EditNameScreen;
import flow.sample.tree.ui.contacts.list.ListContactsScreen;
import flow.sample.tree.ui.welcome.WelcomeScreen;
import java.util.Map;

public class TreeSampleActivity extends AppCompatActivity {

  @Override protected void attachBaseContext(Context newBase) {
    newBase = Flow.configure(newBase, this)
        .addServicesFactory(new FlowServices())
        .defaultKey(new WelcomeScreen())
        .dispatcher(KeyDispatcher.configure(this, new Changer()).build())
        .install();
    super.attachBaseContext(newBase);
  }

  @Override public void onBackPressed() {
    if (!Flow.get(this).goBack()) {
      super.onBackPressed();
    }
  }

  private final class Changer implements KeyChanger {

    @Override public void changeKey(@Nullable State outgoingState, @NonNull State incomingState,
        @NonNull Direction direction, @NonNull Map<Object, Context> incomingContexts,
        @NonNull TraversalCallback callback) {

      Object key = incomingState.getKey();
      Context context = incomingContexts.get(key);

      if (outgoingState != null) {
        ViewGroup view = (ViewGroup) findViewById(android.R.id.content);
        outgoingState.save(view.getChildAt(0));
      }

      View view;
      if (key instanceof WelcomeScreen) {
        view = showKeyAsText(context, key, new ListContactsScreen());
      } else if (key instanceof ListContactsScreen) {
        view = showLayout(context, R.layout.list_contacts_screen);
      } else if (key instanceof EditNameScreen) {
        view = showLayout(context, R.layout.edit_name_screen);
      } else if (key instanceof EditEmailScreen) {
        view = showLayout(context, R.layout.edit_email_screen);
      } else {
        view = showKeyAsText(context, key, null);
      }
      incomingState.restore(view);
      setContentView(view);
      callback.onTraversalCompleted();
    }

    private View showLayout(Context context, @LayoutRes int layout) {
      LayoutInflater inflater = LayoutInflater.from(context);
      return inflater.inflate(layout, null);
    }

    private View showKeyAsText(Context context, Object key, @Nullable final Object nextScreenOnClick) {
      TextView view = new TextView(context);
      view.setText(key.toString());

      if (nextScreenOnClick == null) {
        view.setOnClickListener(null);
      } else {
        view.setOnClickListener(new View.OnClickListener() {
          @Override public void onClick(View v) {
            Flow.get(v).set(nextScreenOnClick);
          }
        });
      }
      return view;
    }
  }
}