android_development/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/MainActivity.java

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * 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 com.example.android.activityscenetransitionbasic;

import com.squareup.picasso.Picasso;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.ActivityOptionsCompat;
import android.support.v4.util.Pair;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.TextView;

/**
 * Our main Activity in this sample. Displays a grid of items which an image and title. When the
 * user clicks on an item, {@link DetailActivity} is launched, using the Activity Scene Transitions
 * framework to animatedly do so.
 */
public class MainActivity extends Activity implements AdapterView.OnItemClickListener {

    private GridView mGridView;
    private GridAdapter mAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.grid);

        // Setup the GridView and set the adapter
        mGridView = (GridView) findViewById(R.id.grid);
        mGridView.setOnItemClickListener(this);
        mAdapter = new GridAdapter();
        mGridView.setAdapter(mAdapter);
    }

    /**
     * Called when an item in the {@link android.widget.GridView} is clicked. Here will launch the
     * {@link DetailActivity}, using the Scene Transition animation functionality.
     */
    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
        Item item = (Item) adapterView.getItemAtPosition(position);

        // Construct an Intent as normal
        Intent intent = new Intent(this, DetailActivity.class);
        intent.putExtra(DetailActivity.EXTRA_PARAM_ID, item.getId());

        // BEGIN_INCLUDE(start_activity)
        /**
         * Now create an {@link android.app.ActivityOptions} instance using the
         * {@link ActivityOptionsCompat#makeSceneTransitionAnimation(Activity, Pair[])} factory
         * method.
         */
        ActivityOptionsCompat activityOptions = ActivityOptionsCompat.makeSceneTransitionAnimation(
                this,

                // Now we provide a list of Pair items which contain the view we can transitioning
                // from, and the name of the view it is transitioning to, in the launched activity
                new Pair<View, String>(view.findViewById(R.id.imageview_item),
                        DetailActivity.VIEW_NAME_HEADER_IMAGE),
                new Pair<View, String>(view.findViewById(R.id.textview_name),
                        DetailActivity.VIEW_NAME_HEADER_TITLE));

        // Now we can start the Activity, providing the activity options as a bundle
        ActivityCompat.startActivity(this, intent, activityOptions.toBundle());
        // END_INCLUDE(start_activity)
    }

    /**
     * {@link android.widget.BaseAdapter} which displays items.
     */
    private class GridAdapter extends BaseAdapter {

        @Override
        public int getCount() {
            return Item.ITEMS.length;
        }

        @Override
        public Item getItem(int position) {
            return Item.ITEMS[position];
        }

        @Override
        public long getItemId(int position) {
            return getItem(position).getId();
        }

        @Override
        public View getView(int position, View view, ViewGroup viewGroup) {
            if (view == null) {
                view = getLayoutInflater().inflate(R.layout.grid_item, viewGroup, false);
            }

            final Item item = getItem(position);

            // Load the thumbnail image
            ImageView image = (ImageView) view.findViewById(R.id.imageview_item);
            Picasso.with(image.getContext()).load(item.getThumbnailUrl()).into(image);

            // Set the TextView's contents
            TextView name = (TextView) view.findViewById(R.id.textview_name);
            name.setText(item.getName());

            return view;
        }
    }
}