ExpandableListItemActivity.java

/*
 * Copyright 2013 Niek Haarman
 *
 * 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.haarman.listviewanimations.itemmanipulationexamples;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v4.util.LruCache;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.haarman.listviewanimations.MyListActivity;
import com.haarman.listviewanimations.R;
import com.nhaarman.listviewanimations.itemmanipulation.ExpandableListItemAdapter;
import com.nhaarman.listviewanimations.swinginadapters.prepared.AlphaInAnimationAdapter;

import java.util.List;

public class ExpandableListItemActivity extends MyListActivity {

    private MyExpandableListItemAdapter mExpandableListItemAdapter;
    private boolean mLimited;

    @Override
    protected void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mExpandableListItemAdapter = new MyExpandableListItemAdapter(this, getItems());
        AlphaInAnimationAdapter alphaInAnimationAdapter = new AlphaInAnimationAdapter(mExpandableListItemAdapter);
        alphaInAnimationAdapter.setAbsListView(getListView());
        alphaInAnimationAdapter.setInitialDelayMillis(500);
        getListView().setAdapter(alphaInAnimationAdapter);

        Toast.makeText(this, R.string.explainexpand, Toast.LENGTH_LONG).show();
    }

    private static class MyExpandableListItemAdapter extends ExpandableListItemAdapter<Integer> {

        private final Context mContext;
        private final LruCache<Integer, Bitmap> mMemoryCache;

        /**
         * Creates a new ExpandableListItemAdapter with the specified list, or an empty list if
         * items == null.
         */
        private MyExpandableListItemAdapter(final Context context, final List<Integer> items) {
            super(context, R.layout.activity_expandablelistitem_card, R.id.activity_expandablelistitem_card_title, R.id.activity_expandablelistitem_card_content, items);
            mContext = context;

            final int cacheSize = (int) (Runtime.getRuntime().maxMemory() / 1024);
            mMemoryCache = new LruCache<Integer, Bitmap>(cacheSize) {
                @Override
                protected int sizeOf(final Integer key, final Bitmap bitmap) {
                    // The cache size will be measured in kilobytes rather than
                    // number of items.
                    return bitmap.getRowBytes() * bitmap.getHeight() / 1024;
                }
            };
        }

        @Override
        public View getTitleView(final int position, final View convertView, final ViewGroup parent) {
            TextView tv = (TextView) convertView;
            if (tv == null) {
                tv = new TextView(mContext);
            }
            tv.setText(mContext.getString(R.string.expandorcollapsecard, getItem(position)));
            return tv;
        }

        @Override
        public View getContentView(final int position, final View convertView, final ViewGroup parent) {
            ImageView imageView = (ImageView) convertView;
            if (imageView == null) {
                imageView = new ImageView(mContext);
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            }

            int imageResId;
            switch (getItem(position) % 5) {
                case 0:
                    imageResId = R.drawable.img_nature1;
                    break;
                case 1:
                    imageResId = R.drawable.img_nature2;
                    break;
                case 2:
                    imageResId = R.drawable.img_nature3;
                    break;
                case 3:
                    imageResId = R.drawable.img_nature4;
                    break;
                default:
                    imageResId = R.drawable.img_nature5;
            }

            Bitmap bitmap = getBitmapFromMemCache(imageResId);
            if (bitmap == null) {
                bitmap = BitmapFactory.decodeResource(mContext.getResources(), imageResId);
                addBitmapToMemoryCache(imageResId, bitmap);
            }
            imageView.setImageBitmap(bitmap);

            return imageView;
        }

        private void addBitmapToMemoryCache(final int key, final Bitmap bitmap) {
            if (getBitmapFromMemCache(key) == null) {
                mMemoryCache.put(key, bitmap);
            }
        }

        private Bitmap getBitmapFromMemCache(final int key) {
            return mMemoryCache.get(key);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(final Menu menu) {
        getMenuInflater().inflate(R.menu.menu_expandablelistitem, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_expandable_limit:
                mLimited = !mLimited;
                item.setChecked(mLimited);
                mExpandableListItemAdapter.setLimit(mLimited ? 2 : 0);
                return true;
        }
        return super.onOptionsItemSelected(item);
    }
}