Caching version of ThaichoteMapTile

ThaichoteMapTile.java

/*
 * Copyright (c) 2016 NECTEC
 *   National Electronics and Computer Technology Center, Thailand
 *
 * 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 org.tanrabad.survey.presenter.maps;


import android.content.Context;
import android.graphics.Bitmap;
import com.google.android.gms.maps.model.Tile;
import com.google.android.gms.maps.model.TileOverlayOptions;
import com.google.android.gms.maps.model.TileProvider;
import com.google.android.gms.maps.model.UrlTileProvider;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;

import java.io.ByteArrayOutputStream;
import java.net.MalformedURLException;
import java.net.URL;

public class ThaichoteMapTile implements TileProvider {

    private static final String TILE_URL =
            "http://giportal.gistda.or.th/arcgis/rest/services/raster/thaichote_update_2014_2016/MapServer/tile/%d/%d/%d";

    private final DisplayImageOptions mOptions;
    public static final int WIDTH = 256;
    public static final int HEIGHT = 256;

    public ThaichoteMapTile(Context context) {
        if (!ImageLoader.getInstance().isInited()) {
            // Create global configuration and initialize ImageLoader with this config
            ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context).build();
            ImageLoader.getInstance().init(config);
        }
        // init ImageLoader display options
        DisplayImageOptions.Builder builder = new DisplayImageOptions.Builder();
        builder.cacheInMemory(true).cacheOnDisk(true);
        mOptions = builder.build();
    }

    @Override
    public Tile getTile(int x, int y, int z) {
        byte[] tileImage = getTileImage(x, y, z);
        if (tileImage != null) {
            return new Tile(WIDTH / 2, HEIGHT / 2, tileImage);
        }
        return NO_TILE;
    }

    private byte[] getTileImage(int x, int y, int z) {
        Bitmap bitmap = ImageLoader.getInstance().loadImageSync(getTileUrl(x, y, z), mOptions);
        if (bitmap == null) {
            return null;
        }
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
        return stream.toByteArray();
    }

    public String getTileUrl(int x, int y, int zoom) {
        return String.format(TILE_URL, zoom, y, x);
    }

    public static TileOverlayOptions createTileOverlayOption(Context context) {
        return new TileOverlayOptions()
                .tileProvider(new ThaichoteMapTile(context))
                .fadeIn(true);
    }
}

Requires Android Universal Image Loader:

dependencies {
    compile 'com.nostra13.universalimageloader:universal-image-loader:1.9.3'
}