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The source code is released under:
Apache License
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/* * Copyright 2014 Google Inc./* w w w . j a v a2 s . c om*/ * * 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.google.maps.android.utils.demo; import android.content.Context; import android.graphics.Color; import android.os.AsyncTask; import android.view.KeyEvent; import android.view.View; import android.view.inputmethod.EditorInfo; import android.view.inputmethod.InputMethodManager; import android.widget.CheckBox; import android.widget.EditText; import android.widget.LinearLayout; import android.widget.ProgressBar; import android.widget.TextView; import android.widget.Toast; import com.google.android.gms.maps.CameraUpdateFactory; import com.google.android.gms.maps.GoogleMap; import com.google.android.gms.maps.model.CircleOptions; import com.google.android.gms.maps.model.LatLng; import com.google.android.gms.maps.model.TileOverlay; import com.google.android.gms.maps.model.TileOverlayOptions; import com.google.maps.android.SphericalUtil; import com.google.maps.android.heatmaps.Gradient; import com.google.maps.android.heatmaps.HeatmapTileProvider; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import java.io.IOException; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.Hashtable; /** * A demo of the heatmaps library incorporating radar search from the Google Places API. * This demonstrates the usefulness of heatmaps for displaying the distribution of points, * as well as demonstrating the various color options and dealing with multiple heatmaps. */ public class HeatmapsPlacesDemoActivity extends BaseDemoActivity { private GoogleMap mMap = null; private final LatLng SYDNEY = new LatLng(-33.873651, 151.2058896); /** * The base URL for the radar search request. */ private static final String PLACES_API_BASE = "https://maps.googleapis.com/maps/api/place"; /** * The options required for the radar search. */ private static final String TYPE_RADAR_SEARCH = "/radarsearch"; private static final String OUT_JSON = "/json"; /** * Places API server key. */ private static final String API_KEY = "YOUR_KEY_HERE"; // TODO place your own here! /** * The colors to be used for the different heatmap layers. */ private static final int[] HEATMAP_COLORS = { HeatmapColors.RED.color, HeatmapColors.BLUE.color, HeatmapColors.GREEN.color, HeatmapColors.PINK.color, HeatmapColors.GREY.color }; public enum HeatmapColors { RED (Color.rgb(238, 44, 44)), BLUE (Color.rgb(60, 80, 255)), GREEN (Color.rgb(20, 170, 50)), PINK (Color.rgb(255, 80, 255)), GREY (Color.rgb(100, 100, 100)); private final int color; HeatmapColors(int color) { this.color = color; } } private static final int MAX_CHECKBOXES = 5; /** * The search radius which roughly corresponds to the radius of the results * from the radar search in meters. */ public static final int SEARCH_RADIUS = 8000; /** * Stores the TileOverlay corresponding to each of the keywords that have been searched for. */ private Hashtable<String, TileOverlay> mOverlays = new Hashtable<String, TileOverlay>(); /** * A layout containing checkboxes for each of the heatmaps rendered. */ private LinearLayout mCheckboxLayout; /** * The number of overlays rendered so far. */ private int mOverlaysRendered = 0; /** * The number of overlays that have been inputted so far. */ private int mOverlaysInput = 0; @Override protected int getLayoutId() { return R.layout.places_demo; } @Override protected void startDemo() { EditText editText = (EditText) findViewById(R.id.input_text); editText.setOnEditorActionListener(new TextView.OnEditorActionListener() { @Override public boolean onEditorAction(TextView textView, int actionId, KeyEvent keyEvent) { boolean handled = false; if (actionId == EditorInfo.IME_NULL) { submit(); handled = true; } return handled; } }); mCheckboxLayout = (LinearLayout) findViewById(R.id.checkboxes); setUpMap(); } private void setUpMap() { if (mMap == null) { mMap = getMap(); if (mMap != null) { mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(SYDNEY, 11)); // Add a circle around Sydney to roughly encompass the results mMap.addCircle(new CircleOptions() .center(SYDNEY) .radius(SEARCH_RADIUS * 1.2) .strokeColor(Color.RED) .strokeWidth(4)); } } } /** * Takes the input from the user and generates the required heatmap. * Called when a search query is submitted */ public void submit() { if ("YOUR_KEY_HERE".equals(API_KEY)) { Toast.makeText(this, "Please sign up for a Places API key and add it to HeatmapsPlacesDemoActivity.API_KEY", Toast.LENGTH_LONG).show(); return; } EditText editText = (EditText) findViewById(R.id.input_text); String keyword = editText.getText().toString(); if (mOverlays.contains(keyword)) { Toast.makeText(this, "This keyword has already been inputted :(", Toast.LENGTH_SHORT).show(); } else if (mOverlaysRendered == MAX_CHECKBOXES) { Toast.makeText(this, "You can only input " + MAX_CHECKBOXES + " keywords. :(", Toast.LENGTH_SHORT).show(); } else if (keyword.length() != 0) { mOverlaysInput++; ProgressBar progressBar = (ProgressBar) findViewById(R.id.progress_bar); progressBar.setVisibility(View.VISIBLE); new MakeOverlayTask().execute(keyword); editText.setText(""); InputMethodManager imm = (InputMethodManager) getSystemService( Context.INPUT_METHOD_SERVICE); imm.hideSoftInputFromWindow(editText.getWindowToken(), 0); } } /** * Makes four radar search requests for the given keyword, then parses the * json output and returns the search results as a collection of LatLng objects. * * @param keyword A string to use as a search term for the radar search * @return Returns the search results from radar search as a collection * of LatLng objects. */ private Collection<LatLng> getPoints(String keyword) { HashMap<String, LatLng> results = new HashMap<String, LatLng>(); // Calculate four equidistant points around Sydney to use as search centers // so that four searches can be done. ArrayList<LatLng> searchCenters = new ArrayList<LatLng>(4); for (int heading = 45; heading < 360; heading += 90) { searchCenters.add(SphericalUtil.computeOffset(SYDNEY, SEARCH_RADIUS / 2, heading)); } for (int j = 0; j < 4; j++) { String jsonResults = getJsonPlaces(keyword, searchCenters.get(j)); try { // Create a JSON object hierarchy from the results JSONObject jsonObj = new JSONObject(jsonResults); JSONArray pointsJsonArray = jsonObj.getJSONArray("results"); // Extract the Place descriptions from the results for (int i = 0; i < pointsJsonArray.length(); i++) { if (!results.containsKey(pointsJsonArray.getJSONObject(i).getString("id"))) { JSONObject location = pointsJsonArray.getJSONObject(i) .getJSONObject("geometry").getJSONObject("location"); results.put(pointsJsonArray.getJSONObject(i).getString("id"), new LatLng(location.getDouble("lat"), location.getDouble("lng"))); } } } catch (JSONException e) { Toast.makeText(this, "Cannot process JSON results", Toast.LENGTH_SHORT).show(); } } return results.values(); } /** * Makes a radar search request and returns the results in a json format. * * @param keyword The keyword to be searched for. * @param location The location the radar search should be based around. * @return The results from the radar search request as a json */ private String getJsonPlaces(String keyword, LatLng location) { HttpURLConnection conn = null; StringBuilder jsonResults = new StringBuilder(); try { URL url = new URL( PLACES_API_BASE + TYPE_RADAR_SEARCH + OUT_JSON + "?location=" + location.latitude + "," + location.longitude + "&radius=" + (SEARCH_RADIUS / 2) + "&sensor=false" + "&key=" + API_KEY + "&keyword=" + keyword.replace(" ", "%20") ); conn = (HttpURLConnection) url.openConnection(); InputStreamReader in = new InputStreamReader(conn.getInputStream()); // Load the results into a StringBuilder int read; char[] buff = new char[1024]; while ((read = in.read(buff)) != -1) { jsonResults.append(buff, 0, read); } } catch (MalformedURLException e) { Toast.makeText(this, "Error processing Places API URL", Toast.LENGTH_SHORT).show(); return null; } catch (IOException e) { Toast.makeText(this, "Error connecting to Places API", Toast.LENGTH_SHORT).show(); return null; } finally { if (conn != null) { conn.disconnect(); } } return jsonResults.toString(); } /** * Creates check box for a given search term * * @param keyword the search terms associated with the check box */ private void makeCheckBox(final String keyword) { mCheckboxLayout.setVisibility(View.VISIBLE); // Make new checkbox CheckBox checkBox = new CheckBox(this); checkBox.setText(keyword); checkBox.setTextColor(HEATMAP_COLORS[mOverlaysRendered]); checkBox.setChecked(true); checkBox.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { CheckBox c = (CheckBox) view; // Text is the keyword TileOverlay overlay = mOverlays.get(keyword); if (overlay != null) { overlay.setVisible(c.isChecked()); } } }); mCheckboxLayout.addView(checkBox); } /** * Async task, because finding the points cannot be done on the main thread, while adding * the overlay must be done on the main thread. */ private class MakeOverlayTask extends AsyncTask<String, Integer, PointsKeywords> { protected PointsKeywords doInBackground(String... keyword) { return new PointsKeywords(getPoints(keyword[0]), keyword[0]); } protected void onPostExecute(PointsKeywords pointsKeywords) { Collection<LatLng> points = pointsKeywords.points; String keyword = pointsKeywords.keyword; // Check that it wasn't an empty query. if (!points.isEmpty()) { if (mOverlays.size() < MAX_CHECKBOXES) { makeCheckBox(keyword); HeatmapTileProvider provider = new HeatmapTileProvider.Builder() .data(new ArrayList<LatLng>(points)) .gradient(makeGradient(HEATMAP_COLORS[mOverlaysRendered])) .build(); TileOverlay overlay = getMap().addTileOverlay(new TileOverlayOptions().tileProvider(provider)); mOverlays.put(keyword, overlay); } mOverlaysRendered++; if (mOverlaysRendered == mOverlaysInput) { ProgressBar progressBar = (ProgressBar) findViewById(R.id.progress_bar); progressBar.setVisibility(View.GONE); } } else { ProgressBar progressBar = (ProgressBar) findViewById(R.id.progress_bar); progressBar.setVisibility(View.GONE); Toast.makeText(HeatmapsPlacesDemoActivity.this, "No results for this query :(", Toast.LENGTH_SHORT).show(); } } } /** * Class to store both the points and the keywords, for use in the MakeOverlayTask class. */ private class PointsKeywords { public Collection<LatLng> points; public String keyword; public PointsKeywords(Collection<LatLng> points, String keyword) { this.points = points; this.keyword = keyword; } } /** * Creates a one colored gradient which varies in opacity. * * @param color The opaque color the gradient should be. * @return A gradient made purely of the given color with different alpha values. */ private Gradient makeGradient(int color) { int[] colors = {color}; float[] startPoints = {1.0f}; return new Gradient(colors, startPoints); } }