Java tutorial
/* Copyright (C) 2016-2017 Andreas Shimokawa, Carsten Pfeiffer, Daniele Gobbetti, Lem Dulfo, Uwe Hermann This file is part of Gadgetbridge. Gadgetbridge is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Gadgetbridge is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ package nodomain.freeyourgadget.gadgetbridge.activities; import android.Manifest; import android.content.Context; import android.content.Intent; import android.content.pm.PackageManager; import android.location.Criteria; import android.location.Location; import android.location.LocationManager; import android.net.Uri; import android.os.Bundle; import android.support.v4.app.ActivityCompat; import android.support.v4.app.NavUtils; import android.util.Log; import android.view.MenuItem; import android.webkit.ConsoleMessage; import android.webkit.JavascriptInterface; import android.webkit.WebChromeClient; import android.webkit.WebSettings; import android.webkit.WebView; import android.webkit.WebViewClient; import android.widget.Toast; import org.json.JSONException; import org.json.JSONObject; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.BufferedWriter; import java.io.File; import java.io.FileWriter; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.io.Writer; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.util.Iterator; import java.util.Scanner; import java.util.UUID; import nodomain.freeyourgadget.gadgetbridge.GBApplication; import nodomain.freeyourgadget.gadgetbridge.R; import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice; import nodomain.freeyourgadget.gadgetbridge.model.DeviceService; import nodomain.freeyourgadget.gadgetbridge.util.FileUtils; import nodomain.freeyourgadget.gadgetbridge.util.GB; import nodomain.freeyourgadget.gadgetbridge.util.PebbleUtils; import nodomain.freeyourgadget.gadgetbridge.util.Prefs; public class ExternalPebbleJSActivity extends GBActivity { private static final Logger LOG = LoggerFactory.getLogger(ExternalPebbleJSActivity.class); private UUID appUuid; private Uri confUri; private GBDevice mGBDevice = null; private WebView myWebView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bundle extras = getIntent().getExtras(); if (extras != null) { mGBDevice = extras.getParcelable(GBDevice.EXTRA_DEVICE); appUuid = (UUID) extras.getSerializable(DeviceService.EXTRA_APP_UUID); } else { throw new IllegalArgumentException("Must provide a device when invoking this activity"); } setContentView(R.layout.activity_external_pebble_js); myWebView = (WebView) findViewById(R.id.configureWebview); myWebView.clearCache(true); myWebView.setWebViewClient(new GBWebClient()); myWebView.setWebChromeClient(new GBChromeClient()); WebSettings webSettings = myWebView.getSettings(); webSettings.setJavaScriptEnabled(true); //needed to access the DOM webSettings.setDomStorageEnabled(true); //needed for localstorage webSettings.setDatabaseEnabled(true); JSInterface gbJSInterface = new JSInterface(this); myWebView.addJavascriptInterface(gbJSInterface, "GBjs"); myWebView.loadUrl("file:///android_asset/app_config/configure.html"); } @Override protected void onNewIntent(Intent incoming) { incoming.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK); super.onNewIntent(incoming); confUri = incoming.getData(); } @Override protected void onResume() { super.onResume(); String queryString = ""; if (confUri != null) { //getting back with configuration data try { appUuid = UUID.fromString(confUri.getHost()); queryString = confUri.getEncodedQuery(); } catch (IllegalArgumentException e) { GB.toast("returned uri: " + confUri.toString(), Toast.LENGTH_LONG, GB.ERROR); } myWebView.loadUrl("file:///android_asset/app_config/configure.html?" + queryString); } } private JSONObject getAppConfigurationKeys() { try { File destDir = new File(FileUtils.getExternalFilesDir() + "/pbw-cache"); File configurationFile = new File(destDir, appUuid.toString() + ".json"); if (configurationFile.exists()) { String jsonstring = FileUtils.getStringFromFile(configurationFile); JSONObject json = new JSONObject(jsonstring); return json.getJSONObject("appKeys"); } } catch (IOException | JSONException e) { e.printStackTrace(); } return null; } private boolean isLocationEnabledForWatchApp() { return true; //as long as we don't give watchapp internet access it's not a problem } private class GBChromeClient extends WebChromeClient { @Override public boolean onConsoleMessage(ConsoleMessage consoleMessage) { if (ConsoleMessage.MessageLevel.ERROR.equals(consoleMessage.messageLevel())) { GB.toast(consoleMessage.message(), Toast.LENGTH_LONG, GB.ERROR); //TODO: show error page } return super.onConsoleMessage(consoleMessage); } } private class GBWebClient extends WebViewClient { @Override public boolean shouldOverrideUrlLoading(WebView view, String url) { if (url.startsWith("http://") || url.startsWith("https://")) { Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse(url)); i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK); startActivity(i); } else { url = url.replaceFirst("^pebblejs://close#", "file:///android_asset/app_config/configure.html?config=true&json="); view.loadUrl(url); } return true; } } private class JSInterface { Context mContext; public JSInterface(Context c) { mContext = c; } @JavascriptInterface public void gbLog(String msg) { Log.d("WEBVIEW", msg); } @JavascriptInterface public void sendAppMessage(String msg) { LOG.debug("from WEBVIEW: " + msg); JSONObject knownKeys = getAppConfigurationKeys(); try { JSONObject in = new JSONObject(msg); JSONObject out = new JSONObject(); String inKey, outKey; boolean passKey; for (Iterator<String> key = in.keys(); key.hasNext();) { passKey = false; inKey = key.next(); outKey = null; int pebbleAppIndex = knownKeys.optInt(inKey, -1); if (pebbleAppIndex != -1) { passKey = true; outKey = String.valueOf(pebbleAppIndex); } else { //do not discard integer keys (see https://developer.pebble.com/guides/communication/using-pebblekit-js/ ) Scanner scanner = new Scanner(inKey); if (scanner.hasNextInt() && inKey.equals("" + scanner.nextInt())) { passKey = true; outKey = inKey; } } if (passKey) { Object obj = in.get(inKey); if (obj instanceof Boolean) { obj = ((Boolean) obj) ? "true" : "false"; } out.put(outKey, obj); } else { GB.toast( "Discarded key " + inKey + ", not found in the local configuration and is not an integer key.", Toast.LENGTH_SHORT, GB.WARN); } } LOG.info(out.toString()); GBApplication.deviceService().onAppConfiguration(appUuid, out.toString()); } catch (JSONException e) { e.printStackTrace(); } } @JavascriptInterface public String getActiveWatchInfo() { JSONObject wi = new JSONObject(); try { wi.put("firmware", mGBDevice.getFirmwareVersion()); wi.put("platform", PebbleUtils.getPlatformName(mGBDevice.getModel())); wi.put("model", PebbleUtils.getModel(mGBDevice.getModel())); //TODO: use real info wi.put("language", "en"); } catch (JSONException e) { e.printStackTrace(); } //Json not supported apparently, we need to cast back and forth return wi.toString(); } @JavascriptInterface public String getAppConfigurationFile() { try { File destDir = new File(FileUtils.getExternalFilesDir() + "/pbw-cache"); File configurationFile = new File(destDir, appUuid.toString() + "_config.js"); if (configurationFile.exists()) { return "file:///" + configurationFile.getAbsolutePath(); } } catch (IOException e) { e.printStackTrace(); } return null; } @JavascriptInterface public String getAppStoredPreset() { try { File destDir = new File(FileUtils.getExternalFilesDir() + "/pbw-cache"); File configurationFile = new File(destDir, appUuid.toString() + "_preset.json"); if (configurationFile.exists()) { return FileUtils.getStringFromFile(configurationFile); } } catch (IOException e) { GB.toast("Error reading presets", Toast.LENGTH_LONG, GB.ERROR); e.printStackTrace(); } return null; } @JavascriptInterface public void saveAppStoredPreset(String msg) { Writer writer; try { File destDir = new File(FileUtils.getExternalFilesDir() + "/pbw-cache"); File presetsFile = new File(destDir, appUuid.toString() + "_preset.json"); writer = new BufferedWriter(new FileWriter(presetsFile)); writer.write(msg); writer.close(); GB.toast("Presets stored", Toast.LENGTH_SHORT, GB.INFO); } catch (IOException e) { GB.toast("Error storing presets", Toast.LENGTH_LONG, GB.ERROR); e.printStackTrace(); } } @JavascriptInterface public String getAppUUID() { return appUuid.toString(); } @JavascriptInterface public String getAppLocalstoragePrefix() { String prefix = mGBDevice.getAddress() + appUuid.toString(); try { MessageDigest digest = MessageDigest.getInstance("SHA-1"); byte[] bytes = prefix.getBytes("UTF-8"); digest.update(bytes, 0, bytes.length); bytes = digest.digest(); final StringBuilder sb = new StringBuilder(); for (int i = 0; i < bytes.length; i++) { sb.append(String.format("%02X", bytes[i])); } return sb.toString().toLowerCase(); } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) { e.printStackTrace(); return prefix; } } @JavascriptInterface public String getWatchToken() { //specification says: A string that is guaranteed to be identical for each Pebble device for the same app across different mobile devices. The token is unique to your app and cannot be used to track Pebble devices across applications. see https://developer.pebble.com/docs/js/Pebble/ return "gb" + appUuid.toString(); } @JavascriptInterface public void closeActivity() { NavUtils.navigateUpFromSameTask((ExternalPebbleJSActivity) mContext); } @JavascriptInterface public String getCurrentPosition() { if (!isLocationEnabledForWatchApp()) { return ""; } //we need to override this because the coarse location is not enough for the android webview, we should add the permission for fine location. JSONObject geoPosition = new JSONObject(); JSONObject coords = new JSONObject(); try { Prefs prefs = GBApplication.getPrefs(); geoPosition.put("timestamp", (System.currentTimeMillis() / 1000) - 86400); //let JS know this value is really old coords.put("latitude", prefs.getFloat("location_latitude", 0)); coords.put("longitude", prefs.getFloat("location_longitude", 0)); if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED && prefs.getBoolean("use_updated_location_if_available", false)) { LocationManager locationManager = (LocationManager) getApplicationContext() .getSystemService(Context.LOCATION_SERVICE); Criteria criteria = new Criteria(); String provider = locationManager.getBestProvider(criteria, false); if (provider != null) { Location lastKnownLocation = locationManager.getLastKnownLocation(provider); if (lastKnownLocation != null) { geoPosition.put("timestamp", lastKnownLocation.getTime()); coords.put("latitude", (float) lastKnownLocation.getLatitude()); coords.put("longitude", (float) lastKnownLocation.getLongitude()); coords.put("accuracy", lastKnownLocation.getAccuracy()); coords.put("altitude", lastKnownLocation.getAltitude()); coords.put("speed", lastKnownLocation.getSpeed()); } } } geoPosition.put("coords", coords); } catch (JSONException e) { e.printStackTrace(); } return geoPosition.toString(); } } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: NavUtils.navigateUpFromSameTask(this); return true; } return super.onOptionsItemSelected(item); } }