Java tutorial
/* * Copyright (C) 2009 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 android.webkit; import android.annotation.SystemApi; import java.util.Set; /** * This class is used to manage permissions for the WebView's Geolocation * JavaScript API. * * Geolocation permissions are applied to an origin, which consists of the * host, scheme and port of a URI. In order for web content to use the * Geolocation API, permission must be granted for that content's origin. * * This class stores Geolocation permissions. An origin's permission state can * be either allowed or denied. This class uses Strings to represent * an origin. * * When an origin attempts to use the Geolocation API, but no permission state * is currently set for that origin, * {@link WebChromeClient#onGeolocationPermissionsShowPrompt(String,GeolocationPermissions.Callback) WebChromeClient.onGeolocationPermissionsShowPrompt()} * is called. This allows the permission state to be set for that origin. * * The methods of this class can be used to modify and interrogate the stored * Geolocation permissions at any time. */ // Within WebKit, Geolocation permissions may be applied either temporarily // (for the duration of the page) or permanently. This class deals only with // permanent permissions. public class GeolocationPermissions { /** * A callback interface used by the host application to set the Geolocation * permission state for an origin. */ public interface Callback { /** * Sets the Geolocation permission state for the supplied origin. * * @param origin the origin for which permissions are set * @param allow whether or not the origin should be allowed to use the * Geolocation API * @param retain whether the permission should be retained beyond the * lifetime of a page currently being displayed by a * WebView */ public void invoke(String origin, boolean allow, boolean retain); }; /** * Gets the singleton instance of this class. This method cannot be * called before the application instantiates a {@link WebView} instance. * * @return the singleton {@link GeolocationPermissions} instance */ public static GeolocationPermissions getInstance() { return WebViewFactory.getProvider().getGeolocationPermissions(); } /** * Gets the set of origins for which Geolocation permissions are stored. * * @param callback a {@link ValueCallback} to receive the result of this * request. This object's * {@link ValueCallback#onReceiveValue(T) onReceiveValue()} * method will be invoked asynchronously with a set of * Strings containing the origins for which Geolocation * permissions are stored. */ // Note that we represent the origins as strings. These are created using // WebCore::SecurityOrigin::toString(). As long as all 'HTML 5 modules' // (Database, Geolocation etc) do so, it's safe to match up origins based // on this string. public void getOrigins(ValueCallback<Set<String>> callback) { // Must be a no-op for backward compatibility: see the hidden constructor for reason. } /** * Gets the Geolocation permission state for the specified origin. * * @param origin the origin for which Geolocation permission is requested * @param callback a {@link ValueCallback} to receive the result of this * request. This object's * {@link ValueCallback#onReceiveValue(T) onReceiveValue()} * method will be invoked asynchronously with a boolean * indicating whether or not the origin can use the * Geolocation API. */ public void getAllowed(String origin, ValueCallback<Boolean> callback) { // Must be a no-op for backward compatibility: see the hidden constructor for reason. } /** * Clears the Geolocation permission state for the specified origin. * * @param origin the origin for which Geolocation permissions are cleared */ public void clear(String origin) { // Must be a no-op for backward compatibility: see the hidden constructor for reason. } /** * Allows the specified origin to use the Geolocation API. * * @param origin the origin for which Geolocation API use is allowed */ public void allow(String origin) { // Must be a no-op for backward compatibility: see the hidden constructor for reason. } /** * Clears the Geolocation permission state for all origins. */ public void clearAll() { // Must be a no-op for backward compatibility: see the hidden constructor for reason. } /** * This class should not be instantiated directly, applications must only use * {@link #getInstance()} to obtain the instance. * Note this constructor was erroneously public and published in SDK levels prior to 16, but * applications using it would receive a non-functional instance of this class (there was no * way to call createHandler() and createUIHandler(), so it would not work). * @hide Only for use by WebViewProvider implementations */ @SystemApi public GeolocationPermissions() { } }