/*
* 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.os.Handler;
import android.os.Message;
import android.util.Log;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.Vector;
/**
* This class is used to get Geolocation permissions from, and set them on the
* WebView. For example, it could be used to allow a user to manage Geolocation
* permissions from a browser's UI.
*
* Permissions are managed on a per-origin basis, as required by the
* Geolocation spec - http://dev.w3.org/geo/api/spec-source.html. An origin
* specifies the scheme, host and port of particular frame. An origin is
* represented here as a string, using the output of
* WebCore::SecurityOrigin::toString.
*
* This class is the Java counterpart of the WebKit C++ GeolocationPermissions
* class. It simply marshalls calls from the UI thread to the WebKit thread.
*
* 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 final class GeolocationPermissions {
/**
* Callback interface used by the browser to report a Geolocation permission
* state set by the user in response to a permissions prompt.
*/
public interface Callback {
public void invoke(String origin, boolean allow, boolean remember);
};
// Log tag
private static final String TAG = "geolocationPermissions";
// Global instance
private static GeolocationPermissions sInstance;
private Handler mHandler;
private Handler mUIHandler;
// A queue to store messages until the handler is ready.
private Vector<Message> mQueuedMessages;
// Message ids
static final int GET_ORIGINS = 0;
static final int GET_ALLOWED = 1;
static final int CLEAR = 2;
static final int ALLOW = 3;
static final int CLEAR_ALL = 4;
// Message ids on the UI thread
static final int RETURN_ORIGINS = 0;
static final int RETURN_ALLOWED = 1;
private static final String ORIGINS = "origins";
private static final String ORIGIN = "origin";
private static final String CALLBACK = "callback";
private static final String ALLOWED = "allowed";
/**
* Gets the singleton instance of the class.
*/
public static GeolocationPermissions getInstance() {
if (sInstance == null) {
sInstance = new GeolocationPermissions();
}
return sInstance;
}
/**
* Creates the UI message handler. Must be called on the UI thread.
* @hide
*/
public void createUIHandler() {
if (mUIHandler == null) {
mUIHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
// Runs on the UI thread.
switch (msg.what) {
case RETURN_ORIGINS: {
Map values = (Map) msg.obj;
Set<String> origins = (Set<String>) values.get(ORIGINS);
ValueCallback<Set<String> > callback = (ValueCallback<Set<String> >) values.get(CALLBACK);
callback.onReceiveValue(origins);
} break;
case RETURN_ALLOWED: {
Map values = (Map) msg.obj;
Boolean allowed = (Boolean) values.get(ALLOWED);
ValueCallback<Boolean> callback = (ValueCallback<Boolean>) values.get(CALLBACK);
callback.onReceiveValue(allowed);
} break;
}
}
};
}
}
/**
* Creates the message handler. Must be called on the WebKit thread.
* @hide
*/
public synchronized void createHandler() {
if (mHandler == null) {
mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
// Runs on the WebKit thread.
switch (msg.what) {
case GET_ORIGINS: {
Set origins = nativeGetOrigins();
ValueCallback callback = (ValueCallback) msg.obj;
Map values = new HashMap<String, Object>();
values.put(CALLBACK, callback);
values.put(ORIGINS, origins);
postUIMessage(Message.obtain(null, RETURN_ORIGINS, values));
} break;
case GET_ALLOWED: {
Map values = (Map) msg.obj;
String origin = (String) values.get(ORIGIN);
ValueCallback callback = (ValueCallback) values.get(CALLBACK);
boolean allowed = nativeGetAllowed(origin);
Map retValues = new HashMap<String, Object>();
retValues.put(CALLBACK, callback);
retValues.put(ALLOWED, Boolean.valueOf(allowed));
postUIMessage(Message.obtain(null, RETURN_ALLOWED, retValues));
} break;
case CLEAR:
nativeClear((String) msg.obj);
break;
case ALLOW:
nativeAllow((String) msg.obj);
break;
case CLEAR_ALL:
nativeClearAll();
break;
}
}
};
// Handle the queued messages
if (mQueuedMessages != null) {
while (!mQueuedMessages.isEmpty()) {
mHandler.sendMessage(mQueuedMessages.remove(0));
}
mQueuedMessages = null;
}
}
}
/**
* Utility function to send a message to our handler.
*/
private synchronized void postMessage(Message msg) {
if (mHandler == null) {
if (mQueuedMessages == null) {
mQueuedMessages = new Vector<Message>();
}
mQueuedMessages.add(msg);
} else {
mHandler.sendMessage(msg);
}
}
/**
* Utility function to send a message to the handler on the UI thread
*/
private void postUIMessage(Message msg) {
if (mUIHandler != null) {
mUIHandler.sendMessage(msg);
}
}
/**
* Gets the set of 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.
*
* Callback is a ValueCallback object whose onReceiveValue method will be
* called asynchronously with the set of origins.
*/
public void getOrigins(ValueCallback<Set<String> > callback) {
if (callback != null) {
if (WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName())) {
Set origins = nativeGetOrigins();
callback.onReceiveValue(origins);
} else {
postMessage(Message.obtain(null, GET_ORIGINS, callback));
}
}
}
/**
* Gets the permission state for the specified origin.
*
* Callback is a ValueCallback object whose onReceiveValue method will be
* called asynchronously with the permission state for the origin.
*/
public void getAllowed(String origin, ValueCallback<Boolean> callback) {
if (callback == null) {
return;
}
if (origin == null) {
callback.onReceiveValue(null);
return;
}
if (WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName())) {
boolean allowed = nativeGetAllowed(origin);
callback.onReceiveValue(new Boolean(allowed));
} else {
Map values = new HashMap<String, Object>();
values.put(ORIGIN, origin);
values.put(CALLBACK, callback);
postMessage(Message.obtain(null, GET_ALLOWED, values));
}
}
/**
* Clears the permission state for the specified origin. This method may be
* called before the WebKit thread has intialized the message handler.
* Messages will be queued until this time.
*/
public void clear(String origin) {
// Called on the UI thread.
postMessage(Message.obtain(null, CLEAR, origin));
}
/**
* Allows the specified origin. This method may be called before the WebKit
* thread has intialized the message handler. Messages will be queued until
* this time.
*/
public void allow(String origin) {
// Called on the UI thread.
postMessage(Message.obtain(null, ALLOW, origin));
}
/**
* Clears the permission state for all origins.
*/
public void clearAll() {
// Called on the UI thread.
postMessage(Message.obtain(null, CLEAR_ALL));
}
// Native functions, run on the WebKit thread.
private static native Set nativeGetOrigins();
private static native boolean nativeGetAllowed(String origin);
private static native void nativeClear(String origin);
private static native void nativeAllow(String origin);
private static native void nativeClearAll();
}