The Tor Browser: mobile/android/base/EventDispatcher.java@6474c204b198 (annotated)

mobile/android/base/EventDispatcher.java@6474c204b198 (annotated)

mobile/android/base/EventDispatcher.java

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 package org.mozilla.gecko;
 import org.mozilla.gecko.GeckoAppShell;
 import org.mozilla.gecko.GeckoEvent;
 import org.mozilla.gecko.util.EventCallback;
 import org.mozilla.gecko.util.GeckoEventListener;
 import org.mozilla.gecko.util.NativeEventListener;
 import org.mozilla.gecko.util.NativeJSContainer;
 import org.json.JSONException;
 import org.json.JSONObject;
 import android.util.Log;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CopyOnWriteArrayList;
 public final class EventDispatcher {
     private static final String LOGTAG = "GeckoEventDispatcher";
     private static final String GUID = "__guid__";
     private static final String STATUS_CANCEL = "cancel";
     private static final String STATUS_ERROR = "error";
     private static final String STATUS_SUCCESS = "success";
     /**
      * The capacity of a HashMap is rounded up to the next power-of-2. Every time the size
      * of the map goes beyond 75% of the capacity, the map is rehashed. Therefore, to
      * empirically determine the initial capacity that avoids rehashing, we need to
      * determine the initial size, divide it by 75%, and round up to the next power-of-2.
      */
     private static final int GECKO_NATIVE_EVENTS_COUNT = 0; // Default for HashMap
     private static final int GECKO_JSON_EVENTS_COUNT = 256; // Empirically measured
     private final Map<String, List<NativeEventListener>> mGeckoThreadNativeListeners =
         new HashMap<String, List<NativeEventListener>>(GECKO_NATIVE_EVENTS_COUNT);
     private final Map<String, List<GeckoEventListener>> mGeckoThreadJSONListeners =
         new HashMap<String, List<GeckoEventListener>>(GECKO_JSON_EVENTS_COUNT);
     private <T> void registerListener(final Class<? extends List<T>> listType,
                                       final Map<String, List<T>> listenersMap,
                                       final T listener,
                                       final String[] events) {
         try {
             synchronized (listenersMap) {
                 for (final String event : events) {
                     List<T> listeners = listenersMap.get(event);
                     if (listeners == null) {
                         listeners = listType.newInstance();
                         listenersMap.put(event, listeners);
                     }
                     if (!AppConstants.RELEASE_BUILD && listeners.contains(listener)) {
                         throw new IllegalStateException("Already registered " + event);
                     }
                     listeners.add(listener);
                 }
             }
         } catch (final IllegalAccessException e) {
             throw new IllegalArgumentException("Invalid new list type", e);
         } catch (final InstantiationException e) {
             throw new IllegalArgumentException("Invalid new list type", e);
         }
     }
     private <T> void checkNotRegistered(final Map<String, List<T>> listenersMap,
                                         final String[] events) {
         synchronized (listenersMap) {
             for (final String event: events) {
                 if (listenersMap.get(event) != null) {
                     throw new IllegalStateException(
                         "Already registered " + event + " under a different type");
                 }
             }
         }
     }
     private <T> void unregisterListener(final Map<String, List<T>> listenersMap,
                                         final T listener,
                                         final String[] events) {
         synchronized (listenersMap) {
             for (final String event : events) {
                 List<T> listeners = listenersMap.get(event);
                 if ((listeners == null ||
                      !listeners.remove(listener)) && !AppConstants.RELEASE_BUILD) {
                     throw new IllegalArgumentException(event + " was not registered");
                 }
             }
         }
     }
     @SuppressWarnings("unchecked")
     public void registerGeckoThreadListener(final NativeEventListener listener,
                                             final String... events) {
         checkNotRegistered(mGeckoThreadJSONListeners, events);
         // For listeners running on the Gecko thread, we want to notify the listeners
         // outside of our synchronized block, because the listeners may take an
         // indeterminate amount of time to run. Therefore, to ensure concurrency when
         // iterating the list outside of the synchronized block, we use a
         // CopyOnWriteArrayList.
         registerListener((Class)CopyOnWriteArrayList.class,
                          mGeckoThreadNativeListeners, listener, events);
     }
     @Deprecated // Use NativeEventListener instead
     @SuppressWarnings("unchecked")
     private void registerGeckoThreadListener(final GeckoEventListener listener,
                                              final String... events) {
         checkNotRegistered(mGeckoThreadNativeListeners, events);
         registerListener((Class)CopyOnWriteArrayList.class,
                          mGeckoThreadJSONListeners, listener, events);
     }
     public void unregisterGeckoThreadListener(final NativeEventListener listener,
                                               final String... events) {
         unregisterListener(mGeckoThreadNativeListeners, listener, events);
     }
     @Deprecated // Use NativeEventListener instead
     private void unregisterGeckoThreadListener(final GeckoEventListener listener,
                                                final String... events) {
         unregisterListener(mGeckoThreadJSONListeners, listener, events);
     }
     @Deprecated // Use one of the variants above.
     public void registerEventListener(final String event, final GeckoEventListener listener) {
         registerGeckoThreadListener(listener, event);
     }
     @Deprecated // Use one of the variants above
     public void unregisterEventListener(final String event, final GeckoEventListener listener) {
         unregisterGeckoThreadListener(listener, event);
     }
     public void dispatchEvent(final NativeJSContainer message) {
         EventCallback callback = null;
         try {
             // First try native listeners.
             final String type = message.getString("type");
             final List<NativeEventListener> listeners;
             synchronized (mGeckoThreadNativeListeners) {
                 listeners = mGeckoThreadNativeListeners.get(type);
             }
             final String guid = message.optString(GUID, null);
             if (guid != null) {
                 callback = new GeckoEventCallback(guid, type);
             }
             if (listeners != null) {
                 if (listeners.size() == 0) {
                     Log.w(LOGTAG, "No listeners for " + type);
                 }
                 for (final NativeEventListener listener : listeners) {
                     listener.handleMessage(type, message, callback);
                 }
                 // If we found native listeners, we assume we don't have any JSON listeners
                 // and return early. This assumption is checked when registering listeners.
                 return;
             }
         } catch (final IllegalArgumentException e) {
             // Message doesn't have a "type" property, fallback to JSON
         }
         try {
             // If we didn't find native listeners, try JSON listeners.
             dispatchEvent(new JSONObject(message.toString()), callback);
         } catch (final JSONException e) {
             Log.e(LOGTAG, "Cannot parse JSON");
         } catch (final UnsupportedOperationException e) {
             Log.e(LOGTAG, "Cannot convert message to JSON");
         }
     }
     public void dispatchEvent(final JSONObject message, final EventCallback callback) {
         // {
         //   "type": "value",
         //   "event_specific": "value",
         //   ...
         try {
             final String type = message.getString("type");
             List<GeckoEventListener> listeners;
             synchronized (mGeckoThreadJSONListeners) {
                 listeners = mGeckoThreadJSONListeners.get(type);
             }
             if (listeners == null || listeners.size() == 0) {
                 Log.w(LOGTAG, "No listeners for " + type);
                 // If there are no listeners, cancel the callback to prevent Gecko-side observers
                 // from being leaked.
                 if (callback != null) {
                     callback.sendCancel();
                 }
                 return;
             }
             for (final GeckoEventListener listener : listeners) {
                 listener.handleMessage(type, message);
             }
         } catch (final JSONException e) {
             Log.e(LOGTAG, "handleGeckoMessage throws " + e, e);
         }
     }
     @Deprecated
     public static void sendResponse(JSONObject message, Object response) {
         sendResponseHelper(STATUS_SUCCESS, message, response);
     }
     @Deprecated
     public static void sendError(JSONObject message, Object response) {
         sendResponseHelper(STATUS_ERROR, message, response);
     }
     @Deprecated
     private static void sendResponseHelper(String status, JSONObject message, Object response) {
         try {
             final JSONObject wrapper = new JSONObject();
             wrapper.put(GUID, message.getString(GUID));
             wrapper.put("status", status);
             wrapper.put("response", response);
             GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent(
                     message.getString("type") + ":Response", wrapper.toString()));
         } catch (final JSONException e) {
             Log.e(LOGTAG, "Unable to send response", e);
         }
     }
     private static class GeckoEventCallback implements EventCallback {
         private final String guid;
         private final String type;
         private boolean sent;
         public GeckoEventCallback(final String guid, final String type) {
             this.guid = guid;
             this.type = type;
         }
         public void sendSuccess(final Object response) {
             sendResponse(STATUS_SUCCESS, response);
         }
         public void sendError(final Object response) {
             sendResponse(STATUS_ERROR, response);
         }
         public void sendCancel() {
             sendResponse(STATUS_CANCEL, null);
         }
         private void sendResponse(final String status, final Object response) {
             if (sent) {
                 throw new IllegalStateException("Callback has already been executed for type=" +
                         type + ", guid=" + guid);
             }
             sent = true;
             try {
                 final JSONObject wrapper = new JSONObject();
                 wrapper.put(GUID, guid);
                 wrapper.put("status", status);
                 wrapper.put("response", response);
                 GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent(type + ":Response",
                         wrapper.toString()));
             } catch (final JSONException e) {
                 Log.e(LOGTAG, "Unable to send response for: " + type, e);
             }
         }
     }
 }

The Tor Browser / annotate

mobile/android/base/EventDispatcher.java@6474c204b198 (annotated)

mobile/android/base/EventDispatcher.java