/**
* Copyright 2010 Google Inc.
*
* 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 org.waveprotocol.wave.client.wavepanel.event;
import org.waveprotocol.wave.client.common.util.KeyCombo;
import java.util.EnumMap;
/**
* A by-key registry of key handlers. At most one handler is permitted for any
* one key combination.
*
*/
public final class KeySignalRouter implements KeySignalHandler {
private final EnumMap<KeyCombo, KeySignalHandler> handlers =
new EnumMap<KeyCombo, KeySignalHandler>(KeyCombo.class);
/**
* Creates a signal router.
*/
static KeySignalRouter create() {
return new KeySignalRouter();
}
/**
* Registers a key handler for a set of keys.
*
* @param keys keys to handle
* @param handler handler for {@code keys}
* @throws IllegalArgumentException if there is already a handler registered
* for any of the keys in {@code keys}.
*/
public void register(Iterable<KeyCombo> keys, KeySignalHandler handler) {
for (KeyCombo key : keys) {
if (handlers.containsKey(key)) {
throw new IllegalArgumentException(
"Feature conflict: multiple handlers registered for key " + key);
}
handlers.put(key, handler);
}
}
@Override
public boolean onKeySignal(KeyCombo key) {
KeySignalHandler handler = handlers.get(key);
return (handler != null) ? handler.onKeySignal(key) : false;
}
}