| /* |
| * Copyright (C) 2013 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 com.android.inputmethod.event; |
| |
| import java.util.ArrayList; |
| |
| import javax.annotation.Nonnull; |
| |
| /** |
| * A generic interface for combiners. Combiners are objects that transform chains of input events |
| * into committable strings and manage feedback to show to the user on the combining state. |
| */ |
| public interface Combiner { |
| /** |
| * Process an event, possibly combining it with the existing state and return the new event. |
| * |
| * If this event does not result in any new event getting passed down the chain, this method |
| * returns null. It may also modify the previous event list if appropriate. |
| * |
| * @param previousEvents the previous events in this composition. |
| * @param event the event to combine with the existing state. |
| * @return the resulting event. |
| */ |
| @Nonnull |
| Event processEvent(ArrayList<Event> previousEvents, Event event); |
| |
| /** |
| * Get the feedback that should be shown to the user for the current state of this combiner. |
| * @return A CharSequence representing the feedback to show users. It may include styles. |
| */ |
| CharSequence getCombiningStateFeedback(); |
| |
| /** |
| * Reset the state of this combiner, for example when the cursor was moved. |
| */ |
| void reset(); |
| } |