Java tutorial
/* * Copyright (C) 2011 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.support.v4.widget; import android.content.Context; import android.os.Build; import android.view.View; /** * Helper for accessing features in {@link android.widget.SearchView} * introduced after API level 4 in a backwards compatible fashion. */ public class SearchViewCompat { interface SearchViewCompatImpl { View newSearchView(Context context); Object newOnQueryTextListener(OnQueryTextListenerCompat listener); void setOnQueryTextListener(Object searchView, Object listener); } static class SearchViewCompatStubImpl implements SearchViewCompatImpl { @Override public View newSearchView(Context context) { return null; } @Override public Object newOnQueryTextListener(OnQueryTextListenerCompat listener) { return null; } @Override public void setOnQueryTextListener(Object searchView, Object listener) { } } static class SearchViewCompatHoneycombImpl extends SearchViewCompatStubImpl { @Override public View newSearchView(Context context) { return SearchViewCompatHoneycomb.newSearchView(context); } @Override public Object newOnQueryTextListener(final OnQueryTextListenerCompat listener) { return SearchViewCompatHoneycomb .newOnQueryTextListener(new SearchViewCompatHoneycomb.OnQueryTextListenerCompatBridge() { @Override public boolean onQueryTextSubmit(String query) { return listener.onQueryTextSubmit(query); } @Override public boolean onQueryTextChange(String newText) { return listener.onQueryTextChange(newText); } }); } @Override public void setOnQueryTextListener(Object searchView, Object listener) { SearchViewCompatHoneycomb.setOnQueryTextListener(searchView, listener); } } private static final SearchViewCompatImpl IMPL; static { if (Build.VERSION.SDK_INT >= 11) { // Honeycomb IMPL = new SearchViewCompatHoneycombImpl(); } else { IMPL = new SearchViewCompatStubImpl(); } } private SearchViewCompat(Context context) { /* Hide constructor */ } /** * Creates a new SearchView. * * @param context The Context the view is running in. * @return A SearchView instance if the class is present on the current * platform, null otherwise. */ public static View newSearchView(Context context) { return IMPL.newSearchView(context); } /** * Sets a listener for user actions within the SearchView. * * @param searchView The SearchView in which to register the listener. * @param listener the listener object that receives callbacks when the user performs * actions in the SearchView such as clicking on buttons or typing a query. */ public static void setOnQueryTextListener(View searchView, OnQueryTextListenerCompat listener) { IMPL.setOnQueryTextListener(searchView, listener.mListener); } /** * Callbacks for changes to the query text. */ public static abstract class OnQueryTextListenerCompat { final Object mListener; public OnQueryTextListenerCompat() { mListener = IMPL.newOnQueryTextListener(this); } /** * Called when the user submits the query. This could be due to a key press on the * keyboard or due to pressing a submit button. * The listener can override the standard behavior by returning true * to indicate that it has handled the submit request. Otherwise return false to * let the SearchView handle the submission by launching any associated intent. * * @param query the query text that is to be submitted * * @return true if the query has been handled by the listener, false to let the * SearchView perform the default action. */ public boolean onQueryTextSubmit(String query) { return false; } /** * Called when the query text is changed by the user. * * @param newText the new content of the query text field. * * @return false if the SearchView should perform the default action of showing any * suggestions if available, true if the action was handled by the listener. */ public boolean onQueryTextChange(String newText) { return false; } } }