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.view; import android.view.ViewConfiguration; /** * Helper for accessing features in {@link ViewConfiguration} * introduced after API level 4 in a backwards compatible fashion. */ public class ViewConfigurationCompat { /** * Interface for the full API. */ interface ViewConfigurationVersionImpl { public int getScaledPagingTouchSlop(ViewConfiguration config); } /** * Interface implementation that doesn't use anything about v4 APIs. */ static class BaseViewConfigurationVersionImpl implements ViewConfigurationVersionImpl { @Override public int getScaledPagingTouchSlop(ViewConfiguration config) { return config.getScaledTouchSlop(); } } /** * Interface implementation for devices with at least v11 APIs. */ static class FroyoViewConfigurationVersionImpl implements ViewConfigurationVersionImpl { @Override public int getScaledPagingTouchSlop(ViewConfiguration config) { return ViewConfigurationCompatFroyo.getScaledPagingTouchSlop(config); } } /** * Select the correct implementation to use for the current platform. */ static final ViewConfigurationVersionImpl IMPL; static { if (android.os.Build.VERSION.SDK_INT >= 11) { IMPL = new FroyoViewConfigurationVersionImpl(); } else { IMPL = new BaseViewConfigurationVersionImpl(); } } // ------------------------------------------------------------------- /** * Call {@link ViewConfiguration#getScaledPagingTouchSlop()}. * If running on a pre-{@link android.os.Build.VERSION_CODES#FROYO} device, * returns {@link ViewConfiguration#getScaledTouchSlop()}. */ public static int getScaledPagingTouchSlop(ViewConfiguration config) { return IMPL.getScaledPagingTouchSlop(config); } }