Java tutorial
/* * Copyright 2015 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 com.arbo.gaogao.util; import android.app.Activity; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.v4.util.Pair; import android.view.View; import java.util.ArrayList; import java.util.Arrays; import java.util.List; /** * Helper class for creating content transitions used with {@link android.app.ActivityOptions}. */ class TransitionHelper { /** * Create the transition participants required during a activity transition while * avoiding glitches with the system UI. * * @param activity The activity used as start for the transition. * @param includeStatusBar If false, the status bar will not be added as the transition * participant. * @return All transition participants. */ public static Pair<View, String>[] createSafeTransitionParticipants(@NonNull Activity activity, boolean includeStatusBar, @Nullable Pair... otherParticipants) { // Avoid system UI glitches as described here: // https://plus.google.com/+AlexLockwood/posts/RPtwZ5nNebb View decor = activity.getWindow().getDecorView(); View statusBar = null; if (includeStatusBar) { statusBar = decor.findViewById(android.R.id.statusBarBackground); } View navBar = decor.findViewById(android.R.id.navigationBarBackground); // Create pair of transition participants. List<Pair> participants = new ArrayList<>(3); addNonNullViewToTransitionParticipants(statusBar, participants); addNonNullViewToTransitionParticipants(navBar, participants); // only add transition participants if there's at least One none-null element if (otherParticipants != null && !(otherParticipants.length == 1 && otherParticipants[0] == null)) { participants.addAll(Arrays.asList(otherParticipants)); } return participants.toArray(new Pair[participants.size()]); } private static void addNonNullViewToTransitionParticipants(View view, List<Pair> participants) { if (view == null) { return; } participants.add(new Pair<>(view, view.getTransitionName())); } }