com.hzx.androidtransitionanimationdemo.TransitionHelper.java Source code

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Here is the source code for com.hzx.androidtransitionanimationdemo.TransitionHelper.java

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/*
 * 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.hzx.androidtransitionanimationdemo;

import android.annotation.TargetApi;
import android.app.Activity;
import android.os.Build;
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;

/**
 * transtions{@link android.app.ActivityOptions}.
 */
public class TransitionHelper {

    private TransitionHelper() {
    }

    /**
     * Active Transition ??UI
     *
     * @param activity ?transtionactivity
     * @param includeStatusBar  false, status bar ? transition 
     * @return  transition ViewList.
     */
    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public static Pair<View, String>[] createSafeTransitionParticipants(@NonNull Activity activity,
            boolean includeStatusBar, @Nullable Pair... otherParticipants) {
        // 1??UI:
        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);

        // 2 transition pair?.
        List<Pair> participants = new ArrayList<>(3);
        addNonNullViewToTransitionParticipants(statusBar, participants);
        addNonNullViewToTransitionParticipants(navBar, participants);

        // 3?otherParticipants??participants
        if (otherParticipants != null && !(otherParticipants.length == 1 && otherParticipants[0] == null)) {
            participants.addAll(Arrays.asList(otherParticipants));
        }

        // 4translation
        return participants.toArray(new Pair[participants.size()]);
    }

    /**
     * View?
     * @param view ?transactionView
     * @param participants transitionList
     */
    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    private static void addNonNullViewToTransitionParticipants(View view, List<Pair> participants) {
        if (view == null) {
            return;
        }
        participants.add(new Pair<>(view, view.getTransitionName()));
    }

}