/*
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* Copyright (C) 2016 - Niklas Baudy, Ruben Gees, Mario Đanić and contributors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*/
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package com.dollearn.student.utils;
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import android.view.View;
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import androidx.viewpager.widget.ViewPager;
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public final class PageTransformer implements ViewPager.PageTransformer {
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private static final float MIN_SCALE = 0.9f;
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private static final float MIN_ALPHA = 0.1f;
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@Override public void transformPage(final View page, final float position) {
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if (position < -1) { // [-Infinity,-1)
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// This page is way off-screen to the left.
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page.setAlpha(0);
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} else if (position <= 1) { // [-1,1]
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page.setScaleX(Math.max(MIN_SCALE, 1 - Math.abs(position)));
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page.setScaleY(Math.max(MIN_SCALE, 1 - Math.abs(position)));
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page.setAlpha(Math.max(MIN_ALPHA, 1 - Math.abs(position)));
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} else { // (1,+Infinity]
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// This page is way off-screen to the right.
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page.setAlpha(0);
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}
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}
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}
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