56 lines
1.9 KiB
Kotlin
56 lines
1.9 KiB
Kotlin
/*
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* Copyright (c) 2019 Hemanth Savarala.
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*
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* Licensed under the GNU General Public License v3
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*
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* This is free software: you can redistribute it and/or modify it under
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* the terms of the GNU General Public License as published by
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* the Free Software Foundation either version 3 of the License, or (at your option) any later version.
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*
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* This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
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* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*/
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package code.name.monkey.retromusic.transform
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import android.annotation.SuppressLint
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import android.view.View
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import androidx.viewpager.widget.ViewPager
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class CascadingPageTransformer : ViewPager.PageTransformer {
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private var mScaleOffset = 40
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fun setScaleOffset(mScaleOffset: Int) {
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this.mScaleOffset = mScaleOffset
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}
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@SuppressLint("NewApi")
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override fun transformPage(page: View, position: Float) {
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if (position <= 0.0f) {//被滑动的那页 position 是-下标~ 0
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page.translationX = 0f
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//旋转角度 45° * -0.1 = -4.5°
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page.rotation = 45 * position
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//X轴偏移 li: 300/3 * -0.1 = -10
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page.translationX = page.width / 3 * position
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} else if (position <= 1f) {
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val scale = (page.width - mScaleOffset * position) / page.width.toFloat()
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page.scaleX = scale
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page.scaleY = scale
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page.translationX = -page.width * position
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page.translationY = mScaleOffset * 0.8f * position
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} else {
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//缩放比例
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val scale = (page.width - mScaleOffset * position) / page.width.toFloat()
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page.scaleX = scale
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page.scaleY = scale
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page.translationX = -page.width * position
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page.translationY = mScaleOffset * 0.7f * position
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}
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}
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} |