PlayerAndroid/app/src/main/java/code/name/monkey/retromusic/transform/HingeTransformation.kt

46 lines
1.4 KiB
Kotlin

/*
* Copyright (c) 2019 Hemanth Savarala.
*
* Licensed under the GNU General Public License v3
*
* This is free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by
* the Free Software Foundation either version 3 of the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*/
package code.name.monkey.retromusic.transform
import android.view.View
import androidx.viewpager.widget.ViewPager
class HingeTransformation : ViewPager.PageTransformer {
override fun transformPage(page: View, position: Float) {
page.translationX = -position * page.width
page.pivotX = 0f
page.pivotY = 0f
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
page.alpha = 0f
} else if (position <= 0) { // [-1,0]
page.rotation = 90 * Math.abs(position)
page.alpha = 1 - Math.abs(position)
} else if (position <= 1) { // (0,1]
page.rotation = 0f
page.alpha = 1f
} else { // (1,+Infinity]
// This page is way off-screen to the right.
page.alpha = 0f
}
}
}