36 lines
1.0 KiB
Kotlin
36 lines
1.0 KiB
Kotlin
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package code.name.monkey.retromusic.transform
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import android.view.View
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import androidx.viewpager.widget.ViewPager
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class HorizontalFlipTransformation : ViewPager.PageTransformer {
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override fun transformPage(page: View, position: Float) {
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page.translationX = -position * page.width
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page.cameraDistance = 20000f
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if (position < 0.5 && position > -0.5) {
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page.visibility = View.VISIBLE
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} else {
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page.visibility = View.INVISIBLE
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}
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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.alpha = 0f
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} else if (position <= 0) { // [-1,0]
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page.alpha = 1f
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page.rotationX = 180 * (1 - Math.abs(position) + 1)
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} else if (position <= 1) { // (0,1]
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page.alpha = 1f
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page.rotationX = -180 * (1 - Math.abs(position) + 1)
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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.alpha = 0f
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}
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}
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}
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