Custom Android App Onboarding Sample using PagerTransformer. [Kotlin]
class CustomPageTransformer : ViewPager.PageTransformer {
override fun transformPage(page: View, position: Float) {
val pageWidth = page.width
val pageHeight = page.height
val imgTop : ImageView = page.findViewById(R.id.top_image)
val imgBottom : ImageView = page.findViewById(R.id.bottom_image)
if (position <= -1.0f || position >= 1.0f) {
imgTop.translationX = pageWidth * position
imgTop.alpha = 0.0f
imgBottom.translationX = pageWidth * position
imgBottom.alpha = 0.0f
} else if (position == 0.0f) {
imgTop.translationX = pageWidth * position
imgTop.alpha = 1.0f
imgBottom.translationX = pageWidth * position
imgBottom.alpha = 1.0f
} else {
// position is between -1.0f & 0.0f OR 0.0f & 1.0f
imgTop.translationX = -position * pageWidth
imgTop.translationY = position * pageHeight
imgTop.alpha = 1.0f - 5 * abs(position)
imgBottom.translationX = -position * pageWidth
imgBottom.translationY = -position * pageHeight
imgBottom.alpha = 1.0f - 5 * abs(position)
}
}
}
val viewPager : ViewPager = findViewById(R.id.viewpager)
viewPager.adapter = PageAdapter(supportFragmentManager)
viewPager.setPageTransformer(/*reversDrawingOrder*/ true, CustomPageTransformer())