ViewPager auto scroll logic

view_pager_auto_scroll.kt

// before onCreate() in acivity/fragment

private val mainHandler = Handler(Looper.getMainLooper())

private val updateBannerItemTask = object : Runnable {
    override fun run() {
        updateCurrentBannerItem()
        mainHandler.postDelayed(this, 3000)
    }
}


// call this function after pages (in oncreate or onViewCreated) loads
// images is the list of viewpager
private fun startSlideShow() {
    if (pages.isEmpty()) return
    mainHandler.postDelayed(updateBannerItemTask, 3000)
}


// define this function somewhere in the screen

private fun updateCurrentBannerItem() {
      val currentItem = if (binding.viewPager.currentItem == pages.size - 1) 0 else binding.viewPager.currentItem + 1
      binding.viewPager.setCurrentItem(currentItem, true)
}