停止刷新底部导航栏片段

Question

I have a bottom navigation bar with 5 items. I want the last button to show a "More" menu. (Hence it should act as a button and not get into a selected state).

For this I'm keeping the last selected item id from the navigation bar and when a menu item is clicked setting the navigation item to the last selected item as follows.

menu_item_1_layout.setOnTouchListener { view, motionEvent ->
        bottomSheetBehaviour.state = BottomSheetBehavior.STATE_HIDDEN
        navigation.selectedItemId = lastSelectedItemId // views are refreshed here
        true
    }

My problem is how to stop the refreshing the last selected view(since it's already visible) when navigation item is set again. Since the menu is a BottomSheet, the view refresh is visible as a blinking. Or is there a better way to do this?

Answer 1

Ok. I found out that this behavior was because I'm always setting the fragment without checking the current selected fragment. When I added a check it works correctly.

 private val mOnNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
    if (item.itemId == lastSelectedItemId) { // added this
        return@OnNavigationItemSelectedListener true
    }
    when (item.itemId) {
        R.id.navigation_home -> {

            val fragment = TestFragment()
            supportFragmentManager.beginTransaction()
                    .replace(frame.id, fragment)
                    .commit()
            lastSelectedItemId = item.itemId
            return@OnNavigationItemSelectedListener true
        }