Provides the height of the keyboard

KeyboardHeightProvider.kt

class KeyboardHeightProvider(activity: Activity) : PopupWindow(activity),
    OnGlobalLayoutListener {
    private val mActivity: Activity = activity
    private val rootView: View = View(activity)

    // Record the maximum height of the pop content area
    private var heightMax = 0
    private val mutHeightChanged = MutableStateFlow(0)
    val onHeightChanged: StateFlow<Int> = mutHeightChanged

    init {
        // Basic configuration
        contentView = rootView

        // Monitor global Layout changes
        rootView.viewTreeObserver.addOnGlobalLayoutListener(this)
        setBackgroundDrawable(ColorDrawable(0))

        // Set width to 0 and height to full screen
        width = 0
        height = LayoutParams.MATCH_PARENT
        
        // Set keyboard pop-up mode
        softInputMode = LayoutParams.SOFT_INPUT_ADJUST_RESIZE
        inputMethodMode = INPUT_METHOD_NEEDED

        if (!isShowing) {
            val view: View = mActivity.window.decorView
            // Delay loading popup window, if not, error will be reported
            view.post { showAtLocation(view, Gravity.NO_GRAVITY, 0, 0) }
        }
    }

    override fun onGlobalLayout() {
        val rect = Rect()
        rootView.getWindowVisibleDisplayFrame(rect)

        if (rect.bottom > heightMax) heightMax = rect.bottom

        // The difference between the two is the height of the keyboard
        val keyboardHeightPx = heightMax - rect.bottom

        // Return rect.bottom if you just need the coordinates of the current bottom of the screen
        mutHeightChanged.value = keyboardHeightPx.toDp
    }

    private val Int.toDp get() = (this / Resources.getSystem().displayMetrics.density).toInt()
}

Note: If this doesn't work as is, you need to add:

android:windowSoftInputMode="adjustResize"

To your AndroidManifest.xml