Android Soft Navigationbar visible check & android FullScreen Keyboard issue

Android FullScreen Keyboard show hide issue

import android.app.Activity
import android.content.Context
import android.graphics.Rect
import android.view.View
import android.widget.FrameLayout
import android.view.ViewConfiguration


class AndroidBug5497Workaround private constructor(activity: Activity) {

    private val mContext: Context
    private val mChildOfContent: View
    private var usableHeightPrevious: Int = 0
    private val frameLayoutParams: FrameLayout.LayoutParams

    init {
        mContext = activity
        val content = activity.findViewById<View>(android.R.id.content) as FrameLayout
        mChildOfContent = content.getChildAt(0)
        mChildOfContent.viewTreeObserver.addOnGlobalLayoutListener { possiblyResizeChildOfContent() }
        frameLayoutParams = mChildOfContent.layoutParams as FrameLayout.LayoutParams
    }

    private fun possiblyResizeChildOfContent() {
        val usableHeightNow = computeUsableHeight()
        val navigationBarHeight = getNavigationBarHeight()
        if (usableHeightNow != usableHeightPrevious) {
            val usableHeightSansKeyboard = mChildOfContent.rootView.height
            val heightDifference = usableHeightSansKeyboard - usableHeightNow
            if (heightDifference > usableHeightSansKeyboard / 4) {
                // keyboard probably just became visible
                frameLayoutParams.height = usableHeightSansKeyboard - heightDifference 
            } else {
                // heightDifference == 0 >> navigationbar invisible
                if (heightDifference == 0)
                {
                    frameLayoutParams.height = usableHeightSansKeyboard 
                }
                else
                {
                    frameLayoutParams.height = usableHeightSansKeyboard - navigationBarHeight
                }
            }
            mChildOfContent.requestLayout()
            usableHeightPrevious = usableHeightNow
        }
    }

    private fun computeUsableHeight(): Int {
        val r = Rect()
        mChildOfContent.getWindowVisibleDisplayFrame(r)
        return r.bottom - r.top
    }

    private fun getNavigationBarHeight(): Int {
        val hasMenuKey = ViewConfiguration.get(mContext).hasPermanentMenuKey()
        val resourceId = mContext.resources.getIdentifier("navigation_bar_height", "dimen", "android")
        return if (resourceId > 0 && !hasMenuKey) {
            mContext.resources.getDimensionPixelSize(resourceId)
        } else 0
    }



    companion object {

        // For more information, see https://code.google.com/p/android/issues/detail?id=5497
        // To use this class, simply invoke assistActivity() on an Activity that already has its content view set.

        fun assistActivity(activity: Activity) {
            AndroidBug5497Workaround(activity)
        }
    }

}