view pdf files in google drive

WebviewPDFActivity.kt

import android.annotation.SuppressLint
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.webkit.WebView
import android.webkit.WebViewClient
import kotlinx.android.synthetic.main.activity_webview_pdf.*


class WebviewPDFActivity : AppCompatActivity() {

    @SuppressLint("SetJavaScriptEnabled")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_webview_pdf)
        progress_circular.visibility = View.VISIBLE
        webView1.settings.javaScriptEnabled = true
        val filename = "http://www3.nd.edu/~cpoellab/teaching/cse40816/android_tutorial.pdf"
       // webView1.loadUrl("http://docs.google.com/gview?embedded=true&url=$filename")
        webView1.loadUrl("https://drive.google.com/open?id=1GvbQhga7rvMBssBKjIrWiL_Wg2rF7DP1&authuser=0")

        webView1.webViewClient = object : WebViewClient() {

            override fun onPageFinished(view: WebView, url: String) {
                // do your stuff here
                webView1.visibility = View.VISIBLE
                progress_circular.visibility=(View.GONE)
            }
        }

    }
}