Handle Redirect Window In Android Webview

Pankaj Tyagi

12 June 2023

To handle the redirect window in android Webview we have to override the “onCreateWindow” of WebChromeClient().

Webview

Android Webview is used to display HTML content or to load webpage pages in the android app.

WebView uses a WebKit engine to display web pages.
To load the webpage in Webview loadUrl() and loadData() methods are used.

Sometimes some web pages redirect to another webpage or another window on any click event.
In Webview either the redirected window will not open directly.
To show redirect pages in Webview we need to write some extra code.

Let’s take an example.

To show the webpage in our sample app we have written some HTML code and added that file to the assets folder.

Let’s have look at the main activity code “MainActivity.kt”.

class MainActivity : AppCompatActivity() {
    var mBinding: ActivityMainBinding? =null;

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        mBinding =  DataBindingUtil.setContentView(
           this,
           R.layout.activity_main
       );
        val settings = web_view.settings
        settings.javaScriptEnabled = true
        settings.domStorageEnabled = true
        settings.setSupportMultipleWindows(true);
        settings.setAllowFileAccess(true);
        settings.setAllowContentAccess(true);
        settings.setAllowFileAccessFromFileURLs(true);
        settings.setAllowUniversalAccessFromFileURLs(true);
        settings.setJavaScriptCanOpenWindowsAutomatically(true);
        settings.setCacheMode(WebSettings.LOAD_NO_CACHE);
        web_view.loadUrl("file:///android_asset/test.html");
        web_view.webChromeClient=MyWebChromeClient();
        web_view.webViewClient=MyBrowser()
    }
    private inner class MyBrowser : WebViewClient() {

        override fun shouldOverrideUrlLoading(
            view: WebView?,
            request: WebResourceRequest?
        ): Boolean {
            return super.shouldOverrideUrlLoading(view, request)
        }

        override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
            super.onPageStarted(view, url, favicon)
        }

        override fun onPageFinished(view: WebView?, url: String?) {
            super.onPageFinished(view, url)
        }
    }
    private inner class MyWebChromeClient : WebChromeClient() {
    }

}

class MainActivity : AppCompatActivity() {

var mBinding: ActivityMainBinding? =null;

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

mBinding = DataBindingUtil.setContentView(

this,

R.layout.activity_main

);

val settings = web_view.settings

settings.javaScriptEnabled = true

settings.domStorageEnabled = true

settings.setSupportMultipleWindows(true);

settings.setAllowFileAccess(true);

settings.setAllowContentAccess(true);

settings.setAllowFileAccessFromFileURLs(true);

settings.setAllowUniversalAccessFromFileURLs(true);

settings.setJavaScriptCanOpenWindowsAutomatically(true);

settings.setCacheMode(WebSettings.LOAD_NO_CACHE);

web_view.loadUrl("file:///android_asset/test.html");

web_view.webChromeClient=MyWebChromeClient();

web_view.webViewClient=MyBrowser()

}

private inner class MyBrowser : WebViewClient() {

override fun shouldOverrideUrlLoading(

view: WebView?,

request: WebResourceRequest?

): Boolean {

return super.shouldOverrideUrlLoading(view, request)

}

override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {

super.onPageStarted(view, url, favicon)

}

override fun onPageFinished(view: WebView?, url: String?) {

super.onPageFinished(view, url)

}

private inner class MyWebChromeClient : WebChromeClient() {

}

Now if we click on the button then it will not redirect/open any new window.

To open the redirected window we have to override “onCreateWindow” of WebChromeClient().

public boolean onCreateWindow (WebView view, 
                boolean isDialog, 
                boolean isUserGesture, 
                Message resultMsg)

public boolean onCreateWindow (WebView view,

boolean isDialog,

boolean isUserGesture,

Message resultMsg)

After overriding the method, we have to create another Webview and a Dialog or view according to the requirement.
Complete Main Activity Code :

class MainActivity : AppCompatActivity() {
    var mBinding: ActivityMainBinding? =null;

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        mBinding =  DataBindingUtil.setContentView(
           this,
           R.layout.activity_main
       );
        val settings = web_view.settings
        settings.javaScriptEnabled = true
        settings.domStorageEnabled = true
        settings.setSupportMultipleWindows(true);
        settings.setAllowFileAccess(true);
        settings.setAllowContentAccess(true);
        settings.setAllowFileAccessFromFileURLs(true);
        settings.setAllowUniversalAccessFromFileURLs(true);
        settings.setJavaScriptCanOpenWindowsAutomatically(true);
        settings.setCacheMode(WebSettings.LOAD_NO_CACHE);
        web_view.loadUrl("file:///android_asset/test.html");
        web_view.webChromeClient=MyWebChromeClient();
        web_view.webViewClient=MyBrowser()
    }
    private inner class MyBrowser : WebViewClient() {

        override fun shouldOverrideUrlLoading(
            view: WebView?,
            request: WebResourceRequest?
        ): Boolean {
            return super.shouldOverrideUrlLoading(view, request)
        }

        override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
            super.onPageStarted(view, url, favicon)
        }

        override fun onPageFinished(view: WebView?, url: String?) {
            super.onPageFinished(view, url)
        }
    }
    private inner class MyWebChromeClient : WebChromeClient() {
        override fun onCreateWindow(
            view: WebView?,
            isDialog: Boolean,
            isUserGesture: Boolean,
            resultMsg: Message
        ): Boolean {
            val redirectWebView = WebView(this@MainActivity)
            redirectWebView.settings.javaScriptEnabled = true
            redirectWebView.settings.setSupportZoom(true)
            redirectWebView.settings.builtInZoomControls = true
            redirectWebView.settings.pluginState = WebSettings.PluginState.ON
            redirectWebView.settings.setSupportMultipleWindows(true)
            val dialog = Dialog(this@MainActivity)
            dialog.setContentView(redirectWebView)
            dialog.show()
            val transport = resultMsg.obj as WebView.WebViewTransport
            transport.webView = redirectWebView
            resultMsg.sendToTarget()

            redirectWebView.webViewClient = object : WebViewClient() {
                override fun shouldOverrideUrlLoading(view: WebView, url: String): Boolean {
                    view.loadUrl(url)
                    return true
                }
            }

            return true
        }
    }

}

class MainActivity : AppCompatActivity() {

var mBinding: ActivityMainBinding? =null;

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

mBinding = DataBindingUtil.setContentView(

this,

R.layout.activity_main

);

val settings = web_view.settings

settings.javaScriptEnabled = true

settings.domStorageEnabled = true

settings.setSupportMultipleWindows(true);

settings.setAllowFileAccess(true);

settings.setAllowContentAccess(true);

settings.setAllowFileAccessFromFileURLs(true);

settings.setAllowUniversalAccessFromFileURLs(true);

settings.setJavaScriptCanOpenWindowsAutomatically(true);

settings.setCacheMode(WebSettings.LOAD_NO_CACHE);

web_view.loadUrl("file:///android_asset/test.html");

web_view.webChromeClient=MyWebChromeClient();

web_view.webViewClient=MyBrowser()

}

private inner class MyBrowser : WebViewClient() {

override fun shouldOverrideUrlLoading(

view: WebView?,

request: WebResourceRequest?

): Boolean {

return super.shouldOverrideUrlLoading(view, request)

}

override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {

super.onPageStarted(view, url, favicon)

}

override fun onPageFinished(view: WebView?, url: String?) {

super.onPageFinished(view, url)

}

private inner class MyWebChromeClient : WebChromeClient() {

override fun onCreateWindow(

view: WebView?,

isDialog: Boolean,

isUserGesture: Boolean,

resultMsg: Message

): Boolean {

val redirectWebView = WebView(this@MainActivity)

redirectWebView.settings.javaScriptEnabled = true

redirectWebView.settings.setSupportZoom(true)

redirectWebView.settings.builtInZoomControls = true

redirectWebView.settings.pluginState = WebSettings.PluginState.ON

redirectWebView.settings.setSupportMultipleWindows(true)

val dialog = Dialog(this@MainActivity)

dialog.setContentView(redirectWebView)

dialog.show()

val transport = resultMsg.obj as WebView.WebViewTransport

transport.webView = redirectWebView

resultMsg.sendToTarget()

redirectWebView.webViewClient = object : WebViewClient() {

override fun shouldOverrideUrlLoading(view: WebView, url: String): Boolean {

view.loadUrl(url)

return true

}

return true

}

After adding the above code to your app you are able to open the redirect window in your hybrid app.

Conclusion

In this blog, we see how we can open a redirected window in our android hybrid app or Webview.

To learn more about Webview, you can also refer to this link -> Android Webview

Thanks for Reading.