WebView Rendering Issue in Android KitKat

Question

I\'ve been working on an application which have a WebView in which a static page get loaded from the assets (Also using JavaScript). This WebView is not working in KitKat, i

Answer 1

In my case, in Android 4.4, I was getting a black background no matter I set what and this error message in my LogCat: nativeOnDraw failed; clearing to background color.

From Googling, it seems to be because hardware accelerated canvas rendering is not supported in Chromium WebView. I added this line to the WebView to turn off hardware accelerated canvas and now it works.

mWebview.setLayerType(View.LAYER_TYPE_SOFTWARE, null);

Answer 2

I ran into the same issue, but I did find a workaround. All you have to do is explicitly set a CSS background for your webpage. Like so:

body {
  background: white;
}

As it turns out if you do not explicitly set a background for a webpage the WebView will fail to draw said background and you'll end up with a transparent WebView.

Answer 3

This seems to be a chromium webview bug.

Here is a thread about the issue: https://jira.appcelerator.org/browse/TIMOB-16479

Apparently, the accepted answer is not a sure fix. A workaround is mentioned in the link.

Answer 4

The disabling of the hardware accelerator comes with heavy performance toll, In my case I found out that in Kitkat this happened to me when I was re instantiating the webview element within an activity that was finished and later restarted. After a lot of trial and error, when I added:

RelativeLayout layout = (RelativeLayout) findViewById(R.id.webViewContainer);
layout.removeAllViews();
webview.destroy();

Just before ending the activity, it seems to have the problem solved. I haven't tested it on many devices yet but if this solution is proper, then it is better by far than disabling the hardware acceleration for KitKat for the webview.

Answer 5

package com.example.testandroid;



public class MainActivity extends ActionBarActivity {

WebView webView=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    if (savedInstanceState != null)
    {
        ((WebView)findViewById(R.id.web_view)).restoreState(savedInstanceState);
    }
    else{

        webView=(WebView)findViewById(R.id.web_view);
        webView.loadUrl("http://www.google.co.in");
        webView.getSettings().getJavaScriptEnabled();
        webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);

        webView.setWebViewClient(new WebViewClient()

        {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view,
                    String url) {
                // TODO Auto-generated method stub
                view.loadUrl(url);
                return true;
            }
        });
    }
}


protected void onSaveInstanceState(Bundle outState) {
    webView.saveState(outState);
}


@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    // Check if the key event was the Back button and if there's history
    if ((keyCode == KeyEvent.KEYCODE_BACK) && webView.canGoBack()) {
        webView.goBack();
        return true;
    }
    // If it wasn't the Back key or there's no web page history, bubble up to the default
    // system behavior (probably exit the activity)
    return super.onKeyDown(keyCode, event);
}

}