simple trick to autoplay an html5 video element in a webview. (inject javascript to play on load)

autoplay.java

import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends Activity {
  private WebView webview;

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        webview = new WebView(this);
        setContentView(webview);

        final WebSettings settings = webview.getSettings();
        settings.setJavaScriptEnabled(true);
        settings.setJavaScriptCanOpenWindowsAutomatically(true);
        settings.setPluginState(WebSettings.PluginState.ON);

        webview.setWebViewClient(new WebViewClient() {
            // autoplay when finished loading via javascript injection
            public void onPageFinished(WebView view, String url) { webview.loadUrl("javascript:(function() { document.getElementsByTagName('video')[0].play(); })()"); }
        });
        webview.setWebChromeClient(new WebChromeClient());

        webview.loadUrl("http://html5demos.com/video");
    }

    @Override
    protected void onPause() {
        super.onPause();
        webview.onPause();
    }

    @Override
    protected void onResume() {
        webview.onResume();
        super.onResume();
    }
}