Android example source code file (WebViewDemo.java)

This example Android source code file (WebViewDemo.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

activity, android, app, application, demojavascriptinterface, handler, jsresult, log_tag, mywebchromeclient, os, override, runnable, string, utilities, webkit, websettings, webviewdemo

The WebViewDemo.java Android example source code

package com.google.android.webviewdemo;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.webkit.JsResult;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;

/**
 * Demonstrates how to embed a WebView in your activity. Also demonstrates how
 * to have javascript in the WebView call into the activity, and how the activity 
 * can invoke javascript.
 * <p>
 * In this example, clicking on the android in the WebView will result in a call into
 * the activities code in {@link DemoJavaScriptInterface#clickOnAndroid()}. This code
 * will turn around and invoke javascript using the {@link WebView#loadUrl(String)}
 * method.
 * <p>
 * Obviously all of this could have been accomplished without calling into the activity
 * and then back into javascript, but this code is intended to show how to set up the 
 * code paths for this sort of communication.
 *
 */
public class WebViewDemo extends Activity {

    private static final String LOG_TAG = "WebViewDemo";

    private WebView mWebView;

    private Handler mHandler = new Handler();

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        mWebView = (WebView) findViewById(R.id.webview);

        WebSettings webSettings = mWebView.getSettings();
        webSettings.setSavePassword(false);
        webSettings.setSaveFormData(false);
        webSettings.setJavaScriptEnabled(true);
        webSettings.setSupportZoom(false);

        mWebView.setWebChromeClient(new MyWebChromeClient());

        mWebView.addJavascriptInterface(new DemoJavaScriptInterface(), "demo");

        mWebView.loadUrl("file:///android_asset/demo.html");
    }

    final class DemoJavaScriptInterface {

        DemoJavaScriptInterface() {
        }

        /**
         * This is not called on the UI thread. Post a runnable to invoke
         * loadUrl on the UI thread.
         */
        public void clickOnAndroid() {
            mHandler.post(new Runnable() {
                public void run() {
                    mWebView.loadUrl("javascript:wave()");
                }
            });

        }
    }

    /**
     * Provides a hook for calling "alert" from javascript. Useful for
     * debugging your javascript.
     */
    final class MyWebChromeClient extends WebChromeClient {
        @Override
        public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
            Log.d(LOG_TAG, message);
            result.confirm();
            return true;
        }
    }
}