Introduction
In this article I explain how to use the assets directory from the directory structure. When we want to use native code in our application, we use the assets directory to save a usable file, so here we are using a HTML file as our own browser to be used in our application. You can see that in the following instructions.
Step 1
As usual, first of all create a new file using "File" -> "New" -> "Android Application Project" with the name "WebBrowser".
![newbrowser.jpg]()
Step 2
Now create native code in a HTML file of a structure like a browser as in the following. And add this file in assets as shown below.
code
<html>
<head>
<meta name="viewport" content="width=device-width,initial-scale=0.25,user-scalable=yes" />
<title>Going Native</title>
</head>
<body onload="window.linuxmag.Info('App loaded!');">
<center>
<h3>My Native Browser</h3>
<input type="text" id="ib"><br />
<button onclick="window.linuxmag.Info(document.getElementById('ib').value);">Log In</button>
<button onclick="window.linuxmag.Error(document.getElementById('ib').value);">Reset</button><br />
<button onclick="if (window.confirm('End App?')) window.linuxmag.EndApp();">Kill Apps</button><br />
<img src="file:///android_asset/Option_icon.jpg">
</center>
</body>
</html>
Image
![assets structure.jpg]()
Step 3
Open the XML file "res/layout/activity_main.xml" and update it with the following code:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<WebView
android:id="@+id/mybrowser"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
/>
</RelativeLayout>
Step 4
Now open the Java file "MainActivity.java" using "src/com.web.browser/MainActivity.java" and update it as in the following code:
package com.web.browser;
import android.os.Bundle;
import android.app.Activity;
import android.webkit.WebView;
import android.webkit.WebSettings;
import android.webkit.WebChromeClient;
import android.util.Log;
public class MainActivity extends Activity {
/** Called when the activity is first created. */
private WebView browser = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
browser = (WebView) findViewById(R.id.mybrowser);
// get settings so we can config our WebView instance
WebSettings settings = browser.getSettings();
settings.setJavaScriptEnabled(true);
// clear cache
browser.clearCache(true);
// this is necessary for "alert()" to work
browser.setWebChromeClient(new WebChromeClient());
MyCoolJSHandler MycoolHandler;
browser.addJavascriptInterface(new MyCoolJSHandler(), "linuxmag");
// load a page to get things started
browser.loadUrl("file:///android_asset/index.html");
}
}
final class MyCoolJSHandler extends Activity
{
// write to LogCat (Info)
public void Info(String str) {
Log.i("GoingNative",str);
}
// write to LogCat (Error)
public void Error(String str) {
Log.e("GoingNative",str);
}
// Kill the app
public void EndApp() {
finish();
}
}
Step 5
Now open the "AndroidManifest.xml" file and update it using the following code:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.web.browser"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.web.browser.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-permission android:name="android.permission.INTERNET" />
</manifest>
See output
![browser.jpg]()