Android Coding

Aug 28, 2011

Load local HTML from /assets

We can load local HTML (under /assets folder) in WebView.

Modify from the former post Handle the Back button in WebView, to back in history.

Create our local HTML, /assets/myweb.html.

<!DOCTYPE html>

<html>

<head>

<meta charset="UTF-8">

<meta name="viewport" content="width=device-width; user-scalable=0;" />

<title>Android Coding</title>

</head>

<body>

 

<h1>Hello!</h1>

It's a local html in /assets.<br/>

Visit <a href="http://android-coding.blogspot.com/?m=1">Android Coding</a>

 

</body>

</html>

Load the local HTML in Java code:


	final String DEFAULT_URL = "file:///android_asset/myweb.html";



	webView.loadUrl(DEFAULT_URL);

Aug 26, 2011

Load ListView contents from XML resources

In the last posts A simple ListView using android.R.layout.simple_list_item_1 layout and ListView with your own layout; contents of ListView is defined in Java code. It can be defined in XML resources, and fill in ArrayAdapter by calling ArrayAdapter.createFromResource() method.

Create /res/values/month.xml file

<?xml version="1.0" encoding="utf-8"?>

<resources>

	<string-array name="month">

		<item>January</item>

		<item>February</item>

		<item>March</item>

		<item>April</item>

		<item>May</item>

		<item>June</item>

		<item>July</item>

		<item>August</item>

		<item>September</item>

		<item>October</item>

		<item>November</item>

		<item>December</item>

	</string-array>

</resources>

Modify onCreate() to create ArrayAdapter from resource.

    @Override

   public void onCreate(Bundle savedInstanceState) {

       super.onCreate(savedInstanceState);

       setContentView(R.layout.main);

       myList = (ListView)findViewById(R.id.list);

      

       ArrayAdapter<CharSequence> adapter

       = ArrayAdapter.createFromResource(this,

       		R.array.month,

       		R.layout.mylistlayout);

      

       myList.setAdapter(adapter);

      

   }

Related:

- ListView with multiple choice

Aug 25, 2011

ListView with your own layout

As stated in last post, A simple ListView using android.R.layout.simple_list_item_1 layout, we can copy and modify the built-in layout to implement our own layout in ListView.

Copy the file android-sdk-linux_x86/platforms/android-7/data/res/layout/layout/simple_list_item_1.xml, rename mylistlayout.xml, and paste into /res/layout/ folder of your project. Modify it:
/res/layout/mylistlayout.xml

<?xml version="1.0" encoding="utf-8"?>

<TextView xmlns:android="http://schemas.android.com/apk/res/android"

 android:id="@android:id/text1"

 android:layout_width="fill_parent"

 android:layout_height="wrap_content"

	android:textStyle="bold|italic"

 android:gravity="center_vertical|right"

 android:paddingRight="30dip"

 android:minHeight="?android:attr/listPreferredItemHeight"

 android:drawableLeft="@drawable/icon"

/>

Modify the onCreate() method to use R.layout.mylistlayout in our ListView

    @Override

 public void onCreate(Bundle savedInstanceState) {

     super.onCreate(savedInstanceState);

     setContentView(R.layout.main);

     myList = (ListView)findViewById(R.id.list);

  

     ArrayAdapter<String> adapter

     = new ArrayAdapter<String>(this,

     		R.layout.mylistlayout,

     		listContent);

     myList.setAdapter(adapter);

  

 }

next:
- Load ListView contents from XML resources

A simple ListView using android.R.layout.simple_list_item_1 layout

It's a very simple and standard example of ListView, using the built-in layout android.R.layout.simple_list_item_1 layout.

package com.AndroidListView;



import android.app.Activity;

import android.os.Bundle;

import android.widget.ArrayAdapter;

import android.widget.ListView;



public class AndroidListViewActivity extends Activity {

	

	ListView myList;

	

	String[] listContent = {

			"January",

			"February",

			"March",

			"April",

			"May",

			"June",

			"July",

			"August",

			"September",

			"October",

			"November",

			"December"

	};

	

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

   super.onCreate(savedInstanceState);

   setContentView(R.layout.main);

   myList = (ListView)findViewById(R.id.list);



   ArrayAdapter<String> adapter

   = new ArrayAdapter<String>(this,

   		android.R.layout.simple_list_item_1,

   		listContent);

   myList.setAdapter(adapter);



}

}

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

<TextView

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>

<ListView

android:id="@+id/list"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

/>

</LinearLayout>

But...what's android.R.layout.simple_list_item_1. You can check it in <android-sdk>/platforms/<android-version>/data/res/layout/simple_list_item_1.xml. Such that you can copy and modify it for your own.

For example, the content of android-sdk-linux_x86/platforms/android-7/data/res/layout/layout/simple_list_item_1.xml is:

<?xml version="1.0" encoding="utf-8"?>

<!-- Copyright (C) 2006 The Android Open Source Project



Licensed under the Apache License, Version 2.0 (the "License");

you may not use this file except in compliance with the License.

You may obtain a copy of the License at



     http://www.apache.org/licenses/LICENSE-2.0



Unless required by applicable law or agreed to in writing, software

distributed under the License is distributed on an "AS IS" BASIS,

WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

See the License for the specific language governing permissions and

limitations under the License.

-->



<TextView xmlns:android="http://schemas.android.com/apk/res/android"

android:id="@android:id/text1"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceLarge"

android:gravity="center_vertical"

android:paddingLeft="6dip"

android:minHeight="?android:attr/listPreferredItemHeight"

/>

Aug 18, 2011

Handle the Back button in WebView, to back in history.

Normally, we will have a Back button on browser, for user to go back in history. The default behaviour of the BACK button on Android system is Exiting the app. In order to change it's behaviour, we can override the onKeyDown() method: if it's BACK button pressed AND there has a back history item, than go back; otherwise pass to super method to handle as normal.

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
     
     if (keyCode == KeyEvent.KEYCODE_BACK){
      if(webView.canGoBack()){
       webView.goBack();
                return true;
      }
     }
     return super.onKeyDown(keyCode, event);
    }

Related Post:

- Display Progress Bar on WebView when loading

next:

- Load local HTML from /assets

related:
- Create your own London 2012 App