.NET Information center: Android tutorial: How to make a simple widget

Wednesday, May 18, 2011

Android tutorial: How to make a simple widget

It's been a while since the last tutorial But here is a new one! In this tutorial i will show you how you can make a nice simple widget that you can update by touching the screen. On the bottom of this tutorial you will find the source code that makes this Widget work.

Here is an overview of all the files we need to make / edit.

WidgetActivity.java

In this class all the logic resides.

Layout file -> widget.xml

This holds the view

Xml file -> widgetprovider.xml

Schematic that is needed to build a Widget

AndroidManifest.xml

To make the Widget work we have to make changes to the Manifest

Lets get started with the first item and work to the bottom!

As i said this is the control center of our plugin! Here is where the magic happens I will not post the entire class here because the source code is in the bottom for those that want to go deeper.

@Override

public void onUpdate( Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds ){

//Save all incomming parameters

if (null == context)

context = WidgetActivity.context;

if (null == appWidgetManager)

appWidgetManager = WidgetActivity.appWidgetManager;

if (null == appWidgetIds)

appWidgetIds = WidgetActivity.appWidgetIds;

WidgetActivity.Widget = this;

WidgetActivity.context = context;

WidgetActivity.appWidgetManager = appWidgetManager;

WidgetActivity.appWidgetIds = appWidgetIds;

Log.i("PXR", "onUpdate");

final int N = appWidgetIds.length;

for (int i=0; i < N; i++) {

int appWidgetId = appWidgetIds[i];

//update the widget

updateAppWidget(context,appWidgetManager, appWidgetId);

}