I just found this article from reddit…
Samsung may drop Windows Mobile for Android
Apparently Samsung is going to stop using Windows Mobile on its cellphones and will concentrate on Android!! I have been a supporter of Android since its inception and stories like these bring tears of joy to my eyes.
Oh, and there’s something about Samsung rolling out their own open source OS called “Bada”. Good for them.
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In my previous post I linked to a terrific website (Working with XML on Android) which describes how you can read and parse XML documents in Android. The code supplied by that website used polymorphism to show 4 different methods for parsing the XML data. I vowed to simplify that and share the new source code.
To download the AndroidXmlSimple project click here. You will be taken to another page where you can click to download to the ZIP file.
Below are some instructions on setting yourself up with this source code and customizing it for your own XML data.
One of the most powerful aspects of any mobile application for a 3G phone is that it can connect to the Internet. By connecting to the Internet the application can offer much more value to the user since it becomes an interface for a web-based component, e.g. using Twitter’s API to create a Twitter application so that you can get your Twitter updates without having to open the mobile browser. The most common way of interfacing with a web-based component is by using web services in XML format.
While trying to developer my own app which reads a web service from my own server, I ran into a lot of difficulties in implementing the client that consumes the web service. Android does not have libraries for XPath handling of XML documents, so it makes deciphering XML data a little bit more difficult. From what I’ve read online the Android team is currently working on including such libraries in future versions.
After some digging around I found an amazing link that shows different methods for consuming an XML file in Android and parsing through it without the use of XPaths. The link is this: Working with XML on Android. To start off, this link is an absolute must-read. Everything that I am going to write in my post here relates to this link. The code offered on that webpage uses polymorphism to show you 4 different methods of working with XML data. It provides a fully-functional Android application and all the source code for it. The source code can be found here: AndroidXML.zip.
My post today will concentrate on how to customize the code from the application in the above link, in order to read and parse your own XML data. If you are a Java pro, you might not need this post. My Java is a little rusty, so I needed some time to figure out exactly what I had to change and where in order to get this to work with my own web service XML. Now that I’ve figured it out, I thought I’d share it. In my next post I will give the simplified version of this code – where there is no polymorphism, and thus there are only the minimum number of classes needed to implement this XML-reading solution. I can’t offer this simplified code right now – because I haven’t coded it yet :).
So until I post the simplified source code for working with XML data in Android, here are some tips on getting through the larger polymorphism-based source code and customizing it for your own XML data:
In my quest to create a “Taxman” Android application I ran into the following problem:
I want to ask the user to enter their yearly income, after which the screen will flip and their after-tax income will be displayed in a table format for all Canadian provinces. (And for the future: all US states). The problem I ran into is creating a TableRow for each Canadian province in my main.xml. There are 13 provinces and territories, so 13 is not that bad to copy & paste in the main.xml; however, as soon as I have to copy & paste more than 2 times I start cringing and nausea kicks in. Personally I think “copy & paste” should not be in the programming vocabulary. Not only that, but I have 13 provinces now, what about when I have to enter 50 states! So, I had to find a way to create these new TableRow rows programmatically inside my TableLayout layout.
A great source for code snippets and answers to Android questions is http://www.anddev.org. I’m sure if you’re dabbling with Android then you’ve already come across this site. The particular post I read to do this is this one: Dynamically add rows to TableLayout. Commenters on that post were having problems getting this to work, but after I imported all the correct classes (android.widget.TableRow.LayoutParams is an important one to use) everything worked from the first time. I forced Eclipse to find most of the classes for me.
Below is the code from anddev.org, with my changes for my Taxman Android app. I’m too lazy to do a full-out beginning-to-end tutorial for this code snippet.
First I set my constants at the top of the Activity class:
public class Activity1 extends Activity implements OnTouchListener{ int PROVINCE_Alberta = 0; int PROVINCE_BC = 1; int PROVINCE_Manitoba = 2; int PROVINCE_NewBrunswick = 3; int PROVINCE_Newfoundland = 4; int PROVINCE_Northwest = 5; int PROVINCE_NovaScotia = 6; int PROVINCE_Nunavut = 7; int PROVINCE_Ontario = 8; int PROVINCE_PEI = 9; int PROVINCE_Quebec = 10; int PROVINCE_Saskatchewan = 11; int PROVINCE_Yukon = 12; int numProvinces = 13;
In this post I will show you how to use the touch screen so that you can drag your finger across the screen, and it will switch the screen for you – “iPhone style”!
For this I will be implemented OnTouchListener and overrided the method OnTouch().
To start off, we need to create an Activity with two screens. The two screens will be implemented using a ViewFlipper in the main.xml layout file. Follow the steps in this blog post to set yourself up: Android: Switching screens in an Activity with animations (using ViewFlipper).
1. Now that you have yourself set up, open the Activity1 class.
2. Make the class implement OnTouchListener. The top of the class will look like this:
... import android.view.View.OnTouchListener; public class Activity1 extends Activity implements OnTouchListener{ ...
2. You will have to override the OnTouch() method as well. If you were using eclipse, it might have created the method stub for you:
@Override
public boolean onTouch(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
Here is the method that you need to use instead:
public boolean onTouch(View arg0, MotionEvent arg1) { // Get the action that was done on this touch event switch (arg1.getAction()) { case MotionEvent.ACTION_DOWN: { // store the X value when the user's finger was pressed down downXValue = arg1.getX(); break; } case MotionEvent.ACTION_UP: { // Get the X value when the user released his/her finger float currentX = arg1.getX(); // going backwards: pushing stuff to the right if (downXValue < currentX) { // Get a reference to the ViewFlipper ViewFlipper vf = (ViewFlipper) findViewById(R.id.details); // Set the animation vf.setAnimation(AnimationUtils.loadAnimation(this, R.anim.push_left_out)); // Flip! vf.showPrevious(); } // going forwards: pushing stuff to the left if (downXValue > currentX) { // Get a reference to the ViewFlipper ViewFlipper vf = (ViewFlipper) findViewById(R.id.details); // Set the animation vf.setInAnimation(AnimationUtils.loadAnimation(this, R.anim.push_left_in)); // Flip! vf.showNext(); } break; } } // if you return false, these actions will not be recorded return true; }
What I’ve done is added a CASE statement. On press down of the finger we save the current X value. On press up of the finger, after the dragging motion has finished, I check the X value again. I compare the two X values and I make a logical decision whether I should switch the screens forwards or backwards.
In this post I’ll show you how to add animations when trying to switch between screens. Usually when you switch between screens it’s a direct “poof” and the new screen appears in a very un-graceful way. The SDK offers a bunch of easy-to-use animations, and I’ll show you how to use them here.
I tried doing animations on the opening and closing of activities, but I haven’t figured that out yet fully. So instead, I will show you how to use animations when switching on objects/layers inside the same activity. It will still look like you are switching screens, but all the layout data will be in one single XML. If we were to switch between activities, each activity would have had (usually) its own layout XML.
And in the post coming after this one, I’ll show you how to start this animation and switch the screen while dragging your fingers on the touch screen. Let me be a little more precise: while dragging one finger on the touch screen. I’m not sure if the OS handles multi-touch right now – or if that’s something the device has to enable – or both.
Back to the topic: how to switch between layers using animations to make it look like you are changing screens… we will be using a ViewFlipper widget in the layout XML.
1. Create a new Android project, unless you already have one
2. Create a new Activity class that extends android.app.Activity.
While developing my Android apps I routinely, regularly, almost every time, without a miss, get some kind of exception. And the error you see on screen is not developer friendly, though it is very end-user friendly:
WTF? Why? What did I do wrong this time, again?
