Unlikely other elevation app, you can drop the pin anywhere you want, then find out the elevation right away. The app also allows you to export the data in various formats, such as KML, CSV, summary text, image, and so on.

Get this app while it is promotional price.

Download Geo Elevation for Android NOW!

Check out the demo movie here

The app also works for tablet device.

In addition, we will cover some of those programming materials in our new online course, Mobile GIS (Starting this september).

Download Geo Measure from Google Play

Geo Elevation is a powerful tool to build a cross-sectional elevation chart from any paths/points on the map with a few clicks. Simply create a path and click on “Get Elevation” you will see a nice chart. Now, this app works on both iPhone and iPad! Buy only once, and enjoy in both platform. We definitely recommend you to try it on iPad.

How does Mt. Everest look like if you cut through the peak, and view it from the side? Try to draw a path from your place to the nearest shoreline. See how slope decline as it approach the ocean? How about investingating the Mariana Trench’s steep slope, which goes down to the deepest place on the Earth?

In addition, the line of the elevation profile is clickable to indicate corresponding location on the path that you draw.

[Features]
- Get Elevation from single point
- Get Elevation from a path
- Path will automatically allocate 100 points (really high-definition of elevation profiles!)
- Export cross-sectional chart in PDF
- Export cross-sectional chart in PNG
- Export raw data in CSV format
- Export the path in KML
- Single-click to export all formats
- Indicator to match the side view and the top view
- Retina display compatible
- Customized UI for NEW iPad
- Multi-touch in the chart screen
- Current Location On/Off
- Draggable Waypoints (Adjust the path later)
- Instant calculation of the distance
- State of art intuitive path draw tool
- Universal binary works both iPhone and iPad.
- Unlimited Undo / Redo
- Convenient “Clear All” button to reset
- Navigation Mode (Lock the screen to browse)
- Search location to zoom the target location quickly

[Usage]
- As a bike / running route builder: It’s convenient to research your bike road profile in order to figure out the schematics of hills.

- Mobile Learning Experience in the Classroom. If you are teaching Geology or Earth Science, you might have a handout to build a cross-sectional elevation chart from a contour map, and you can let students to verify their answer by themselves. Don’t forget, Geo Elevation will provide infinite locations to investigate! The usage is unlimited.

- Possible flood area investigation: Before storm surge or high tide hit your town, verify locations or road that could be flooded. Draw the path from your house to the nearest shoreline to see the vertical profile.

- Plan your Walk or Run: If you host a walk or run event, Geo Elevation will help you to find out the slope so that you can map challenging hill in your event. Additionally, it might help you to setup multiple routs depend of the slope.

- For hiker and mountaineers (send us your review if you used for your activities!)

Add your feedback in comments or send us email to iphone [-at-] objectgraph.com.

We would like to hear more user experiences! How did you use it? What did you use it for? Is there anything to improve?

Bike Path Builder!

In this smartphone generation, we expected have a full browser functionality in API; iOS SDK is coming with UIWebView and Android has WebView.

This means, developer is able to take advantage the core engine, such as JavaScript parser. This might make developer’s life easier sometime because we can reuse same libraries from JavaScript – e.g form + validations, drawing chart and so on.

I looked around android documentations, StackOverflow and some forums but I could not find a good summary and organized complete example.
Here, I demonstrate my experiment of a full cycle of JavaScript / Java function calls from both sides.

Setup

1. Add WebView in your layout, and add HTML file in asset folder.

<WebView android:id="@+id/myWebView"
         android:layout_width="fill_parent"
         android:layout_height="fill_parent"></WebView>

2. Create a JavaScriptHandler class which has a reference to parent activity.

public class JavaScriptHandler {
    MyActivity parentActivity;
    public JavaScriptHandler(MyActivity activity) {
        parentActivity = activity;
    }
 
    public void setResult(int val){
        this.parentActivity.javascriptCallFinished(val);
    }
 
    public void calcSomething(int x, int y){
        this.parentActivity.changeText("Result is : " + (x * y));
    }
}

3. Load HTML and JavaScript in the Activity class and add the JavaScriptHandler class above.

myWebView = (WebView)this.findViewById(R.id.myWebView);
myWebView.getSettings().setJavaScriptEnabled(true);
myWebView.addJavascriptInterface(new JavaScriptHandler(this), "MyHandler");
myWebView.loadUrl("file:///android_asset/index.html");

4. Now, it’s ready to call from both side.

A) Call JavaScript from Java
In step 3, we added the handler in the WebView, and “MyHandler” would be the object that you can call in the html as below:

window.MyHandler.myfunction();

B) Call JavaScript from Java

On the other hand, if you need to call JavaScript from Java side, we use loadUrl with javascript keyword as below:

myWebView.loadUrl("javascript:myjavascriptfunc()");

or you can directly manipulate something like:

myWebView.loadUrl("javascript:document.getElementById('test1').innerHTML = '<strong>"+someText+"</strong>'");

So how about the full cycle? What if I want to call JavaScript function from Java, then I would get the result back from the process?

Here is important key point: loadUrl function is asynchronous call. Let’s say, your Java function wants to call a JavaScript function via loadUrl.
However, loadUrl dispatch the thread and you need to let WebView call your handler’s function inside. So let’s create two functions: call and finished.

Calling JavaScript

public void callJavaScriptFunctionAndGetResultBack(int val1, int val2){
    myWebView.loadUrl("javascript:window.MyHandler.setResult( addSomething("+val1+","+val2+") )");
}

Catching when the JavaScript call finished

public void javascriptCallFinished(int val){
    Toast.makeText(this, "Callback got val: " + val, 5).show();
}

In this example, I’m passing two integer values in the first call function. In the argument, it’ll call addSomething() JavaScript function, and then
it places the result back by calling MyHandler’s function, which is an interface object, in order to call Java function over there. Let’s come back to
Java side. In Java side, since we get reference from the parent Activity class, we just call one of member functions.

public class JavaScriptHandler {
//....
    public void setResult(int val){
        this.parentActivity.javascriptCallFinished(val);
    }
//....

Here is the function to be called in Activity.

public void javascriptCallFinished(int val){
     Log.v("mylog","MyActivity.javascriptCallFinished is called : " + val);
}

… however this would not give a good result when you write a real app because you often put the value back to UI which need to be run in the main thread!

So use a runOnUiThread (such a nice name). If you need to pass something, you must add final keyword, which allows the variable to be used inline Runnable class.

Finally, the “Finished” function will be look like this:

public void javascriptCallFinished(final int val){
    Log.v("mylog","MyActivity.javascriptCallFinished is called : " + val);
    // I need to run set operation of UI on the main thread.
    // therefore, the above parameter "val" must be final
    runOnUiThread(new Runnable() {
        public void run() {
            myResult.setText("Callback got val: " + val);
        }
    });
}

Below is the diagram how it goes from Java to JavaScript and from JavaScript to Java.

That’s it! This could be confusing in the first look, so please download the sample code. The project is created with IntelliJ and this is 100 times better IDE than eclipse.

Download

https://github.com/kiichi/AndroidJavasScript

Demo

Reference

Most of information were published on those documentation pages:

http://developer.android.com/guide/webapps/webview.html

http://developer.android.com/resources/articles/using-webviews.html

I am pleased to announce Android version of our popular iRectangles puzzle for iOS.

You can download it here for Free.

For people who might not know.. Rectangles is the next generation of puzzle game from the same inventor of Sudoku!
The objective of the game is to create rectangles that fill the entire board. Each of the rectangle should correspond to the number of cells posted.
You can select the cells to create a rectangle by simply dragging your finger on the board. To deselect just double tap on the selected cells.

Video

Additional Screenshots

The device costs only $99 and the installation process is extremely simple. Hook up the little black antenna into your iPhone, then wait for 1 second for LED on. If you did not install Free WiPry app before, it will automatically ask you to download  the app for you.

The main screen looks like a heat map, which active channels are represented as red-yellow spikes. Press the icon to toggle different channels and use your finger to drag across all channels. For example, if you are operating your WiFi router on channel 6, scrub the frame to the middle of screen. You will see some “hot area” within the range.

This is the example of channel 1 signals in my work environment.

Other channels like 10 or 11 dominates in this screenshot.

Select your channels to investigate.

The reason that I started looking for WiFi signal scanners is because iOS5 completely hide the Apples 802.11 WiFi manager framework, even it’s for private API usage. Our academic project, WiFi Mapping, used to use the functionality but it’s not available anymore. I start exploring different data collecting methods outside of iOS native, such as accessories, Android or Windows Phone.

As far as I see the current version of WiPry, I could not find SSID information along the signal strength. This could be the same restriction from Apple for those semiconductor companies (just like I experienced in above example…). Basically, Apple is not happy to give features that developers or manufactures are able to build a WiFi scanner app / device.

WiPry could be useful to analyze conflicted channels for network engineer; however, I could not use it for my WiFi mapper app due to lack of SSID information. I show this to folks in our network team and they show me some interests to purchase this device. The response on the screen is real-time and the user is expected to have some kind of special knowledge about WiFi. I would like to hear from real network engineers’ opinion. Please leave comments if you have any thoughts.

Lantronix xPrintServer

Size: LxWxH 4.50″ x 2.37″ x .87″,

Weight:.27 Kg/0.6 pounds (xPrintServer device + power supply)

Ethernet and power connections

Power Adapter

Set up is very simple and straight forward. There’s no need to download any software or driver. You just need to connect the device to your network (router, switch, etc.) by using ethernet cable. The device will automatically discover all your network printers. Now all you need to do is connect your iPhone or iPad to the network via wifi, select the printer and print the documents.

• Connect Lantronix xPrintServer to your network and power adapter
• Open your idevices to the same network via wifi
• Choose what you want to print, select print and select your printer

You can get more details at their website: lantronix.com

You can grab one for $149.95 Here

We also added a new measure for area (Tsubo)

Here are some screenshots from Japanese version:

Also the iPad version has also been localized for Japan

Download the Version 1.1 from the app store.

Creating DB

SQLiteDatabase db = openOrCreateDatabase("mydb",MODE_PRIVATE,null);

This is a neat function which does open and create at the same time. You need to name your database (e.g. “mydb”) and specify the mode to open. In this example, I’m opening the database as private mode that allows only your app to touch the file.

Execute SQL

1
2

db.execSQL("CREATE TABLE IF NOT EXISTS mydata (first_name,last_name,age)");
db.execSQL("INSERT INTO mydata (first_name,last_name,age) VALUES('Jon','Doe',20)");

Since it’s already opened, executing CRUID operation is available via execSQL function.

Query data

1
2
3
4
5
6
7

Cursor cursor = db.rawQuery("SELECT * FROM mydata ORDER BY age",null);
if (cursor.moveToFirst()){
    do {
       Log.v("mylog", cursor.getString(0) + "," + cursor.getString(1) + "," + cursor.getString(2));
    }
    while(cursor.moveToNext());
}

To query data, you need two steps:

1. Create a cursor from the result of your select statement
2. Move the cursor and retrieve data via get… functions.

I often make a mistake to retrieve data from the cursor without calling moveToFirst() function. Let’s call it first and this returns if there is a row to return or not. After moving to the first row, keep calling moveToNext() function until you reach the end of rows.

Closing

1
2

cursor.close();
db.close();

Let’s make sure to close all connection to db. Avoid unnecessary memory usage.

That’s it. If you want to see a sample project (created by IntelliJ), please click here. You can browse the entire source code from here.

Check your forecast with our updated FengShui app 2012 Edition.

Year of the Dragon

Gong Yi Fa Cai 恭喜發財! In 2012, the Chinese New Year falls on January 23rd in
China, which occurs before the official solar start of the year on February 4th, known as Li Chun 立春 or Spring Begins. It is a powerful and dangerous year that starts fluidly; be sure to act smart and move fast. The calendar of this year is very complicated because the first new moon after the Winter Solstice on December 21, 2011 is December 23, 2012, followed by the second new moon and start of the lunar New Year, January 23, 2012 (January 22nd
in Asia). This tight start indicates a “whipping” effect that will bring about strong winds and discontent. Be sure to leave the front door of your home open this evening, especially if it is facing in a beneficial direction, so that you can gather good fortune throughout the night. It is an important year to use Feng Shui, as there will be very dangerous periods during the year for which it will feel as if you are fighting for your life to survive.

Screenshots:

You will download now!

We called it MoPic.

MoPic is a free app that makes it easy to create fun GIFs and share them with your friends.

Create a hilarious GIF animation of your cat in the washing machine, a donut disappearing in the mouth of your buddy as it’s being eaten, or anything else that comes to your mind. The possibilities are endless. Animations created with MoPic can easily be shared with your family and friends. Make them laugh endlessly as these GIFs replay these funny moments over and over again.

.

How it works:
1. Tap on “Take a Video” or “Choose from Library” buttons to select your video or single frames.
2. Tap on “Done” to generate a preview of the GIF and adjust the speed
3. Share it with your friends over Email, Twitter or Save it for later. (More options in upcoming updates)

Features:
✓ Generate random GIFs based on the video you provide
✓ Select frames you would like to use in your GIF animation
✓ Share it with your friends.
✓ Works only with 30 FPS at the moment.

Compatible Hardware: iPhone 3GS, iPhone 4, 4th gen iPod Touch, iPad 2 (in 2x mode only)
Compatible OS: iOS 4.1 and greater.

Please write us and feel free to give us your feedback or request new features that you would like to see in future updates.

• Know how to use Location Manager
• Convert degree to radian
• Understanding Core Animation to rotate an image

Step 1: Create a project (e.g. CompassExample) and include frameworks

#import <CoreLocation/CoreLocation.h>
#import <QuartzCore/QuartzCore.h>

Step 2: In .h file, create Location Manager Object

CLLocationManager *locationManager;

Implement delegate

<CLLocationManagerDelegate>

Next, add parameter

@property (nonatomic,retain) CLLocationManager *locationManager;

… don’t forget to synthesize it in .m file.

@synthesize locationManager;

Step 3: In .h file, create UIImageView and add reference in Interface Builder

IBOutlet UIImageView *compassImage;

Download Image from here

Step 4: In .m file’s viewDidLoad function, initialize the location manager.

	locationManager=[[CLLocationManager alloc] init];
	locationManager.desiredAccuracy = kCLLocationAccuracyBest;
	locationManager.headingFilter = 1;
	locationManager.delegate=self;
	[locationManager startUpdatingHeading];

Step 5: In .m file, implement delegate function.

First, you need to convert degree (e.g 360) to radian (e.g 3.14=2PI).
Second, multiply -1 in order to rotate opposite direction that you twist your phone.
Third, apply rotation with core animation function. In this example, I’m rotating from the current value to the new value. The duration is 0.5 second as you see below.

- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading{
	// Convert Degree to Radian and move the needle
	float oldRad =  -manager.heading.trueHeading * M_PI / 180.0f;
	float newRad =  -newHeading.trueHeading * M_PI / 180.0f;
	CABasicAnimation *theAnimation;
	theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.rotation"];
	theAnimation.fromValue = [NSNumber numberWithFloat:oldRad];
	theAnimation.toValue=[NSNumber numberWithFloat:newRad];
	theAnimation.duration = 0.5f;
	[compassImage.layer addAnimation:theAnimation forKey:@"animateMyRotation"];
	compassImage.transform = CGAffineTransformMakeRotation(newRad);
	NSLog(@"%f (%f) => %f (%f)", manager.heading.trueHeading, oldRad, newHeading.trueHeading, newRad);
}

That’s it! Of course, you have to deploy the app on your device to check the direction.

Source Code:

https://github.com/kiichi/CompassExample

Lets say you are building a game and would like to pass data between your menu screen and the game screen. You show a bunch of options to the user in the menu screen and you have to pass the appropriate paramater to the Game Screen. Lets call our Activities GameActivity and MenuActivity

Loading a different GameActivity from MenuActivity:

First thing you need to understand is how to load a different activity from current activity. In order to do this, we use Intent class. Here is some code.

Intent intent=new Intent(view.getContext(),GameActivity.class);
startActivity(intent);

As you can see Intent class will load the class dynamically (reflection) and show you the new activity on the screen. Lets assume you created 3 buttons on the menu screen

1. Easy
2. Medium
3. Hard

You have to pass a parameter to your GameActivity which level the user wants to play. Here is some code that will accomplish it.

1
2
3
4
5

Intent intent=new Intent(view.getContext(),GameActivity.class);
Bundle bundle=new Bundle();
bundle.putString("gameLevel","Easy");
intent.putExtras(bundle);
startActivity(intent);

You would repeat the same code above for different Game Level selections on your MenuActivity.

In the Game Activity you need to retrieve the passed bundle.

Bundle bundle=getIntent().getExtras();
String level=bundle.getString("gameLevel");
if(level.equals("Easy"){
...
}
else if(level.equals("Medium")}
...
}

You can pass various other types in a bundle. Check Android documentation at http://developer.android.com/reference/android/os/Bundle.html

Download Source for the sample project Below

Sample Project.

I chose one of our simplest sounds apps for Christmas. Here is a screenshot of the same.

The top buttons play the background music and the individual icons on the shelf play simple sounds.

My first struggle was with the layout and making it work with various other android devices. I will write an another post for that. But with regards to playing the actual sound files there were problems also.

There are 2 ways of playing sounds.

1. MediaPlayer class
2. SoundPool class

MediaPlayer:

Using media player is simple.

MediaPlayer backgroundMusicPlayer1;
backgroundMusicPlayer1 = MediaPlayer.create(this, R.raw.music1);
backgroundMusicPlayer1.setLooping(true);

And in order to play the music, just call

backgroundMusicPlayer1.start();

This is fine for playing a few files, but as you keep calling MediaPlayer.create(..), You will run out of memory and your app will crash. The better way to do this is using SoundPool class.

Instantiate SoundPool class

 
//Declaration
SoundPool soundPool;
 
//Initialization 
soundPool = new SoundPool(8, AudioManager.STREAM_MUSIC, 0);

The first parameter is number of simultaneous streams you can have. second is type of stream and third is quality. 3rd parameter has not been implemented as of this writing, so you can safely just put a zero.

Here is documentation for SoundPool: http://developer.android.com/reference/android/media/SoundPool.html

Unfortunately whenever a sound is loaded to the soundPool, it generates its own SoundID (An integer) that you have to keep track of. In my app, I just created a hashmap that takes cares of mapping the loaded soundIDs to Icon tags.

//Declaration
HashMap<String, Integer> soundPlayers;
 
//Initialization
soundPlayers = new HashMap<String, Integer>();

I load sounds dynamically when an icon is clicked. Here is my code.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

btn.setOnClickListener(new OnClickListener() {
 public void onClick(View v) {
     v.startAnimation(AnimationUtils.loadAnimation(ChristmasSoundsActivity.this, R.anim.image_click));
     if(soundPlayers.containsKey(v.getTag())){
         int sound = (int) soundPlayers.get(v.getTag());
         soundPool.play(sound, 1.0f, 1.0f, 1, 0, 1.0f);
 
     }
     else{
         int sound = soundPool.load(ChristmasSoundsActivity.this, getResources().getIdentifier("sound" + v.getTag(), "raw", "com.objectgraph.ChristmasSounds"), 1);
         soundPlayers.put(v.getTag().toString(), sound);
 
     }
 
 }
});

In Line6 as you can see, I am calling the soundPool.play

The first parameter is the soundID which i get from my hashmap. The parameters are listed below.

paramter 1:soundID	a soundID returned by the load() function
paramter 2:leftVolume	left volume value (range = 0.0 to 1.0)
paramter 3:rightVolume	right volume value (range = 0.0 to 1.0)
paramter 4:priority	stream priority (0 = lowest priority)
paramter 5:loop	loop mode (0 = no loop, -1 = loop forever)
paramter 6:rate	playback rate (1.0 = normal playback, range 0.5 to 2.0)

• CIImage: holds the image data
• CIFilter: holds filters information and attributes
• CIContext: is where all the image processing are taking place

For this article we will try out “CISepiaTone” filter. Let’s start

1. Open your Xcode and create a single view application
2. Add CoreImage.framework framework to the project
3. Add an image (any image in jpg or png) to our project
4. Let’s add an UIImageView to our xib and add the UIImageView in our .h file and connect with our UIImageView in the xib

UIImageView *imageView;

5. In the viewDidLoad method, add the following code

  //First load our image
   NSString *filePath = [[NSBundle mainBundle] pathForResource:@"image_name" ofType:@"jpg"];
   NSURL *fileNameAndPath = [NSURL fileURLWithPath:filePath];
 
    //We need context, filter, sourceimage and outputimage
    CIContext *context;
    CIFilter *filter;
    CIImage *sourceImage;
    CIImage *outputImage;
 
    //Get the source image from NSURL 
    sourceImage = [CIImage imageWithContentsOfURL:fileNameAndPath];
 
    //Create context, here you can also specify cpu or gpu option
    context = [CIContext contextWithOptions:nil];
 
    //Declare our filter and attribute value
    filter = [CIFilter filterWithName:@"CISepiaTone"
                        keysAndValues: kCIInputImageKey, sourceImage,
                        @"inputIntensity", [NSNumber numberWithFloat:0.8], nil];
 
    //Apply filter and write to output image
    outputImage = [filter outputImage];
 
    //Assign outputimage to cgimage, cgimage to UIImage and then to our UIImageView
    CGImageRef cgimg = [context createCGImage:outputImage fromRect:[outputImage extent]];
    UIImage *newImg = [UIImage imageWithCGImage:cgimg];
 
    [imageView setImage:newImg];
 
    CGImageRelease(cgimg);

Run the project and you will see your image is transformed by the filter. You can read more about the framework and additional filters on developer.apple.com
Here are the screen shots of before and after effects of our filter:

I found Sparrow extremely easy to learn and if you have prior 2D or 3D game development experience, it should be even easier to pick up. To get started, download the latest package from:

http://www.sparrow-framework.org/download/

This package comes with the Sparrow library, a demo project, and a scaffold project that can be used as a starting point for all of your Sparrow apps.

For more detail, you can always read the Getting Started guide at:

http://www.sparrow-framework.org/help/gettingstarted/

When you first try to compile, you may get some errors related to the Sparrow source path. To remedy this, go to Xcode preferences > Locations > Source Trees. Create a variable called SPARROW_SRC and point it to the absolute path of your /sparrow/src/ folder.

For example, mine is:

/Users/ken/Work/Sparrow-Framework/sparrow/src

Try testing out the scaffold project to see if it works. If you’re able to see a red square rendered on the screen, Sparrow is setup correctly. Pretty boring so far, right?

I wanted to take it a step further and had an idea in my mind. My first inspiration came from typing in “let it snow” in Google. Determined to produce something with a somewhat similar effect on the iPhone, I had to see what Sparrow was capable of. The concept was to show a glass window on a snowy night. As time passes, snow will accumulate on the window. You may then use your finger to swipe away the snow.

First I created a canvas of type SPRenderTexture to draw on.

SPRenderTexture *mTexCanvas;
SPImage *mImgCanvas;

mTexCanvas = [[SPRenderTexture alloc] initWithWidth:320 height:480];
[mTexCanvas clearWithColor:0xffffff alpha:0];
mImgCanvas = [SPImage imageWithTexture:mTexCanvas];
[self addChild:mImgCanvas];

Next, I needed snowflakes of type SPImage for a few different sizes.

SPImage *mImgSnowLarge;
SPImage *mImgSnowMed;
SPImage *mImgSnowSmall;

mImgSnowLarge = [SPImage imageWithContentsOfFile:@"snow_l.png"];
mImgSnowMed = [SPImage imageWithContentsOfFile:@"snow_m.png"];
mImgSnowSmall = [SPImage imageWithContentsOfFile:@"snow_s.png"];

We will also need to create an eraser brush to wipe away the snow.

SPImage *brush;

brush = [SPImage imageWithContentsOfFile:@"erase.png"];

I also created an SPImage for the background of the sky.

SPImage *mImgSky;

mImgSky = [SPImage imageWithContentsOfFile:@"night.png"];
[mImgSky retain];
[self addChild:mImgSky];

Since I wanted the snow to accumulate on the window glass over time, I also added a timer.

NSTimer *mTimer;

mTimer = [NSTimer scheduledTimerWithTimeInterval:0.1f target:self selector:@selector(ticked) userInfo:nil repeats:YES];

To keep track of the touch events when you drag the eraser brush over the snow, I added event listeners to check when erasing firt took place and when erasing finished.

[self addEventListener:@selector(update:) atObject:self forType:SP_EVENT_TYPE_ENTER_FRAME];
[self addEventListener:@selector(touched:) atObject:self forType:SP_EVENT_TYPE_TOUCH];

One thing that I had noticed was that Sparrow did not support erasing out of the box. After digging through some of the Sparrow extensions, I stumbled upon SPRenderTexture+Erase that might be able to do what I wanted.

After some experimentation, it did exactly what I needed it to do. This extension allowed me to erase a SPRenderTexture with an SPDisplayObject. In my case, my eraser brush was an SPImage. Erasing is simply one line of code whenever erasing took place.

[mTexCanvas eraseWithObject:brush];

My update and touched event handlers look like this.

- (void)update:(SPEnterFrameEvent*)event{
	if(drawing){
		// group the draw calls together for speed
		[mTexCanvas bundleDrawCalls:^{
			double incX = (newTouch.x - lastTouch.x)/numSteps;
			double incY = (newTouch.y - lastTouch.y)/numSteps;
			brush.x = lastTouch.x - (brush.width/2);
			brush.y = lastTouch.y - (brush.height/2);
 
			// loop through so that if our touches are far apart we still create a line
			for (int i=0; i<numSteps; i++){
				[mTexCanvas eraseWithObject:brush];
				brush.x += incX;
				brush.y += incY;
			}
		}];
		lastTouch = CGPointMake(newTouch.x, newTouch.y);
	}
}

- (void)touched:(SPTouchEvent*)event{
	SPTouch *touchStart = [[event touchesWithTarget:self andPhase:SPTouchPhaseBegan] anyObject];
	SPPoint *touchPosition;
	if(touchStart){
		touchPosition = [touchStart locationInSpace:self];
		lastTouch = CGPointMake(touchPosition.x, touchPosition.y);
		newTouch = CGPointMake(touchPosition.x, touchPosition.y);
	}
 
	SPTouch *touchMove = [[event touchesWithTarget:self andPhase:SPTouchPhaseMoved] anyObject];
	if(touchMove){
		touchPosition = [touchMove locationInSpace:self];
		newTouch = CGPointMake(touchPosition.x, touchPosition.y);
		drawing = YES;
	}
 
	SPTouch *touchEnd = [[event touchesWithTarget:self andPhase:SPTouchPhaseEnded] anyObject];
	if(touchEnd){
		touchPosition = [touchEnd locationInSpace:self];
		lastTouch = CGPointMake(touchPosition.x, touchPosition.y);
		newTouch = CGPointMake(touchPosition.x, touchPosition.y);
		drawing = NO;
	}
}

That’s all there is to it. Once I build and run, I get something like this.

I’ve also posted a short 30 seconds video below.

Sorry to all Eclipse lovers, I just hate developing in Eclipse. Coming from Visual Studio and XCode, I just felt that eclipse was not responsive enough for Android development. I started my research for a good alternative. I even contemplated building everything manually using TextMate. But I think I finally found some good Android development tool that does not suck. Its IntelliJ IDEA and I use their free community edition. IDEA can open your eclipse projects and works seamlessly with Android emulator.

Downloading:

Download IntelliJ IDEA community edition from http://www.jetbrains.com and install it on your platform. The rest of the post is for Mac OSX Lion. But it should be similar for others platforms.

Setting Up:

First thing you would do is download the android SDK and install some where. I put mine @

/Users/gavi/work/android-sdk-mac

Add the android path in your profile. Edit your .bash_profile

vi ~/.bash_profile

Add SDK tools paths

export PATH=$PATH:/Users/gavi/work/android-sdk-mac/platform-tools:/Users/gavi/work/android-sdk-mac/tools

Save the file and execute

source ~/.bash_profile
android

Then you can download the necessary SDKs you need(Android 2.3.3, ICS etc). Here is a screen shot.

Once your sdk is setup. Start up IntelliJ

The first thing you want to do is setup your Java SDK. On Mac, The path is similar to below

/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home

Then you can add Android SDKs. Here is a quick video I recorded which makes it simple.

Setting Up IntelliJ SDKs for Android from ObjectGraph LLC on Vimeo.

Thats it. Just have fun developing for Andorid!

1
2
3
4

[WebMethod]
public static int Sum(int a, int b) {
    return a + b;
}

Make sure your page method is static

The JQuery way of calling this function would be something similar to this.

1
2
3
4
5
6
7
8
9
10
11
12
13
14

$(document).ready(function () {
    $("#btnSum").click(function () {
        $.ajax({
            type: "POST",
            url: "Default.aspx/Sum",
            data: "{'a':" + $("#txtA").val() + ",'b':" + $("#txtB").val() + "}",
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function (result) {
                $("#lblOutput").html(result.d);
            }
        });
    });
});

In Line 5, I am assuming the file name is Default.aspx and thus you call Default.aspx/Sum. If you notice on line 10, the result is enclosed in a json object called “d”. So to unpack you would have to call result.d

HTML Form would be something like this

1
2
3
4
5
6
7
8

<form id="form1" runat="server">
    <div>
          A: <input type="text" id="txtA" />
          B: <input type="text" id="txtB"/>
          <input type="button" value="Sum" id="btnSum"/>
          <div id="lblOutput"></div>
    </div>
</form>

You can download the file below

Page Methods Sample

Step 1. Add ASIHTTPRequest in your project.

Step 2. Add ShareKit in your project.

Step 3. Get TwitPic application key and add it in SHKConfig.h

#define SHKTwitPicKey				@"a2f2c8902414d2c624d10403463c50c9"

Step 4. Replace codes around sendImage function in ShareKit > Sharers > Services > Twitter > SHKTwitter.m

#import "ASIHTTPRequest.h"
#import "ASIFormDataRequest.h"
 
- (void)sendImage {
	NSURL *url = [NSURL URLWithString:@"http://api.twitpic.com/1/uploadAndPost.json"];
	ASIFormDataRequest *req = [ASIFormDataRequest requestWithURL:url];
	[req addPostValue:SHKTwitPicKey forKey:@"key"];
	[req addPostValue:consumerKey forKey:@"consumer_token"];
	[req addPostValue:SHKTwitterSecret forKey:@"consumer_secret"];
	[req addPostValue:accessToken.key forKey:@"oauth_token"];
	[req addPostValue:accessToken.secret forKey:@"oauth_secret"];
	[req addPostValue:[item customValueForKey:@"status"] forKey:@"message"];
	[req addData:UIImageJPEGRepresentation([item image], 0.8) forKey:@"media"];
	req.requestMethod = @"POST";
	[req setDelegate:self];
	[req startAsynchronous];
	return;
}
 
- (void)requestFinished:(ASIHTTPRequest *)request{
	//NSString *responseString = [request responseString]; // do json parsing if you want.
	[self sendDidFinish]; // remove the spining shit
}
 
- (void)requestFailed:(ASIHTTPRequest *)request{
//	NSError *error = [request error];
	[self sendDidFinish]; // remove the spining shit
}

Step 4. Call Twitter service from ShareKit like:

	SHKItem *item = [SHKItem image:[UIImage imageWithContentsOfFile:mFileName] title:@"Look at this picture!"];
	[SHKTwitter shareItem:item];