View source for Android Phone development from the Linux command-line

Here is how I got the Android "HelloWorld" application to build/run from the command-line under Linux.

  cd /home/android/tools
  activitycreator --out helloproject hello.world.packages.helloActivity
  cd helloproject/src/hello/world/packages/
  vi helloActivity.java
  cd ../../../..
  ant
  cd ..
  emulator &
  adb install helloproject/bin/helloActivity-debug.apk

== Step-by-Step ==

ActivityCreator sets up all of the junk that the system needs - it's recommended that you run it from the android tools directory (why?):

  cd /home/android/tools
  activitycreator --out helloproject hello.world.packages.helloActivity

This creates a directory under tools called 'helloproject' - and under that is a 'src' directory containing hello/world/packages - with 'helloActivity.java' pre-created, ready for editing. 

So to edit our single source file application:

  cd helloproject/src/hello/world/packages/
  vi helloActivity.java

The simple program it creates doesn't do anything - so change it to read:

  package hello.world.packages;
  import android.app.Activity;
  import android.os.Bundle;
  import android.widget.TextView;
  public class helloActivity extends Activity
  {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       TextView tv = new TextView(this);
       tv.setText("Hello, Android");
       setContentView(tv);
    }
  }

Then, to compile it - head back up to the 'helloProject' directory and use 'ant' (which is like 'make' for Java - and uses 'build.xml' as it's 'Makefile').  The activitycreator made use a build.xml - so we just need:
 
  cd ../../../..
  ant

(That builds a 'debug' version that's "signed" so it'll only run on your system - to make a released version, you have to build with 'ant Release' - and then mess around with digital signature tools and stuff.  More on that on another page in the future!)

Assuming all goes well, we have a 'helloActivity-debug.apk' file in the helloproject/bin directory.  Next we go up to the 'tools' directory and start the phone emulator running:

  cd ..
  emulator &

...once it's all started up, we use the 'adb' program to install the executable onto the phone:

  adb install helloproject/bin/helloActivity-debug.apk

The program ends up in the main menu - just tap the screen there and it'll say "Hello Android".

Tadaaaaa!