• Handle intents
• Start activities
• Make phone calls
• Send text messages
• Scan bar codes
• Poll location and sensor data
• Use text-to-speech

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    WebView webview = new WebView(this);
    webview.getSettings().setJavaScriptEnabled(true);
    webview.setWebViewClient(new WebViewClient() {
        @Override public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
    	    return true;
    	}
    });
    webview.loadUrl("http://google.com");
    setContentView(webview);
}

However, if you follow a link to an image it downloads instead of opens in the view. That’s the same thing the built in browser does, but wasn’t the behavior I expected. I’ll have to figure out how to handle that a bit better.

• Install Wireshark
• Follow the instructions in the readme to also install the ChmodBPF script
• Under Sharing area of the OS X settings app configure your system to use an ethernet connection and share it out to wifi clients
• Now configure your device to connect to the wifi network provided by your system, test to make sure it works
• Startup Wireshark and set it to capture traffic (wifi is en1 on MacBook Pro systems, what I normally use)

And that’s it, you should now get quite readable dumps of what applications are doing to communicate. Lots of interesting things you can learn digging into how folks structure their client/server interaction.

When you tap the widget once it brings up a selector with launchers for each of the apps you’ve added plus an icon to start the widget configuration interface. Here’s what mine looks like after tapping on the widget:

And what the configuration interface looks like if you tap on that center icon:

I think it’s a pretty slick widget. Great way to increase launcher density if you have a few widgets taking up some space. And it looks pretty good there on the home screen.

1. Follow the instructions to download and build Android from source. Follow the whole thing (I had to create a case-sensitive disk image and all), including the actual build step. Otherwise you won’t have the libraries necessary and agcc will error out when you try to run it.
2. Add the prebuilt/darwin-x86/toolchain/arm-eabi-4.2.1/bin subdirectory of where ever you built the source to your PATH, add it to your .bash_profile if you want.
3. Download the agcc wrapper script, put it somewhere in your path, and make it executable.

Now you should be ready to compile a program and download it to your phone. This was my test app:

#include <stdio.h>

int main( int argc, char **argv ) {
  printf("Hello from Droid Hacks!\n");
  return 0;
}

And you should be able to compile it with “agcc hello.c -o hello” and end up with a hello executable:

~ > agcc hello.c -o hello
~ > file hello
hello: ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically linked (uses shared libs), not stripped
~ >

And you can move the file across to the phone and run it. You’ll have to make a directory to push it into. The sdcard is marked as noexec, so you can’t run stuff from there. And the data directory has more restrictive permissions. So you’ll have to su and create a directory on the data partition, and relax the perms on that directory:

~ > adb shell
$ su
# mkdir /data/droidtest
# chmod 777 /data/droidtest
# exit
$ exit
~ > adb push hello /data/droidtest
418 KB/s (6747 bytes in 0.015s)
~ > adb shell
$ cd /data/droidtest
$ ls -l
-rwxrwxrwx shell    shell        6747 2009-05-27 08:56 hello
$ ./hello
Hello from Droid Hacks!
$

And of course you can run the same thing from the terminal on your device as well:

• mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system
• cd /system/bin
• cat sh > usu
• chmod 4755 usu

Some of the instructions I found online suggested just calling the new binary su, but I was concerned about that overriding the default su depending on what path is getting used. So I just created a whole name “user su” which won’t reject the handset user when I try to change to root:

• Turn on and off airline mode
• Turn on and off autosync
• Turn on and off bluetooth
• Turn on and off GPS
• Turn on and off Wifi, and show what network you’re connected to if you are connected
• Control the brightness level and screen timeout, or disable screen timeout completely
• Turn on and off silent mode
• Control the volume