Droid Hacks

Tips and Tricks for Android Users

Posts Tagged howto

Getting WebView To Load New Pages

Jun 3

Posted by Lead Hacker in Development

There are a bunch of examples of using WebView to display HTML content loaded from the web in an Android app, including the sample from Google for the WebView class. However the ones I found generally don’t load new pages on their own. I can load up Google, but if you click on anything in the app it launches a browser and takes the user out of the app. The answer to the problem is in the additional points on that Hello, WebView page – you need to set a new WebViewClient to handle the URL load requests. Their example is very helpful, but I prefer to do the override with an anonymous inner class:

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.

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Compiling C Code for Android Using OS X

May 27

Posted by Lead Hacker in Tips

I wanted to try out compiling some native C code for use on my device, but I wanted to do it using my OS X machine. I found this post about using the prebuilt toolchain over at Android Tricks, but figured I would write up some additional details for those who might also be looking.

  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:terminal_c_app_rotated

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