A blast from my past...

An old colleague of mine (he is in the video) posted this to FB.

Many moons ago, I was the Technical Product Manager for MKS Internet Anywhere...

Thanks Sean!

So, ever since moving from Eclipse to Android Studio, I've been annoyed by the fact that importing an old project copies all the libraries under the project directory. This makes sharing libraries a bit more difficult, since you now need to manage them in two locations.

Apparently Gradle likes dependencies is under its root, for example:

Project
  |--build.gradle
  |--settings.gradle
  |--Dependency
  |    |--build.gradle

Now in most of my cases, I have my libraries as separate projects that I DO NOT want located under the app's root. So today, I finally got off my ass to figure out how to do that. (Yes, I've been very lazy about this)

The fix it turns out is rather simple. To achieve a directory structure like this:

Project
  |--build.gradle
  |--settings.gradle
Dependency
  |--build.gradle

In the project/settings.gradle, add the following:

include ':Dependency'
project(':Dependency').projectDir = new File(settingsDir, '../Dependency/module_build_gradle_location')

If you've just finished an import, you can now manually delete the imported module and rebuild the project.

ActivityCompat.requestPermissions : Can only use lower 8 bits for requestCode

So, my latest got'cha is that ActivityCompat.requestPermissions forces you to use a value between 0 and 255. The android developers are playing tricks with the result code, thus restricting you to this range. Now, it would be nice if this was documented in the online ActivityCompat documentation, since this is going to be rarely hit in testing.

Documenting the findings for future reference:
The following are code from android.support.v4.app.FragmentActivity

 /**
 * Modifies the standard behavior to allow results to be delivered to fragments.
 * This imposes a restriction that requestCode be <= 0xffff.
 */
@Override
public void startActivityForResult(Intent intent, int requestCode) {
    if (requestCode != -1 && (requestCode&0xffff0000) != 0) {
        throw new IllegalArgumentException("Can only use lower 16 bits for requestCode");
    }
    super.startActivityForResult(intent, requestCode);
}

@Override
public final void validateRequestPermissionsRequestCode(int requestCode) {
    // We use 8 bits of the request code to encode the fragment id when
    // requesting permissions from a fragment. Hence, requestPermissions()
    // should validate the code against that but we cannot override it as
    // we can not then call super and also the ActivityCompat would call
    // back to this override. To handle this we use dependency inversion
    // where we are the validator of request codes when requesting
    // permissions in ActivityCompat.
    if (mRequestedPermissionsFromFragment) {
        mRequestedPermissionsFromFragment = false;
    } else if ((requestCode & 0xffffff00) != 0) {
        throw new IllegalArgumentException("Can only use lower 8 bits for requestCode");
    }
}

RANGE
startActivityForResult() in FragmentActivity requires the requestCode to be of 16 bits, meaning the range is from 0 to 65535.
Also, validateRequestPermissionsRequestCode in FragmentActivity requires requestCode to be of 8 bits, meaning the range is from 0 to 255.

see: http://stackoverflow.com/questions/33331073/android-what-to-choose-for-requestcode-values

DatePicker, Sony Xperia and dates before 1980

I had a user report that they could not set a birth date before 1980 on their Sony Xperia phone. Bit of a problem if you are older than 36.

To fix this, first add the following to where ever you are inflating your datepicker:

this.datePicker = (DatePicker) view.findViewById(R.id.datePicker);
// hack also added to styleif (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
    Calendar calendar1 = Calendar.getInstance();
    calendar1.set(1900, Calendar.JANUARY, 1, 0, 0, 0);
    datePicker.setMinDate(calendar1.getTimeInMillis());
}

Unfortunately, the DatePicker.setMinDate is not exposed pre HONEYCOMB so to fix those apps, you can try adding this to your base application style

<!-- Base application theme. --><style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->    <item name="android:startYear">1900</item>
</style>

I failed sharing in Kindergarten, so when asked to do a simple sample app, I had to create myself a GitHub account. Normally I use Bitbucket due to their more commercial friendly approach.

Set up was reasonably painless and my first impressions are positive.

My challenge, as given was as follows:

Framework:

• Android Studio 2.0+
• Gradle build system
• Target SDK Marshmallow
• Min SDK Ice Cream Sandwich
• The use of 3rd-party libraries to facilitate development is encouraged

Task

• Create a new android project
• The Root Activity should be a Navigation Drawer
• The application should follow the material design principles
• The core view of the main activity should be a Recycler View
• The Recyler should implement some sort of custom view
• The custom view should download and display images downloaded from the internet (imgur)

To see my sample app, CLICK HERE

Android DialogPreference validation

I've created a custom DialogPreference for one of my apps, but the problem was, I needed to validate the supplied input. I didn't want the dialog to close when the OK button was clicked, if the input was not correct.

To do it, I did as follows, in my custom DialogPreference

@Override
protected void showDialog(Bundle state) {
    super.showDialog(state);
    final AlertDialog dialog = (AlertDialog) getDialog();
    Button button = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
    button.setOnClickListener(new View.OnClickListener() {
         @Override         
         public void onClick(View view) {
             // Validation
             if (mNameEditText.getText().toString().isEmpty()) {
                 mNameEditText.setError(getContext().getString(R.string.pref_error_empty));
                 return;
             }
             PersonPreference.super.onClick(dialog, DialogInterface.BUTTON_POSITIVE);
             dialog.dismiss();
         }
     }
    );
}

Using a java library created with Android Studio, throws the following error in the build, when you include it in another project:

Error:com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000)

The fix, dumb as it is, is to include the following two settings in the build.gradle file for the library, in the project.

sourceCompatibility = 1.7 

targetCompatibility = 1.7

after inclusion, it should look something like this:

apply plugin: 'java'
sourceCompatibility = 1.7
targetCompatibility = 1.7
dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'junit:junit:4.12'
}