Pocket Knife

// Bundle Keys
private static final String BUNDLE_COUNTER = "BUNDLE_COUNTER";

public void saveInstanceState(Fragment fragment, Bundle bundle) {
    bundle.putInt(BUNDLE_COUNTER, fragment.counter);
}

To save a field to the save state bundle in activities and fragments first annotate the field with @SaveState

...
@SaveState
int anInt;
...

Then in onSaveInstanceState call PocketKnife.saveInstanceState(this, outState); to save annotated fields to the bundle.

public void onSaveInstanceState(Bundle outState) {
  ...
  PocketKnife.saveInstanceState(this, outState);
  ...
}

To restore from the bundle call PocketKnife.restoreInstanceState(this, savedInstanceState); in onCreate.

public void onCreate(Bundle savedInstanceState) {
  ...
  PocketKnife.restoreInstanceState(this, savedInstanceState);
  ...
}

To bind arguments into a field for a Fragment first annotate the field with @BindArgument. Pocket Knife will find and automatically cast the corresponding value.

...
@BindArgument
int anInt;
@BindArgument(ARG_LONG)
long aLong;
...

Then in onActivityCreated or another appropriate method call in a fragment PocketKnife.bindArguments(this);

public void onActivityCreated(Bundle savedInstanceState) {
  ...
  PocketKnife.bindArguments(this);
  ...
}

To bind extras into a field for an activity first annotate the field with @BindExtra. Pocket Knife will find and automatically cast the corresponding value.

...
@BindExtra
int anInt;
@BindExtra(EXTRA_LONG)
long aLong;
...

Then in onCreate or another appropriate method call in an activity PocketKnife.bindExtras(this);

public void onActivityCreated(Bundle savedInstanceState) {
  ...
  PocketKnife.bindExtras(this);
        ...
}

To create a bundle, create an interface and annotate the methods with @BundleBuilder.

public interface Bundles {
  ...
  @BundleBuilder
  Bundle getBundle(long individualId);
  ...
}

Pocket Knife will generate the class PocketKnife<interface name> (PocketKnifeBundles for the example above).

To create an intent create an interface and annotate the methods with @IntentBuilder and at least an action or a class. Data values for the intent are passed as a String or Uri argument annotated with @Data.

public interface Intents {
  ...
  @IntentBuilder(cls=SimpleActivity.class)
  Intent getIntent(long individualId);

  @IntentBuilder(action=Intent.ACTION_VIEW)
  Intent getIntent(@Data String data);
  ...
}

Pocket Knife will generate the class PocketKnife<interface name> (PocketKnifeIntents for the example above).

To serialize nonstandard types to bundles and intents annotate variables and parameters with @BundleBuilder and @IntentBuilder respectively. These annotations take a PocketKnifeBundleSerializer and PocketKnifeIntentSerializer as parameters as follows.

Example saving class Foo to bundles and intents

public class Foo {
    private String bar;
    private int baz;
    ...
}

Example serializer

public class FooSerializer implements PocketKnifeBundleSerializer<Foo>,
                                      PocketKnifeIntentSerializer<Foo> {
  private static final String BAR = ".BAR";
  private static final String BAZ = ".BAZ";

  @Override
  public void put(Bundle bundle, Foo foo, String keyPrefix) {
    bundle.putString(keyPrefix + BAR, foo.getBar());
    bundle.putInt(keyPrefix + BAZ, foo.getBaz());
  }

  @Override
  public Foo get(Bundle bundle, Foo foo, String keyPrefix) {
    foo.setBar(bundle.getString(keyPrefix + BAR));
    foo.setBaz(bundle.getInt(keyPrefix + BAZ));
    return foo;
  }

  @Override
  public void put(Intent intent, Foo foo, String keyPrefix) {
    intent.putExtra(keyPrefix + BAZ, foo.getBaz());
    intent.putExtra(keyPrefix + BAR, foo.getBar());
  }

  @Override
  public Foo get(Intent intent, Foo foo, String keyPrefix) {
    foo.setBar(intent.getStringExtra(keyPrefix + BAR));
    foo.setBaz(intent.getIntExtra(keyPrefix + BAZ, 0));
    return foo;
  }
}

Example usage

  ...
  @SaveState
  @BundleSerializer(FooSerializer.class)
  Foo saveFoo;

  @BindArgument
  @BundleSerializer(FooSerializer.class)
  Foo argFoo;

  @BindExtra
  @IntentSerializer(FooSerializer.class)
  Foo extraFoo;
  ...

  public interface Builder {
    @BundleBuilder
    Bundle buildBundle(@BundleSerializer(FooSerializer.class) Foo argFoo);

    @IntentBuilder(action = "test")
    Intent buildIntent(@IntentSerializer(FooSerializer.class)Foo extraFoo);

    @FragmentBuilder
    Fragment buildFragment(@BundleSerializer(FooSerializer.class) Foo argFoo);
  }