Bugstick

Flexible joystick widget for Android.

Why Bugstick?

Other joystick widgets are a hassle to include in modern Gradle-based Android projects, support only limited visual customization, and suffer from overly prescriptive output.

So how does Bugstick solve these issues?

Painless Dependency - try it out quickly with a simple Gradle dependency.
Configurable Look - the joystick base and stick are a completely decoupled, standard ViewGroup - View pair. Use an ImageView, Button, LinearLayout, or any other View as the stick, and use standard Drawables to theme Bugstick so it looks at home in your app.
Unopinionated Output - the widget reports proportional offset of the stick from its center as well as the current angle via a standard listener interface. Choose to interpret these raw outputs in the way that suits your use case.

Usage

Add it to your project using Gradle:

compile 'com.jmedeisis:bugstick:0.2.2'

Example XML layout file:

<com.jmedeisis.bugstick.Joystick
    android:id="@+id/joystick"
    android:layout_width="@dimen/base_size"
    android:layout_height="@dimen/base_size"
    android:background="@drawable/bg_base">

    <!-- You may use any View here. -->
    <Button
        android:layout_width="@dimen/stick_size"
        android:layout_height="@dimen/stick_size"
        android:background="@drawable/bg_stick" />

</com.jmedeisis.bugstick.Joystick>

Note that the Joystick ViewGroup supports only one direct child, but that child can be another ViewGroup such as a FrameLayout with multiple children.

After inflating the layout, you will typically listen for joystick events using a JoystickListener:

Joystick joystick = (Joystick) findViewById(R.id.joystick);
joystick.setJoystickListener(new JoystickListener() {
    @Override
    public void onDown() {
        // ..
    }

    @Override
    public void onDrag(float degrees, float offset) {
        // ..
    }

    @Override
    public void onUp() {
        // ..
    }
});

Please refer to the included sample project for a thorough example.

Configuration

You can configure the following attributes for the Joystick class:

start_on_first_touch - If true (default), the stick activates immediately on the initial touch. If false, the user must begin to drag their finger across the joystick for the stick to activate.
force_square - If true (default), the joystick always measures itself to force a square layout.
radius - If specified, this is the maximum physical offset from the center that the stick is allowed to move. If not specified (default), the radius is determined based on the dimensions of the base and the stick.
motion_constraint - One of None (default), Horizontal, or Vertical. Specifies whether the stick motion should be constrained to a particular direction. If None, the stick is allowed to move freely around the center of the base.

Example configuration:

<com.jmedeisis.bugstick.Joystick
    android:id="@+id/joystick"
    android:layout_width="@dimen/base_width"
    android:layout_height="match_parent"
    android:background="@drawable/bg_base"
    app:start_on_first_touch="false"
    app:force_square="false"
    app:radius="@dimen/stick_offset_max_radius"
    app:motion_constraint="Vertical">

    <!-- Any View here. -->

</com.jmedeisis.bugstick.Joystick>

Development

Pull requests are welcome and encouraged for bugfixes and features such as:

accessibility support
more powerful motion constraints, e.g. constrain to arbitrary path

License