Handle controller actions

Controllers have two kinds of actions:

  • KeyEvent used for any button with a binary state of "on" and "off"
  • MotionEvent used for any axis that returns a range of values. Such as -1 to 1 for analog sticks or 0 to 1 for analog triggers.

You can read these inputs from the View that has focus.

Kotlin

override fun onKeyDown(keyCode: Int, event: KeyEvent): Boolean {
  if (event.isFromSource(SOURCE_GAMEPAD)
      && event.repeatCount == 0
  ) {
      Log.d("GameView", "Gamepad key pressed: $keyCode")
      return true
  }

  return super.onKeyDown(keyCode, event)
}

override fun onGenericMotionEvent(event: MotionEvent): Boolean {
  if (event.isFromSource(SOURCE_JOYSTICK)) {
      Log.d("GameView", "Gamepad event: $event")
      return true
  }

  return super.onGenericMotionEvent(event)
}

Java

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
  if (event.isFromSource(SOURCE_GAMEPAD)
          && event.getRepeatCount() == 0
  ) {
      Log.d("GameView", "Gamepad key pressed: " + keyCode);
      return true;
  }

  return super.onKeyDown(keyCode, event);
}

@Override
public boolean onGenericMotionEvent(MotionEvent event) {
  if (event.isFromSource(SOURCE_JOYSTICK)) {
      Log.d("GameView", "Gamepad event: " + event);
      return true;
  }
  return super.onGenericMotionEvent(event);
}

If needed, you can read events from the Activity directly instead.

Verify a game controller is connected

When reporting input events, Android will reuse the same key or axis ids for different input device types. For example, a touchscreen action generates an AXIS_X event that represents the X coordinate of the touch surface, but a gamepad generates an AXIS_X event that represents the X position of the left stick. This means that you must check the source type to properly interpret input events.

To verify that a connected InputDevice is a game controller, use the supportsSource(int) function:

  • A source type of SOURCE_GAMEPAD indicates that the input device has controller buttons (for example, KEYCODE_BUTTON_A). Note that this source type does not strictly indicate if the game controller has D-pad buttons, although most controllers typically have directional controls.
  • A source type of SOURCE_DPAD indicates that the input device has D-pad buttons (for example, DPAD_UP).
  • A source type of SOURCE_JOYSTICK indicates that the input device has analog control sticks (for example, a joystick that records movements along AXIS_X and AXIS_Y).

The following code snippet shows a helper method that lets you check whether the connected input devices are game controllers. If so, the method retrieves the device IDs for the game controllers. You can then associate each device ID with a player in your game, and process game actions for each connected player separately. To learn more about supporting multiple game controllers that are simultaneously connected on the same Android-powered device, see Support multiple game controllers.

Kotlin

fun getGameControllerIds(): List<Int> {
  val gameControllerDeviceIds = mutableListOf<Int>()
  val deviceIds = InputDevice.getDeviceIds()
  deviceIds.forEach { deviceId ->
      InputDevice.getDevice(deviceId)?.apply {

          // Verify that the device has gamepad buttons, control sticks, or both.
          if (supportsSource(SOURCE_GAMEPAD)
              || supportsSource(SOURCE_JOYSTICK)) {
              // This device is a game controller. Store its device ID.
              gameControllerDeviceIds
                  .takeIf { !it.contains(deviceId) }
                  ?.add(deviceId)
          }
      }
  }
  return gameControllerDeviceIds
}

Java

 public ArrayList<Integer> getGameControllerIds() {
  ArrayList<Integer> gameControllerDeviceIds = new ArrayList<Integer>();
  int[] deviceIds = InputDevice.getDeviceIds();
  for (int deviceId : deviceIds) {
      InputDevice dev = InputDevice.getDevice(deviceId);

      if (dev == null) {
          continue;
      }

      // Verify that the device has gamepad buttons, control sticks, or both.
      if (dev.supportsSource(SOURCE_GAMEPAD) || dev.supportsSource(SOURCE_JOYSTICK)) {
          // This device is a game controller. Store its device ID.
          if (!gameControllerDeviceIds.contains(deviceId)) {
              gameControllerDeviceIds.add(deviceId);
          }
      }
  }
  return gameControllerDeviceIds;
}

Process controller inputs

This section describes the types for game controllers that are supported on Android.

C++ developers should use the Game Controller Library. It unifies all controllers to the most common subset of features and provides a consistent interface between them, including the ability to detect the button layout.

This figure shows what an Android game developer can expect a common controller to look like on Android.

Generic game controller with labeled inputs including D-Pad, analog sticks, and buttons
Figure 1. Profile for a generic game controller.

The table lists the standard event names and types for game controllers. For a complete list of events, see Common variants. The system sends MotionEvent events through onGenericMotionEvent and KeyEvent events through onKeyDown and onKeyUp.

Controller Input KeyEvent MotionEvent
1. D-Pad
 AXIS_HAT_X
(horizontal input)
AXIS_HAT_Y
(vertical input)
2. Left Analog Stick
 KEYCODE_BUTTON_THUMBL
(when pressed in)		 AXIS_X
(horizontal movement)
AXIS_Y
(vertical movement)
3. Right Analog Stick
 KEYCODE_BUTTON_THUMBR
(when pressed in)		 AXIS_Z
(horizontal movement)
AXIS_RZ
(vertical movement)
4. X Button KEYCODE_BUTTON_X
5. A Button KEYCODE_BUTTON_A
6. Y Button KEYCODE_BUTTON_Y
7. B Button KEYCODE_BUTTON_B
8. Right Bumper
 KEYCODE_BUTTON_R1
9. Right Trigger
 AXIS_RTRIGGER
10. Left Trigger AXIS_LTRIGGER
11. Left Bumper KEYCODE_BUTTON_L1
12. Start KEYCODE_BUTTON_START
13. Select KEYCODE_BUTTON_SELECT

Handle button presses

Since Android reports controller button presses identically to keyboard button presses, you need to:

  • Validate that the event is coming from a SOURCE_GAMEPAD.
  • Make sure you only receive the button once with KeyEvent.getRepeatCount(), Android will send repeat key events just like if you held down a keyboard key.
  • Indicate that an event is handled by returning true.

  • Pass unhandled events to super to verify that Android's various compatibility layers function appropriately.

    Kotlin

    class GameView : View {
// ...
override fun onKeyDown(keyCode: Int, event: KeyEvent): Boolean {
    event.apply {
        var handled = false

        // make sure we're handling gamepad events
        if (isFromSource(SOURCE_GAMEPAD)) {

            // avoid processing the keycode repeatedly
            if (repeatCount == 0) {
                when (keyCode) {
                    // handle the "A" button
                    KEYCODE_BUTTON_A -> {
                      handled = true
                    }
                }
                // ...
            }
        }
        if (handled) {
            return true
        }
   }
   return super.onKeyDown(keyCode, event)
  }
}

    Java

    public class GameView extends View {
// ...

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    boolean handled = false;
    // make sure we're handling gamepad events
    if (event.isFromSource(SOURCE_GAMEPAD)) {
        // avoid processing the keycode repeatedly
        if (event.getRepeatCount() == 0) {
            switch (keyCode) {
                case KEYCODE_BUTTON_A:
                    // handle the "A" button
                    handled = true;
                    break;
                // ...
            }
        }
        // mark this event as handled
        if (handled) {
            return true;
        }
    }
    // Always do this instead of "return false"
    // it allows Android's input compatibility layers to work
    return super.onKeyDown(keyCode, event);
  }
}

Process directional pad input

The 4-way directional pad, or D-pad, is a common physical control in many game controllers. Android reports D-pad UP and DOWN presses as AXIS_HAT_Y events, with -1.0 indicating up and 1.0 indicating down. It reports D-pad LEFT or RIGHT presses as AXIS_HAT_X events, with -1.0 indicating left and 1.0 indicating right.

Some controllers instead report D-pad presses with a key code. If your game cares about D-pad presses, you should treat the hat axis events and the D-pad key codes as the same input events, as recommended in table 2.

Table 2. Recommended default game actions for D-pad key codes and hat axis values.

Game Action D-pad Key Code Hat Axis Code
Move Up KEYCODE_DPAD_UP AXIS_HAT_Y (for values 0 to -1.0)
Move Down KEYCODE_DPAD_DOWN AXIS_HAT_Y (for values 0 to 1.0)
Move Left KEYCODE_DPAD_LEFT AXIS_HAT_X (for values 0 to -1.0)
Move Right KEYCODE_DPAD_RIGHT AXIS_HAT_X (for values 0 to 1.0)

The following code snippet shows a helper class that lets you check the hat axis and key code values from an input event to determine the D-pad direction.

Kotlin

class Dpad {

    private var directionPressed = -1 // initialized to -1

    fun getDirectionPressed(event: InputEvent): Int {
        if (!isDpadDevice(event)) {
            return -1
        }

        // If the input event is a MotionEvent, check its hat axis values.
        (event as? MotionEvent)?.apply {

            // Use the hat axis value to find the D-pad direction
            val xaxis: Float = event.getAxisValue(MotionEvent.AXIS_HAT_X)
            val yaxis: Float = event.getAxisValue(MotionEvent.AXIS_HAT_Y)

            directionPressed = when {
                // Check if the AXIS_HAT_X value is -1 or 1, and set the D-pad
                // LEFT and RIGHT direction accordingly.
                xaxis.compareTo(-1.0f) == 0 -> Dpad.LEFT
                xaxis.compareTo(1.0f) == 0 -> Dpad.RIGHT
                // Check if the AXIS_HAT_Y value is -1 or 1, and set the D-pad
                // UP and DOWN direction accordingly.
                yaxis.compareTo(-1.0f) == 0 -> Dpad.UP
                yaxis.compareTo(1.0f) == 0 -> Dpad.DOWN
                else -> directionPressed
            }
        }
        // If the input event is a KeyEvent, check its key code.
        (event as? KeyEvent)?.apply {

            // Use the key code to find the D-pad direction.
            directionPressed = when(event.keyCode) {
                KeyEvent.KEYCODE_DPAD_LEFT -> Dpad.LEFT
                KeyEvent.KEYCODE_DPAD_RIGHT -> Dpad.RIGHT
                KeyEvent.KEYCODE_DPAD_UP -> Dpad.UP
                KeyEvent.KEYCODE_DPAD_DOWN -> Dpad.DOWN
                KeyEvent.KEYCODE_DPAD_CENTER ->  Dpad.CENTER
                else -> directionPressed
            }
        }
        return directionPressed
    }

    companion object {
        internal const val UP = 0
        internal const val LEFT = 1
        internal const val RIGHT = 2
        internal const val DOWN = 3
        internal const val CENTER = 4

        fun isDpadDevice(event: InputEvent): Boolean =
            // Check that input comes from a device with directional pads.
            return event.isFromSource(InputDevice.SOURCE_DPAD)
    }
}

Java

public class Dpad {
    final static int UP       = 0;
    final static int LEFT     = 1;
    final static int RIGHT    = 2;
    final static int DOWN     = 3;
    final static int CENTER   = 4;

    int directionPressed = -1; // initialized to -1

    public int getDirectionPressed(InputEvent event) {
        if (!isDpadDevice(event)) {
           return -1;
        }

        // If the input event is a MotionEvent, check its hat axis values.
        if (event instanceof MotionEvent) {

            // Use the hat axis value to find the D-pad direction
            MotionEvent motionEvent = (MotionEvent) event;
            float xaxis = motionEvent.getAxisValue(MotionEvent.AXIS_HAT_X);
            float yaxis = motionEvent.getAxisValue(MotionEvent.AXIS_HAT_Y);

            // Check if the AXIS_HAT_X value is -1 or 1, and set the D-pad
            // LEFT and RIGHT direction accordingly.
            if (Float.compare(xaxis, -1.0f) == 0) {
                directionPressed =  Dpad.LEFT;
            } else if (Float.compare(xaxis, 1.0f) == 0) {
                directionPressed =  Dpad.RIGHT;
            }
            // Check if the AXIS_HAT_Y value is -1 or 1, and set the D-pad
            // UP and DOWN direction accordingly.
            else if (Float.compare(yaxis, -1.0f) == 0) {
                directionPressed =  Dpad.UP;
            } else if (Float.compare(yaxis, 1.0f) == 0) {
                directionPressed =  Dpad.DOWN;
            }
        }

        // If the input event is a KeyEvent, check its key code.
        else if (event instanceof KeyEvent) {

           // Use the key code to find the D-pad direction.
            KeyEvent keyEvent = (KeyEvent) event;
            if (keyEvent.getKeyCode() == KeyEvent.KEYCODE_DPAD_LEFT) {
                directionPressed = Dpad.LEFT;
            } else if (keyEvent.getKeyCode() == KeyEvent.KEYCODE_DPAD_RIGHT) {
                directionPressed = Dpad.RIGHT;
            } else if (keyEvent.getKeyCode() == KeyEvent.KEYCODE_DPAD_UP) {
                directionPressed = Dpad.UP;
            } else if (keyEvent.getKeyCode() == KeyEvent.KEYCODE_DPAD_DOWN) {
                directionPressed = Dpad.DOWN;
            } else if (keyEvent.getKeyCode() == KeyEvent.KEYCODE_DPAD_CENTER) {
                directionPressed = Dpad.CENTER;
            }
        }
        return directionPressed;
    }

    public static boolean isDpadDevice(InputEvent event) {
        // Check that input comes from a device with directional pads.
        return event.isFromSource(InputDevice.SOURCE_DPAD);
     }
}

You can use this helper class in your game wherever you want to process D-pad input (for example, in the onGenericMotionEvent() or onKeyDown() callbacks).

For example:

Kotlin

private val dpad = Dpad()
...
override fun onGenericMotionEvent(event: MotionEvent): Boolean {
    if (Dpad.isDpadDevice(event)) {
        when (dpad.getDirectionPressed(event)) {
            Dpad.LEFT -> {
                // Do something for LEFT direction press
                ...
                return true
            }
            Dpad.RIGHT -> {
                // Do something for RIGHT direction press
                ...
                return true
            }
            Dpad.UP -> {
                // Do something for UP direction press
                ...
                return true
            }
            ...
        }
    }

    // Check if this event is from a joystick movement and process accordingly.
    ...
}

Java

Dpad dpad = new Dpad();
...
@Override
public boolean onGenericMotionEvent(MotionEvent event) {

    // Check if this event if from a D-pad and process accordingly.
    if (Dpad.isDpadDevice(event)) {

       int press = dpad.getDirectionPressed(event);
       switch (press) {
            case LEFT:
                // Do something for LEFT direction press
                ...
                return true;
            case RIGHT:
                // Do something for RIGHT direction press
                ...
                return true;
            case UP:
                // Do something for UP direction press
                ...
                return true;
            ...
        }
    }

    // Check if this event is from a joystick movement and process accordingly.
    ...
}

Process joystick movements

When players move a joystick on their game controllers, Android reports a MotionEvent that contains the ACTION_MOVE action code and the updated positions of the joystick's axes. Your game can use the data provided by the MotionEvent to determine if a joystick movement it cares about happened.

Note that joystick motion events may batch multiple movement samples together within a single object. The MotionEvent object contains the current position for each joystick axis as well as multiple historical positions for each axis. When reporting motion events with action code ACTION_MOVE (such as joystick movements), Android batches up the axis values for efficiency. The historical values for an axis consists of the set of distinct values older than the current axis value, and more recent than values reported in any previous motion events. See the MotionEvent reference for details.

To accurately render a game object's movement based on joystick input, you can use the historical information provided by MotionEvent objects.

You can retrieve current and historical values using the following methods:

The following snippet shows how you might override the onGenericMotionEvent() callback to process joystick input. You should first process the historical values for an axis, then process its current position.

Kotlin

class GameView(...) : View(...) {

    override fun onGenericMotionEvent(event: MotionEvent): Boolean {

        // Check that the event came from a game controller
        return if (event.source and InputDevice.SOURCE_JOYSTICK == InputDevice.SOURCE_JOYSTICK
                && event.action == MotionEvent.ACTION_MOVE) {

            // Process the movements starting from the
            // earliest historical position in the batch
            (0 until event.historySize).forEach { i ->
                // Process the event at historical position i
                processJoystickInput(event, i)
            }

            // Process the current movement sample in the batch (position -1)
            processJoystickInput(event, -1)
            true
        } else {
            super.onGenericMotionEvent(event)
        }
    }
}

Java

public class GameView extends View {

    @Override
    public boolean onGenericMotionEvent(MotionEvent event) {

        // Check that the event came from a game controller
        if ((event.getSource() & InputDevice.SOURCE_JOYSTICK) ==
                InputDevice.SOURCE_JOYSTICK &&
                event.getAction() == MotionEvent.ACTION_MOVE) {

            // Process all historical movement samples in the batch
            final int historySize = event.getHistorySize();

            // Process the movements starting from the
            // earliest historical position in the batch
            for (int i = 0; i < historySize; i++) {
                // Process the event at historical position i
                processJoystickInput(event, i);
            }

            // Process the current movement sample in the batch (position -1)
            processJoystickInput(event, -1);
            return true;
        }
        return super.onGenericMotionEvent(event);
    }
}

Before using joystick input, you need to determine if the joystick is centered, then calculate its axis movements accordingly. Joysticks typically have a flat area, that is, a range of values near the (0,0) coordinate at which the axis is considered to be centered. If the axis value reported by Android falls within the flat area, you should treat the controller to be at rest (that is, motionless along both axes).

The snippet shows a helper method that calculates the movement along each axis. You invoke this helper in the processJoystickInput() method described further in the following sample:

Kotlin

private fun getCenteredAxis(
        event: MotionEvent,
        device: InputDevice,
        axis: Int,
        historyPos: Int
): Float {
    val range: InputDevice.MotionRange? = device.getMotionRange(axis, event.source)

    // A joystick at rest does not always report an absolute position of
    // (0,0). Use the getFlat() method to determine the range of values
    // bounding the joystick axis center.
    range?.apply {
        val value: Float = if (historyPos < 0) {
            event.getAxisValue(axis)
        } else {
            event.getHistoricalAxisValue(axis, historyPos)
        }

        // Ignore axis values that are within the 'flat' region of the
        // joystick axis center.
        if (Math.abs(value) > flat) {
            return value
        }
    }
    return 0f
}

Java

private static float getCenteredAxis(MotionEvent event,
        InputDevice device, int axis, int historyPos) {
    final InputDevice.MotionRange range =
            device.getMotionRange(axis, event.getSource());

    // A joystick at rest does not always report an absolute position of
    // (0,0). Use the getFlat() method to determine the range of values
    // bounding the joystick axis center.
    if (range != null) {
        final float flat = range.getFlat();
        final float value =
                historyPos < 0 ? event.getAxisValue(axis):
                event.getHistoricalAxisValue(axis, historyPos);

        // Ignore axis values that are within the 'flat' region of the
        // joystick axis center.
        if (Math.abs(value) > flat) {
            return value;
        }
    }
    return 0;
}

Putting it all together, here is how you might process joystick movements in your game:

Kotlin

private fun processJoystickInput(event: MotionEvent, historyPos: Int) {

    val inputDevice = event.device

    // Calculate the horizontal distance to move by
    // using the input value from one of these physical controls:
    // the left control stick, hat axis, or the right control stick.
    var x: Float = getCenteredAxis(event, inputDevice, MotionEvent.AXIS_X, historyPos)
    if (x == 0f) {
        x = getCenteredAxis(event, inputDevice, MotionEvent.AXIS_HAT_X, historyPos)
    }
    if (x == 0f) {
        x = getCenteredAxis(event, inputDevice, MotionEvent.AXIS_Z, historyPos)
    }

    // Calculate the vertical distance to move by
    // using the input value from one of these physical controls:
    // the left control stick, hat switch, or the right control stick.
    var y: Float = getCenteredAxis(event, inputDevice, MotionEvent.AXIS_Y, historyPos)
    if (y == 0f) {
        y = getCenteredAxis(event, inputDevice, MotionEvent.AXIS_HAT_Y, historyPos)
    }
    if (y == 0f) {
        y = getCenteredAxis(event, inputDevice, MotionEvent.AXIS_RZ, historyPos)
    }

    // Update the ship object based on the new x and y values
}

Java

private void processJoystickInput(MotionEvent event,
        int historyPos) {

    InputDevice inputDevice = event.getDevice();

    // Calculate the horizontal distance to move by
    // using the input value from one of these physical controls:
    // the left control stick, hat axis, or the right control stick.
    float x = getCenteredAxis(event, inputDevice,
            MotionEvent.AXIS_X, historyPos);
    if (x == 0) {
        x = getCenteredAxis(event, inputDevice,
                MotionEvent.AXIS_HAT_X, historyPos);
    }
    if (x == 0) {
        x = getCenteredAxis(event, inputDevice,
                MotionEvent.AXIS_Z, historyPos);
    }

    // Calculate the vertical distance to move by
    // using the input value from one of these physical controls:
    // the left control stick, hat switch, or the right control stick.
    float y = getCenteredAxis(event, inputDevice,
            MotionEvent.AXIS_Y, historyPos);
    if (y == 0) {
        y = getCenteredAxis(event, inputDevice,
                MotionEvent.AXIS_HAT_Y, historyPos);
    }
    if (y == 0) {
        y = getCenteredAxis(event, inputDevice,
                MotionEvent.AXIS_RZ, historyPos);
    }

    // Update the ship object based on the new x and y values
}

To support game controllers that have more sophisticated features beyond a single joystick, follow these best practices:

  • Handle dual controller sticks. Many game controllers have both a left and right joystick. For the left stick, Android reports horizontal movements as AXIS_X events and vertical movements as AXIS_Y events. For the right stick, Android reports horizontal movements as AXIS_Z events and vertical movements as AXIS_RZ events. Make sure to handle both controller sticks in your code.
  • Handle shoulder trigger presses (and make sure your game works with AXIS_ and KEYCODE_BUTTON_ events). Some controllers have left and right shoulder triggers. When these triggers are present, they emit an AXIS_*TRIGGER or KEYCODE_BUTTON_*2 event or both. For the left trigger, this would be AXIS_LTRIGGER and KEYCODE_BUTTON_L2. For the right trigger this would be AXIS_RTRIGGER and KEYCODE_BUTTON_R2. Axis events only occur if the trigger emits a range of values between 0 and 1, and some controllers with analog output emit button events in addition to axis events. Games must support both AXIS_ and KEYCODE_BUTTON_ events to remain compatible with all common game controllers, but prefer the event that makes the most sense for your gameplay if a controller reports both. On Android 4.3 (API level 18) and higher, a controller that produces a AXIS_LTRIGGER also reports an identical value for the AXIS_BRAKE axis. The same is true for AXIS_RTRIGGER and AXIS_GAS. Android reports all analog trigger presses with a normalized value from 0.0 (released) to 1.0 (fully pressed).
  • Specific behaviors and support may differ in emulated environments. Emulated platforms, such as Google Play Games, may differ slightly in behaviour based on the capabilities of the host operating system. For example, some controllers that emit both AXIS_ and KEYCODE_BUTTON_ events only emit AXIS_ events, and support for some controllers may be missing entirely.

Common variants

With the wide variety of support Android has for controllers, it may be unclear how to build and test to verify your game works bug-free among your playerbase. We find that despite this apparent variety, controller manufacturers around the world tend to consistently adhere to three different styles of controller. Some provide hardware toggles between two or more of these.

This means that you can test with as few as three controllers among your dev team and remain confident that your game is playable without resorting to allow and deny lists.

Common Controller Types

The most common style of controllers tend to mimic the layouts of popular game consoles. This is both aesthetic in the button labels and layout and functional by what events are raised. Controllers with hardware toggles between different console types will change the events they send and often even their logical button layout.

When testing we recommend you validate that your game works with one controller in each of the categories. You may choose to test with first party controllers, or popular third party manufacturers. Generally we will map the most popular controllers to the definition above by best effort.

Controller Type Behavioural Differences Labelling Variations
Xbox Style Controllers

These are controllers typically made for the Microsoft Xbox and Windows* platform.

 These controllers match the feature set outlined in Process controller inputs The L2/R2 buttons on these controllers are labelled LT/RT
Switch Style Controllers

These controllers typically are designed for the Nintendo Switch* family of consoles.

 These controllers send the KeyEvent KEYCODE_BUTTON_R2 KEYCODE_BUTTON_L2 MotionEvents The L2/R2 buttons on these controllers are labelled ZL/ZR.

These controllers also swap the A and B buttons and the X and Y buttons, so KEYCODE_BUTTON_A is the button labeled B and conversely.
PlayStation Style Controllers

These controllers typically are designed for the Sony PlayStation* family of consoles.

 These controllers send MotionEvents like the Xbox Style Controllers, but also send KeyEvents like the Switch Style Controllers when fully depressed. These controllers use a different set of glyphs for face buttons.

* Microsoft, Xbox, and Windows are registered trademarks of Microsoft; Nintendo Switch is a registered trademark of Nintendo of America Inc.; PlayStation is a registered trademark of Sony Interactive Entertainment Inc.

Disambiguate trigger buttons

Some controllers send AXIS_LTRIGGER and AXIS_RTRIGGER, some send KEYCODE_BUTTON_L2 and KEYCODE_BUTTON_R2, and others send all these events based on their hardware capabilities. Maximize compatibility by supporting all of these events.

All controllers that send AXIS_LTRIGGER will also send AXIS_BRAKE, similarly for AXIS_RTRIGGER and AXIS_GAS to help maximize compatibility between racing wheels and typical game controllers. Generally this won't cause issues, but be aware for features like key remapping screens.

Trigger MotionEvent KeyEvent
Left Trigger AXIS_LTRIGGER
AXIS_BRAKE 		KEYCODE_BUTTON_L2
Right Trigger AXIS_RTRIGGER
AXIS_GAS 		KEYCODE_BUTTON_R2

Care should be taken to verify your game can handle both KeyEvent and MotionEvent to maintain compatibility with as many controllers as possible, and that events are de-duplicated.

Supported Controllers

When testing we recommend you validate that your game works with one controller in each of the categories.

  • Xbox Style
  • Nintendo Switch Style
  • PlayStation Style

You can test with first-party controllers or popular third-party manufacturers, and we generally map the most popular controllers to the definition as closely as possible.