Gamepad.buttons

The Gamepad.buttons property of the Gamepad interface returns an array of gamepadButton objects representing the buttons present on the device.

Each entry in the array is 0 if the button is not pressed, and non-zero (typically 1.0) if the button is pressed. Each gamepadButton object has two properties: pressed and value:

  • The pressed property is a boolean indicating whether the button is currently pressed (true) or unpressed (false).
  • The value property is a floating point value used to enable representing analog buttons, such as the triggers on many modern gamepads. The values are normalized to the range 0.0 – 1.0, with 0.0 representing a button that is not pressed, and 1.0 representing a button that is fully pressed.

Syntax

readonly    attribute GamepadButton[]     buttons;

Example

The following code is taken from my Gamepad API button demo (you can view the demo live, and find the source code on Github.) Note the code fork — in Chrome Navigator.getGamepads needs a webkit prefix and the button values are stores as an array of double values, whereas in Firefox Navigator.getGamepads doesn't need a prefix, and the button values are stored as an array of GamepadButton objects; it is the GamepadButton.value or GamepadButton.pressed properties of these we need to access, depending on what type of buttons they are. In this simple example I've just allowed either.

function gameLoop() {
  if(navigator.webkitGetGamepads) {
    var gp = navigator.webkitGetGamepads()[0];

    if(gp.buttons[0] == 1) {
      b--;
    } else if(gp.buttons[1] == 1) {
      a++;
    } else if(gp.buttons[2] == 1) {
      b++;
    } else if(gp.buttons[3] == 1) {
      a--;
    }
  } else {
    var gp = navigator.getGamepads()[0];

    if(gp.buttons[0].value > 0 || gp.buttons[0].pressed == true) {
      b--;
    } else if(gp.buttons[1].value > 0 || gp.buttons[1].pressed == true) {
      a++;
    } else if(gp.buttons[2].value > 0 || gp.buttons[2].pressed == true) {
      b++;
    } else if(gp.buttons[3].value > 0 || gp.buttons[3].pressed == true) {
      a--;
    }
  }

  ball.style.left = a*2 + "px";
  ball.style.top = b*2 + "px";

  var start = rAF(gameLoop);
};

Value

An array of gamepadButton objects.

Specifications

Specification Status Comment
Gamepad
The definition of 'Gamepad.buttons' in that specification.
Working Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
General support 21.0 webkit
35.0
29.0 (29.0) Not supported 15.0 webkit
22.0
Not supported
Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
General support Not supported 32.0 (32.0) Not supported Not supported Not supported

See also

Using the Gamepad API

Document Tags and Contributors

Last updated by: Sebastianz,