Gamepad: buttons property
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
pressedproperty is a boolean indicating whether the button is currently pressed (true) or unpressed (false). -
The
valueproperty 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.
Value
An array of gamepadButton objects.
Examples
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.
js
function gameLoop() {
let a = 0;
let b = 0;
if (navigator.webkitGetGamepads) {
const 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 {
const gp = navigator.getGamepads()[0];
if (gp.buttons[0].value > 0 || gp.buttons[0].pressed) {
b--;
} else if (gp.buttons[1].value > 0 || gp.buttons[1].pressed) {
a++;
} else if (gp.buttons[2].value > 0 || gp.buttons[2].pressed) {
b++;
} else if (gp.buttons[3].value > 0 || gp.buttons[3].pressed) {
a--;
}
}
ball.style.left = `${a * 2}px`;
ball.style.top = `${b * 2}px`;
const start = rAF(gameLoop);
}
Specifications
| Specification |
|---|
| Gamepad # dom-gamepad-buttons |
Browser compatibility
BCD tables only load in the browser