Skip to content
Nostalgist.js

press

Press a button and then release it programmatically. This is a shortcut for a combination of pressDown and pressUp.

Analog joysticks are not supported at this time.

Since

0.4.0

Usage

const nostalgist = await Nostalgist.nes('flappybird.nes')


await nostalgist.press('select')
await nostalgist.press('start')
await nostalgist.press('a')
await nostalgist.press('left')
await nostalgist.press('l')
await nostalgist.press({ button: 'a', player: 2 }) // press the button "a" on player 2's controller
await nostalgist.press({ button: 'a', time: 200 }) // press the button "a" for 200 milliseconds
await nostalgist.press({ button: 'a', player: 2, time: 200 }) // press the button "a" on player 2's controller for 200 milliseconds

Arguments

  • options

    type: string | { button: string, player?: number, time?: number }

    If it’s a string, then it’s the same as { button: <options> }.

    If it’s an object, please see below.

    • button

      type: string The button you want to press. Can be: up, down, left, right, select, start, a, b, x, y, l, l2, l3, r, r2, r3.

      The ‘a’, ‘b’, ‘x’, ‘y’ buttons here use the SNES layout:

       x
      y a
       b

    • player

      type: number default: 1

      The player you want to control.

      If you want to control a player other than 1, make sure you have set a key binding for that player in the retroarchConfig option while launching. For example:

      await Nostalgist.launch({
        // see https://github.com/libretro/RetroArch/blob/575859e5d76d921cb490f55afcd0bbca90d4a742/retroarch.cfg#L468-L483
        retroarchConfig: {
          input_player2_down: 'num3',
          input_player2_left: 'num2',
          input_player2_right: 'num4',
          input_player2_up: 'num1',
        },
      

        /* ...other options */
      })

      Because we are using these key bindings to simulate the control.

    • time

      type: number default: 100

      How long to press the button in milliseconds.