Button Clicks

This extension expands the behaviors supported by the A & B buttons. It supports (mutually exclusive) detection of a single click of a button, a double click of a button, or holding a button down.

These behave a lot like the touch screen, where the user can tap, double tap, or hold down.

They are different than [input.onButtonPressed()], which detects when a button is pressed. When a button is “double clicked” would call the event handler twice. Holding a button would cause the event handler to be called once. The basic eveng handler does not have an be easy way to distinguish between the three different types of behavior.

Single Button Clicks

buttonClicks.onButtonSingleClicked(button: buttonClicks.AorB, body: Action) : void

Set the actions to do on a single click.

Double Button Clicks

buttonClicks.onButtonDoubleClicked(button: buttonClicks.AorB, body: Action) : void

Set the actions to do on a double click.

Holding Buttons (Long Clicks)

buttonClicks.onButtonHeld(button: buttonClicks.AorB, body: Action) : void

Set the actions to do while the button is held down.

~alert

Holding a button down

Holding the button will cause this event to happen repeated while the button is held.

~

Button Down

buttonClicks.onButtonDown(button: buttonClicks.AorB, body: Action) : void

Set the actions to do when the button first makes contact when being pressed. This will run before other events, like single click, double click, and button held.

Button Up

buttonClicks.onButtonUp(button: buttonClicks.AorB, body: Action) : void

Set the actions to do when the button is released. This will run before before events, like single click, double click, and button held.

Example

The following program will show the behavior on both the LED grid and the serial console.

• The buttons that cause a click event will be shown at the top row of LEDs:
  • Interaction with button A will be indicated with a single LED in the upper left.
  • Interaction with button B will be indicated with a single LED in the upper right.
• The second row will show the up/down events briefly (it may be erased when other events happen)
  • The left LED will toggle on/off when button A is pressed/released
  • The right LED will toggle on/off when button A is pressed/released
• The specific event will be indicated on the bottom row:
  • A single click will be shown with a single LED on the bottom left.
  • A double click will be shown with a two LEDs on the bottom (leftmost and middle).
  • Holding a button will be shown by lighting all five LEDs.

buttonClicks.onButtonSingleClicked(buttonClicks.AorB.B, function () {
    serial.writeLine("B single")
    basic.showLeds(`
        . . . . #
        . . . . .
        . . . . .
        . . . . .
        # . . . .
        `)
    showClear()
})
buttonClicks.onButtonDown(buttonClicks.AorB.B, function () {
    serial.writeLine("B down")
    led.toggle(4, 1)
})
buttonClicks.onButtonDoubleClicked(buttonClicks.AorB.A, function () {
    serial.writeLine("A double")
    basic.showLeds(`
        # . . . .
        . . . . .
        . . . . .
        . . . . .
        # . # . .
        `)
    showClear()
})
buttonClicks.onButtonUp(buttonClicks.AorB.B, function () {
    serial.writeLine("B up")
    led.toggle(4, 1)
})
buttonClicks.onButtonUp(buttonClicks.AorB.A, function () {
    serial.writeLine("A up")
    led.toggle(0, 1)
})
function showClear () {
    basic.pause(100)
    basic.clearScreen()
}
buttonClicks.onButtonDown(buttonClicks.AorB.A, function () {
    serial.writeLine("A down")
    led.toggle(0, 1)
})
buttonClicks.onButtonHeld(buttonClicks.AorB.B, function () {
    serial.writeLine("B held")
    basic.showLeds(`
        . . . . #
        . . . . .
        . . . . .
        . . . . .
        # # # # #
        `)
    showClear()
})
buttonClicks.onButtonSingleClicked(buttonClicks.AorB.A, function () {
    serial.writeLine("A single")
    basic.showLeds(`
        # . . . .
        . . . . .
        . . . . .
        . . . . .
        # . . . .
        `)
    showClear()
})
buttonClicks.onButtonDoubleClicked(buttonClicks.AorB.B, function () {
    serial.writeLine("B double")
    basic.showLeds(`
        . . . . #
        . . . . .
        . . . . .
        . . . . .
        # . # . .
        `)
    showClear()
})
buttonClicks.onButtonHeld(buttonClicks.AorB.A, function () {
    serial.writeLine("A held")
    basic.showLeds(`
        # . . . .
        . . . . .
        . . . . .
        . . . . .
        # # # # #
        `)
    showClear()
})
basic.showIcon(IconNames.Heart)

Acknowledgements

Icon based on Font Awesome icon 0xF0A7 SVG.

This extension was partly imspired by a question from Daniel Gallichan on the micro:bit Slack forums. I wanted this sort of behavior too, but Daniel’s question made me think carefully about it.

Jonny Austin and Martin Williams provided guidance on additional features and a lot of pre-release cleanup.

Thanks to Daniel, Jonny, and Martin!

Misc.

I develop micro:bit extensions in my spare time to support activities I’m enthusiastic about, like summer camps and science curricula. You are welcome to become a sponsor of my micro:bit work (one time or recurring payments), which helps offset equipment costs: here. Any support at all is greatly appreciated!

Supported targets

for PXT/microbit

microbit-pxt-clicks=github:bsiever/microbit-pxt-clicks