swipe-events.js

A vanilla JavaScript library that publishes custom swipe events with telemetry from screen touch movement.

• Swipe events are fired for every touchstart, touchmove, touchend, and touchcancel event.
• A single tap will fire at least two events (for touchstart and touchend).
• All distances and speeds report 0 on touchstart.
• Latest distances and speeds report 0 on touchend because it has the same coordinates as the prior event.
• Cardinal directions and theta report null on touchstart, and also on touchend if there was no touchmove event.
• Event publish rate is touchmove publish rate, which is up to as fast as screen refresh rate.
• All values are positive; use the cardinal directions to determine direction.

Kind: global namespace
Version: 1.1.1
Author: Eric Eldard
License: MIT
See: Demo
Example

document.addEventListener("swipe", e => {
    console.debug(`
        event time: ${e.detail.eventTime}
        ongoing:    ${e.detail.ongoing}
        direction:  ${e.detail.cardinal4}
    `)
})

Documentation: Markdown generated by jsdoc-to-markdown

SwipeEvents : object

• SwipeEvents : object
  • .telemetryLoggingEnabled() ⇒ boolean
  • .toggleTelemetryLogging() ⇒ boolean

SwipeEvents.telemetryLoggingEnabled() ⇒ boolean

Determine whether event logging is currently enabled. Useful for chaining your own logging to this value.

Kind: static method of SwipeEvents
Returns: boolean - true if logging is enabled, false if it's disabled
Since: 1.0
Example

document.addEventListener("swipe", e => {
    if (SwipeEvents.telemetryLoggingEnabled()) {
        console.log("I will log also");
    }
})

SwipeEvents.toggleTelemetryLogging() ⇒ boolean

Turn on/off console event logging (debug level). This is generally intended to be run from the console, while debugging.

Kind: static method of SwipeEvents
Returns: boolean - true if logging is enabled as a result of this operation, false if it's disabled
Since: 1.0
Example

SwipeEvents.toggleTelemetryLogging()

Event detail structure

Kind: global variable
Properties

Name	Type	Description
event	TouchEvent	the TouchEvent that triggered this swipe event (only its type is logged to console)
eventTime	number	timestamp for the creation of this event, as milliseconds since Unix epoch
duration	number	total time since touchstart event in milliseconds
initial	boolean	true if the triggering touch event is touchstart
ongoing	boolean	false if the triggering touch event is terminal (touchend, touchcancel)
cardinal4	string	current direction from the origin: N | S | E | W
cardinal8	string	current direction from the origin: N | S | E | W | NE | NW | SE | SW
theta	number	the number of degrees from East, going clockwise (0=E, 90=S, 180=W, 270=N)
originX	number	X coordinate of the initial touch (from touchstart)
originY	number	Y coordinate of the initial touch (from touchstart)
currentX	number	X coordinate of the latest touch event (from touchmove or touchend)
currentY	number	Y coordinate of the latest touch event (from touchmove or touchend)
totalDistanceX	number	total horizontal distance travelled in pixels from originX
totalDistanceY	number	total vertical distance travelled in pixels from originY
totalDistance	number	total real distance travelled in pixels from touchstart origin
latestDistanceX	number	total horizontal linear distance travelled in pixels since last swipe event
latestDistanceY	number	total vertical linear distance travelled in pixels since last swipe event
latestDistance	number	total linear distance travelled in pixels since last swipe event
overallSpeedX	number	totalDistanceX / duration
overallSpeedY	number	totalDistanceY / duration
overallSpeed	number	totalDistance / duration
latestSpeedX	number	latestDistanceX / milliseconds since last swipe event
latestSpeedY	number	latestDistanceY / milliseconds since last swipe event
latestSpeed	number	latestDistance / milliseconds since last swipe event