import { findPos } from './Util.js'
/**
* Whether a value is `null` or `undefined`.
* @param {any} val
* @returns {boolean}
*/
const isNullish = (val) => {
return val === null || val === undefined
}
/**
* Encapsulate slider functionality for the ColorMap and ColorBar -
* could be useful to use a jQuery UI draggable for this with certain extensions.
* @memberof module:jPicker
*/
export default class Slider {
/**
* @param {external:jQuery} bar
* @param {module:jPicker.SliderOptions} options
*/
constructor (bar, options) {
const that = this
/**
* Fire events on the supplied `context`
* @param {module:jPicker.JPickerInit} context
* @returns {void}
*/
function fireChangeEvents (context) {
changeEvents.forEach((changeEvent) => {
changeEvent.call(that, that, context)
})
}
/**
* Bind the mousedown to the bar not the arrow for quick snapping to the clicked location.
* @param {external:jQuery.Event} e
* @returns {void}
*/
function mouseDown (e) {
const off = findPos(bar)
offset = { l: off.left | 0, t: off.top | 0 }
clearTimeout(timeout)
// using setTimeout for visual updates - once the style is updated the browser will re-render internally allowing the next Javascript to run
timeout = setTimeout(function () {
setValuesFromMousePosition.call(that, e)
}, 0)
// Bind mousemove and mouseup event to the document so it responds when dragged of of the bar - we will unbind these when on mouseup to save processing
document.addEventListener('mousemove', mouseMove)
document.addEventListener('mouseup', mouseUp)
e.preventDefault() // don't try to select anything or drag the image to the desktop
}
/**
* Set the values as the mouse moves.
* @param {external:jQuery.Event} e
* @returns {false}
*/
function mouseMove (e) {
clearTimeout(timeout)
timeout = setTimeout(function () {
setValuesFromMousePosition.call(that, e)
}, 0)
e.stopPropagation()
e.preventDefault()
return false
}
/**
* Unbind the document events - they aren't needed when not dragging.
* @param {external:jQuery.Event} e
* @returns {false}
*/
function mouseUp (e) {
document.removeEventListener('mousemove', mouseMove)
document.removeEventListener('mouseup', mouseUp)
e.stopPropagation()
e.preventDefault()
return false
}
/**
* Calculate mouse position and set value within the current range.
* @param {Event} e
* @returns {void}
*/
function setValuesFromMousePosition (e) {
const barW = bar.w // local copies for YUI compressor
const barH = bar.h
let locX = e.pageX - offset.l
let locY = e.pageY - offset.t
// keep the arrow within the bounds of the bar
if (locX < 0) locX = 0
else if (locX > barW) locX = barW
if (locY < 0) locY = 0
else if (locY > barH) locY = barH
val.call(that, 'xy', {
x: ((locX / barW) * rangeX) + minX,
y: ((locY / barH) * rangeY) + minY
})
}
/**
*
* @returns {void}
*/
function draw () {
const
barW = bar.w
const barH = bar.h
const arrowW = arrow.w
const arrowH = arrow.h
let arrowOffsetX = 0
let arrowOffsetY = 0
setTimeout(function () {
if (rangeX > 0) { // range is greater than zero
// constrain to bounds
if (x === maxX) arrowOffsetX = barW
else arrowOffsetX = ((x / rangeX) * barW) | 0
}
if (rangeY > 0) { // range is greater than zero
// constrain to bounds
if (y === maxY) arrowOffsetY = barH
else arrowOffsetY = ((y / rangeY) * barH) | 0
}
// if arrow width is greater than bar width, center arrow and prevent horizontal dragging
if (arrowW >= barW) arrowOffsetX = (barW >> 1) - (arrowW >> 1) // number >> 1 - superfast bitwise divide by two and truncate (move bits over one bit discarding lowest)
else arrowOffsetX -= arrowW >> 1
// if arrow height is greater than bar height, center arrow and prevent vertical dragging
if (arrowH >= barH) arrowOffsetY = (barH >> 1) - (arrowH >> 1)
else arrowOffsetY -= arrowH >> 1
// set the arrow position based on these offsets
arrow.style.left = arrowOffsetX + 'px'
arrow.style.top = arrowOffsetY + 'px'
})
}
/**
* Get or set a value.
* @param {?("xy"|"x"|"y")} name
* @param {module:math.XYObject} value
* @param {module:jPicker.Slider} context
* @returns {module:math.XYObject|Float|void}
*/
function val (name, value, context) {
const set = value !== undefined
if (!set) {
if (isNullish(name)) name = 'xy'
switch (name.toLowerCase()) {
case 'x': return x
case 'y': return y
case 'xy':
default: return { x, y }
}
}
if (!isNullish(context) && context === that) return undefined
let changed = false
let newX; let newY
if (isNullish(name)) name = 'xy'
switch (name.toLowerCase()) {
case 'x':
newX = (value && ((value.x && value.x | 0) || value | 0)) || 0
break
case 'y':
newY = (value && ((value.y && value.y | 0) || value | 0)) || 0
break
case 'xy':
default:
newX = (value && value.x && value.x | 0) || 0
newY = (value && value.y && value.y | 0) || 0
break
}
if (!isNullish(newX)) {
if (newX < minX) newX = minX
else if (newX > maxX) newX = maxX
if (x !== newX) {
x = newX
changed = true
}
}
if (!isNullish(newY)) {
if (newY < minY) newY = minY
else if (newY > maxY) newY = maxY
if (y !== newY) {
y = newY
changed = true
}
}
changed && fireChangeEvents.call(that, context || that)
return undefined
}
/**
* @typedef {PlainObject} module:jPicker.MinMaxRangeX
* @property {Float} minX
* @property {Float} maxX
* @property {Float} rangeX
*/
/**
* @typedef {PlainObject} module:jPicker.MinMaxRangeY
* @property {Float} minY
* @property {Float} maxY
* @property {Float} rangeY
*/
/**
* @typedef {module:jPicker.MinMaxRangeY|module:jPicker.MinMaxRangeX} module:jPicker.MinMaxRangeXY
*/
/**
*
* @param {"minx"|"maxx"|"rangex"|"miny"|"maxy"|"rangey"|"all"} name
* @param {module:jPicker.MinMaxRangeXY} value
* @returns {module:jPicker.MinMaxRangeXY|module:jPicker.MinMaxRangeX|module:jPicker.MinMaxRangeY|void}
*/
function range (name, value) {
const set = value !== undefined
if (!set) {
if (isNullish(name)) name = 'all'
switch (name.toLowerCase()) {
case 'minx': return minX
case 'maxx': return maxX
case 'rangex': return { minX, maxX, rangeX }
case 'miny': return minY
case 'maxy': return maxY
case 'rangey': return { minY, maxY, rangeY }
case 'all':
default: return { minX, maxX, rangeX, minY, maxY, rangeY }
}
}
let // changed = false,
newMinX
let newMaxX
let newMinY
let newMaxY
if (isNullish(name)) name = 'all'
switch (name.toLowerCase()) {
case 'minx':
newMinX = (value && ((value.minX && value.minX | 0) || value | 0)) || 0
break
case 'maxx':
newMaxX = (value && ((value.maxX && value.maxX | 0) || value | 0)) || 0
break
case 'rangex':
newMinX = (value && value.minX && value.minX | 0) || 0
newMaxX = (value && value.maxX && value.maxX | 0) || 0
break
case 'miny':
newMinY = (value && ((value.minY && value.minY | 0) || value | 0)) || 0
break
case 'maxy':
newMaxY = (value && ((value.maxY && value.maxY | 0) || value | 0)) || 0
break
case 'rangey':
newMinY = (value && value.minY && value.minY | 0) || 0
newMaxY = (value && value.maxY && value.maxY | 0) || 0
break
case 'all':
default:
newMinX = (value && value.minX && value.minX | 0) || 0
newMaxX = (value && value.maxX && value.maxX | 0) || 0
newMinY = (value && value.minY && value.minY | 0) || 0
newMaxY = (value && value.maxY && value.maxY | 0) || 0
break
}
if (!isNullish(newMinX) && minX !== newMinX) {
minX = newMinX
rangeX = maxX - minX
}
if (!isNullish(newMaxX) && maxX !== newMaxX) {
maxX = newMaxX
rangeX = maxX - minX
}
if (!isNullish(newMinY) && minY !== newMinY) {
minY = newMinY
rangeY = maxY - minY
}
if (!isNullish(newMaxY) && maxY !== newMaxY) {
maxY = newMaxY
rangeY = maxY - minY
}
return undefined
}
/**
* @param {GenericCallback} callback
* @returns {void}
*/
function bind (callback) {
if (typeof callback === 'function') changeEvents.push(callback)
}
/**
* @param {GenericCallback} callback
* @returns {void}
*/
function unbind (callback) {
if (typeof callback !== 'function') return
let i
while ((i = changeEvents.includes(callback))) changeEvents.splice(i, 1)
}
/**
*
* @returns {void}
*/
function destroy () {
// unbind all possible events and null objects
document.removeEventListener('mousemove', mouseMove)
document.removeEventListener('mouseup', mouseUp)
bar.removeEventListener('mousedown', mouseDown)
bar = null
arrow = null
changeEvents = null
}
let offset
let timeout
let x = 0
let y = 0
let minX = 0
let maxX = 100
let rangeX = 100
let minY = 0
let maxY = 100
let rangeY = 100
let arrow = bar.querySelector('img') // the arrow image to drag
let changeEvents = []
Object.assign(that, {
val,
range,
bind,
unbind,
destroy
})
// initialize this control
arrow.src = options.arrow && options.arrow.image
arrow.w = (options.arrow && options.arrow.width) || parseFloat(getComputedStyle(arrow, null).width.replace('px', ''))
arrow.h = (options.arrow && options.arrow.height) || parseFloat(getComputedStyle(arrow, null).height.replace('px', ''))
bar.w = (options.map && options.map.width) || parseFloat(getComputedStyle(bar, null).width.replace('px', ''))
bar.h = (options.map && options.map.height) || parseFloat(getComputedStyle(bar, null).height.replace('px', ''))
bar.addEventListener('mousedown', mouseDown)
bind.call(that, draw)
}
}