lib/timeline/Range.js
var util = require('../util');
var moment = require('../module/moment');
var Component = require('./component/Component');
var DateUtil = require('./DateUtil');
/**
* A Range controls a numeric range with a start and end value.
* The Range adjusts the range based on mouse events or programmatic changes,
* and triggers events when the range is changing or has been changed.
* @param {{dom: Object, domProps: Object, emitter: Emitter}} body
* @param {Object} [options] See description at Range.setOptions
* @constructor Range
* @extends Component
*/
function Range(body, options) {
var now = moment().hours(0).minutes(0).seconds(0).milliseconds(0);
var start = now.clone().add(-3, 'days').valueOf();
var end = now.clone().add(3, 'days').valueOf();
this.millisecondsPerPixelCache = undefined;
if(options === undefined) {
this.start = start;
this.end = end;
} else {
this.start = options.start || start;
this.end = options.end || end
}
this.rolling = false;
this.body = body;
this.deltaDifference = 0;
this.scaleOffset = 0;
this.startToFront = false;
this.endToFront = true;
// default options
this.defaultOptions = {
rtl: false,
start: null,
end: null,
moment: moment,
direction: 'horizontal', // 'horizontal' or 'vertical'
moveable: true,
zoomable: true,
min: null,
max: null,
zoomMin: 10, // milliseconds
zoomMax: 1000 * 60 * 60 * 24 * 365 * 10000, // milliseconds
rollingMode: {
follow: false,
offset: 0.5
}
};
this.options = util.extend({}, this.defaultOptions);
this.props = {
touch: {}
};
this.animationTimer = null;
// drag listeners for dragging
this.body.emitter.on('panstart', this._onDragStart.bind(this));
this.body.emitter.on('panmove', this._onDrag.bind(this));
this.body.emitter.on('panend', this._onDragEnd.bind(this));
// mouse wheel for zooming
this.body.emitter.on('mousewheel', this._onMouseWheel.bind(this));
// pinch to zoom
this.body.emitter.on('touch', this._onTouch.bind(this));
this.body.emitter.on('pinch', this._onPinch.bind(this));
// on click of rolling mode button
this.body.dom.rollingModeBtn.addEventListener('click', this.startRolling.bind(this));
this.setOptions(options);
}
Range.prototype = new Component();
/**
* Set options for the range controller
* @param {Object} options Available options:
* {number | Date | String} start Start date for the range
* {number | Date | String} end End date for the range
* {number} min Minimum value for start
* {number} max Maximum value for end
* {number} zoomMin Set a minimum value for
* (end - start).
* {number} zoomMax Set a maximum value for
* (end - start).
* {boolean} moveable Enable moving of the range
* by dragging. True by default
* {boolean} zoomable Enable zooming of the range
* by pinching/scrolling. True by default
*/
Range.prototype.setOptions = function (options) {
if (options) {
// copy the options that we know
var fields = [
'animation', 'direction', 'min', 'max', 'zoomMin', 'zoomMax', 'moveable', 'zoomable',
'moment', 'activate', 'hiddenDates', 'zoomKey', 'rtl', 'showCurrentTime', 'rollingMode', 'horizontalScroll'
];
util.selectiveExtend(fields, this.options, options);
if (options.rollingMode && options.rollingMode.follow) {
this.startRolling();
}
if ('start' in options || 'end' in options) {
// apply a new range. both start and end are optional
this.setRange(options.start, options.end);
}
}
};
/**
* Test whether direction has a valid value
* @param {string} direction 'horizontal' or 'vertical'
*/
function validateDirection (direction) {
if (direction != 'horizontal' && direction != 'vertical') {
throw new TypeError('Unknown direction "' + direction + '". ' +
'Choose "horizontal" or "vertical".');
}
}
/**
* Start auto refreshing the current time bar
*/
Range.prototype.startRolling = function() {
var me = this;
/**
* Updates the current time.
*/
function update () {
me.stopRolling();
me.rolling = true;
var interval = me.end - me.start;
var t = util.convert(new Date(), 'Date').valueOf();
var start = t - interval * (me.options.rollingMode.offset);
var end = t + interval * (1 - me.options.rollingMode.offset);
var options = {
animation: false
};
me.setRange(start, end, options);
// determine interval to refresh
var scale = me.conversion(me.body.domProps.center.width).scale;
interval = 1 / scale / 10;
if (interval < 30) interval = 30;
if (interval > 1000) interval = 1000;
me.body.dom.rollingModeBtn.style.visibility = "hidden";
// start a renderTimer to adjust for the new time
me.currentTimeTimer = setTimeout(update, interval);
}
update();
};
/**
* Stop auto refreshing the current time bar
*/
Range.prototype.stopRolling = function() {
if (this.currentTimeTimer !== undefined) {
clearTimeout(this.currentTimeTimer);
this.rolling = false;
this.body.dom.rollingModeBtn.style.visibility = "visible";
}
};
/**
* Set a new start and end range
* @param {Date | number | string} [start]
* @param {Date | number | string} [end]
* @param {Object} options Available options:
* {boolean | {duration: number, easingFunction: string}} [animation=false]
* If true, the range is animated
* smoothly to the new window. An object can be
* provided to specify duration and easing function.
* Default duration is 500 ms, and default easing
* function is 'easeInOutQuad'.
* {boolean} [byUser=false]
* {Event} event Mouse event
* @param {Function} callback a callback function to be executed at the end of this function
* @param {Function} frameCallback a callback function executed each frame of the range animation.
* The callback will be passed three parameters:
* {number} easeCoefficient an easing coefficent
* {boolean} willDraw If true the caller will redraw after the callback completes
* {boolean} done If true then animation is ending after the current frame
*/
Range.prototype.setRange = function(start, end, options, callback, frameCallback) {
if (!options) {
options = {};
}
if (options.byUser !== true) {
options.byUser = false;
}
var me = this;
var finalStart = start != undefined ? util.convert(start, 'Date').valueOf() : null;
var finalEnd = end != undefined ? util.convert(end, 'Date').valueOf() : null;
this._cancelAnimation();
this.millisecondsPerPixelCache = undefined;
if (options.animation) { // true or an Object
var initStart = this.start;
var initEnd = this.end;
var duration = (typeof options.animation === 'object' && 'duration' in options.animation) ? options.animation.duration : 500;
var easingName = (typeof options.animation === 'object' && 'easingFunction' in options.animation) ? options.animation.easingFunction : 'easeInOutQuad';
var easingFunction = util.easingFunctions[easingName];
if (!easingFunction) {
throw new Error('Unknown easing function ' + JSON.stringify(easingName) + '. ' +
'Choose from: ' + Object.keys(util.easingFunctions).join(', '));
}
var initTime = new Date().valueOf();
var anyChanged = false;
var next = function () {
if (!me.props.touch.dragging) {
var now = new Date().valueOf();
var time = now - initTime;
var ease = easingFunction(time / duration);
var done = time > duration;
var s = (done || finalStart === null) ? finalStart : initStart + (finalStart - initStart) * ease;
var e = (done || finalEnd === null) ? finalEnd : initEnd + (finalEnd - initEnd) * ease;
changed = me._applyRange(s, e);
DateUtil.updateHiddenDates(me.options.moment, me.body, me.options.hiddenDates);
anyChanged = anyChanged || changed;
var params = {
start: new Date(me.start),
end: new Date(me.end),
byUser: options.byUser,
event: options.event
};
if (frameCallback) { frameCallback(ease, changed, done); }
if (changed) {
me.body.emitter.emit('rangechange', params);
}
if (done) {
if (anyChanged) {
me.body.emitter.emit('rangechanged', params);
if (callback) { return callback() }
}
}
else {
// animate with as high as possible frame rate, leave 20 ms in between
// each to prevent the browser from blocking
me.animationTimer = setTimeout(next, 20);
}
}
};
return next();
}
else {
var changed = this._applyRange(finalStart, finalEnd);
DateUtil.updateHiddenDates(this.options.moment, this.body, this.options.hiddenDates);
if (changed) {
var params = {
start: new Date(this.start),
end: new Date(this.end),
byUser: options.byUser,
event: options.event
};
this.body.emitter.emit('rangechange', params);
clearTimeout( me.timeoutID );
me.timeoutID = setTimeout( function () {
me.body.emitter.emit('rangechanged', params);
}, 200 );
if (callback) { return callback() }
}
}
};
/**
* Get the number of milliseconds per pixel.
*
* @returns {undefined|number}
*/
Range.prototype.getMillisecondsPerPixel = function() {
if (this.millisecondsPerPixelCache === undefined) {
this.millisecondsPerPixelCache = (this.end - this.start) / this.body.dom.center.clientWidth;
}
return this.millisecondsPerPixelCache;
};
/**
* Stop an animation
* @private
*/
Range.prototype._cancelAnimation = function () {
if (this.animationTimer) {
clearTimeout(this.animationTimer);
this.animationTimer = null;
}
};
/**
* Set a new start and end range. This method is the same as setRange, but
* does not trigger a range change and range changed event, and it returns
* true when the range is changed
* @param {number} [start]
* @param {number} [end]
* @return {boolean} changed
* @private
*/
Range.prototype._applyRange = function(start, end) {
var newStart = (start != null) ? util.convert(start, 'Date').valueOf() : this.start,
newEnd = (end != null) ? util.convert(end, 'Date').valueOf() : this.end,
max = (this.options.max != null) ? util.convert(this.options.max, 'Date').valueOf() : null,
min = (this.options.min != null) ? util.convert(this.options.min, 'Date').valueOf() : null,
diff;
// check for valid number
if (isNaN(newStart) || newStart === null) {
throw new Error('Invalid start "' + start + '"');
}
if (isNaN(newEnd) || newEnd === null) {
throw new Error('Invalid end "' + end + '"');
}
// prevent end < start
if (newEnd < newStart) {
newEnd = newStart;
}
// prevent start < min
if (min !== null) {
if (newStart < min) {
diff = (min - newStart);
newStart += diff;
newEnd += diff;
// prevent end > max
if (max != null) {
if (newEnd > max) {
newEnd = max;
}
}
}
}
// prevent end > max
if (max !== null) {
if (newEnd > max) {
diff = (newEnd - max);
newStart -= diff;
newEnd -= diff;
// prevent start < min
if (min != null) {
if (newStart < min) {
newStart = min;
}
}
}
}
// prevent (end-start) < zoomMin
if (this.options.zoomMin !== null) {
var zoomMin = parseFloat(this.options.zoomMin);
if (zoomMin < 0) {
zoomMin = 0;
}
if ((newEnd - newStart) < zoomMin) {
// compensate for a scale of 0.5 ms
var compensation = 0.5;
if ((this.end - this.start) === zoomMin && newStart >= this.start - compensation && newEnd <= this.end) {
// ignore this action, we are already zoomed to the minimum
newStart = this.start;
newEnd = this.end;
}
else {
// zoom to the minimum
diff = (zoomMin - (newEnd - newStart));
newStart -= diff / 2;
newEnd += diff / 2;
}
}
}
// prevent (end-start) > zoomMax
if (this.options.zoomMax !== null) {
var zoomMax = parseFloat(this.options.zoomMax);
if (zoomMax < 0) {
zoomMax = 0;
}
if ((newEnd - newStart) > zoomMax) {
if ((this.end - this.start) === zoomMax && newStart < this.start && newEnd > this.end) {
// ignore this action, we are already zoomed to the maximum
newStart = this.start;
newEnd = this.end;
}
else {
// zoom to the maximum
diff = ((newEnd - newStart) - zoomMax);
newStart += diff / 2;
newEnd -= diff / 2;
}
}
}
var changed = (this.start != newStart || this.end != newEnd);
// if the new range does NOT overlap with the old range, emit checkRangedItems to avoid not showing ranged items (ranged meaning has end time, not necessarily of type Range)
if (!((newStart >= this.start && newStart <= this.end) || (newEnd >= this.start && newEnd <= this.end)) &&
!((this.start >= newStart && this.start <= newEnd) || (this.end >= newStart && this.end <= newEnd) )) {
this.body.emitter.emit('checkRangedItems');
}
this.start = newStart;
this.end = newEnd;
return changed;
};
/**
* Retrieve the current range.
* @return {Object} An object with start and end properties
*/
Range.prototype.getRange = function() {
return {
start: this.start,
end: this.end
};
};
/**
* Calculate the conversion offset and scale for current range, based on
* the provided width
* @param {number} width
* @param {number} [totalHidden=0]
* @returns {{offset: number, scale: number}} conversion
*/
Range.prototype.conversion = function (width, totalHidden) {
return Range.conversion(this.start, this.end, width, totalHidden);
};
/**
* Static method to calculate the conversion offset and scale for a range,
* based on the provided start, end, and width
* @param {number} start
* @param {number} end
* @param {number} width
* @param {number} [totalHidden=0]
* @returns {{offset: number, scale: number}} conversion
*/
Range.conversion = function (start, end, width, totalHidden) {
if (totalHidden === undefined) {
totalHidden = 0;
}
if (width != 0 && (end - start != 0)) {
return {
offset: start,
scale: width / (end - start - totalHidden)
}
}
else {
return {
offset: 0,
scale: 1
};
}
};
/**
* Start dragging horizontally or vertically
* @param {Event} event
* @private
*/
Range.prototype._onDragStart = function(event) {
this.deltaDifference = 0;
this.previousDelta = 0;
// only allow dragging when configured as movable
if (!this.options.moveable) return;
// only start dragging when the mouse is inside the current range
if (!this._isInsideRange(event)) return;
// refuse to drag when we where pinching to prevent the timeline make a jump
// when releasing the fingers in opposite order from the touch screen
if (!this.props.touch.allowDragging) return;
this.stopRolling();
this.props.touch.start = this.start;
this.props.touch.end = this.end;
this.props.touch.dragging = true;
if (this.body.dom.root) {
this.body.dom.root.style.cursor = 'move';
}
};
/**
* Perform dragging operation
* @param {Event} event
* @private
*/
Range.prototype._onDrag = function (event) {
if (!event) return;
if (!this.props.touch.dragging) return;
// only allow dragging when configured as movable
if (!this.options.moveable) return;
// TODO: this may be redundant in hammerjs2
// refuse to drag when we where pinching to prevent the timeline make a jump
// when releasing the fingers in opposite order from the touch screen
if (!this.props.touch.allowDragging) return;
var direction = this.options.direction;
validateDirection(direction);
var delta = (direction == 'horizontal') ? event.deltaX : event.deltaY;
delta -= this.deltaDifference;
var interval = (this.props.touch.end - this.props.touch.start);
// normalize dragging speed if cutout is in between.
var duration = DateUtil.getHiddenDurationBetween(this.body.hiddenDates, this.start, this.end);
interval -= duration;
var width = (direction == 'horizontal') ? this.body.domProps.center.width : this.body.domProps.center.height;
var diffRange;
if (this.options.rtl) {
diffRange = delta / width * interval;
} else {
diffRange = -delta / width * interval;
}
var newStart = this.props.touch.start + diffRange;
var newEnd = this.props.touch.end + diffRange;
// snapping times away from hidden zones
var safeStart = DateUtil.snapAwayFromHidden(this.body.hiddenDates, newStart, this.previousDelta-delta, true);
var safeEnd = DateUtil.snapAwayFromHidden(this.body.hiddenDates, newEnd, this.previousDelta-delta, true);
if (safeStart != newStart || safeEnd != newEnd) {
this.deltaDifference += delta;
this.props.touch.start = safeStart;
this.props.touch.end = safeEnd;
this._onDrag(event);
return;
}
this.previousDelta = delta;
this._applyRange(newStart, newEnd);
var startDate = new Date(this.start);
var endDate = new Date(this.end);
// fire a rangechange event
this.body.emitter.emit('rangechange', {
start: startDate,
end: endDate,
byUser: true,
event: event
});
// fire a panmove event
this.body.emitter.emit('panmove');
};
/**
* Stop dragging operation
* @param {event} event
* @private
*/
Range.prototype._onDragEnd = function (event) {
if (!this.props.touch.dragging) return;
// only allow dragging when configured as movable
if (!this.options.moveable) return;
// TODO: this may be redundant in hammerjs2
// refuse to drag when we where pinching to prevent the timeline make a jump
// when releasing the fingers in opposite order from the touch screen
if (!this.props.touch.allowDragging) return;
this.props.touch.dragging = false;
if (this.body.dom.root) {
this.body.dom.root.style.cursor = 'auto';
}
// fire a rangechanged event
this.body.emitter.emit('rangechanged', {
start: new Date(this.start),
end: new Date(this.end),
byUser: true,
event: event
});
};
/**
* Event handler for mouse wheel event, used to zoom
* Code from http://adomas.org/javascript-mouse-wheel/
* @param {Event} event
* @private
*/
Range.prototype._onMouseWheel = function(event) {
// retrieve delta
var delta = 0;
if (event.wheelDelta) { /* IE/Opera. */
delta = event.wheelDelta / 120;
} else if (event.detail) { /* Mozilla case. */
// In Mozilla, sign of delta is different than in IE.
// Also, delta is multiple of 3.
delta = -event.detail / 3;
}
// don't allow zoom when the according key is pressed and the zoomKey option or not zoomable but movable
if ((this.options.zoomKey && !event[this.options.zoomKey] && this.options.zoomable)
|| (!this.options.zoomable && this.options.moveable)) {
return;
}
// only allow zooming when configured as zoomable and moveable
if (!(this.options.zoomable && this.options.moveable)) return;
// only zoom when the mouse is inside the current range
if (!this._isInsideRange(event)) return;
// If delta is nonzero, handle it.
// Basically, delta is now positive if wheel was scrolled up,
// and negative, if wheel was scrolled down.
if (delta) {
// perform the zoom action. Delta is normally 1 or -1
// adjust a negative delta such that zooming in with delta 0.1
// equals zooming out with a delta -0.1
var scale;
if (delta < 0) {
scale = 1 - (delta / 5);
}
else {
scale = 1 / (1 + (delta / 5)) ;
}
// calculate center, the date to zoom around
var pointerDate;
if (this.rolling) {
pointerDate = this.start + ((this.end - this.start) * this.options.rollingMode.offset);
} else {
var pointer = this.getPointer({x: event.clientX, y: event.clientY}, this.body.dom.center);
pointerDate = this._pointerToDate(pointer);
}
this.zoom(scale, pointerDate, delta, event);
// Prevent default actions caused by mouse wheel
// (else the page and timeline both scroll)
event.preventDefault();
}
};
/**
* Start of a touch gesture
* @param {Event} event
* @private
*/
Range.prototype._onTouch = function (event) { // eslint-disable-line no-unused-vars
this.props.touch.start = this.start;
this.props.touch.end = this.end;
this.props.touch.allowDragging = true;
this.props.touch.center = null;
this.scaleOffset = 0;
this.deltaDifference = 0;
// Disable the browser default handling of this event.
util.preventDefault(event);
};
/**
* Handle pinch event
* @param {Event} event
* @private
*/
Range.prototype._onPinch = function (event) {
// only allow zooming when configured as zoomable and moveable
if (!(this.options.zoomable && this.options.moveable)) return;
// Disable the browser default handling of this event.
util.preventDefault(event);
this.props.touch.allowDragging = false;
if (!this.props.touch.center) {
this.props.touch.center = this.getPointer(event.center, this.body.dom.center);
}
this.stopRolling();
var scale = 1 / (event.scale + this.scaleOffset);
var centerDate = this._pointerToDate(this.props.touch.center);
var hiddenDuration = DateUtil.getHiddenDurationBetween(this.body.hiddenDates, this.start, this.end);
var hiddenDurationBefore = DateUtil.getHiddenDurationBefore(this.options.moment, this.body.hiddenDates, this, centerDate);
var hiddenDurationAfter = hiddenDuration - hiddenDurationBefore;
// calculate new start and end
var newStart = (centerDate - hiddenDurationBefore) + (this.props.touch.start - (centerDate - hiddenDurationBefore)) * scale;
var newEnd = (centerDate + hiddenDurationAfter) + (this.props.touch.end - (centerDate + hiddenDurationAfter)) * scale;
// snapping times away from hidden zones
this.startToFront = 1 - scale <= 0; // used to do the right auto correction with periodic hidden times
this.endToFront = scale - 1 <= 0; // used to do the right auto correction with periodic hidden times
var safeStart = DateUtil.snapAwayFromHidden(this.body.hiddenDates, newStart, 1 - scale, true);
var safeEnd = DateUtil.snapAwayFromHidden(this.body.hiddenDates, newEnd, scale - 1, true);
if (safeStart != newStart || safeEnd != newEnd) {
this.props.touch.start = safeStart;
this.props.touch.end = safeEnd;
this.scaleOffset = 1 - event.scale;
newStart = safeStart;
newEnd = safeEnd;
}
var options = {
animation: false,
byUser: true,
event: event
};
this.setRange(newStart, newEnd, options);
this.startToFront = false; // revert to default
this.endToFront = true; // revert to default
};
/**
* Test whether the mouse from a mouse event is inside the visible window,
* between the current start and end date
* @param {Object} event
* @return {boolean} Returns true when inside the visible window
* @private
*/
Range.prototype._isInsideRange = function(event) {
// calculate the time where the mouse is, check whether inside
// and no scroll action should happen.
var clientX = event.center ? event.center.x : event.clientX;
var x;
if (this.options.rtl) {
x = clientX - util.getAbsoluteLeft(this.body.dom.centerContainer);
} else {
x = util.getAbsoluteRight(this.body.dom.centerContainer) - clientX;
}
var time = this.body.util.toTime(x);
return time >= this.start && time <= this.end;
};
/**
* Helper function to calculate the center date for zooming
* @param {{x: number, y: number}} pointer
* @return {number} date
* @private
*/
Range.prototype._pointerToDate = function (pointer) {
var conversion;
var direction = this.options.direction;
validateDirection(direction);
if (direction == 'horizontal') {
return this.body.util.toTime(pointer.x).valueOf();
}
else {
var height = this.body.domProps.center.height;
conversion = this.conversion(height);
return pointer.y / conversion.scale + conversion.offset;
}
};
/**
* Get the pointer location relative to the location of the dom element
* @param {{x: number, y: number}} touch
* @param {Element} element HTML DOM element
* @return {{x: number, y: number}} pointer
* @private
*/
Range.prototype.getPointer = function (touch, element) {
if (this.options.rtl) {
return {
x: util.getAbsoluteRight(element) - touch.x,
y: touch.y - util.getAbsoluteTop(element)
};
} else {
return {
x: touch.x - util.getAbsoluteLeft(element),
y: touch.y - util.getAbsoluteTop(element)
};
}
};
/**
* Zoom the range the given scale in or out. Start and end date will
* be adjusted, and the timeline will be redrawn. You can optionally give a
* date around which to zoom.
* For example, try scale = 0.9 or 1.1
* @param {number} scale Scaling factor. Values above 1 will zoom out,
* values below 1 will zoom in.
* @param {number} [center] Value representing a date around which will
* be zoomed.
* @param {number} delta
* @param {Event} event
*/
Range.prototype.zoom = function(scale, center, delta, event) {
// if centerDate is not provided, take it half between start Date and end Date
if (center == null) {
center = (this.start + this.end) / 2;
}
var hiddenDuration = DateUtil.getHiddenDurationBetween(this.body.hiddenDates, this.start, this.end);
var hiddenDurationBefore = DateUtil.getHiddenDurationBefore(this.options.moment, this.body.hiddenDates, this, center);
var hiddenDurationAfter = hiddenDuration - hiddenDurationBefore;
// calculate new start and end
var newStart = (center-hiddenDurationBefore) + (this.start - (center-hiddenDurationBefore)) * scale;
var newEnd = (center+hiddenDurationAfter) + (this.end - (center+hiddenDurationAfter)) * scale;
// snapping times away from hidden zones
this.startToFront = delta > 0 ? false : true; // used to do the right autocorrection with periodic hidden times
this.endToFront = -delta > 0 ? false : true; // used to do the right autocorrection with periodic hidden times
var safeStart = DateUtil.snapAwayFromHidden(this.body.hiddenDates, newStart, delta, true);
var safeEnd = DateUtil.snapAwayFromHidden(this.body.hiddenDates, newEnd, -delta, true);
if (safeStart != newStart || safeEnd != newEnd) {
newStart = safeStart;
newEnd = safeEnd;
}
var options = {
animation: false,
byUser: true,
event: event
};
this.setRange(newStart, newEnd, options);
this.startToFront = false; // revert to default
this.endToFront = true; // revert to default
};
/**
* Move the range with a given delta to the left or right. Start and end
* value will be adjusted. For example, try delta = 0.1 or -0.1
* @param {number} delta Moving amount. Positive value will move right,
* negative value will move left
*/
Range.prototype.move = function(delta) {
// zoom start Date and end Date relative to the centerDate
var diff = (this.end - this.start);
// apply new values
var newStart = this.start + diff * delta;
var newEnd = this.end + diff * delta;
// TODO: reckon with min and max range
this.start = newStart;
this.end = newEnd;
};
/**
* Move the range to a new center point
* @param {number} moveTo New center point of the range
*/
Range.prototype.moveTo = function(moveTo) {
var center = (this.start + this.end) / 2;
var diff = center - moveTo;
// calculate new start and end
var newStart = this.start - diff;
var newEnd = this.end - diff;
var options = {
animation: false,
byUser: true,
event: null
};
this.setRange(newStart, newEnd, options);
};
module.exports = Range;