docs/assets/split.js
/*! Split.js - v1.3.5 */
// https://github.com/nathancahill/Split.js
// Copyright (c) 2017 Nathan Cahill; Licensed MIT
(function(global, factory) {
typeof exports === 'object' && typeof module !== 'undefined'
? (module.exports = factory())
: typeof define === 'function' && define.amd
? define(factory)
: (global.Split = factory());
})(this, function() {
'use strict';
// The programming goals of Split.js are to deliver readable, understandable and
// maintainable code, while at the same time manually optimizing for tiny minified file size,
// browser compatibility without additional requirements, graceful fallback (IE8 is supported)
// and very few assumptions about the user's page layout.
var global = window;
var document = global.document;
// Save a couple long function names that are used frequently.
// This optimization saves around 400 bytes.
var addEventListener = 'addEventListener';
var removeEventListener = 'removeEventListener';
var getBoundingClientRect = 'getBoundingClientRect';
var NOOP = function() {
return false;
};
// Figure out if we're in IE8 or not. IE8 will still render correctly,
// but will be static instead of draggable.
var isIE8 = global.attachEvent && !global[addEventListener];
// This library only needs two helper functions:
//
// The first determines which prefixes of CSS calc we need.
// We only need to do this once on startup, when this anonymous function is called.
//
// Tests -webkit, -moz and -o prefixes. Modified from StackOverflow:
// http://stackoverflow.com/questions/16625140/js-feature-detection-to-detect-the-usage-of-webkit-calc-over-calc/16625167#16625167
var calc =
['', '-webkit-', '-moz-', '-o-']
.filter(function(prefix) {
var el = document.createElement('div');
el.style.cssText = 'width:' + prefix + 'calc(9px)';
return !!el.style.length;
})
.shift() + 'calc';
// The second helper function allows elements and string selectors to be used
// interchangeably. In either case an element is returned. This allows us to
// do `Split([elem1, elem2])` as well as `Split(['#id1', '#id2'])`.
var elementOrSelector = function(el) {
if (typeof el === 'string' || el instanceof String) {
return document.querySelector(el);
}
return el;
};
// The main function to initialize a split. Split.js thinks about each pair
// of elements as an independant pair. Dragging the gutter between two elements
// only changes the dimensions of elements in that pair. This is key to understanding
// how the following functions operate, since each function is bound to a pair.
//
// A pair object is shaped like this:
//
// {
// a: DOM element,
// b: DOM element,
// aMin: Number,
// bMin: Number,
// dragging: Boolean,
// parent: DOM element,
// isFirst: Boolean,
// isLast: Boolean,
// direction: 'horizontal' | 'vertical'
// }
//
// The basic sequence:
//
// 1. Set defaults to something sane. `options` doesn't have to be passed at all.
// 2. Initialize a bunch of strings based on the direction we're splitting.
// A lot of the behavior in the rest of the library is paramatized down to
// rely on CSS strings and classes.
// 3. Define the dragging helper functions, and a few helpers to go with them.
// 4. Loop through the elements while pairing them off. Every pair gets an
// `pair` object, a gutter, and special isFirst/isLast properties.
// 5. Actually size the pair elements, insert gutters and attach event listeners.
var Split = function(ids, options) {
if (options === void 0) options = {};
var dimension;
var clientDimension;
var clientAxis;
var position;
var paddingA;
var paddingB;
var elements;
// All DOM elements in the split should have a common parent. We can grab
// the first elements parent and hope users read the docs because the
// behavior will be whacky otherwise.
var parent = elementOrSelector(ids[0]).parentNode;
var parentFlexDirection = global.getComputedStyle(parent).flexDirection;
// Set default options.sizes to equal percentages of the parent element.
var sizes =
options.sizes ||
ids.map(function() {
return 100 / ids.length;
});
// Standardize minSize to an array if it isn't already. This allows minSize
// to be passed as a number.
var minSize = options.minSize !== undefined ? options.minSize : 100;
var minSizes = Array.isArray(minSize)
? minSize
: ids.map(function() {
return minSize;
});
var gutterSize = options.gutterSize !== undefined ? options.gutterSize : 10;
var snapOffset = options.snapOffset !== undefined ? options.snapOffset : 30;
var direction = options.direction || 'horizontal';
var cursor =
options.cursor ||
(direction === 'horizontal' ? 'ew-resize' : 'ns-resize');
var gutter =
options.gutter ||
function(i, gutterDirection) {
var gut = document.createElement('div');
gut.className = 'gutter gutter-' + gutterDirection;
return gut;
};
var elementStyle =
options.elementStyle ||
function(dim, size, gutSize) {
var style = {};
if (typeof size !== 'string' && !(size instanceof String)) {
if (!isIE8) {
style[dim] = calc + '(' + size + '% - ' + gutSize + 'px)';
} else {
style[dim] = size + '%';
}
} else {
style[dim] = size;
}
return style;
};
var gutterStyle =
options.gutterStyle ||
function(dim, gutSize) {
return (obj = {}), (obj[dim] = gutSize + 'px'), obj;
var obj;
};
// 2. Initialize a bunch of strings based on the direction we're splitting.
// A lot of the behavior in the rest of the library is paramatized down to
// rely on CSS strings and classes.
if (direction === 'horizontal') {
dimension = 'width';
clientDimension = 'clientWidth';
clientAxis = 'clientX';
position = 'left';
paddingA = 'paddingLeft';
paddingB = 'paddingRight';
} else if (direction === 'vertical') {
dimension = 'height';
clientDimension = 'clientHeight';
clientAxis = 'clientY';
position = 'top';
paddingA = 'paddingTop';
paddingB = 'paddingBottom';
}
// 3. Define the dragging helper functions, and a few helpers to go with them.
// Each helper is bound to a pair object that contains it's metadata. This
// also makes it easy to store references to listeners that that will be
// added and removed.
//
// Even though there are no other functions contained in them, aliasing
// this to self saves 50 bytes or so since it's used so frequently.
//
// The pair object saves metadata like dragging state, position and
// event listener references.
function setElementSize(el, size, gutSize) {
// Split.js allows setting sizes via numbers (ideally), or if you must,
// by string, like '300px'. This is less than ideal, because it breaks
// the fluid layout that `calc(% - px)` provides. You're on your own if you do that,
// make sure you calculate the gutter size by hand.
var style = elementStyle(dimension, size, gutSize);
// eslint-disable-next-line no-param-reassign
Object.keys(style).forEach(function(prop) {
return (el.style[prop] = style[prop]);
});
}
function setGutterSize(gutterElement, gutSize) {
var style = gutterStyle(dimension, gutSize);
// eslint-disable-next-line no-param-reassign
Object.keys(style).forEach(function(prop) {
return (gutterElement.style[prop] = style[prop]);
});
}
// Actually adjust the size of elements `a` and `b` to `offset` while dragging.
// calc is used to allow calc(percentage + gutterpx) on the whole split instance,
// which allows the viewport to be resized without additional logic.
// Element a's size is the same as offset. b's size is total size - a size.
// Both sizes are calculated from the initial parent percentage,
// then the gutter size is subtracted.
function adjust(offset) {
var a = elements[this.a];
var b = elements[this.b];
var percentage = a.size + b.size;
a.size = offset / this.size * percentage;
b.size = percentage - offset / this.size * percentage;
setElementSize(a.element, a.size, this.aGutterSize);
setElementSize(b.element, b.size, this.bGutterSize);
}
// drag, where all the magic happens. The logic is really quite simple:
//
// 1. Ignore if the pair is not dragging.
// 2. Get the offset of the event.
// 3. Snap offset to min if within snappable range (within min + snapOffset).
// 4. Actually adjust each element in the pair to offset.
//
// ---------------------------------------------------------------------
// | | <- a.minSize || b.minSize -> | |
// | | | <- this.snapOffset || this.snapOffset -> | | |
// | | | || | | |
// | | | || | | |
// ---------------------------------------------------------------------
// | <- this.start this.size -> |
function drag(e) {
var offset;
if (!this.dragging) {
return;
}
// Get the offset of the event from the first side of the
// pair `this.start`. Supports touch events, but not multitouch, so only the first
// finger `touches[0]` is counted.
if ('touches' in e) {
offset = e.touches[0][clientAxis] - this.start;
} else {
offset = e[clientAxis] - this.start;
}
// If within snapOffset of min or max, set offset to min or max.
// snapOffset buffers a.minSize and b.minSize, so logic is opposite for both.
// Include the appropriate gutter sizes to prevent overflows.
if (offset <= elements[this.a].minSize + snapOffset + this.aGutterSize) {
offset = elements[this.a].minSize + this.aGutterSize;
} else if (
offset >=
this.size - (elements[this.b].minSize + snapOffset + this.bGutterSize)
) {
offset = this.size - (elements[this.b].minSize + this.bGutterSize);
}
// Actually adjust the size.
adjust.call(this, offset);
// Call the drag callback continously. Don't do anything too intensive
// in this callback.
if (options.onDrag) {
options.onDrag();
}
}
// Cache some important sizes when drag starts, so we don't have to do that
// continously:
//
// `size`: The total size of the pair. First + second + first gutter + second gutter.
// `start`: The leading side of the first element.
//
// ------------------------------------------------
// | aGutterSize -> ||| |
// | ||| |
// | ||| |
// | ||| <- bGutterSize |
// ------------------------------------------------
// | <- start size -> |
function calculateSizes() {
// Figure out the parent size minus padding.
var a = elements[this.a].element;
var b = elements[this.b].element;
this.size =
a[getBoundingClientRect]()[dimension] +
b[getBoundingClientRect]()[dimension] +
this.aGutterSize +
this.bGutterSize;
this.start = a[getBoundingClientRect]()[position];
}
// stopDragging is very similar to startDragging in reverse.
function stopDragging() {
var self = this;
var a = elements[self.a].element;
var b = elements[self.b].element;
if (self.dragging && options.onDragEnd) {
options.onDragEnd();
}
self.dragging = false;
// Remove the stored event listeners. This is why we store them.
global[removeEventListener]('mouseup', self.stop);
global[removeEventListener]('touchend', self.stop);
global[removeEventListener]('touchcancel', self.stop);
self.parent[removeEventListener]('mousemove', self.move);
self.parent[removeEventListener]('touchmove', self.move);
// Delete them once they are removed. I think this makes a difference
// in memory usage with a lot of splits on one page. But I don't know for sure.
delete self.stop;
delete self.move;
a[removeEventListener]('selectstart', NOOP);
a[removeEventListener]('dragstart', NOOP);
b[removeEventListener]('selectstart', NOOP);
b[removeEventListener]('dragstart', NOOP);
a.style.userSelect = '';
a.style.webkitUserSelect = '';
a.style.MozUserSelect = '';
a.style.pointerEvents = '';
b.style.userSelect = '';
b.style.webkitUserSelect = '';
b.style.MozUserSelect = '';
b.style.pointerEvents = '';
self.gutter.style.cursor = '';
self.parent.style.cursor = '';
}
// startDragging calls `calculateSizes` to store the inital size in the pair object.
// It also adds event listeners for mouse/touch events,
// and prevents selection while dragging so avoid the selecting text.
function startDragging(e) {
// Alias frequently used variables to save space. 200 bytes.
var self = this;
var a = elements[self.a].element;
var b = elements[self.b].element;
// Call the onDragStart callback.
if (!self.dragging && options.onDragStart) {
options.onDragStart();
}
// Don't actually drag the element. We emulate that in the drag function.
e.preventDefault();
// Set the dragging property of the pair object.
self.dragging = true;
// Create two event listeners bound to the same pair object and store
// them in the pair object.
self.move = drag.bind(self);
self.stop = stopDragging.bind(self);
// All the binding. `window` gets the stop events in case we drag out of the elements.
global[addEventListener]('mouseup', self.stop);
global[addEventListener]('touchend', self.stop);
global[addEventListener]('touchcancel', self.stop);
self.parent[addEventListener]('mousemove', self.move);
self.parent[addEventListener]('touchmove', self.move);
// Disable selection. Disable!
a[addEventListener]('selectstart', NOOP);
a[addEventListener]('dragstart', NOOP);
b[addEventListener]('selectstart', NOOP);
b[addEventListener]('dragstart', NOOP);
a.style.userSelect = 'none';
a.style.webkitUserSelect = 'none';
a.style.MozUserSelect = 'none';
a.style.pointerEvents = 'none';
b.style.userSelect = 'none';
b.style.webkitUserSelect = 'none';
b.style.MozUserSelect = 'none';
b.style.pointerEvents = 'none';
// Set the cursor, both on the gutter and the parent element.
// Doing only a, b and gutter causes flickering.
self.gutter.style.cursor = cursor;
self.parent.style.cursor = cursor;
// Cache the initial sizes of the pair.
calculateSizes.call(self);
}
// 5. Create pair and element objects. Each pair has an index reference to
// elements `a` and `b` of the pair (first and second elements).
// Loop through the elements while pairing them off. Every pair gets a
// `pair` object, a gutter, and isFirst/isLast properties.
//
// Basic logic:
//
// - Starting with the second element `i > 0`, create `pair` objects with
// `a = i - 1` and `b = i`
// - Set gutter sizes based on the _pair_ being first/last. The first and last
// pair have gutterSize / 2, since they only have one half gutter, and not two.
// - Create gutter elements and add event listeners.
// - Set the size of the elements, minus the gutter sizes.
//
// -----------------------------------------------------------------------
// | i=0 | i=1 | i=2 | i=3 |
// | | isFirst | | isLast |
// | pair 0 pair 1 pair 2 |
// | | | | |
// -----------------------------------------------------------------------
var pairs = [];
elements = ids.map(function(id, i) {
// Create the element object.
var element = {
element: elementOrSelector(id),
size: sizes[i],
minSize: minSizes[i]
};
var pair;
if (i > 0) {
// Create the pair object with it's metadata.
pair = {
a: i - 1,
b: i,
dragging: false,
isFirst: i === 1,
isLast: i === ids.length - 1,
direction: direction,
parent: parent
};
// For first and last pairs, first and last gutter width is half.
pair.aGutterSize = gutterSize;
pair.bGutterSize = gutterSize;
if (pair.isFirst) {
pair.aGutterSize = gutterSize / 2;
}
if (pair.isLast) {
pair.bGutterSize = gutterSize / 2;
}
// if the parent has a reverse flex-direction, switch the pair elements.
if (
parentFlexDirection === 'row-reverse' ||
parentFlexDirection === 'column-reverse'
) {
var temp = pair.a;
pair.a = pair.b;
pair.b = temp;
}
}
// Determine the size of the current element. IE8 is supported by
// staticly assigning sizes without draggable gutters. Assigns a string
// to `size`.
//
// IE9 and above
if (!isIE8) {
// Create gutter elements for each pair.
if (i > 0) {
var gutterElement = gutter(i, direction);
setGutterSize(gutterElement, gutterSize);
gutterElement[addEventListener](
'mousedown',
startDragging.bind(pair)
);
gutterElement[addEventListener](
'touchstart',
startDragging.bind(pair)
);
parent.insertBefore(gutterElement, element.element);
pair.gutter = gutterElement;
}
}
// Set the element size to our determined size.
// Half-size gutters for first and last elements.
if (i === 0 || i === ids.length - 1) {
setElementSize(element.element, element.size, gutterSize / 2);
} else {
setElementSize(element.element, element.size, gutterSize);
}
var computedSize = element.element[getBoundingClientRect]()[dimension];
if (computedSize < element.minSize) {
element.minSize = computedSize;
}
// After the first iteration, and we have a pair object, append it to the
// list of pairs.
if (i > 0) {
pairs.push(pair);
}
return element;
});
function setSizes(newSizes) {
newSizes.forEach(function(newSize, i) {
if (i > 0) {
var pair = pairs[i - 1];
var a = elements[pair.a];
var b = elements[pair.b];
a.size = newSizes[i - 1];
b.size = newSize;
setElementSize(a.element, a.size, pair.aGutterSize);
setElementSize(b.element, b.size, pair.bGutterSize);
}
});
}
function destroy() {
pairs.forEach(function(pair) {
pair.parent.removeChild(pair.gutter);
elements[pair.a].element.style[dimension] = '';
elements[pair.b].element.style[dimension] = '';
});
}
if (isIE8) {
return {
setSizes: setSizes,
destroy: destroy
};
}
return {
setSizes: setSizes,
getSizes: function getSizes() {
return elements.map(function(element) {
return element.size;
});
},
collapse: function collapse(i) {
if (i === pairs.length) {
var pair = pairs[i - 1];
calculateSizes.call(pair);
if (!isIE8) {
adjust.call(pair, pair.size - pair.bGutterSize);
}
} else {
var pair$1 = pairs[i];
calculateSizes.call(pair$1);
if (!isIE8) {
adjust.call(pair$1, pair$1.aGutterSize);
}
}
},
destroy: destroy
};
};
return Split;
});