Files
mkdocs-material/src/assets/javascripts/components/Material/Sidebar/Position.js
2017-03-11 14:42:55 +01:00

134 lines
4.4 KiB
JavaScript

/*
* Copyright (c) 2016-2017 Martin Donath <martin.donath@squidfunk.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/* ----------------------------------------------------------------------------
* Class
* ------------------------------------------------------------------------- */
export default class Position {
/**
* Set sidebars to locked state and limit height to parent node
*
* @constructor
*
* @property {HTMLElement} el_ - Sidebar
* @property {HTMLElement} parent_ - Sidebar container
* @property {HTMLElement} header_ - Header
* @property {number} height_ - Current sidebar height
* @property {number} offset_ - Current page y-offset
*
* @param {(string|HTMLElement)} el - Selector or HTML element
* @param {(string|HTMLElement)} header - Selector or HTML element
*/
constructor(el, header) {
let ref = (typeof el === "string")
? document.querySelector(el)
: el
if (!(ref instanceof HTMLElement) ||
!(ref.parentNode instanceof HTMLElement))
throw new ReferenceError
this.el_ = ref
this.parent_ = ref.parentNode
/* Retrieve header */
ref = (typeof header === "string")
? document.querySelector(header)
: header
if (!(ref instanceof HTMLElement))
throw new ReferenceError
this.header_ = ref
/* Initialize current height */
this.height_ = 0
}
/**
* Initialize sidebar state
*/
setup() {
const top = Array.prototype.reduce.call(
this.parent_.children, (offset, child) => {
return Math.max(offset, child.offsetTop)
}, 0)
/* Set lock offset for element with largest top offset */
this.offset_ = top - this.header_.offsetHeight
this.update()
}
/**
* Update locked state and height
*
* The inner height of the window (= the visible area) is the maximum
* possible height for the stretching sidebar. This height must be deducted
* by the height of the fixed header (56px). Depending on the page y-offset,
* the top offset of the sidebar must be taken into account, as well as the
* case where the window is scrolled beyond the sidebar container.
*
* @param {Event?} ev - Event
*/
update(ev) {
const offset = window.pageYOffset
const visible = window.innerHeight
/* Update offset, in case window is resized */
if (ev && ev.type === "resize")
this.setup()
/* Set bounds of sidebar container - must be calculated on every run, as
the height of the content might change due to loading images etc. */
const bounds = {
top: this.header_.offsetHeight,
bottom: this.parent_.offsetTop + this.parent_.offsetHeight
}
/* Calculate new offset and height */
const height = visible - bounds.top
- Math.max(0, this.offset_ - offset)
- Math.max(0, offset + visible - bounds.bottom)
/* If height changed, update element */
if (height !== this.height_)
this.el_.style.height = `${this.height_ = height}px`
/* Sidebar should be locked, as we're below parent offset */
if (offset >= this.offset_) {
if (this.el_.dataset.mdState !== "lock")
this.el_.dataset.mdState = "lock"
/* Sidebar should be unlocked, if locked */
} else if (this.el_.dataset.mdState === "lock") {
this.el_.dataset.mdState = ""
}
}
/**
* Reset locked state and height
*/
reset() {
this.el_.dataset.mdState = ""
this.el_.style.height = ""
this.height_ = 0
}
}