| // Copyright 2015 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| "use strict"; |
| |
| function computeScrollTop(container, element) { |
| const height = container.offsetHeight; |
| const margin = Math.floor(height / 4); |
| const pos = element.offsetTop; |
| const currentScrollTop = container.scrollTop; |
| if (pos < currentScrollTop + margin) { |
| return Math.max(0, pos - margin); |
| } else if (pos > (currentScrollTop + 3 * margin)) { |
| return Math.max(0, pos - 3 * margin); |
| } |
| return pos; |
| } |
| |
| class ViewElements { |
| constructor(container) { |
| this.container = container; |
| this.scrollTop = undefined; |
| } |
| |
| consider(element, doConsider) { |
| if (!doConsider) return; |
| const newScrollTop = computeScrollTop(this.container, element); |
| if (isNaN(newScrollTop)) { |
| console.log("NOO") |
| } |
| if (this.scrollTop === undefined) { |
| this.scrollTop = newScrollTop; |
| } else { |
| this.scrollTop = Math.min(this.scrollTop, newScrollTop); |
| } |
| } |
| |
| apply(doApply) { |
| if (!doApply || this.scrollTop === undefined) return; |
| this.container.scrollTop = this.scrollTop; |
| } |
| } |
| |
| |
| function lowerBound(a, value, compare, lookup) { |
| let first = 0; |
| let count = a.length; |
| while (count > 0) { |
| let step = Math.floor(count / 2); |
| let middle = first + step; |
| let middle_value = (lookup === undefined) ? a[middle] : lookup(a, middle); |
| let result = (compare === undefined) ? (middle_value < value) : compare(middle_value, value); |
| if (result) { |
| first = middle + 1; |
| count -= step + 1; |
| } else { |
| count = step; |
| } |
| } |
| return first; |
| } |
| |
| |
| function upperBound(a, value, compare, lookup) { |
| let first = 0; |
| let count = a.length; |
| while (count > 0) { |
| let step = Math.floor(count / 2); |
| let middle = first + step; |
| let middle_value = (lookup === undefined) ? a[middle] : lookup(a, middle); |
| let result = (compare === undefined) ? (value < middle_value) : compare(value, middle_value); |
| if (!result) { |
| first = middle + 1; |
| count -= step + 1; |
| } else { |
| count = step; |
| } |
| } |
| return first; |
| } |
| |
| |
| function sortUnique(arr, f, equal) { |
| if (arr.length == 0) return arr; |
| arr = arr.sort(f); |
| let ret = [arr[0]]; |
| for (var i = 1; i < arr.length; i++) { |
| if (!equal(arr[i-1], arr[i])) { |
| ret.push(arr[i]); |
| } |
| } |
| return ret; |
| } |
| |
| // Partial application without binding the receiver |
| function partial(f) { |
| var arguments1 = Array.prototype.slice.call(arguments, 1); |
| return function() { |
| var arguments2 = Array.from(arguments); |
| f.apply(this, arguments1.concat(arguments2)); |
| } |
| } |
| |
| function isIterable(obj) { |
| return obj != null && obj != undefined |
| && typeof obj != 'string' && typeof obj[Symbol.iterator] === 'function'; |
| } |