123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778 |
- 'use strict';
- var _ = {
- sum: require('lodash/sum'),
- flatten: require('lodash/flatten'),
- };
- var chalk = require('chalk');
- /**
- * The paginator returns a subset of the choices if the list is too long.
- */
- class Paginator {
- constructor(screen, options = {}) {
- const { isInfinite = true } = options;
- this.lastIndex = 0;
- this.screen = screen;
- this.isInfinite = isInfinite;
- }
- paginate(output, active, pageSize) {
- pageSize = pageSize || 7;
- var lines = output.split('\n');
- if (this.screen) {
- lines = this.screen.breakLines(lines);
- active = _.sum(lines.map((lineParts) => lineParts.length).splice(0, active));
- lines = _.flatten(lines);
- }
- // Make sure there's enough lines to paginate
- if (lines.length <= pageSize) {
- return output;
- }
- const visibleLines = this.isInfinite
- ? this.getInfiniteLines(lines, active, pageSize)
- : this.getFiniteLines(lines, active, pageSize);
- this.lastIndex = active;
- return (
- visibleLines.join('\n') +
- '\n' +
- chalk.dim('(Move up and down to reveal more choices)')
- );
- }
- getInfiniteLines(lines, active, pageSize) {
- if (this.pointer === undefined) {
- this.pointer = 0;
- }
- var middleOfList = Math.floor(pageSize / 2);
- // Move the pointer only when the user go down and limit it to the middle of the list
- if (
- this.pointer < middleOfList &&
- this.lastIndex < active &&
- active - this.lastIndex < pageSize
- ) {
- this.pointer = Math.min(middleOfList, this.pointer + active - this.lastIndex);
- }
- // Duplicate the lines so it give an infinite list look
- var infinite = _.flatten([lines, lines, lines]);
- var topIndex = Math.max(0, active + lines.length - this.pointer);
- return infinite.splice(topIndex, pageSize);
- }
- getFiniteLines(lines, active, pageSize) {
- var topIndex = active - pageSize / 2;
- if (topIndex < 0) {
- topIndex = 0;
- } else if (topIndex + pageSize > lines.length) {
- topIndex = lines.length - pageSize;
- }
- return lines.splice(topIndex, pageSize);
- }
- }
- module.exports = Paginator;
|