// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Emoji auto complete.
*
* @module core/emoji/auto_complete
* @copyright 2019 Ryan Wyllie <ryan@moodle.com>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
import * as EmojiData from 'core/emoji/data';
import {render as renderTemplate} from 'core/templates';
import {debounce} from 'core/utils';
import LocalStorage from 'core/localstorage';
import KeyCodes from 'core/key_codes';
const INPUT_DEBOUNCE_TIMER = 200;
const SUGGESTION_LIMIT = 50;
const MAX_RECENT_COUNT = 27;
const RECENT_EMOJIS_STORAGE_KEY = 'moodle-recent-emojis';
const SELECTORS = {
EMOJI_BUTTON: '[data-region="emoji-button"]',
ACTIVE_EMOJI_BUTTON: '[data-region="emoji-button"].active',
};
/**
* Get the list of recent emojis data from local storage.
*
* @return {Array}
*/
const getRecentEmojis = () => {
const storedData = LocalStorage.get(RECENT_EMOJIS_STORAGE_KEY);
return storedData ? JSON.parse(storedData) : [];
};
/**
* Add an emoji data to the set of recent emojis. The new set of recent emojis are
* saved in local storage.
*
* @param {String} unified The char chodes for the emoji
* @param {String} shortName The emoji short name
*/
const addRecentEmoji = (unified, shortName) => {
const newEmoji = {
unified,
shortnames: [shortName]
};
const recentEmojis = getRecentEmojis();
// Add the new emoji to the start of the list of recent emojis.
let newRecentEmojis = [newEmoji, ...recentEmojis.filter(emoji => emoji.unified != newEmoji.unified)];
// Limit the number of recent emojis.
newRecentEmojis = newRecentEmojis.slice(0, MAX_RECENT_COUNT);
LocalStorage.set(RECENT_EMOJIS_STORAGE_KEY, JSON.stringify(newRecentEmojis));
};
/**
* Get the actual emoji string from the short name.
*
* @param {String} shortName Emoji short name
* @return {String|null}
*/
const getEmojiTextFromShortName = (shortName) => {
const unified = EmojiData.byShortName[shortName];
if (unified) {
const charCodes = unified.split('-').map(code => `0x${code}`);
return String.fromCodePoint.apply(null, charCodes);
} else {
return null;
}
};
/**
* Render the auto complete list for the given short names.
*
* @param {Element} root The root container for the emoji auto complete
* @param {Array} shortNames The list of short names for emoji suggestions to show
*/
const render = async(root, shortNames) => {
const renderContext = {
emojis: shortNames.map((shortName, index) => {
return {
active: index === 0,
emojitext: getEmojiTextFromShortName(shortName),
displayshortname: `:${shortName}:`,
shortname: shortName,
unified: EmojiData.byShortName[shortName]
};
})
};
const html = await renderTemplate('core/emoji/auto_complete', renderContext);
root.innerHTML = html;
};
/**
* Get the list of emoji short names that include the given search term. If
* the search term is an empty string then the list of recently used emojis
* will be returned.
*
* @param {String} searchTerm Text to match on
* @param {Number} limit Maximum number of results to return
* @return {Array}
*/
const searchEmojis = (searchTerm, limit) => {
if (searchTerm === '') {
return getRecentEmojis().map(data => data.shortnames[0]).slice(0, limit);
} else {
searchTerm = searchTerm.toLowerCase();
return Object.keys(EmojiData.byShortName)
.filter(shortName => shortName.includes(searchTerm))
.slice(0, limit);
}
};
/**
* Get the current word at the given position (index) within the text.
*
* @param {String} text The text to process
* @param {Number} position The position (index) within the text to match the word
* @return {String}
*/
const getWordFromPosition = (text, position) => {
const startMatches = text.slice(0, position).match(/(\S*)$/);
const endMatches = text.slice(position).match(/^(\S*)/);
let startText = '';
let endText = '';
if (startMatches) {
startText = startMatches[startMatches.length - 1];
}
if (endMatches) {
endText = endMatches[endMatches.length - 1];
}
return `${startText}${endText}`;
};
/**
* Check if the given text is a full short name, i.e. has leading and trialing colon
* characters.
*
* @param {String} text The text to process
* @return {Bool}
*/
const isCompleteShortName = text => /^:[^:\s]+:$/.test(text);
/**
* Check if the given text is a partial short name, i.e. has a leading colon but no
* trailing colon.
*
* @param {String} text The text to process
* @return {Bool}
*/
const isPartialShortName = text => /^:[^:\s]*$/.test(text);
/**
* Remove the colon characters from the given text.
*
* @param {String} text The text to process
* @return {String}
*/
const getShortNameFromText = text => text.replace(/:/g, '');
/**
* Get the currently active emoji button element in the list of suggestions.
*
* @param {Element} root The emoji auto complete container element
* @return {Element|null}
*/
const getActiveEmojiSuggestion = (root) => {
return root.querySelector(SELECTORS.ACTIVE_EMOJI_BUTTON);
};
/**
* Make the previous sibling of the current active emoji active.
*
* @param {Element} root The emoji auto complete container element
*/
const selectPreviousEmojiSuggestion = (root) => {
const activeEmojiSuggestion = getActiveEmojiSuggestion(root);
const previousSuggestion = activeEmojiSuggestion.previousElementSibling;
if (previousSuggestion) {
activeEmojiSuggestion.classList.remove('active');
previousSuggestion.classList.add('active');
previousSuggestion.scrollIntoView({behaviour: 'smooth', inline: 'center'});
}
};
/**
* Make the next sibling to the current active emoji active.
*
* @param {Element} root The emoji auto complete container element
*/
const selectNextEmojiSuggestion = (root) => {
const activeEmojiSuggestion = getActiveEmojiSuggestion(root);
const nextSuggestion = activeEmojiSuggestion.nextElementSibling;
if (nextSuggestion) {
activeEmojiSuggestion.classList.remove('active');
nextSuggestion.classList.add('active');
nextSuggestion.scrollIntoView({behaviour: 'smooth', inline: 'center'});
}
};
/**
* Trigger the select callback for the given emoji button element.
*
* @param {Element} element The emoji button element
* @param {Function} selectCallback The callback for when the user selects an emoji
*/
const selectEmojiElement = (element, selectCallback) => {
const shortName = element.getAttribute('data-short-name');
const unified = element.getAttribute('data-unified');
addRecentEmoji(unified, shortName);
selectCallback(element.innerHTML.trim());
};
/**
* Initialise the emoji auto complete.
*
* @method
* @param {Element} root The root container element for the auto complete
* @param {Element} textArea The text area element to monitor for auto complete
* @param {Function} hasSuggestionCallback Callback for when there are auto-complete suggestions
* @param {Function} selectCallback Callback for when the user selects an emoji
*/
export default (root, textArea, hasSuggestionCallback, selectCallback) => {
let hasSuggestions = false;
let previousSearchText = '';
// Debounce the listener so that each keypress delays the execution of the handler. The
// handler should only run 200 milliseconds after the last keypress.
textArea.addEventListener('keyup', debounce(() => {
// This is a "keyup" listener so that it only executes after the text area value
// has been updated.
const text = textArea.value;
const cursorPos = textArea.selectionStart;
const searchText = getWordFromPosition(text, cursorPos);
if (searchText === previousSearchText) {
// Nothing has changed so no need to take any action.
return;
} else {
previousSearchText = searchText;
}
if (isCompleteShortName(searchText)) {
// If the user has entered a full short name (with leading and trialing colons)
// then see if we can find a match for it and auto complete it.
const shortName = getShortNameFromText(searchText);
const emojiText = getEmojiTextFromShortName(shortName);
hasSuggestions = false;
if (emojiText) {
addRecentEmoji(EmojiData.byShortName[shortName], shortName);
selectCallback(emojiText);
}
} else if (isPartialShortName(searchText)) {
// If the user has entered a partial short name (leading colon but no trailing) then
// search on the text to see if we can find some suggestions for them.
const suggestions = searchEmojis(getShortNameFromText(searchText), SUGGESTION_LIMIT);
if (suggestions.length) {
render(root, suggestions);
hasSuggestions = true;
} else {
hasSuggestions = false;
}
} else {
hasSuggestions = false;
}
hasSuggestionCallback(hasSuggestions);
}, INPUT_DEBOUNCE_TIMER));
textArea.addEventListener('keydown', (e) => {
if (hasSuggestions) {
const isModifierPressed = (e.shiftKey || e.metaKey || e.altKey || e.ctrlKey);
if (!isModifierPressed) {
switch (e.which) {
case KeyCodes.escape:
// Escape key closes the auto complete.
hasSuggestions = false;
hasSuggestionCallback(false);
break;
case KeyCodes.arrowLeft:
// Arrow keys navigate through the list of suggetions.
selectPreviousEmojiSuggestion(root);
e.preventDefault();
break;
case KeyCodes.arrowRight:
// Arrow keys navigate through the list of suggetions.
selectNextEmojiSuggestion(root);
e.preventDefault();
break;
case KeyCodes.enter:
// Enter key selects the current suggestion.
selectEmojiElement(getActiveEmojiSuggestion(root), selectCallback);
e.preventDefault();
e.stopPropagation();
break;
}
}
}
});
root.addEventListener('click', (e) => {
const target = e.target;
if (target.matches(SELECTORS.EMOJI_BUTTON)) {
selectEmojiElement(target, selectCallback);
}
});
};