avocado-old/packages/input/index.js
2019-03-17 23:45:48 -05:00

124 lines
2.9 KiB
JavaScript

import * as I from 'immutable';
import {compose} from '@avocado/core';
import {EventEmitter} from '@avocado/mixins';
const decorate = compose(
EventEmitter,
);
class ActionRegistryBase {
static normalizeKey(key) {
return key.toLowerCase();
}
constructor() {
// Track events.
this.target = undefined;
this.mapActionToKey = {};
this.mapKeyToAction = {};
// Track actions.
this._state = I.Set();
// Handle lame OS input event behavior. See: https://mzl.la/2Ob0WQE
this.keysDown = {};
this.keyUpDelays = {};
// Bind event handlers.
this.onBlur = this.onBlur.bind(this);
this.onKeyDown = this.onKeyDown.bind(this);
this.onKeyUp = this.onKeyUp.bind(this);
}
actionForKey(key) {
return this.mapKeyToAction[key];
}
listen(target = window.document) {
// Only listen once.
if (this.target) {
return;
}
this.target = target;
this.target.addEventListener('blur', this.onBlur);
this.target.addEventListener('keydown', this.onKeyDown);
this.target.addEventListener('keyup', this.onKeyUp);
}
keyForAction(action) {
return this.mapActionToKey[action];
}
mapKeysToActions(map) {
for (const key in map) {
const action = map[key];
this.mapKeyToAction[key] = action;
this.mapActionToKey[action] = key;
}
}
onBlur(event) {
event = event || window.event;
this.setAllKeysUp();
}
onKeyDown(event) {
event = event || window.event;
const key = this.constructor.normalizeKey(event.key);
if (this.keysDown[key]) {
if (this.keyUpDelays[key]) {
clearTimeout(this.keyUpDelays[key]);
delete this.keyUpDelays[key];
}
return;
}
this.keysDown[key] = true;
if (this.mapKeyToAction[key]) {
const action = this.mapKeyToAction[key];
this._state = this._state.add(action);
this.emit('actionStart', action);
}
}
onKeyUp(event) {
event = event || window.event;
const key = this.constructor.normalizeKey(event.key);
this.keyUpDelays[key] = setTimeout(() => {
delete this.keyUpDelays[key];
delete this.keysDown[key];
if (this.mapKeyToAction[key]) {
const action = this.mapKeyToAction[key];
this._state = this._state.delete(action);
this.emit('actionStop', action);
}
}, 20);
}
setAllKeysUp() {
this.keysDown = {};
for (const key in this.keyUpDelays) {
const handle = this.keyUpDelays[key];
clearTimeout(handle);
}
this.keyUpDelays = {};
this._state = I.Set();
}
state() {
return this._state;
}
stopListening() {
this.setAllKeysUp();
if (!this.target) {
return;
}
this.target.removeEventListener('blur', this.onBlur);
this.target.removeEventListener('keydown', this.onKeyDown);
this.target.removeEventListener('keyup', this.onKeyUp);
this.target = undefined;
}
}
export class ActionRegistry extends decorate(ActionRegistryBase) {};