gnome-shell/js/misc/history.js
Evan Welsh a88e59c1a8 Adopt EventEmitter class instead of injecting Signal methods
Introduce a new class, EventEmitter, which implements signal
handling for pure JavaScript classes. EventEmitter still
utilizes GJS' addSignalMethods internally.

EventEmitter allows static typechecking to understand the
structure of event-emitting JS classes and makes creating
child classes simpler.

The name 'EventEmitter' mirrors a common name for this pattern
in Node and in JS libraries.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2043>
2022-07-04 18:30:49 -04:00

115 lines
3.1 KiB
JavaScript

// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
/* exported HistoryManager */
const Signals = imports.misc.signals;
const Clutter = imports.gi.Clutter;
const Params = imports.misc.params;
var DEFAULT_LIMIT = 512;
var HistoryManager = class extends Signals.EventEmitter {
constructor(params) {
super();
params = Params.parse(params, {
gsettingsKey: null,
limit: DEFAULT_LIMIT,
entry: null,
});
this._key = params.gsettingsKey;
this._limit = params.limit;
this._historyIndex = 0;
if (this._key) {
this._history = global.settings.get_strv(this._key);
global.settings.connect(`changed::${this._key}`,
this._historyChanged.bind(this));
} else {
this._history = [];
}
this._entry = params.entry;
if (this._entry) {
this._entry.connect('key-press-event',
this._onEntryKeyPress.bind(this));
}
}
_historyChanged() {
this._history = global.settings.get_strv(this._key);
this._historyIndex = this._history.length;
}
_setPrevItem(text) {
if (this._historyIndex <= 0)
return false;
if (text)
this._history[this._historyIndex] = text;
this._historyIndex--;
this._indexChanged();
return true;
}
_setNextItem(text) {
if (this._historyIndex >= this._history.length)
return false;
if (text)
this._history[this._historyIndex] = text;
this._historyIndex++;
this._indexChanged();
return true;
}
lastItem() {
if (this._historyIndex !== this._history.length) {
this._historyIndex = this._history.length;
this._indexChanged();
}
return this._historyIndex ? this._history[this._historyIndex - 1] : null;
}
addItem(input) {
input = input.trim();
if (input &&
(this._history.length === 0 ||
this._history[this._history.length - 1] !== input)) {
this._history = this._history.filter(entry => entry !== input);
this._history.push(input);
this._save();
}
this._historyIndex = this._history.length;
return input; // trimmed
}
_onEntryKeyPress(entry, event) {
let symbol = event.get_key_symbol();
if (symbol === Clutter.KEY_Up)
return this._setPrevItem(entry.get_text().trim());
else if (symbol === Clutter.KEY_Down)
return this._setNextItem(entry.get_text().trim());
return Clutter.EVENT_PROPAGATE;
}
_indexChanged() {
let current = this._history[this._historyIndex] || '';
this.emit('changed', current);
if (this._entry)
this._entry.set_text(current);
}
_save() {
if (this._history.length > this._limit)
this._history.splice(0, this._history.length - this._limit);
if (this._key)
global.settings.set_strv(this._key, this._history);
}
};