From e4283f6d48b98e764b988b43bbc86b9d52e6ec94 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:54:43 +0200 Subject: Adding upstream version 43.9. Signed-off-by: Daniel Baumann --- js/gdm/batch.js | 206 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) create mode 100644 js/gdm/batch.js (limited to 'js/gdm/batch.js') diff --git a/js/gdm/batch.js b/js/gdm/batch.js new file mode 100644 index 0000000..f841f0f --- /dev/null +++ b/js/gdm/batch.js @@ -0,0 +1,206 @@ +// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*- +/* + * Copyright 2011 Red Hat, Inc + * + * This program 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 2, or (at your option) + * any later version. + * + * This program 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 this program; if not, see . + */ + +/* + * In order for transformation animations to look good, they need to be + * incremental and have some order to them (e.g., fade out hidden items, + * then shrink to close the void left over). Chaining animations in this way can + * be error-prone and wordy using just ease() callbacks. + * + * The classes in this file help with this: + * + * - Task. encapsulates schedulable work to be run in a specific scope. + * + * - ConsecutiveBatch. runs a series of tasks in order and completes + * when the last in the series finishes. + * + * - ConcurrentBatch. runs a set of tasks at the same time and completes + * when the last to finish completes. + * + * - Hold. prevents a batch from completing the pending task until + * the hold is released. + * + * The tasks associated with a batch are specified in a list at batch + * construction time as either task objects or plain functions. + * Batches are task objects, themselves, so they can be nested. + * + * These classes aren't specific to GDM, but were found to be unintuitive and so + * are not used elsewhere. These APIs may ultimately get dropped entirely and + * replaced by something else. + */ +/* exported ConcurrentBatch, ConsecutiveBatch */ + +const { GObject } = imports.gi; +const Signals = imports.misc.signals; + +var Task = class extends Signals.EventEmitter { + constructor(scope, handler) { + super(); + + if (scope) + this.scope = scope; + else + this.scope = this; + + this.handler = handler; + } + + run() { + if (this.handler) + return this.handler.call(this.scope); + + return null; + } +}; + +var Hold = class extends Task { + constructor() { + super(null, () => this); + + this._acquisitions = 1; + } + + acquire() { + if (this._acquisitions <= 0) + throw new Error("Cannot acquire hold after it's been released"); + this._acquisitions++; + } + + acquireUntilAfter(hold) { + if (!hold.isAcquired()) + return; + + this.acquire(); + let signalId = hold.connect('release', () => { + hold.disconnect(signalId); + this.release(); + }); + } + + release() { + this._acquisitions--; + + if (this._acquisitions == 0) + this.emit('release'); + } + + isAcquired() { + return this._acquisitions > 0; + } +}; + +var Batch = class extends Task { + constructor(scope, tasks) { + super(); + + this.tasks = []; + + for (let i = 0; i < tasks.length; i++) { + let task; + + if (tasks[i] instanceof Task) + task = tasks[i]; + else if (typeof tasks[i] == 'function') + task = new Task(scope, tasks[i]); + else + throw new Error('Batch tasks must be functions or Task, Hold or Batch objects'); + + this.tasks.push(task); + } + } + + process() { + throw new GObject.NotImplementedError(`process in ${this.constructor.name}`); + } + + runTask() { + if (!(this._currentTaskIndex in this.tasks)) + return null; + + return this.tasks[this._currentTaskIndex].run(); + } + + _finish() { + this.hold.release(); + } + + nextTask() { + this._currentTaskIndex++; + + // if the entire batch of tasks is finished, release + // the hold and notify anyone waiting on the batch + if (this._currentTaskIndex >= this.tasks.length) { + this._finish(); + return; + } + + this.process(); + } + + _start() { + // acquire a hold to get released when the entire + // batch of tasks is finished + this.hold = new Hold(); + this._currentTaskIndex = 0; + this.process(); + } + + run() { + this._start(); + + // hold may be destroyed at this point + // if we're already done running + return this.hold; + } + + cancel() { + this.tasks = this.tasks.splice(0, this._currentTaskIndex + 1); + } +}; + +var ConcurrentBatch = class extends Batch { + process() { + let hold = this.runTask(); + + if (hold) + this.hold.acquireUntilAfter(hold); + + // Regardless of the state of the just run task, + // fire off the next one, so all the tasks can run + // concurrently. + this.nextTask(); + } +}; + +var ConsecutiveBatch = class extends Batch { + process() { + let hold = this.runTask(); + + if (hold && hold.isAcquired()) { + // This task is inhibiting the batch. Wait on it + // before processing the next one. + let signalId = hold.connect('release', () => { + hold.disconnect(signalId); + this.nextTask(); + }); + } else { + // This task finished, process the next one + this.nextTask(); + } + } +}; -- cgit v1.2.3