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mpv/player/javascript/defaults.js
Avi Halachmi (:avih) d223a63bc5 js: add javascript scripting support using MuJS
Implements JS with almost identical API to the Lua support.

Key differences from Lua:
- The global mp, mp.msg and mp.utils are always available.
- Instead of returning x, error, return x and expose mp.last_error().
- Timers are JS standard set/clear Timeout/Interval.
- Supports CommonJS modules/require.
- Added at mp.utils: getenv, read_file, write_file and few more.
- Global print and dump (expand objects) functions.
- mp.options currently not supported.

See DOCS/man/javascript.rst for more details.
2017-06-14 12:29:32 +02:00

496 lines
18 KiB
JavaScript

"use strict";
(function main_default_js(g) {
// - g is the global object.
// - User callbacks called without 'this', global only if callee is non-strict.
// - The names of function expressions are not required, but are used in stack
// traces. We name them where useful to show up (fname:#line always shows).
mp.msg = { log: mp.log };
mp.msg.verbose = mp.log.bind(null, "v");
var levels = ["fatal", "error", "warn", "info", "debug"];
levels.forEach(function(l) { mp.msg[l] = mp.log.bind(null, l) });
// same as {} but without inherited stuff, e.g. o["toString"] doesn't exist.
// used where we try to fetch items by keys which we don't absolutely trust.
function new_cache() {
return Object.create(null, {});
}
/**********************************************************************
* event handlers, property observers, client messages, hooks
*********************************************************************/
var ehandlers = new_cache() // items of event-name: array of {maybe cb: fn}
mp.register_event = function(name, fn) {
if (!ehandlers[name])
ehandlers[name] = [];
ehandlers[name] = ehandlers[name].concat([{cb: fn}]); // replaces the arr
return mp._request_event(name, true);
}
mp.unregister_event = function(fn) {
for (var name in ehandlers) {
ehandlers[name] = ehandlers[name].filter(function(h) {
if (h.cb != fn)
return true;
delete h.cb; // dispatch could have a ref to h
}); // replacing, not mutating the array
if (!ehandlers[name].length) {
delete ehandlers[name];
mp._request_event(name, false);
}
}
}
// call only pre-registered handlers, but not ones which got unregistered
function dispatch_event(e) {
var handlers = ehandlers[e.event];
if (handlers) {
for (var len = handlers.length, i = 0; i < len; i++) {
var cb = handlers[i].cb; // 'handlers' won't mutate, but unregister
if (cb) // could remove cb from some items
cb(e);
}
}
}
// ----- property observers -----
var next_oid = 1,
observers = new_cache(); // items of id: fn
mp.observe_property = function(name, format, fn) {
var id = next_oid++;
observers[id] = fn;
return mp._observe_property(id, name, format || undefined); // allow null
}
mp.unobserve_property = function(fn) {
for (var id in observers) {
if (observers[id] == fn) {
delete observers[id];
mp._unobserve_property(id);
}
}
}
function notify_observer(e) {
var cb = observers[e.id];
if (cb)
cb(e.name, e.data);
}
// ----- Client messages -----
var messages = new_cache(); // items of name: fn
// overrides name. no libmpv API to reg/unreg specific messages.
mp.register_script_message = function(name, fn) {
messages[name] = fn;
}
mp.unregister_script_message = function(name) {
delete messages[name];
}
function dispatch_message(ev) {
var cb = ev.args.length ? messages[ev.args[0]] : false;
if (cb)
cb.apply(null, ev.args.slice(1));
}
// ----- hooks -----
var next_hid = 1,
hooks = new_cache(); // items of id: fn
function hook_run(id, cont) {
var cb = hooks[id];
if (cb)
cb();
mp.commandv("hook-ack", cont);
}
mp.add_hook = function add_hook(name, pri, fn) {
if (next_hid == 1) // doesn't really matter if we do it once or always
mp.register_script_message("hook_run", hook_run);
var id = next_hid++;
hooks[id] = fn;
return mp.commandv("hook-add", name, id, pri);
}
/**********************************************************************
* key bindings
*********************************************************************/
// binds: items of (binding) name which are objects of:
// {cb: fn, forced: bool, maybe input: str, repeatable: bool, complex: bool}
var binds = new_cache();
function dispatch_key_binding(name, state) {
var cb = binds[name] ? binds[name].cb : false;
if (cb) // "script-binding [<script_name>/]<name>" command was invoked
cb(state);
}
function update_input_sections() {
var def = [], forced = [];
for (var n in binds) // Array.join() will later skip undefined .input
(binds[n].forced ? forced : def).push(binds[n].input);
var sect = "input_" + mp.script_name;
mp.commandv("define-section", sect, def.join("\n"), "default");
mp.commandv("enable-section", sect, "allow-hide-cursor+allow-vo-dragging");
sect = "input_forced_" + mp.script_name;
mp.commandv("define-section", sect, forced.join("\n"), "force");
mp.commandv("enable-section", sect, "allow-hide-cursor+allow-vo-dragging");
}
// name/opts maybe omitted. opts: object with optional bool members: repeatable,
// complex, forced, or a string str which is evaluated as object {str: true}.
var next_bid = 1;
function add_binding(forced, key, name, fn, opts) {
if (typeof name == "function") { // as if "name" is not part of the args
opts = fn;
fn = name;
name = "__keybinding" + next_bid++; // new unique binding name
}
var key_data = {forced: forced};
switch (typeof opts) { // merge opts into key_data
case "string": key_data[opts] = true; break;
case "object": for (var o in opts) key_data[o] = opts[o];
}
if (key_data.complex) {
mp.register_script_message(name, function msg_cb() {
fn({event: "press", is_mouse: false});
});
var KEY_STATES = { u: "up", d: "down", r: "repeat", p: "press" };
key_data.cb = function key_cb(state) {
fn({
event: KEY_STATES[state[0]] || "unknown",
is_mouse: state[1] == "m"
});
}
} else {
mp.register_script_message(name, fn);
key_data.cb = function key_cb(state) {
// Emulate the semantics at input.c: mouse emits on up, kb on down.
// Also, key repeat triggers the binding again.
var e = state[0],
emit = (state[1] == "m") ? (e == "u") : (e == "d");
if (emit || e == "p" || e == "r" && key_data.repeatable)
fn();
}
}
if (key)
key_data.input = key + " script-binding " + mp.script_name + "/" + name;
binds[name] = key_data; // used by user and/or our (key) script-binding
update_input_sections();
}
mp.add_key_binding = add_binding.bind(null, false);
mp.add_forced_key_binding = add_binding.bind(null, true);
mp.remove_key_binding = function(name) {
mp.unregister_script_message(name);
delete binds[name];
update_input_sections();
}
/**********************************************************************
Timers: compatible HTML5 WindowTimers - set/clear Timeout/Interval
- Spec: https://www.w3.org/TR/html5/webappapis.html#timers
- Guaranteed to callback a-sync to [re-]insertion (event-loop wise).
- Guaranteed to callback by expiration order, or, if equal, by insertion order.
- Not guaranteed schedule accuracy, though intervals should have good average.
*********************************************************************/
// pending 'timers' ordered by expiration: latest at index 0 (top fires first).
// Earlier timers are quicker to handle - just push/pop or fewer items to shift.
var next_tid = 1,
timers = [], // while in process_timers, just insertion-ordered (push)
tset_is_push = false, // signal set_timer that we're in process_timers
tcanceled = false, // or object of items timer-id: true
now = mp.get_time_ms; // just an alias
function insert_sorted(arr, t) {
for (var i = arr.length - 1; i >= 0 && t.when >= arr[i].when; i--)
arr[i + 1] = arr[i]; // move up timers which fire earlier than t
arr[i + 1] = t; // i is -1 or fires later than t
}
// args (is "arguments"): fn_or_str [,duration [,user_arg1 [, user_arg2 ...]]]
function set_timer(repeat, args) {
var fos = args[0],
duration = Math.max(0, (args[1] || 0)), // minimum and default are 0
t = {
id: next_tid++,
when: now() + duration,
interval: repeat ? duration : -1,
callback: (typeof fos == "function") ? fos : Function(fos),
args: (args.length < 3) ? false : [].slice.call(args, 2),
};
if (tset_is_push) {
timers.push(t);
} else {
insert_sorted(timers, t);
}
return t.id;
}
g.setTimeout = function setTimeout() { return set_timer(false, arguments) };
g.setInterval = function setInterval() { return set_timer(true, arguments) };
g.clearTimeout = g.clearInterval = function(id) {
if (id < next_tid) { // must ignore if not active timer id.
if (!tcanceled)
tcanceled = {};
tcanceled[id] = true;
}
}
// arr: ordered timers array. ret: -1: no timers, 0: due, positive: ms to wait
function peek_wait(arr) {
return arr.length ? Math.max(0, arr[arr.length - 1].when - now()) : -1;
}
// Callback all due non-canceled timers which were inserted before calling us.
// Returns wait in ms till the next timer (possibly 0), or -1 if nothing pends.
function process_timers() {
var wait = peek_wait(timers);
if (wait != 0)
return wait;
var actives = timers; // only process those already inserted by now
timers = []; // we'll handle added new timers at the end of processing.
tset_is_push = true; // signal set_timer to just push-insert
do {
var t = actives.pop();
if (tcanceled && tcanceled[t.id])
continue;
if (t.args) {
t.callback.apply(null, t.args);
} else {
(0, t.callback)(); // faster, nicer stack trace than t.cb.call()
}
if (t.interval >= 0) {
// allow 20 ms delay/clock-resolution/gc before we skip and reset
t.when = Math.max(now() - 20, t.when + t.interval);
timers.push(t); // insertion order only
}
} while (peek_wait(actives) == 0);
// new 'timers' are insertion-ordered. remains of actives are fully ordered
timers.forEach(function(t) { insert_sorted(actives, t) });
timers = actives; // now we're fully ordered again, and with all timers
tset_is_push = false;
if (tcanceled) {
timers = timers.filter(function(t) { return !tcanceled[t.id] });
tcanceled = false;
}
return peek_wait(timers);
}
/**********************************************************************
CommonJS module/require
Spec: http://wiki.commonjs.org/wiki/Modules/1.1.1
- All the mandatory requirements are implemented, all the unit tests pass.
- The implementation makes the following exception:
- Allows the chars [~@:\\] in module id for meta-dir/builtin/dos-drive/UNC.
Implementation choices beyond the specification:
- A module may assign to module.exports (rather than only to exports).
- A module's 'this' is the global object, also if it sets strict mode.
- No 'global'/'self'. Users can do "this.global = this;" before require(..)
- A module has "privacy of its top scope", runs in its own function context.
- No id identity with symlinks - a valid choice which others make too.
- require("X") always maps to "X.js" -> require("foo.js") is file "foo.js.js".
- Global modules search paths are 'scripts/modules.js/' in mpv config dirs.
- A main script could e.g. require("./abc") to load a non-global module.
- Module id supports mpv path enhancements, e.g. ~/foo, ~~/bar, ~~desktop/baz
*********************************************************************/
// Internal meta top-dirs. Users should not rely on these names.
var MODULES_META = "~~modules",
SCRIPTDIR_META = "~~scriptdir", // relative script path -> meta absolute id
main_script = mp.utils.split_path(mp.script_file); // -> [ path, file ]
function resolve_module_file(id) {
var sep = id.indexOf("/"),
base = id.substring(0, sep),
rest = id.substring(sep + 1) + ".js";
if (base == SCRIPTDIR_META)
return mp.utils.join_path(main_script[0], rest);
if (base == MODULES_META) {
var path = mp.find_config_file("scripts/modules.js/" + rest);
if (!path)
throw(Error("Cannot find module file '" + rest + "'"));
return path;
}
return id + ".js";
}
// Delimiter '/', remove redundancies, prefix with modules meta-root if needed.
// E.g. c:\x -> c:/x, or ./x//y/../z -> ./x/z, or utils/x -> ~~modules/utils/x .
function canonicalize(id) {
var path = id.replace(/\\/g,"/").split("/"),
t = path[0],
base = [];
// if not strictly relative then must be top-level. figure out base/rest
if (t != "." && t != "..") {
// global module if it's not fs-root/home/dos-drive/builtin/meta-dir
if (!(t == "" || t == "~" || t[1] == ":" || t == "@" || t.match(/^~~/)))
path.unshift(MODULES_META); // add an explicit modules meta-root
if (id.match(/^\\\\/)) // simple UNC handling, preserve leading \\srv
path = ["\\\\" + path[2]].concat(path.slice(3)); // [ \\srv, shr..]
if (t[1] == ":" && t.length > 2) { // path: [ "c:relative", "path" ]
path[0] = t.substring(2);
path.unshift(t[0] + ":."); // -> [ "c:.", "relative", "path" ]
}
base = [path.shift()];
}
// path is now logically relative. base, if not empty, is its [meta] root.
// normalize the relative part - always id-based (spec Module Id, 1.3.6).
var cr = []; // canonicalized relative
for (var i = 0; i < path.length; i++) {
if (path[i] == "." || path[i] == "")
continue;
if (path[i] == ".." && cr.length && cr[cr.length - 1] != "..") {
cr.pop();
continue;
}
cr.push(path[i]);
}
if (!base.length && cr[0] != "..")
base = ["."]; // relative and not ../<stuff> so must start with ./
return base.concat(cr).join("/");
}
function resolve_module_id(base_id, new_id) {
new_id = canonicalize(new_id);
if (!new_id.match(/^\.\/|^\.\.\//)) // doesn't start with ./ or ../
return new_id; // not relative, we don't care about base_id
var combined = mp.utils.join_path(mp.utils.split_path(base_id)[0], new_id);
return canonicalize(combined);
}
var req_cache = new_cache(); // global for all instances of require
// ret: a require function instance which uses base_id to resolve relative id's
function new_require(base_id) {
return function require(id) {
id = resolve_module_id(base_id, id); // id is now top-level
if (req_cache[id])
return req_cache[id].exports;
var new_module = {id: id, exports: {}};
req_cache[id] = new_module;
try {
var filename = resolve_module_file(id);
// we need dedicated free vars + filename in traces + allow strict
var str = "mp._req = function(require, exports, module) {" +
mp.utils.read_file(filename) +
"\n;}";
mp.utils.compile_js(filename, str)(); // only runs the assignment
var tmp = mp._req; // we have mp._req, or else we'd have thrown
delete mp._req;
tmp.call(g, new_require(id), new_module.exports, new_module);
} catch (e) {
delete req_cache[id];
throw(e);
}
return new_module.exports;
};
}
g.require = new_require(SCRIPTDIR_META + "/" + main_script[1]);
/**********************************************************************
* various
*********************************************************************/
g.print = mp.msg.info; // convenient alias
mp.get_script_name = function() { return mp.script_name };
mp.get_script_file = function() { return mp.script_file };
mp.get_time = function() { return mp.get_time_ms() / 1000 };
mp.utils.getcwd = function() { return mp.get_property("working-directory") };
mp.dispatch_event = dispatch_event;
mp.process_timers = process_timers;
mp.get_opt = function(key, def) {
var v = mp.get_property_native("options/script-opts")[key];
return (typeof v != "undefined") ? v : def;
}
mp.osd_message = function osd_message(text, duration) {
mp.commandv("show_text", text, Math.round(1000 * (duration || -1)));
}
// ----- dump: like print, but expands objects/arrays recursively -----
function replacer(k, v) {
var t = typeof v;
if (t == "function" || t == "undefined")
return "<" + t + ">";
if (Array.isArray(this) && t == "object" && v !== null) { // "safe" mode
if (this.indexOf(v) >= 0)
return "<VISITED>";
this.push(v);
}
return v;
}
function obj2str(v) {
try { // can process objects more than once, but throws on cycles
return JSON.stringify(v, replacer, 2);
} catch (e) { // simple safe: exclude visited objects, even if not cyclic
return JSON.stringify(v, replacer.bind([]), 2);
}
}
g.dump = function dump() {
var toprint = [];
for (var i = 0; i < arguments.length; i++) {
var v = arguments[i];
toprint.push((typeof v == "object") ? obj2str(v) : replacer(0, v));
}
print.apply(null, toprint);
}
/**********************************************************************
* main listeners and event loop
*********************************************************************/
mp.keep_running = true;
g.exit = function() { mp.keep_running = false }; // user-facing too
mp.register_event("shutdown", g.exit);
mp.register_event("property-change", notify_observer);
mp.register_event("client-message", dispatch_message);
mp.register_script_message("key-binding", dispatch_key_binding);
g.mp_event_loop = function mp_event_loop() {
var wait = 0; // seconds
do { // distapch events as long as they arrive, then do the timers
var e = mp.wait_event(wait);
if (e.event != "none") {
dispatch_event(e);
wait = 0; // poll the next one
} else {
wait = process_timers() / 1000;
}
} while (mp.keep_running);
};
})(this)