gnome-shell/js/ui/tweener.js

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// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
/* exported init, addCaller, addTween, getTweenCount, removeTweens,
pauseTweens, resumeTweens, registerSpecialProperty,
registerSpecialPropertyModifier, registerSpecialPropertySplitter */
const { Clutter, GLib, Shell } = imports.gi;
const Signals = imports.signals;
const Tweener = imports.tweener.tweener;
const { adjustAnimationTime } = imports.ui.environment;
// This is a wrapper around imports.tweener.tweener that adds a bit of
// Clutter integration. If the tweening target is a Clutter.Actor, then
// the tweenings will automatically be removed if the actor is destroyed.
// ActionScript Tweener methods that imports.tweener.tweener doesn't
// currently implement: getTweens, getVersion, registerTransition,
// setTimeScale, updateTime.
// imports.tweener.tweener methods that we don't re-export:
// pauseAllTweens, removeAllTweens, resumeAllTweens. (It would be hard
// to clean up properly after removeAllTweens, and also, any code that
// calls any of these is almost certainly wrong anyway, because they
// affect the entire application.)
// Called from Main.start
function init() {
Tweener.setFrameTicker(new ClutterFrameTicker());
}
function addCaller(target, tweeningParameters) {
_wrapTweening(target, tweeningParameters);
Tweener.addCaller(target, tweeningParameters);
}
function addTween(target, tweeningParameters) {
_wrapTweening(target, tweeningParameters);
Tweener.addTween(target, tweeningParameters);
}
function _wrapTweening(target, tweeningParameters) {
let state = _getTweenState(target);
if (!state.destroyedId) {
if (target instanceof Clutter.Actor) {
state.actor = target;
state.destroyedId = target.connect('destroy', _actorDestroyed);
} else if (target.actor && target.actor instanceof Clutter.Actor) {
state.actor = target.actor;
state.destroyedId = target.actor.connect('destroy', () => _actorDestroyed(target));
}
}
let { time, delay } = tweeningParameters;
if (!isNaN(time))
tweeningParameters['time'] = adjustAnimationTime(1000 * time) / 1000;
if (!isNaN(delay))
tweeningParameters['delay'] = adjustAnimationTime(1000 * delay) / 1000;
_addHandler(target, tweeningParameters, 'onComplete', _tweenCompleted);
}
function _getTweenState(target) {
// If we were paranoid, we could keep a plist mapping targets to
// states... but we're not that paranoid.
if (!target.__ShellTweenerState)
target.__ShellTweenerState = {};
return target.__ShellTweenerState;
}
function _resetTweenState(target) {
let state = target.__ShellTweenerState;
if (state) {
if (state.destroyedId)
state.actor.disconnect(state.destroyedId);
}
target.__ShellTweenerState = {};
}
function _addHandler(target, params, name, handler) {
if (params[name]) {
let oldHandler = params[name];
let oldScope = params[`${name}Scope`];
let oldParams = params[`${name}Params`];
let eventScope = oldScope ? oldScope : target;
params[name] = () => {
oldHandler.apply(eventScope, oldParams);
handler(target);
};
} else {
params[name] = () => handler(target);
}
}
function _actorDestroyed(target) {
_resetTweenState(target);
Tweener.removeTweens(target);
}
function _tweenCompleted(target) {
if (!isTweening(target))
_resetTweenState(target);
}
function getTweenCount(scope) {
return Tweener.getTweenCount(scope);
}
// imports.tweener.tweener doesn't provide this method (which exists
// in the ActionScript version) but it's easy to implement.
function isTweening(scope) {
return Tweener.getTweenCount(scope) != 0;
}
function removeTweens(...args) {
if (Tweener.removeTweens(args)) {
let [scope] = args;
// If we just removed the last active tween, clean up
if (Tweener.getTweenCount(scope) == 0)
_tweenCompleted(scope);
return true;
} else {
return false;
}
}
function pauseTweens(...args) {
return Tweener.pauseTweens(...args);
}
function resumeTweens(...args) {
return Tweener.resumeTweens(...args);
}
function registerSpecialProperty(...args) {
Tweener.registerSpecialProperty(...args);
}
function registerSpecialPropertyModifier(name, modifyFunction, getFunction) {
Tweener.registerSpecialPropertyModifier(name, modifyFunction, getFunction);
}
function registerSpecialPropertySplitter(name, splitFunction, parameters) {
Tweener.registerSpecialPropertySplitter(name, splitFunction, parameters);
}
// The 'FrameTicker' object is an object used to feed new frames to
// Tweener so it can update values and redraw. The default frame
// ticker for Tweener just uses a simple timeout at a fixed frame rate
// and has no idea of "catching up" by dropping frames.
//
// We substitute it with custom frame ticker here that connects
// Tweener to a Clutter.TimeLine. Now, Clutter.Timeline itself isn't a
// whole lot more sophisticated than a simple timeout at a fixed frame
// rate, but at least it knows how to drop frames. (See
// HippoAnimationManager for a more sophisticated view of continuous
// time updates; even better is to pay attention to the vertical
// vblank and sync to that when possible.)
//
var ClutterFrameTicker = class {
constructor() {
// We don't have a finite duration; tweener will tell us to stop
// when we need to stop, so use 1000 seconds as "infinity", and
// set the timeline to loop. Doing this means we have to track
// time ourselves, since clutter timeline's time will cycle
// instead of strictly increase.
this._timeline = new Clutter.Timeline({ duration: 1000 * 1000 });
this._timeline.set_loop(true);
this._startTime = -1;
this._currentTime = -1;
this._timeline.connect('new-frame', () => {
this._onNewFrame();
});
let perfLog = Shell.PerfLog.get_default();
perfLog.define_event("tweener.framePrepareStart",
"Start of a new animation frame",
"");
perfLog.define_event("tweener.framePrepareDone",
"Finished preparing frame",
"");
}
get FRAME_RATE() {
return 60;
}
_onNewFrame() {
// If there is a lot of setup to start the animation, then
// first frame number we get from clutter might be a long ways
// into the animation (or the animation might even be done).
// That looks bad, so we always start at the first frame of the
// animation then only do frame dropping from there.
if (this._startTime < 0)
this._startTime = GLib.get_monotonic_time() / 1000.0;
// currentTime is in milliseconds
let perfLog = Shell.PerfLog.get_default();
this._currentTime = GLib.get_monotonic_time() / 1000.0 - this._startTime;
perfLog.event("tweener.framePrepareStart");
this.emit('prepare-frame');
perfLog.event("tweener.framePrepareDone");
}
getTime() {
return this._currentTime;
}
start() {
this._timeline.start();
global.begin_work();
}
stop() {
this._timeline.stop();
this._startTime = -1;
this._currentTime = -1;
global.end_work();
}
};
Signals.addSignalMethods(ClutterFrameTicker.prototype);