gnome-shell/js/ui/tweener.js

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/* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */
const Clutter = imports.gi.Clutter;
const GLib = imports.gi.GLib;
const Lang = imports.lang;
const Mainloop = imports.mainloop;
const Signals = imports.signals;
const Tweener = imports.tweener.tweener;
// This is a wrapper around imports.tweener.tweener that adds a bit of
// Clutter integration and some additional callbacks:
//
// 1. If the tweening target is a Clutter.Actor, then the tweenings
// will automatically be removed if the actor is destroyed
//
// 2. If target._delegate.onAnimationStart() exists, it will be
// called when the target starts being animated.
//
// 3. If target._delegate.onAnimationComplete() exists, it will be
// called once the target is no longer being animated.
//
// The onAnimationStart() and onAnimationComplete() callbacks differ
// from the tweener onStart and onComplete parameters, in that (1)
// they track whether or not the target has *any* tweens attached to
// it, as opposed to be called for *each* tween, and (2)
// onAnimationComplete() is always called when the object stops being
// animated, regardless of whether it stopped normally or abnormally.
//
// onAnimationComplete() is called at idle time, which means that if a
// tween completes and then another is added before returning to the
// main loop, the complete callback will not be called (until the new
// tween finishes).
// 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.)
let slowDownFactor = 1.0;
// Called from Main.start
function init() {
let slowdownEnv = GLib.getenv('GNOME_SHELL_SLOWDOWN_FACTOR');
if (slowdownEnv) {
let factor = parseFloat(slowdownEnv);
if (!isNaN(factor) && factor > 0.0)
slowDownFactor = factor;
}
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 (target instanceof Clutter.Actor && !state.destroyedId)
state.destroyedId = target.connect('destroy', _actorDestroyed);
_addHandler(target, tweeningParameters, 'onStart', _tweenStarted);
_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)
_resetTweenState(target);
return target.__ShellTweenerState;
}
function _resetTweenState(target) {
let state = target.__ShellTweenerState;
if (state) {
if (state.destroyedId)
target.disconnect(state.destroyedId);
if (state.idleCompletedId)
Mainloop.source_remove(state.idleCompletedId);
}
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] = function () {
oldHandler.apply(eventScope, oldParams);
handler(target);
};
} else
params[name] = function () { handler(target); };
}
function _actorDestroyed(target) {
_resetTweenState(target);
Tweener.removeTweens(target);
}
function _tweenStarted(target) {
let state = _getTweenState(target);
let delegate = target._delegate;
if (!state.running && delegate && delegate.onAnimationStart)
delegate.onAnimationStart();
state.running = true;
}
function _tweenCompleted(target) {
let state = _getTweenState(target);
if (!state.idleCompletedId)
state.idleCompletedId = Mainloop.idle_add(Lang.bind(null, _idleCompleted, target));
}
function _idleCompleted(target) {
let state = _getTweenState(target);
let delegate = target._delegate;
if (!isTweening(target)) {
_resetTweenState(target);
if (delegate && delegate.onAnimationComplete)
delegate.onAnimationComplete();
}
return false;
}
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(scope) {
if (Tweener.removeTweens.apply(null, arguments)) {
// If we just removed the last active tween, clean up
if (Tweener.getTweenCount(scope) == 0)
_tweenCompleted(scope);
return true;
} else
return false;
}
function pauseTweens() {
return Tweener.pauseTweens.apply(null, arguments);
}
function resumeTweens() {
return Tweener.resumeTweens.apply(null, arguments);
}
function registerSpecialProperty(name, getFunction, setFunction,
parameters, preProcessFunction) {
Tweener.registerSpecialProperty(name, getFunction, setFunction,
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parameters, preProcessFunction);
}
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 continous
// time updates; even better is to pay attention to the vertical
// vblank and sync to that when possible.)
//
function ClutterFrameTicker() {
this._init();
}
ClutterFrameTicker.prototype = {
FRAME_RATE : 60,
_init : function() {
// We don't have a finite duration; tweener will tell us to stop
// when we need to stop, so use 1000 seconds as "infinity"
this._timeline = new Clutter.Timeline({ duration: 1000*1000 });
this._startTime = -1;
this._currentTime = -1;
this._timeline.connect('new-frame', Lang.bind(this,
function(timeline, frame) {
this._onNewFrame(frame);
}));
},
_onNewFrame : function(frame) {
// 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 = this._timeline.get_elapsed_time();
// currentTime is in milliseconds
this._currentTime = (this._timeline.get_elapsed_time() - this._startTime) / slowDownFactor;
this.emit('prepare-frame');
},
getTime : function() {
return this._currentTime;
},
start : function() {
this._timeline.start();
global.begin_work();
},
stop : function() {
this._timeline.stop();
this._startTime = -1;
this._currentTime = -1;
global.end_work();
}
};
Signals.addSignalMethods(ClutterFrameTicker.prototype);