I am using PIXI.extras.MovieClip to play a short animation (about 60 frames) and due to not knowing how many FPS there will be on users device I can't tell how much time exactly does it take to play all the frames. setTimeout also does not guarantee that function will be triggered exactly after specified time so it's kinda not my way of solving this too.
When the playing of animation is finished I want to trigger some events in code to remove the MovieClip and write some logs.
The problem is that I can't find any kind of trigger/callback that will be called when last frame of animation was rendered.
example code:
movie = new PIXI.extras.MovieClip(someFrames);
movie.animationSpeed = 1;
movie.onComplete = animationFinished;
movie.play()
animationFinished = function () {
console.log("Animation just reached it's end.");
movie.gotoAndStop(0);
};
the obvious problem is, that movie.onComplete is never called. Is there any way to make this work?
Thanks for any suggestions and ideas.
Happy coding!
movie = new PIXI.extras.MovieClip(someFrames);
movie.animationSpeed = 1;
movie.onComplete = animationFinished;
movie.loop = false;
movie.play();
animationFinished = function () {
console.log("Animation just reached it's end.");
movie.gotoAndStop(0);
};
Related
When events are queued with setTimeout/setInterval, and the user is viewing a separate tab, Chrome and Firefox enforce a minimum 1000ms lag before the event is executed. This article details the behaviour.
This has been discussed on StackOverflow previously, but the questions and answers only applied to animations. Obviously, an animation can just be forced to update to the latest state when a user re-enters the tab.
But the solution does not work for sequenced audio. I have Web Audio API playing several audio files in sequence, and setTimeout is used to countdown to when the next audio file plays. If you put the tab in the background, you get an annoying 1 second gap between each pattern -- an extreme flaw in an API designed for advanced audio.
You can witness this behaviour in various HTML5 sequencers, e.g. with PatternSketch -- just by entering a pattern, playing, and going to another tab.
So I'm in need of a workaround: a way to queue events without the 1000ms clamp. Does anyone know of a way?
The only solution I can think of is to have window.postMessage run every single millisecond and check each time if the event is to execute. That is definitely detrimental to performance. Is this the only option?
Apparently there is no event system planned for Web Audio API, so that is out of question.
EDIT: Another answer is to use WebWorkers per https://stackoverflow.com/a/12522580/1481489 - this answer is a little specific, so here's something more generic:
interval.js
var intervalId = null;
onmessage = function(event) {
if ( event.data.start ) {
intervalId = setInterval(function(){
postMessage('interval.start');
},event.data.ms||0);
}
if ( event.data.stop && intervalId !== null ) {
clearInterval(intervalId);
}
};
and your main program:
var stuff = { // your custom class or object or whatever...
first: Date.now(),
last: Date.now(),
callback: function callback() {
var cur = Date.now();
document.title = ((cur-this.last)/1000).toString()+' | '+((cur-this.first)/1000).toString();
this.last = cur;
}
};
var doWork = new Worker('interval.js');
doWork.onmessage = function(event) {
if ( event.data === 'interval.start' ) {
stuff.callback(); // queue your custom methods in here or whatever
}
};
doWork.postMessage({start:true,ms:250}); // tell the worker to start up with 250ms intervals
// doWork.postMessage({stop:true}); // or tell it just to stop.
Totally ugly, but you could open up a child popup window. However, all this does is transfer some of the caveats to the child window, i.e. if child window is minimized the 1000ms problem appears, but if it is simply out of focus, there isn't an issue. Then again, if it is closed, then it stops, but all the user has to do is click the start button again.
So, I suppose this doesn't really solve your problem... but here's a rough draft:
var mainIntervalMs = 250;
var stuff = { // your custom class or object or whatever...
first: Date.now(),
last: Date.now(),
callback: function callback(){
var cur = Date.now();
document.title = ((cur-this.last)/1000).toString()+' | '+((cur-this.first)/1000).toString();
this.last = cur;
}
};
function openerCallbackHandler() {
stuff.callback(); // queue your custom methods in here or whatever
}
function openerTick(childIntervalMs) { // this isn't actually used in this window, but makes it easier to embed the code in the child window
setInterval(function() {
window.opener.openerCallbackHandler();
},childIntervalMs);
}
// build the popup that will handle the interval
function buildIntervalWindow() {
var controlWindow = window.open('about:blank','controlWindow','width=10,height=10');
var script = controlWindow.document.createElement('script');
script.type = 'text/javascript';
script.textContent = '('+openerTick+')('+mainIntervalMs+');';
controlWindow.document.body.appendChild(script);
}
// write the start button to circumvent popup blockers
document.write('<input type="button" onclick="buildIntervalWindow();return false;" value="Start" />');
I'd recommend working out a better way to organize, write, etc. but at the least it should point you in the right direction. It should also work in a lot of diff browsers (in theory, only tested in chrome). I'll leave you to the rest.
Oh, and don't forget to build in auto-closing of the child window if the parent drops.
So I'm attempting to make a Pomodoro Timer without using an API (I know, stupid choice) but I feel as if I'm over-complicating this issue.
I forked my CodePen so I could post the current code here without confusing anyone. My Code Pen
To see my issue: Just set Timer to .1 and Break to .1 - You'll see the Start to Resume works fine, but the Resume to start has issues.
I built in consoleLogs to track it and I see the Work Timer TRIES to start but then breakTimer over-runs it, and duplicates on every pass.
Why isn't my clearInterval working?
Things I've tried:
Adjusting names of clearInterval,
Setting it so it goes back to startTimer instead of start
force quitting it (instead of looping it back to startInterval.
The function is virtually identical to my startFunction yet fails to work properly. Would appreciate any input (I'm new to clearInterval but I believe I am using it right.)
function breakTimer() {
$('.jumbotron').css('visibility', 'visible');
setInterval(function() {
console.log("Break Timer...");
breakTime--;
if (breakTime < 0) {
clearInterval(timer);
working = false;
start();
} else {
showTime(breakTime);
}
}, 1000);
}
Edit:
To answer the reply:
function start() {
if (working == true){ //This keeps it from being spammable
return;
} //Else
workTime = $('#work').val()*60;
breakTime = $('#break').val()*60;
working = true;
checkStatus();
timer = startTimer();
}
Unsure if I should post every Function here
As per definition, the value returned by setInterval(...) is the ID of the created timer. As such, with your code you can only stop the last created timer because the ID in the timer variable gets overwritten, causing it to lose control over the previously created (and still running) timers.
The ID is what you pass on to clearInterval(...) to stop a timer. You will have to do this in a different way. You may ask for a different way in https://codereview.stackexchange.com/
I am currently working on a drum machine and I am using setTimeout to make it run. Here is the heart of the code:
var sequencerRun = function(){
var currentTime = 0
var starting = 200;
for(var k = 0; k < 16; k++){
$(".instrument td .beat" + k).each(function(){
setTimeout(blinker, currentTime,$(this));
})
currentTime += starting;
}
}
var timerId, setInt;
var runSeq = function(){
setInt = setInterval(sequencerRun,3200);
}
$('.play').click(function(){
stopped = false
sequencerRun();
runSeq();
})
$('.stop').click(function(){
clearInterval(setInt);
stopped = true;
})
The drum machine has a matrix HTML structure built using a table. When .play is clicked a scheduling process occurs, which is encapsulated in sequencerRun. This involves a run through the columns of my matrix to determine whether there should be a drum hit or not. This is done through blinker. The scheduling creates a check on each column 1 - 16 at times 0,200,...,3200 respectively. This is what creates the effect of a sequencer. I also have a setInterval that reruns this process every 3200, which is how it takes for a run to finish.
Programmatically my code seems to make sense and my hope was that it would execute on time. The thing is that my actual app tends to stutter a lot and is stuttering even more since I deployed it. Here is a deployed version of my app.
This stuttering side effect can be best heard when you click on a full row. My question here is can anyone tell if this side effect is a result of setTimeout's timing inconsistency and if so how could I go about fixing this? Or is this related to something else that I am missing?
I think the stuttering issue has more to do with you not preloading the instruments but rather loading them on every hit, more than it has to do with settimeout.
In any case, I think I would have solved this differently. Rather than setting a fresh timeout for each beat, create one beat timeout and put the logic in there. Something like (pseudo-code-ish, lots of stuff missing just the general idea):
var MAX_BEATS = 16; // I think you had 16 beats in your example?
var BPM = 200;
var preloadedInstruments = [];
function preloadInstruments(){
for(i of myInstruments) { // myInstruments would be a list of your instruments (probably just strings with a filename)
preloadedInstruments.push(new instrument(i)); // You need an instrument class, that would preload the sound and provide a play function
}
}
var currentbeat = 1;
function beat() {
var activeInstruments = getActiveInstruments(currentbeat); // You could cache this also for every beat, but I think a simple loop here would be quick enough
for(instrument of activeInstruments) {
preloadedInstruments[instrument].play(); // play method of the instrument class called
}
currentbeat++;
if (currentbeat > MAX_BEATS) {
currentbeat = 1;
}
}
setInterval(beat, 60e3 / BPM);
I am trying to make a simple hidden object game using javascript. When the user finds and clicks an image, I want 3 things to happen in the following order; a sound plays, the image size increases, and the image goes invisible. The problem I am running into is getting the 3 events to happen sequentially, not concurrent. Right now, seems that all three events happen all at the same time.
I've tried using setTimeout(), and while that does create a delay, it still runs all functions at the same time, even if each function is nested in setTimeout.
Example: (all this does is waits 1.5 sec then plays the sound and makes the image invisible):
function FindIt(image, id){
var t = setTimeout('sound()',10);
var b = setTimeout('bigger(' + image + ')',30);
var h = setTimeout('hide(' + image + ')',1500);
}
Below are the functions I am currently using and the actual results are: click the image, nothing happens for 2 seconds, then the sound plays and the image goes invisible.
function FindIt(image, id){
sound();
bigger(image);
hide(image);
}
function sound(){
document.getElementById("sound_element").innerHTML= "<embed src='chime.wav' hidden=true autostart=true loop=false>";
}
function bigger(image){
var img = document.getElementById(image);
img.style.width = 112;
img.style.height = 112;
}
function hide(id){
var ms = 2000;
ms += new Date().getTime();
while (new Date() < ms){} //Create a 2 second delay
var img = document.getElementById(id);
img.style.visibility='hidden';
}
Any guidance would be greatly appreciated!
To trigger things sequentially, you need to execute the second item some amount of time after the first one completes, execute the third item some amount of time after the second one completes, etc...
Only your sound() function actually takes some time, so I'd suggest the following:
function FindIt(image, id){
sound();
// set timer to start next action a certain time after the sound starts
setTimeout(function() {
bigger(image);
// set timer to start next action a certain time after making the image bigger
setTimeout (function() {
hide(image);
}, 1000); // set this time for how long you want to wait after bigger, before hide
}, 1000); // set the time here for how long you want to wait after starting the sound before making it bigger
}
FYI, the animation capabilities in libraries like jQuery or YUI make this sort of thing a lot easier.
Also, please don't use this kind of construct in your JS:
while (new Date() < ms){}
That locks up the browser for that delay and is very unfriendly to the viewer. Use setTimeout to create a delay.
For reference, using the animation libraries in jQuery, the jQuery code to handle a click on the object and then animate it over a 2 second period to a larger size, delay for 1 second, then slideup to disappear is as follows:
$("#rect").click(function() {
$(this).animate({height: 200, width: 400}, 2000).delay(1000).slideUp();
});
jQuery manages an animation queue and handles setting all the timers and doing all the sequencing and animation for you. It's a lot, lot easier to program and gives a very nice result.
You can see it work and play with it here: http://jsfiddle.net/kC4Mz/.
why don't use "event" approach. like onTaskDone();
function task1(arg, onTask1Done){
console.log(arg);
if(onTask1Done)onTask1Done();
}
task1("working", function(){console.log("task2");});
The Frame.js library is designed to elegantly handle situations like this:
function FindIt(image, id){
Frame(10, function(next) { sound(); next(); });
Frame(30, function(next) { bigger(image); next(); });
Frame(1500, function(next) { hide(image); next(); });
Frame.start();
}
Frame.js offers many advantages over using standard timeouts, especially if you are doing a lot of this kind of thing, which for a game, you likely are.
https://github.com/bishopZ/Frame.js
I have a jQuery slider on my site and the code going to the next slide is in a function called nextImage. I used setInterval to run my function on a timer, and it does exactly what I want: it runs my slides on a timer. BUT, if I go to the site in Chrome, switch to another tab and return, the slider runs through the slides continuously until it 'catches up'. Does anyone know of a way to fix this. The following is my code.
setInterval(function() {
nextImage();
}, 8000);
How to detect when a tab is focused or not in Chrome with Javascript?
window.addEventListener('focus', function() {
document.title = 'focused';
},false);
window.addEventListener('blur', function() {
document.title = 'not focused';
},false);
To apply to your situation:
var autopager;
function startAutopager() {
autopager = window.setInterval(nextImage, 8000);
}
function stopAutopager() {
window.clearInterval(autopager);
}
window.addEventListener('focus', startAutopager);
window.addEventListener('blur', stopAutopager);
Note that in the latest version of Chromium, there is either a bug or a 'feature' which is making this less reliable, requiring that the user has clicked at least once anywhere in the window. See linked question above for details.
I post an answer here: How can I make setInterval also work when a tab is inactive in Chrome?
Just do this:
setInterval(function() {
$("#your-image-container").stop(true,true);
nextImage();
}, 1000);
inactive browser tabs buffer some of the setInterval or setTimeout functions.
stop(true,true) - will stop all buffered events and execute immadietly only last animation.
The window.setTimeout() method now clamps to send no more than one timeout per second in inactive tabs. In addition, it now clamps nested timeouts to the smallest value allowed by the HTML5 specification: 4 ms (instead of the 10 ms it used to clamp to).
A few ideas comes to mind:
Idea #1
You can make it so that a short burst is idempotent. For example, you could say:
function now() {
return (new Date()).getTime();
}
var autopagerInterval = 8000;
function startAutopager() {
var startImage = getCurrentImageNumber();
var startTime = now();
var autopager = setInterval(
function() {
var timeSinceStart = now() - startTime();
var targetImage = getCurrentImageNumber + Math.ceil(timeSinceStart/autopagerInterval);
if (getCurrentImageNumber() != targetImage)
setImageNumber(targetImage); // trigger animation, etc.
},
autopagerInterval
);
return autopager;
}
This way even if the function runs 1000 times, it will still run in only a few milliseconds and animate only once.
note: If the user leaves the page and comes back, it will have scrolled. This is probably not what the original poster wants, but I leave this solution up since it is sometimes what you want.
Idea #2
Another way to add idempotence (while still keeping your nextImage() function and not having it scroll to the bottom of the page) would be to have the function set a mutex lock which disappears after a second (cleared by another timeout). Thus even if the setInterval function was called 1000 times, only the first instance would run and the others would do nothing.
var locked = false;
var autopager = window.setInterval(function(){
if (!locked) {
locked = true;
window.setTimeout(function(){
locked=false;
}, 1000);
nextImage();
}
}, 8000);
edit: this may not work, see below
Idea #3
I tried the following test:
function f() {
console.log((new Date()) + window.focus());
window.setTimeout(f, 1000);
}
f();
It seems to indicate that the function is being called every second. This is odd... but I think this means that the callbacks are being called, but that the page renderer refuses to update the page in any graphical way while the tab is unfocused, delaying all operations until the user returns, but operations keep piling up.
Also the window.focus() function doesn't say if the window has focus; it GIVES focus to the window, and is thus irrelevant.
What we want is probably this: How to detect when a tab is focused or not in Chrome with Javascript? -- you can unset your interval when the window loses focus (blur), and reset it when it gains focus.
I don't know exactly what is going on in your function nextImage(), but I had a similar issue. I was using animate() with setInterval() on a jQuery image slider that I created, and I was experiencing the same thing as you when I switched to a different tab and back again. In my case the animate() function was being queued, so once the window regained focus the slider would go crazy. To fix this I just stopped the animate() function from queuing.
There are a couple ways you can do this. the easiest is with .stop(), but this issue and ways to fix it are documented in the jQuery docs. Check this page near the bottom under the heading additional notes: http://api.jquery.com/animate/
I had faced similar issue, somehow this code below works fine for me.
var t1= window.setInterval('autoScroll()', 8000);
window.addEventListener('focus', function() {
focused = true;
window.clearInterval(t1);
t1 = window.setInterval('autoScroll()', 8000);
},false);
window.addEventListener('blur', function() {
focused = false;
window.clearInterval(t1);
},false)
function autoScroll()
{
if ( running == true){
if ( focused = true){
forwardSlide();
}
}
else {
running = true;
}
}
If you are using Soh Tanaka's image slider then just add this...to solve your Google Chrome issue:
$(".image_reel").stop(true, true).fadeOut(300).animate({ left: -image_reelPosition}, 500 ).fadeIn(300);
Take note of the .stop() function. Ignore the fading in and out stuff, that's what I used on my version
Thanks
Seconding the comment by jgerstle to use page visibility events instead, see https://www.w3.org/TR/page-visibility/#example-1-visibility-aware-video-playback for more around subscribing to 'visibilitychange' for hidden/visible states.
This seems to be more useful than focus/blur these days as it covers visible-but-not-selected windows if concerned also about multi-window operating systems.