dojo animation on interrupt? - animation

Is there an equivalent of an 'on interrupt' function when using dojo.fx animations?
On my site, I clear an area by sliding the div off the screen to the left and then clearing the innerHTML. So that the div is available for future use in the same place, I set its final position to be equal to its original position (though it's empty and invisible, so the user doesn't see). I do this by referencing the position when the function is fired to avoid hard coding the position in.
function clear (node) {
// get the current position
var position = domGeom.position (node, true);
// slide the calendar off the screen
var anim = dojo.fx.slideTo ({
node: node,
left: -2000,
unit: "px"
});
// attach on onEnd function
dojo.connect (anim, "onEnd", function (n1, n2) {
node.innerHTML = "";
// Reset the node's position
domStyle.set (node, "left", position.x + "px");
});
anim.play();
}
The problem is that if the user clicks 'clear' while the function is in progress, for example if they accidentally double click, then the 'position' variable takes the value of the node mid-animation. If I later put some content in the node, it's in the wrong place, or sometimes completely off screen.
What I was thinking of doing was adding a listener to the animation so that if it was ever interrupted, it would stop the animation and instead execute the 'onEnd' function immediately, so that the second clear function would have the correct position variable.
Unfortunately, I can't find such a listener; could anyone point me in the right direction, or suggest an alternative solution?

You might be interrupting the flow of events in your page, but you're not really 'interrupting' in Animation terms: there's no way an Animation could give you an event to tell you that Clear has been pressed, I'm afraid.
If you want the animation to be stopped when the user presses Clear, you'll have to stop the animation manually when the user presses Clear: Dojo can't automatically detect there's any link between the two things, and indeed there may well be other animations that you want to continue even if the user does press Clear.
So, you'll probably be looking to call .stop on the animation when appropriate.

Related

Slowly move a circle in PIXIJS

I have a circle with PIXI and I need that when the touch is fulfilled another object said circle returns to its original position, but it happens that I do not know any function or method for the movement to be appreciable, all I have achieved is that it disappear and appear in its initial position. How did the transition happen?
Just add the movement into rendering loop
I use PIXI.tickerTicker() for loop
let ticker = new PIXI.ticker.Ticker();
the rendering loop in your situation should be
function loop(){
renderer.render(stageContainer);
yourCircle.position.x += moveSpeed; //your question
if(resetCirclePosition)
yourCircle.position.x = defaultPos;
}
and then to start ticker use
ticker.add(loop);
ticker.start();
Look at ticker documentation http://pixijs.download/dev/docs/PIXI.ticker.Ticker.html

How can I make my D3 code cleaner

i've managed to hack together a d3 transition, check it out here.
https://jsfiddle.net/guanzo/k1xw6ace/14/
Here's the basic idea:
I need to handle the possibility of 2 columns in case the svg height is not enough.
All transitions are a fade in/out and a translate +/- 30px on the x-axis;
On initialLoad, all legends transition into view.
When you click the "Reposition" button and data exits, exiting legends will immediately transition out, after the last legend exits the remaining legends will transition to their new position.
When you click the button again and data enters, updated legends will immediately transition to their new positions (taking into account entering legends), after the last update transition, the entering legends will transition in.
My problem is that my code is relying on setTimeouts and a couple hacks to deal with clumsy selections and conflicting enter/update states.
For example when data enters i need to selectAll update AND enter legends, in order to determine their new position. However i need to set different transitions to both groups.
The transition order depends on if data is entering or exiting. If data is entering, the update selection transitions first, then the enter selection. if data is exiting, the exit selection transitions first, then the update selection. How do i elegantly code this inverse relationship?
I'm just confused on the best way to do this.
I learnt this trick to chain transitions after the first transition has completed:
function endall(transition, callback) {
if (transition.size() === 0) {
callback()
}
var n = 0;
transition
.each(function() {
++n;
})
.each("end", function() {
if (!--n) callback.apply(this, arguments);
});
}
then in your transition function:
selection.transition()
.attr("cx", xMap)
.attr("cy", yMap)
.call(endall, function() {
console.log("all loaded");
// do your next transition
});

d3.js tween factory return function applied to non-interpolable property values

This question builds on the (correct) answer provided to this. I simply haven't been able to get any further..
With the help of an interpolator function, d3.js's tween allows smooth graphical transition between existing and new (ie to be set) DOM element values. At the simplest level, for a given animation we have a target element, an start state, an end state, a transition, a tween function and an interpolator.
Now, say I want every so often to programmatically update the contents of an input (text field) element. The value to be entered is non-interpolable (either the text is submitted, or it is not. There is no in-between state). In providing a closure (allowing for text retrieval at the scheduled transition time), tween would seem to be a good vehicle for the updates. Either I replace the interpolator with a fixed value, ensure the start and end values are identical, or find some other way of forcing it to fire at t=1. That's the theory..
To this end, in my case each property (not value) is modified in it's own update call, into which are passed transition, element index and parent element selection.
First cut:
an outer, 'governing' transition with delay values staggered using a multiple of the current element's index
playback_transition = d3.transition()
.delay(function(d, i, j) {
return (time_interval * i);
})
.duration(function() {
return 1; // the minimum
});
within a call to playback_transition.each() pass the transition as a parameter to a dependent animation by means of an update() interface
within this dependent animation, apply the transition and tween to the current element(s):
input // a UI dialog element
.transition()
.tween(i.toString(), setChordname( waveplot.chordname ));
Where:
function setChordname(newValue) {
return function() {
var i = newValue; // a string
return function(t) {
this.value = i;
inputChanged.call(this);
};
};
};
and
function inputChanged() {
if (!this.value) return;
try {
var chord = chordify.chordObjFromChordName(this.value);
purge(); // rid display of superceded elements
plotChord(chord, options); // calculate & draw chord using new input property
} catch (e) {
console.log(e.toString());
}
}
PROBLEM
While setChordname always fires (each chord is in turn correctly found and it's value stored), of the scheduled returned functions, only the first fires and results in display of the associated waveform. For all subsequent return function occurrences, it is as if they had never been scheduled.
From the display:
direct user update to the input field still works fine
only the first of setChordname's return functions fire, but, for this initial chord, carries right through, correctly displaying the cluster of associated chord and note waves.
From this, we can say that the problem has nothing to do with the integrity of the waveplotting functions.
From the console
transitions are accumulating correctly.
chord supply is all good
associated (ie initial) tween fires at t=1. (specifically, tween appears to accept omission of an interpolator function).
looking at the output of transition.toSource(), though the associated outer index increases by single figure leaps, tween itself is always paired with an empty pair of curly brackets.
transition = [[{__transition__:{8:{tween:{}, time:1407355314749, eas..
For the moment, apart from this and the initial execution, the tween factory return function behaviour is a mystery.
From Experiment
Neither of the following have any impact:
Extending the period before the initial transition takes effect
Extending (by a multiple) each staggered transition delay
Furthermore
the same transition configuration used in a different scenario works fine.
These seem to eliminate timing issues as a possible cause, leaving the focus more on the integrity of the tween setup, or conditions surrounding waveplot append/remove.
Afraid it might be interfering with input property text submission via the tween, I also tried disabling a parallel event listener (listening for 'change' events, triggering a call to inputChanged()). Apart from no longer being able to enter own chordnames by hand, no impact.
In addition to 'change', I tried out a variety of event.types ('submit', 'input', 'click' etc). No improvement.
The single most important clue is (to my mind) that only the first setChordname() return function is executed. This suggests that some fundamental rule of tween usage is being breached. The most likely candidate seems to be that the return value of tween **must* be an interpolator.
3 related questions, glad of answers to any:
Anything blatently wrong in this approach?
For a shared transition scenario such as this, do you see a better approach to transitioning a non-interpolable (and normally user-supplied) input property than using tween ?
Provided they are staggered in time, multiple transitions may be scheduled on the same element - but what about multiple tweens? Here, as the staggered transition/tween combos are operating on only one element, they seem likely to be passed identical data (d) and index(i) in every call. Impact?
I'm now able to answer my own question. Don't be put off by the initial couple of paragraphs: there are a couple of valuable lessons further down..
Ok, there were one or two trivial DOM-to-d3 reworking issues in my adoption of the original code. Moreover, an extra returned function construct managed to find it's way into this:
Was:
function setChordname(newValue) {
return function() { <--- Nasty..
var i = newValue;
return function(t) {
this.value = i;
inputChanged.call(this);
};
};
};
Should have been:
function setChordname(newValue) {
var i = newValue;
return function(t) {
this.value = i;
inputChanged.call(this);
};
};
The fundamental problem, however, was that the transition -passed in as a parameter to an update() function- seems in this case to have been blocked or ignored.
Originally (as documented in the question) defined as:
input // a UI dialog element
.transition()
.tween(i.toString(), setChordname( waveplot.chordname ));
..but should have been defined as:
transition
.select("#chordinput") // id attribute of the input element
.tween(i.toString(), setChordname( waveplot.chordname ));
My guess is that the first version tries to create a new transition (with no delay or duration defined), whereas the second uses the transition passed in through the update() interface.
Strange is that:
what worked for another dependent animation did not for this.
the staggered delays and their associated durations were nevertheless accepted by the original version, allowing me to be misled by console logs..
Just to round this topic off, I can point out the the following (event-based) approach seems to work just as well as the tween variant with non-interpolable values documented above. I can switch freely between the two with no apparent difference in the resulting animations:
transition
.select("#chordinput") // id attribute of the input element
.each("start", setChordname( waveplot.chordname ));
Thug

Example on how to control tweens using Ticker in CreateJS

I'm working with CreateJS and wondered if anyone here has examples of controlling tweens using the Ticker object. I'm trying to get a sprite to follow a path defined by waypoints but i don't want to control each tween (in between waypoints) by time. I want to have smooth movement between each waypoint controlled by the Ticker object. I tried this code which doesn't seem to work at all.
var index = 0;
function move(){
index++;
if (index < path.length) {
createjs.Tween.get(person)
.to({x:gridSize * path[index][0] - pathOffset,y:gridSize * path[index][1] - pathOffset})
.call(move);
}
}
move();
createjs.Ticker.setFPS(30);
createjs.Ticker.addEventListener("tick", function(event){
createjs.Tween.tick(1);
stage.update();
});
This code seems to only jump between waypoints and not tween at all. Any ideas what i may be doing wrong or any code/tutorials which might help?
You need to add a duration(in milliseconds) to your tween, otherwise it would default to 0, this will cause the "jump", e.g.: 500 for half a second
instead of: .to({x:..., y:...})
use: .to({x:..., y:...},500)
And a second thing: You don't NEED to call createjs.Tween.tick(1); this is usually called automatically by the Tween-class.
Here is some help and some small examples: http://www.createjs.com/Docs/TweenJS/classes/Tween.html
Advanced Examples:
https://github.com/CreateJS/TweenJS/tree/master/examples

FabricJS Canvas, Scrolling parent container moves child hit area

I am using FabricJS to create an application. I am finding that scrolling a parent div/container offsets the selectable area of an object to the right in direct relation to amount scrolled.
So, if I have a canvas that is 1200x600 and a container div that is 600x600 and I add a rect to that canvas at 400, 120; when I scroll 200px, I can't click on the rect to select it. Rather, I have to move my mouse to 600, 120 (empty space) to get the cross bar and select the rect.
Not sure if this is known, or has a work around - but I would appreciate any help possible.
You'll have to modify FabricJs code to make it work.
The problem is in the getPointer function, if you search for it in all.js you'll notice the comment "this method needs fixing" from kangax.
A workaround can be substituting this function with
function getPointer(event) {
// TODO (kangax): this method needs fixing
return { x: pointerX(event) + document.getElementById("container").scrollLeft, y: pointerY(event) + document.getElementById("container").scrollTop };
}
where "container" is the wrapper div of you canvas. It's not nice, since you have to put the exact id, but it works.
Hope this helps.

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