Usage of Toolkit firePulse

Tomas Mikula tomas.mikula at
Thu Sep 24 22:03:47 UTC 2015

Hi Michael,

attached see your original file updated with the continuation-style


On Thu, Sep 24, 2015 at 2:44 PM, Dr. Michael Paus <mp at> wrote:

> I have written a little test program to evaluate the various strategies
> which have
> been discussed here. You can download it via this link:
> <>
> The program creates a large canvas inside a scroll pane and fills it with
> some
> butterflies. When you scroll the pane the canvas is redrawn when a certain
> threshold is exceeded. With some boolean flags at the top of the program
> you can select the redraw strategy.
> This was just a quick and dirty hack, so I hope I haven't made any mistakes
> but the result so far is that only the AnimationTimer strategy leads to a
> amazingly
> smooth result. For all other strategies the scrolling performance is
> terrible.
> (I have not yet tried the proposal from Tomas.)
> Give it a try yourself. The initial setting are for AnimationTimer.
> Michael
> Am 24.09.15 um 17:17 schrieb Kevin Rushforth:
> Yes, I think this might be a better approach.
>> -- Kevin
>> Scott Palmer wrote:
>>> For some of these use cases I wonder if an AnimationTimer could be used
>>> to handle spreading work out.
>>> E.g in the case of rendering to a canvas across multiple pulses, do a
>>> bit at a time in the AnimationTimer’s handle() method.
>>> Scott
>>> On Sep 24, 2015, at 5:53 AM, Fisher, Robert <robert.fisher.ext at>
>>>> wrote:
>>>> I was naively thinking something like:
>>>> 1. Make small change to canvas
>>>> 2. Fire pulse
>>>> 3. Make next small change to canvas
>>>> 4. Fire pulse
>>>> 5. Etc..
>>>> But I was actually also unaware of this firePulse method until this
>>>> morning (and I couldn't have used it anyway since it's not public API).
>>>> -----Original Message-----
>>>> From: openjfx-dev [mailto:openjfx-dev-bounces at] On
>>>> Behalf Of Dr. Michael Paus
>>>> Sent: Donnerstag, 24. September 2015 11:07
>>>> To: openjfx-dev at
>>>> Subject: Re: Usage of Toolkit firePulse
>>>> Hi,
>>>> I wasn't aware of this Toolkit method when I wrote the mail you are
>>>> referring to. Can you or anybody else explain what this method exactly
>>>> does. It sounds indeed as if I could solve some problems with it although I
>>>> am not sure yet and of course only if Jonathan does not block it in the
>>>> future :-) Michael
>>>> Am 24.09.15 um 09:31 schrieb Fisher, Robert:
>>>>> I think it would be great to have in the public API. It looks like it
>>>>> would allow you to spread large UI updates out over several pulses in a
>>>>> well-defined way.
>>>>> See also this post from a month or so ago:
>>>>> Hi,
>>>>>> I want to do some performance tuning of a JavaFX application of mine
>>>>>> but before I can start with that I have to learn a little bit about the
>>>>>> scene graph redraw handling.
>>>>>> Maybe there is someone on this list who can help me there.
>>>>>> What I want to achieve is a super smooth animation (movement) of my
>>>>>> scene graph.
>>>>>> Let's assume the scene graph itself can be redrawn fast enough in
>>>>>> less than 1/60s.
>>>>>> In addition let's assume the scene graph contains a canvas which only
>>>>>> has to be updated from time to time but an update of the canvas takes
>>>>>> substantially longer.
>>>>>> Let's say it takes 1s.
>>>>>> When an update of the canvas is in progress will this delay the next
>>>>>> pulse until all internal drawing within the canvas is finished? From my
>>>>>> observations I think so.
>>>>>> If I submit my drawing calls to the canvas in smaller chunks via
>>>>>> Platform.runLater calls will these also delay the next pulse or will the
>>>>>> execution of these calls be delayed in favor of the scene graph update?
>>>>>> I hope my goal has become clear. I would like to be able to spread
>>>>>> the update of the canvas over several scene graph redraw cycles so that an
>>>>>> animation of the canvas stays smooth although the content builds up more
>>>>>> slowly.
>>>>>> Michael
>>>>> -----Original Message-----
>>>>> From: openjfx-dev [mailto:openjfx-dev-bounces at] On
>>>>> Behalf Of Jonathan Giles
>>>>> Sent: Donnerstag, 24. September 2015 01:49
>>>>> To: openjfx-dev at
>>>>> Subject: Usage of Toolkit firePulse
>>>>> Hi all,
>>>>> Today I am keen to get your help on understanding use of the
>>>>> Toolkit.getToolkit().firePulse() private API. If you could spare a few
>>>>> minutes to grep your source directory for any usage of 'firePulse', and
>>>>> email me your findings, that would be really interesting.
>>>>> As a gentle motivational tool I'll conclude by saying that,
>>>>> surprisingly, this private API is barely used inside the openjfx production
>>>>> code. If you look at the openjfx unit tests, it is used massively. The
>>>>> question is - how much is this being used by other community members. If
>>>>> the answer is 'not much' or less, then this private API may not be made
>>>>> public in JDK 9. Your feedback therefore is critical!
>>>>> Thanks,
>>>>> -- Jonathan

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