Why Javafx UI hangs or become unresponsive on using Plarform.runLater() ?

Tom Schindl tom.schindl at bestsolution.at
Sun Oct 19 18:18:03 UTC 2014

TextArea in JavaFx is very ineffecient because it is not virtual! Codeeditors like the styledtext one i wrote use virtualflow/Listview to perform with many lines.


Von meinem iPhone gesendet

> Am 19.10.2014 um 20:11 schrieb Navdeep Singh Sidhu <navdeepsingh.sidhu95 at gmail.com>:
> Thanks sir, that is really a great suggestion. So i have to add a listener
> to scroll bar. Am i right ??
> And there is not such thing like silly question :) . Not having knowledge
> is not bad, but having no curiosity to pursue knowledge is bad. I'm working
> on parallel computing framework and my target is to multiply matrices with
> BigInt elements and dimensions, for any number of given matrices (that also
> can be in BigInt). On Netbeans my sample problem gives me the output
> without crashing it or making it unresponsive. So i'm trying to achieve
> similar in JavaFX. The main target of my project is to implement problems
> in parallel computing and i'm using JFX as front-end because it is good
> looking and easy to implement than Swing. But this is my first project in
> JFX and i am facing many problems while implementing, main problem is UI
> lag bcz in back-end different threads collect data and those threads do the
> computations concurrently and send result data to UI.
> And also is there anyway i can apply monokai like theme (or any other
> coding style theme)  to my TextArea which i'm using in Code editor for JAVA
> with suggestion popups like Netbeans or eclipse?
>> On Sun, Oct 19, 2014 at 9:59 PM, Michael Berry <mjrb5 at kent.ac.uk> wrote:
>> Perhaps a silly question - but do you really need millions of lines in the
>> text area? When you're displaying this much text then from my understanding
>> things are bound to hang (simply because of the processing overload) and
>> there's not really a great deal you can do about it. You can see if there's
>> any extraneous delay by profiling and seeing if there's any GC bottlenecks
>> (or suchlike) then tweak those options, but I doubt you'll ever get to no
>> delay at all with dumping this much data in a textarea.
>> I'm not aware of the details of your application, but can you just create
>> the text in memory somewhere else, and create an FX component that acts
>> like a text area, but dynamically reads the text in from memory as the user
>> scrolls? This way you'll just be altering a relatively small amount of text
>> much more continuously, and shouldn't notice much of a delay. (I took a
>> similar approach with Swing a long while ago for a project, but sadly can't
>> find the source for that now.)
>> Michael
>> On 19 October 2014 16:58, Navdeep Singh Sidhu <
>> navdeepsingh.sidhu95 at gmail.com> wrote:
>>> Hello,
>>> I know this mailing list is for OpenJFX developers and to discuss
>>> development related issues. I don't know it is OK to post my query here or
>>> not. But i assume if you people are developing the OpenJFX, so there will
>>> be no other person better than you or have more knowledge related OpenJFX
>>> than you guys :) .
>>> My query is that i'm trying to develop an IDE for parallel computing
>>> integrated with framework and output from all nodes has to be represented
>>> in TextArea. I am using multiple threads to collect Output from all the
>>> nodes and appending that output on TextArea using Platform.runLater(), i
>>> am
>>> even using flags to reduce the flood on UI thread, that output will be
>>> appended if the output is larger than 50000 lines then after each 50000
>>> lines to TextArea else it will be appended as it is. Even submitting one
>>> task in the system, UI hangs when trying to print millions of line output
>>> on TextArea and i couldn't test it with multiple tasks. Can you suggest me
>>> something to prevent UI thread from becoming unresponsive. I know i'm not
>>> good programmer as you guys but i'm trying to learn JFX and new to this.
>>> BTW thank you guys for such a beautiful interface in JAVA. :)
>>> Regards
>>> Navdeep Singh Sidhu

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