3 Replies Latest reply on Oct 30, 2009 2:46 PM by Ken Ampel

    TextArea gets very slow after text amounth gets larger


      I am currently collecting experience with the textarea component.

      Unfortunately I have to realize that actually - not significant but still
      perhaps larger amounth of text, lets the textarea become so slow that typing
      into it becomes unusable.

      The text size is starting from 18 kbyte + of text, meaning after around 1500
      lines of moderate text with 1 line containing perhaps 6 words.

      Is there any recomendation on how to use it for increased performance.

      I would need to fit into the textarea between 3000 - 10 000 lines without
      performance lack.

      It seems that the slowdown occurs because the textarea tries to render all
      the text even just a small part is visible.
      Does the textarea render all the text or does it just render the visible

      Are any improvements expected in the upcoming release?

      Thank you for information,



        • 1. Re: TextArea gets very slow after text amounth gets larger
          Steve Loker Level 1



          I'm having the same problem - I'm trying to put a couple MB of text in a TextArea.  It takes around 15 seconds before the UI becomes responsive again and then each keystroke inside the text area takes about a second to register.  Have you made any progress on this problem?  Have you given up?

          • 2. Re: TextArea gets very slow after text amounth gets larger
            Gregory Lafrance Level 6

            The Flash text engine, and thus Flex in general, does not handle large amounts of text well.


            Your best bet is to bring in part of the text at a time. You can read it all into an array perhaps, or maybe some other object, but don't put it all in the TextArea at once.


            I don't think extending TextArea will help much, as the underlying text engine is the same.

            • 3. Re: TextArea gets very slow after text amounth gets larger
              Ken Ampel

              Just read your comment to another flex user regarding slower performance from TextArea as the text files get bigger.


              I am developing a word-processing application in Adobe AIR and am running into the same limitation, either in Flex 3 or Gumbo.


              Could you detail your comment out a bit (or provide an example) regarding the use of arrays to render only those sections of text visible, instead of loading the entire text file?


              In particular, how do you tie in what gets loaded from the array to the user's scrolling the text file up and down.


              Thanks very much.