Please file a bug on the minor problem you're seeing. This will be a common thing to want to do.
- Gordon -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Lesser Sent: Thursday, February 02, 2006 4:38 AM To: [email protected] Subject: Re: [flexcoders] Re: Scrolling a TextArea to the bottom? Hi Gordon, I wrote too soon! This DOES work (with a really minor rendering problem) : public function writeln(msg:String):void{ traceArea.text += msg + "\n"; traceArea.validateNow(); traceArea.vPosition = traceArea.maxVPosition; } The minor problem is that the first time I ran the app and the TextArea scrolled to the bottom, the scroll bar elevator appeared briefly well below the a scroll bar area. I can't make it do it all the time either so I'm much further ahead. Thanks again, -Brian Brian Lesser wrote: >Hi Gordon, >Thanks for the suggestion, even though I couldn't get it to work, I >really appreciate your taking the time to explain how things work. It's >good to know that stuff. > >Here's what I tried that didn't work: > >public function writeln(msg:String):void{ > traceArea.text += msg + "\n"; > traceArea.vPosition = traceArea.maxVPosition; > traceArea.validateNow(); >} > >Earlier Jesse suggested the line below but I have no idea (being new to >Flex) how to incorporate that into a function: > ><mx:TextArea id="my_ta" change="my_ta.vPosition = my_ta.maxVPosition" /> > >Any ideas how I could get reliable scrolling to the bottom of a text area with the least amount of code/complexity? > >Yours truly, >-Brian > > > >Gordon Smith wrote: > > > >>Try calling traceArea.validateNow() after setting the text. >> >>Here is some background about this... >> >>Flex relies heavily on "invalidation": you set a property but it doesn't >>take effect until later. That allows you, for example, to set a bunch of >>properties and have a component only redraw once, instead of redrawing >>after each property is changed. >> >>There are three invalidation APIs on a UIComponent >> >> invalidateProperties(); >> invalidateSize(); >> invalidateDisplayList(); >> >>and most property setters call one or more of these. For example, the >>setter for the 'text' property of a TextArea calls >>invalidateProperties() and invalidateDisplayList(). >> >>These APIs push the component onto various queues that the LayoutManager >>maintains. >> >>When the Flash Player is about to render the tree of DisplayObjects onto >>the screen, we "validate" the components in these queues by calling >>three "validation" APIs, which bring the component up-to-date: >> >> validateProperties() -> commitProperties() >> validateSize() -> measure() >> validateDisplayList() -> updateDisplayList() >> >>The call to commitProperties() pushes the text into the underlying Flash >>TextField. >> >>You can cause these three methods to be called prematurely (i.e., before >>the player is about to render) by calling validateNow() on the >>component. >> >>- Gordon >> >> >>-----Original Message----- >>From: [email protected] [mailto:[EMAIL PROTECTED] On >>Behalf Of Brian Lesser >>Sent: Wednesday, February 01, 2006 9:24 PM >>To: [email protected] >>Subject: Re: [flexcoders] Re: Scrolling a TextArea to the bottom? >> >>Thanks Mac, >>You know, I just assumed it would work in Flex. In Flash I used to be >>able to call redraw() right after setting the vPosition property and it >>would work ok. I don't suppose there is a simple one liner that does the >> >>job in Flex?? >>Yours truly, >>-Brian >> >>vardpenguin wrote: >> >> >> >> >> >>>You're doing it correctly, the problem is that when you set the >>>vPosition, the 'msg' string has not been fully loaded into the >>>textArea yet. >>> >>>You need to do some sort of check to make sure the textArea content >>>change has been completed, or wait a few moments before you set >>> >>> >>> >>> >>vPosition. >> >> >> >> >>>-Mac >>> >>> >>>--- In [email protected], Brian Lesser <[EMAIL PROTECTED]> wrote: >>> >>> >>> >>> >>> >>> >>>>Possibly really dumb question but shouldn't this scroll a TextArea to >>>>the bottom: >>>> >>>>public function writeln(msg:String):void{ >>>> traceArea.text += msg + "\n"; >>>> traceArea.vPosition = traceArea.maxVPosition; >>>>} >>>> >>>>Where traceArea is a TextArea. >>>> >>>>It doesn't seem to work for me in Flex Beta 1. >>>> >>>>Yours truly, >>>>-Brian >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>> >>> >>>-- >>>Flexcoders Mailing List >>>FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt >>>Search Archives: >>> >>> >>> >>> >>http://www.mail-archive.com/flexcoders%40yahoogroups.com >> >> >> >> >>>Yahoo! Groups Links >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >> >> >> >> > > > > -- ______________________________________________________________________ Brian Lesser Assistant Director, Teaching and Technology Support Computing and Communications Services Ryerson University 350 Victoria St. Toronto, Ontario Phone: (416) 979-5000 ext. 6835 M5B 2K3 Fax: (416) 979-5220 Office: AB48D E-mail: [EMAIL PROTECTED] (Enter through LB66) Web: http://www.ryerson.ca/~blesser ______________________________________________________________________ -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com Yahoo! Groups Links -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com Yahoo! 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