Try calling validateNow() after setting the text, before setting the vPosition to maxVPosition.
The validateNow() should cause the text you specified to be pushed into the underlying Flash TextField; after that happens, maxVPosition should have the appropriate value for the new text. - Gordon -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Lesser Sent: Thursday, February 02, 2006 4:13 AM To: [email protected] Subject: Re: [flexcoders] Re: Scrolling a TextArea to the bottom? 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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