Autoscroll Text Area

Ignition
1

Is it possible to autoscroll the text area component to the end if more text is added to it? In Java, I used to be able to do:

JTextArea area = new JTextArea();
area.setCaretPosition( area.getDocument().getLength() );

Thanks!

2

Oh man, you already know how to do it in Java? You’re in luck - you can do all of that same stuff through Jython.

The only trick is that the “Text Area” component is actually a JScrollPane with a JTextArea in it.

So you’d do it like this:

scrollPane = ... (grab the text area) area = scrollPane.viewport.view area.setCaretPosition(area.getDocument().getLength())

3

I tried the code in a property change event for the text area so when new text would be added it would auto scroll.

if( event.propertyName == 'text' ):
    scrollPane = event.source
    area = scrollPane.viewport.view
    area.setCaretPosition( area.getDocument().getLength() )

It does not throw any errors, but does not scroll the text area. I know the script runs since I had inserted a simple print statement to check for sure. Ideas?

4

Yeah, you probably need to wrap your code in an invokeLater call to ensure it occurs after the text area itself has actually responded to the new text being added.

if( event.propertyName == 'text' ): def doScroll(scrollPane = event.source): area = scrollPane.viewport.view area.setCaretPosition( area.getDocument().getLength() ) system.util.invokeLater(doScroll)

5

Yep, worked perfectly. I keep forgetting about invokeLater.

Thanks!

6

Hi,

Geez, hate to revive this ancient thread, but I want to auto scroll the text area component and the solution in this thread doesn’t work if the text property of the component is bound to a tag.
It looks like the event.propertyName == 'text' doesn’t fire if the property is bound and then the auto scroll script doesn’t run.
Is there a way to auto scroll the text area with the text property bound?

Thanks

7

I didn’t read the entire thread, but maybe use a custom property instead and have the script on it write to text?

8

Working on implementing a log sink. I found another thread (My Perspective Logger Component) with great sample code. It’s writing new lines to the top of the log rather than appending to the bottom, perhaps to avoid the need to keep the TextArea scrolled to the bottom.

Searching for how to do that, I’m not following the sample code shared in this thread. Anyone have a modern solution. This thread is 12yr old.