[Advanced-java] TextArea, large file and setCaretPosition(0)

[jorti@xxxxxxxxx (Jose Ortiz)]

Try placing the JTextArea inside a JScrollPane,

	JScrollPane scroller.setViewportView( jtextarea );

then, get the Viewport,

	JViewport viewport = scroller.getViewport();

and do
	viewport.setViewPosition( new Point(0,0) );

you may need to do this constantly in a loop while the loading is not
finished.
 
An alternative is to inspect the source code of JTextArea and see what
append(String) or setText(String) are doing (obviously, they are placing
the caret at the end after appending more text). The idea is to subclass
JTextArea and overwrite say the append method taking care of removing
the caret placement whenever you set a flag. 

	class myJTextArea extends JTextArea {
	public void append(String s ) {
	   if( !flagSet ) {
		super.append(s);
	   	return;
	  }
	  // here place the code from super class without
	  // the caret placement.
	}

flagSet should be true for the loading job. It should be false for
normal behaviour.

Jose

ribchr00@xxxxxxxxxxxxxx wrote:
> 
> Hi,
> 
> To avoid the waiting for a large file to be loaded in a
> TextArea, when a certain number of lines is read, I send
> them to the TextArea. I would like the process running
> out in the background. The user should not notice
> anything. My problem is that the caret position always
> changes to the end when text is appended. I tried some
> ideas like a loop or a thread setting the caret position
> to 0 but it did not work. Has anybody a better idea? For
> any suggestion I would be glad. Cheers,
> 
> richard
> _______________________________________________
> Advanced-java mailing list
> Advanced-java@xxxxxxxxxxxxxxxxxxxxxx
> http://lists.xcf.berkeley.edu/mailman/listinfo/advanced-java

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                                      Jose L. Ortiz, Ph.D.
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