Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #24281

Re: How To Determine Position of JScrollPane in One JTable and Scroll Second JTable

Show all headers | View raw

Jim Gibson wrote:
> Haircuts Are Important wrote:
>> How can I determine how much a  JTable's JScrollPane has been moved,
>> and then scroll a second JTable based on that movement.
> 
> JScrollPane has two JScrollBar members: horizontalScrollBar and
> verticalScrollBar. Use the getVerticalScrollBar() method of
> JScrollPane, for example, to get the vertical scroll bar object.
> 
> Then use the getValue() method of JScrollBar to find out where the
> scrollbar is positioned. You can define an AdjustmentListener object to
> listen for scroll bar events. Then use the setValue() method to apply
> the same offset to the other JScrollPane (assuming everything else
> about the two JScrollPanes is equal).

That is a beautifully succinct and informative post that I shall find 
useful. Thank you.

OP (Original Poster): You can generalize from Jim's answer to coordinate 
arbitrary widgets.

You can apply Jim's suggestion by using the Javadocs to find an equivalent 
listener for the widget you want to track. 

For example, some screen designs involve coordinated drop-down selections 
and text or choices in other screen elements. For the drop-down widget you 
use a JComboBox. Instead of an AdjustmentListener, you'd define an ActionListener and add it to the JComboBox with 

http://docs.oracle.com/javase/7/docs/api/javax/swing/JComboBox.html#addActionListener(java.awt.event.ActionListener)

You might update the contents of a prompt elsewhere on the screen with the 
choice made in the combo box, using the listener to trigger the update. 

Extending into another dimension, if you study the "model-view-controller" 
(MVC) architecture of a good Swing screen, the same approach allows multiple 
widgets to update based on a change to a data or object model. For example, 
a stock-market ticker app could use a listener to a stock-price model
to update a visual chart of the price, at the same time as another part 
of the display logic updates a moving average line on that chart using a 
listener to get the latest data from the model.

-- 
Lew

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

How To Determine Position of JScrollPane in One JTable and Scroll Second JTable Haircuts Are Important <clusardi2k@aol.com> - 2013-06-03 11:37 -0700
  Re: How To Determine Position of JScrollPane in One JTable and Scroll Second JTable Jim Gibson <jimsgibson@gmail.com> - 2013-06-03 16:56 -0700
    Re: How To Determine Position of JScrollPane in One JTable and Scroll Second JTable Lew <lewbloch@gmail.com> - 2013-06-03 23:46 -0700
    Re: How To Determine Position of JScrollPane in One JTable and Scroll Second JTable Haircuts Are Important <clusardi2k@aol.com> - 2013-06-04 07:20 -0700

csiph-web