de.griefed.serverpackcreator.swing.utilities

Class SmartScroller

java.lang.Object

de.griefed.serverpackcreator.swing.utilities.SmartScroller

All Implemented Interfaces:

java.awt.event.AdjustmentListener, java.util.EventListener

public class SmartScroller
extends java.lang.Object
implements java.awt.event.AdjustmentListener

Hey, Griefed here. I was playing around with scrolling in Swing and was getting fed up with the ways I came up with which would allow me to set the scrollbar to the bottom at all times....I mean, it worked, sorta? The problem was that you couldn't scroll up...making any previous log messages unreadable...I couldn't figure out how to make it, so it would stop scrolling to the end if the user scrolled up, and when I was about to give up and just not deal with any of that scrolling business, I came across this beauty here. Add your scrollpane to this SmartScroller and BAM! You've got yourself a smartscrolling scroll pane which stops going to the end of the pane after you've scrolled up, and resumes autoscrolling when you've scrolled to the bottom again. It's beautiful!
Rob, you absolute madlad. You did it again.
Links:
See Smart Scrolling
And SmartScroller.java Seriously, give this man an award, because this class is a BEAST.

Rob, if you somehow ever get wind of your class being used here: Thank you, thank you, thank you, thank you, thank you so very much! You seriously made my day here.
Rob, you rule.

The SmartScroller will attempt to keep the viewport positioned based on
the users interaction with the scrollbar. The normal behaviour is to keep
the viewport positioned to see new data as it is dynamically added.

Assuming vertical scrolling and data is added to the bottom:

- when the viewport is at the bottom and new data is added,
then automatically scroll the viewport to the bottom
- when the viewport is not at the bottom and new data is added,
then do nothing with the viewport

Assuming vertical scrolling and data is added to the top:

- when the viewport is at the top and new data is added,
then do nothing with the viewport
- when the viewport is not at the top and new data is added, then adjust
the viewport to the relative position it was at before the data was added

Similar logic would apply for horizontal scrolling.

Field Summary

Fields

Modifier and Type	Field and Description
static int	END
static int	HORIZONTAL
static int	START
static int	VERTICAL

Constructor Summary

Constructors

Constructor and Description
SmartScroller(javax.swing.JScrollPane scrollPane) Convenience constructor. Scroll direction is VERTICAL and viewport position is at the END.
SmartScroller(javax.swing.JScrollPane scrollPane, int viewportPosition) Convenience constructor. Scroll direction is VERTICAL.
SmartScroller(javax.swing.JScrollPane scrollPane, int scrollDirection, int viewportPosition) Specify how the SmartScroller will function.

Method Summary

Modifier and Type	Method and Description
void	adjustmentValueChanged(java.awt.event.AdjustmentEvent e)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

HORIZONTAL

public static final int HORIZONTAL

See Also:

Constant Field Values

VERTICAL

public static final int VERTICAL

See Also:

Constant Field Values

START

public static final int START

See Also:

Constant Field Values

END

public static final int END

See Also:

Constant Field Values

Constructor Detail

SmartScroller

public SmartScroller(javax.swing.JScrollPane scrollPane)

Convenience constructor.
Scroll direction is VERTICAL and viewport position is at the END.

Parameters:

scrollPane - the scroll pane to monitor

SmartScroller

public SmartScroller(javax.swing.JScrollPane scrollPane,
                     int viewportPosition)

Convenience constructor.
Scroll direction is VERTICAL.

Parameters:

scrollPane - the scroll pane to monitor

viewportPosition - valid values are START and END

SmartScroller

public SmartScroller(javax.swing.JScrollPane scrollPane,
                     int scrollDirection,
                     int viewportPosition)

Specify how the SmartScroller will function.

Parameters:

scrollPane - the scroll pane to monitor

scrollDirection - indicates which JScrollBar to monitor. Valid values are HORIZONTAL and VERTICAL.

viewportPosition - indicates where the viewport will normally be positioned as data is added. Valid values are START and END

Method Detail

adjustmentValueChanged

public void adjustmentValueChanged(java.awt.event.AdjustmentEvent e)

Specified by:

adjustmentValueChanged in interface java.awt.event.AdjustmentListener