com.wordpress.tipsforjava.swing
[Java] Class JumpScrollBarModel

java.lang.Object
  javax.swing.DefaultBoundedRangeModel
      com.wordpress.tipsforjava.swing.JumpScrollBarModel

All Implemented Interfaces:

SwingConstants

public class JumpScrollBarModel
extends DefaultBoundedRangeModel

This class is used to create a scroll bar model which continues to return the initial value as long as the scroll thumb is being dragged, and returns the updated value when it is released, or optionally after a specified delay.

This can be useful in two perceived situations:

• When the rendering of the scrollable component is time consuming, so as to render the component once at the end of the scrolling instead of several times over.
• When detail to be displayed in different areas of the scrollable component is dynamically loaded at runtime, and it is desirable to load only the data for the final visible rectangle.

If the JumpScrollBarModel is constructed with a reference to the scroll bar or scroll pane to which it is attached, the original model can be restored by invoking the class's dispose() method.

Authors:

Rob Camick

Darryl Burke

See Also:

oldModel

private BoundedRangeModel oldModel

oldValue

private int oldValue

scrollBar

private JScrollBar scrollBar

timer

private Timer timer

JumpScrollBarModel

public JumpScrollBarModel()

Creates a JumpScrollBarModel with all of the properties set to default values. Those values are:

• value = 0
• extent = 0
• minimum = 0
• maximum = 100
• adjusting = false

JumpScrollBarModel

public JumpScrollBarModel(int value, int extent, int min, int max)

Creates a JumpScrollBarModel with the specified value, extent, minimum and maximum. Adjusting is false.

Throws an IllegalArgumentException if the following constraints aren't satisfied: min <= value <= value+extent <= max

Parameters:

value - the value

extent - the extent

min - the minimum of the range

max - the maximum of the range

JumpScrollBarModel

public JumpScrollBarModel(JScrollPane scrollPane)

Creates a JumpScrollBarModel for the vertical scroll bar of a JScrollPane. The properties are initialized from the scroll bar's original model.

Parameters:

scrollPane - the JScrollPane

JumpScrollBarModel

public JumpScrollBarModel(JScrollPane scrollPane, int scrollBarType)

Creates a JumpScrollBarModel for the specified scroll bar of a JScrollPane. The properties are initialized from the scroll bar's original model.

Parameters:

scrollPane - the JScrollPane

scrollBarType - should be either of

• SwingConstants.HORIZONTAL
• SwingConstants.VERTICAL

In case of an illegal value, the vertical scroll bar will be selected by default.

JumpScrollBarModel

public JumpScrollBarModel(JScrollBar scrollBar)

Creates a JumpScrollBarModel for a JScrollBar. The properties are initialized from the scroll bar's original model.

Parameters:

scrollBar - the JScrollBar

dispose

public void dispose()

Invoking this method will restore the scroll bar's original model. In case this JumpScrollBarModel was constructed without a reference to a scroll bar or scroll pane, the method will do nothing.

getJumpInterval

public int getJumpInterval()

Returns the jump interval in milliseconds, or -1 if the model does not auto jump.

Returns:

the jump interval, or -1 if the model does not auto jump.

getTrueValue

public int getTrueValue()

Returns the true value of the scroll bar, as retrieved from the superclass. This method is provided as a convenience for consumers that require the true value, for example to post a tool tip or status message while adjusting.

Returns:

the true value

getValue

@Override
public int getValue()

Overridden to return the previous value while the scroll bar's value is adjusting, and to return the current value only when not adjusting.

Returns:

the model's value, adjusted as noted.

setJumpInterval

public void setJumpInterval(int interval)

Sets the interval in milliseconds after which the scrollbar will jump if paused at one point. A value of -1 will stop the auto jump.

Any other negative value or 0 will do nothing.

Parameters:

interval - the jump interval, or -1 to stop auto jump.

setJumpScrollBarModel

public static JumpScrollBarModel setJumpScrollBarModel(JScrollPane scrollPane)

Returns a JumpScrollBarModel for the vertical scroll bar of a JScrollPane. The properties are initialized from the scroll bar's original model.

Parameters:

scrollPane - the JScrollPane

Returns:

the JumpScrollBarModel

setJumpScrollBarModel

public static JumpScrollBarModel setJumpScrollBarModel(JScrollPane scrollPane, int scrollBarType)

Returns a JumpScrollBarModel for the specified scroll bar of a JScrollPane. The properties are initialized from the scroll bar's original model.

Parameters:

scrollPane - the JScrollPane

scrollBarType - should be either of

• SwingConstants.HORIZONTAL
• SwingConstants.VERTICAL

In case of an illegal value, the vertical scroll bar will be selected by default.

Returns:

the JumpScrollBarModel

setJumpScrollBarModel

public static JumpScrollBarModel setJumpScrollBarModel(JScrollBar scrollBar)

Returns a JumpScrollBarModel for a JScrollBar. The properties are initialized from the scroll bar's original model.

Parameters:

scrollBar - the JScrollBar

Returns:

the JumpScrollBarModel

Groovy Documentation