Java Reference
In-Depth Information
Besides enabling you to add the JViewport and two JScrollBar components for scrolling,
the JScrollPane allows you to provide two more JViewport objects for row and column headers
and four Component objects to display in the scroll pane corners. The placement of all these
components is managed by the ScrollPaneLayout manager, introduced in Chapter 10 and
described more fully here. The actual JScrollBar components used by JScrollPane are a
subclass of JScrollBar called JScrollPane.ScrollBar . They are used instead of the regular
JScrollBar to properly handle scrolling the component inside the inner JViewport , when that
component implements the Scrollable interface.
To help you see how all the components fit within the JScrollPane , Figure 11-15 demon-
strates how the ScrollPaneLayout positions the various pieces.
UPPER_
LEFT_
CORNER
UPPER_
RIGHT_
CORNER
COLUMN_HEADER
VIEWPORT
LOWER_
LEFT_
CORNER
LOWER_
RIGHT_
CORNER
VERTICAL_SCROLLBAR
Figure 11-15. ScrollPaneLayout regions
Caution The JScrollPane component supports scrolling only lightweight components. You should not
add regular, heavyweight AWT components to the container.
Creating a JScrollPane
There are four JScrollPane constructors:
 
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