Class BasicScrollPaneUI

protected ChangeListener hsbChangeListener

The horizontal scrollbar listener.

protected JScrollPane scrollpane

The Scrollpane for which the UI is provided by this class.

protected PropertyChangeListener spPropertyChangeListener

The scrollpane property change listener.

protected ChangeListener viewportChangeListener

The viewport listener.

protected ChangeListener vsbChangeListener

The vertical scrollbar listener.

protected ChangeListener createHSBChangeListener()

Creates and returns the change listener for the horizontal scrollbar.

Returns:

the change listener for the horizontal scrollbar

protected MouseWheelListener createMouseWheelListener()

Creates and returns the mouse wheel listener for the scrollpane.

Returns:

the mouse wheel listener for the scrollpane

Since:

1.4

protected PropertyChangeListener createPropertyChangeListener()

Creates and returns the property change listener for the scrollpane.

Returns:

the property change listener for the scrollpane

public static ComponentUI createUI(JComponent c)

Creates a delegate object for the specified component. Users should use the createUI method of a suitable subclass. The implementation of ComponentUI always throws an error.

Overrides:

createUI in interface ComponentUI

Parameters:

c - the component for which a UI delegate is requested.

protected ChangeListener createVSBChangeListener()

Creates and returns the change listener for the vertical scrollbar.

Returns:

the change listener for the vertical scrollbar

protected ChangeListener createViewportChangeListener()

Creates and returns the change listener for the viewport.

Returns:

the change listener for the viewport

public Dimension getMinimumSize(JComponent c)

Determines the minimum size of a component. The default implementation calls ComponentUI.getPreferredSize(JComponent), but subclasses might want to override this.

Overrides:

getMinimumSize in interface ComponentUI

Parameters:

c - the component for which this delegate performs services.

Returns:

the minimum size, or null to indicate that c’s layout manager should be asked to calculate the minimum size.

protected void installDefaults(JScrollPane p)

protected void installKeyboardActions(JScrollPane sp)

Installs additional keyboard actions on the scrollpane. This is a hook method provided to subclasses in order to install their own keyboard actions.

Parameters:

sp - the scrollpane to install keyboard actions on

protected void installListeners(JScrollPane sp)

Installs the listeners on the scrollbars, the viewport and the scrollpane.

Parameters:

sp - the scrollpane on which to install the listeners

public void installUI(JComponent c)

Sets up the specified component so it conforms the the design guidelines of the implemented look and feel. When the look and feel changes, a ComponentUI delegate is created. The delegate object then receives an installUI message.

This method should perform the following tasks:

• Set visual properties such as borders, fonts, colors, or icons. However, no change should be performed for those properties whose values have been directly set by the client application. To allow the distinction, LookAndFeels are expected to use values that implement the UIResource marker interface, such as BorderUIResource or ColorUIResource.
• If necessary, install a LayoutManager.
• Embed custom sub-components. For instance, the UI delegate for a JSplitPane might install a special component for the divider.
• Register event listeners.
• Set up properties related to keyborad navigation, such as mnemonics or focus traversal policies.

Overrides:

installUI in interface ComponentUI

Parameters:

c - the component for which this delegate will provide services.

See Also:

ComponentUI.uninstallUI(JComponent), JComponent.setUI(ComponentUI), JComponent.updateUI()

public void paint(Graphics g,
                  JComponent c)

Paints the component according to the design guidelines of the look and feel. Most subclasses will want to override this method.

Overrides:

paint in interface ComponentUI

Parameters:

g - the graphics for painting.

c - the component for which this delegate performs services.

protected void syncScrollPaneWithViewport()

Synchronizes the scrollbar and header settings positions and extent with the viewport's view position and extent.

protected void uninstallDefaults(JScrollPane p)

protected void uninstallKeyboardActions(JScrollPane sp)

Uninstalls all keyboard actions from the JScrollPane that have been installed by installKeyboardActions(JScrollPane). This is a hook method provided to subclasses to add their own keyboard actions.

Parameters:

sp - the scrollpane to uninstall keyboard actions from

protected void uninstallListeners(JComponent c)

Uninstalls all the listeners that have been installed in installListeners(JScrollPane).

Parameters:

c - the scrollpane from which to uninstall the listeners

public void uninstallUI(JComponent c)

Puts the specified component into the state it had before ComponentUI.installUI(JComponent) was called.

Overrides:

uninstallUI in interface ComponentUI

Parameters:

c - the component for which this delegate has provided services.

See Also:

ComponentUI.installUI(JComponent), JComponent.setUI(ComponentUI), JComponent.updateUI()

protected void updateColumnHeader(PropertyChangeEvent ev)

Receives notification when the columnHeader property has changed on the scrollpane.

Parameters:

ev - the property change event

protected void updateRowHeader(PropertyChangeEvent ev)

Receives notification when the rowHeader property has changed on the scrollpane.

Parameters:

ev - the property change event

protected void updateScrollBarDisplayPolicy(PropertyChangeEvent ev)

Receives notification when the scrollBarDisplayPolicy property has changed on the scrollpane.

Parameters:

ev - the property change event

protected void updateViewport(PropertyChangeEvent ev)

Receives notification when the viewport property has changed on the scrollpane. This method sets removes the viewportChangeListener from the old viewport and adds it to the new viewport.

Parameters:

ev - the property change event