Java javax.swing.plaf.basic Class BasicScrollPaneUI（JDK8）

Field Detail

• scrollpane

  protected JScrollPane scrollpane

• vsbChangeListener

  protected ChangeListener vsbChangeListener

• hsbChangeListener

  protected ChangeListener hsbChangeListener

• viewportChangeListener

  protected ChangeListener viewportChangeListener

• spPropertyChangeListener

  protected PropertyChangeListener spPropertyChangeListener

Constructor Detail

• BasicScrollPaneUI

  public BasicScrollPaneUI()

Method Detail

• createUI

  public static ComponentUI createUI(JComponent x)

• paint

  public void paint(Graphics g,
                    JComponent c)

  Description copied from class: ComponentUI
  Paints the specified component appropriately for the look and feel. This method is invoked from the ComponentUI.update method when the specified component is being painted. Subclasses should override this method and use the specified Graphics object to render the content of the component.

  Overrides:

  paint in class ComponentUI

  Parameters:

  g - the Graphics context in which to paint

  c - the component being painted; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components

  See Also:

  ComponentUI.update(java.awt.Graphics, javax.swing.JComponent)

• getMaximumSize

  public Dimension getMaximumSize(JComponent c)

  Description copied from class: ComponentUI
  Returns the specified component's maximum size appropriate for the look and feel. If null is returned, the maximum size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method invokes getPreferredSize and returns that value.

  Overrides:

  getMaximumSize in class ComponentUI

  Parameters:

  c - the component whose maximum size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components

  Returns:

  new Dimension(Short.MAX_VALUE, Short.MAX_VALUE)

  See Also:

  JComponent.getMaximumSize(), LayoutManager2.maximumLayoutSize(java.awt.Container)

• installDefaults

  protected void installDefaults(JScrollPane scrollpane)

• installListeners

  protected void installListeners(JScrollPane c)

• installKeyboardActions

  protected void installKeyboardActions(JScrollPane c)

• installUI

  public void installUI(JComponent x)

  Description copied from class: ComponentUI
  Configures the specified component appropriately for the look and feel. This method is invoked when the ComponentUI instance is being installed as the UI delegate on the specified component. This method should completely configure the component for the look and feel, including the following:

  1. Install default property values for color, fonts, borders, icons, opacity, etc. on the component. Whenever possible, property values initialized by the client program should not be overridden.
  2. Install a LayoutManager on the component if necessary.
  3. Create/add any required sub-components to the component.
  4. Create/install event listeners on the component.
  5. Create/install a PropertyChangeListener on the component in order to detect and respond to component property changes appropriately.
  6. Install keyboard UI (mnemonics, traversal, etc.) on the component.
  7. Initialize any appropriate instance data.

  Overrides:

  installUI in class ComponentUI

  Parameters:

  x - the component where this UI delegate is being installed

  See Also:

  ComponentUI.uninstallUI(javax.swing.JComponent), JComponent.setUI(javax.swing.plaf.ComponentUI), JComponent.updateUI()

• uninstallDefaults

  protected void uninstallDefaults(JScrollPane c)

• uninstallListeners

  protected void uninstallListeners(JComponent c)

• uninstallKeyboardActions

  protected void uninstallKeyboardActions(JScrollPane c)

• uninstallUI

  public void uninstallUI(JComponent c)

  Description copied from class: ComponentUI
  Reverses configuration which was done on the specified component during installUI. This method is invoked when this UIComponent instance is being removed as the UI delegate for the specified component. This method should undo the configuration performed in installUI, being careful to leave the JComponent instance in a clean state (no extraneous listeners, look-and-feel-specific property objects, etc.). This should include the following:

  1. Remove any UI-set borders from the component.
  2. Remove any UI-set layout managers on the component.
  3. Remove any UI-added sub-components from the component.
  4. Remove any UI-added event/property listeners from the component.
  5. Remove any UI-installed keyboard UI from the component.
  6. Nullify any allocated instance data objects to allow for GC.

  Overrides:

  uninstallUI in class ComponentUI

  Parameters:

  c - the component from which this UI delegate is being removed; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components

  See Also:

  ComponentUI.installUI(javax.swing.JComponent), JComponent.updateUI()

• syncScrollPaneWithViewport

  protected void syncScrollPaneWithViewport()

• getBaseline

  public int getBaseline(JComponent c,
                         int width,
                         int height)

  Returns the baseline.

  Overrides:

  getBaseline in class ComponentUI

  Parameters:

  c - JComponent baseline is being requested for

  width - the width to get the baseline for

  height - the height to get the baseline for

  Returns:

  baseline or a value < 0 indicating there is no reasonable baseline

  Throws:

  NullPointerException - if c is null

  IllegalArgumentException - if width or height is < 0

  Since:

  1.6

  See Also:

  JComponent.getBaseline(int, int)

• getBaselineResizeBehavior

  public Component.BaselineResizeBehavior getBaselineResizeBehavior(JComponent c)

  Returns an enum indicating how the baseline of the component changes as the size changes.

  Overrides:

  getBaselineResizeBehavior in class ComponentUI

  Parameters:

  c - JComponent to return baseline resize behavior for

  Returns:

  an enum indicating how the baseline changes as the component size changes

  Throws:

  NullPointerException - if c is null

  Since:

  1.6

  See Also:

  JComponent.getBaseline(int, int)

• createViewportChangeListener

  protected ChangeListener createViewportChangeListener()

• createHSBChangeListener

  protected ChangeListener createHSBChangeListener()

• createVSBChangeListener

  protected ChangeListener createVSBChangeListener()

• createMouseWheelListener

  protected MouseWheelListener createMouseWheelListener()

  Creates an instance of MouseWheelListener, which is added to the JScrollPane by installUI(). The returned MouseWheelListener is used to handle mouse wheel-driven scrolling.

  Returns:

  MouseWheelListener which implements wheel-driven scrolling

  Since:

  1.4

  See Also:

  installUI(javax.swing.JComponent), BasicScrollPaneUI.MouseWheelHandler

• updateScrollBarDisplayPolicy

  protected void updateScrollBarDisplayPolicy(PropertyChangeEvent e)

• updateViewport

  protected void updateViewport(PropertyChangeEvent e)

• updateRowHeader

  protected void updateRowHeader(PropertyChangeEvent e)

• updateColumnHeader

  protected void updateColumnHeader(PropertyChangeEvent e)

• createPropertyChangeListener

  protected PropertyChangeListener createPropertyChangeListener()

  Creates an instance of PropertyChangeListener that's added to the JScrollPane by installUI(). Subclasses can override this method to return a custom PropertyChangeListener, e.g.

   class MyScrollPaneUI extends BasicScrollPaneUI {
      protected PropertyChangeListener createPropertyChangeListener() {
          return new MyPropertyChangeListener();
      }
      public class MyPropertyChangeListener extends PropertyChangeListener {
          public void propertyChange(PropertyChangeEvent e) {
              if (e.getPropertyName().equals("viewport")) {
                  // do some extra work when the viewport changes
              }
              super.propertyChange(e);
          }
      }
   }
   

  See Also:

  PropertyChangeListener, installUI(javax.swing.JComponent)