Module java.desktop
Package javax.swing.plaf.basic

Class BasicScrollPaneUI

    • Field Detail

      • scrollpane

        protected JScrollPane scrollpane
        The instance of JScrollPane.

      • vsbChangeListener

        protected ChangeListener vsbChangeListener
        ChangeListener installed on the vertical scrollbar.

      • hsbChangeListener

        protected ChangeListener hsbChangeListener
        ChangeListener installed on the horizontal scrollbar.

      • viewportChangeListener

        protected ChangeListener viewportChangeListener
        ChangeListener installed on the viewport.

      • spPropertyChangeListener

        protected PropertyChangeListener spPropertyChangeListener
        PropertyChangeListener installed on the scroll pane.

    • Constructor Detail

      • BasicScrollPaneUI

        public BasicScrollPaneUI​()

    • Method Detail

      • createUI

        public static ComponentUI createUI​(JComponent x)
        Returns a new instance of BasicScrollPaneUI.
        Parameters:
        x - a component.
        Returns:
        a new instance of BasicScrollPaneUI

      • 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)
        Installs default properties.
        Parameters:
        scrollpane - an instance of JScrollPane

      • installListeners

        protected void installListeners​(JScrollPane c)
        Registers listeners.
        Parameters:
        c - an instance of JScrollPane

      • installKeyboardActions

        protected void installKeyboardActions​(JScrollPane c)
        Registers keyboard actions.
        Parameters:
        c - an instance of JScrollPane

      • 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)
        Uninstalls default properties.
        Parameters:
        c - an instance of JScrollPane

      • uninstallListeners

        protected void uninstallListeners​(JComponent c)
        Unregisters listeners.
        Parameters:
        c - a component

      • uninstallKeyboardActions

        protected void uninstallKeyboardActions​(JScrollPane c)
        Unregisters keyboard actions.
        Parameters:
        c - an instance of JScrollPane

      • 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​()
        Synchronizes the JScrollPane with Viewport.

      • createViewportChangeListener

        protected ChangeListener createViewportChangeListener​()
        Returns an instance of viewport ChangeListener.
        Returns:
        an instance of viewport ChangeListener

      • createHSBChangeListener

        protected ChangeListener createHSBChangeListener​()
        Returns an instance of horizontal scroll bar ChangeListener.
        Returns:
        an instance of horizontal scroll bar ChangeListener

      • createVSBChangeListener

        protected ChangeListener createVSBChangeListener​()
        Returns an instance of vertical scroll bar ChangeListener.
        Returns:
        an instance of vertical scroll bar ChangeListener

      • updateScrollBarDisplayPolicy

        protected void updateScrollBarDisplayPolicy​(PropertyChangeEvent e)
        Updates a scroll bar display policy.
        Parameters:
        e - the property change event

      • updateViewport

        protected void updateViewport​(PropertyChangeEvent e)
        Updates viewport.
        Parameters:
        e - the property change event

      • updateRowHeader

        protected void updateRowHeader​(PropertyChangeEvent e)
        Updates row header.
        Parameters:
        e - the property change event

      • updateColumnHeader

        protected void updateColumnHeader​(PropertyChangeEvent e)
        Updates column header.
        Parameters:
        e - the property change event

      • 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);
        }
    }
 }
        Returns:
        an instance of PropertyChangeListener
        See Also:
        PropertyChangeListener, installUI(javax.swing.JComponent)