Class CellRendererPane

public class CellRendererPane
extends Container
implements Accessible

This class is inserted in between cell renderers and the components that use them. It just exists to thwart the repaint() and invalidate() methods which would otherwise propagate up the tree when the renderer was configured. It's used by the implementations of JTable, JTree, and JList. For example, here's how CellRendererPane is used in the code the paints each row in a JList:

cellRendererPane = new CellRendererPane();
   ...
   Component rendererComponent = renderer.getListCellRendererComponent();
   renderer.configureListCellRenderer(dataModel.getElementAt(row), row);
   cellRendererPane.paintComponent(g, rendererComponent, this, x, y, w, h);

A renderer component must override isShowing() and unconditionally return true to work correctly because the Swing paint does nothing for components with isShowing false.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans™ has been added to the java.beans package. Please see XMLEncoder.

Fields

accessibleContext

protected AccessibleContext accessibleContext

Constructors

CellRendererPane

public CellRendererPane()

Construct a CellRendererPane object.

Methods

invalidate

public void invalidate()

Overridden to avoid propagating a invalidate up the tree when the cell renderer child is configured.

Overrides:

invalidate in class Container

See Also:

Container.validate(), Container.layout(), LayoutManager2

paint

public void paint(Graphics g)

Shouldn't be called.

Overrides:

paint in class Container

Parameters:

g - the specified Graphics window

See Also:

Component.update(Graphics)

update

public void update(Graphics g)

Shouldn't be called.

Overrides:

update in class Container

Parameters:

g - the specified Graphics window

See Also:

Component.update(Graphics)

addImpl

protected void addImpl(Component x,
                       Object constraints,
                       int index)

If the specified component is already a child of this then we don't bother doing anything - stacking order doesn't matter for cell renderer components (CellRendererPane doesn't paint anyway).

Overrides:

addImpl in class Container

Parameters:

x - the component to be added

constraints - an object expressing layout constraints for this component

index - the position in the container's list at which to insert the component, where -1 means append to the end

See Also:

Container.add(Component), Container.add(Component, int), Container.add(Component, java.lang.Object), Container.invalidate(), LayoutManager, LayoutManager2

paintComponent

public void paintComponent(Graphics g,
                           Component c,
                           Container p,
                           int x,
                           int y,
                           int w,
                           int h,
                           boolean shouldValidate)

Paint a cell renderer component c on graphics object g. Before the component is drawn it's reparented to this (if that's necessary), it's bounds are set to w,h and the graphics object is (effectively) translated to x,y. If it's a JComponent, double buffering is temporarily turned off. After the component is painted it's bounds are reset to -w, -h, 0, 0 so that, if it's the last renderer component painted, it will not start consuming input. The Container p is the component we're actually drawing on, typically it's equal to this.getParent(). If shouldValidate is true the component c will be validated before painted.

paintComponent

public void paintComponent(Graphics g,
                           Component c,
                           Container p,
                           int x,
                           int y,
                           int w,
                           int h)

Calls this.paintComponent(g, c, p, x, y, w, h, false).

paintComponent

public void paintComponent(Graphics g,
                           Component c,
                           Container p,
                           Rectangle r)

Calls this.paintComponent() with the rectangles x,y,width,height fields.

getAccessibleContext

public AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this CellRendererPane. For CellRendererPanes, the AccessibleContext takes the form of an AccessibleCellRendererPane. A new AccessibleCellRendererPane instance is created if necessary.

Specified by:

getAccessibleContext in interface Accessible

Overrides:

getAccessibleContext in class Component

Returns:

an AccessibleCellRendererPane that serves as the AccessibleContext of this CellRendererPane