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CellRendererPane.javaAPI DocJava SE 5 API6243Fri Aug 26 14:57:54 BST 2005javax.swing

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 JavaBeansTM has been added to the java.beans package. Please see {@link java.beans.XMLEncoder}.

version
1.39 12/19/03
author
Hans Muller

Fields Summary
protected AccessibleContext
accessibleContext
Constructors Summary
public CellRendererPane()
Construct a CellRendererPane object.

	super();
	setLayout(null);
	setVisible(false);
Methods Summary
protected voidaddImpl(java.awt.Component x, java.lang.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).<

	if (x.getParent() == this) {
	    return;
	}
	else {
	    super.addImpl(x, constraints, index);
	}
public javax.accessibility.AccessibleContextgetAccessibleContext()
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.

return
an AccessibleCellRendererPane that serves as the AccessibleContext of this CellRendererPane


                                                         
       
	if (accessibleContext == null) {
	    accessibleContext = new AccessibleCellRendererPane();
	}
	return accessibleContext;
public voidinvalidate()
Overridden to avoid propagating a invalidate up the tree when the cell renderer child is configured.
public voidpaint(java.awt.Graphics g)
Shouldn't be called.
public voidpaintComponent(java.awt.Graphics g, java.awt.Component c, java.awt.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.

	if (c == null) {
	    if (p != null) {
		Color oldColor = g.getColor();
		g.setColor(p.getBackground());
		g.fillRect(x, y, w, h);
		g.setColor(oldColor);
	    }
	    return;
	}

	if (c.getParent() != this) {
	    this.add(c);
	}

	c.setBounds(x, y, w, h);

	if(shouldValidate) {
	    c.validate();
	}

	boolean wasDoubleBuffered = false;
	if ((c instanceof JComponent) && ((JComponent)c).isDoubleBuffered()) {
	    wasDoubleBuffered = true;
	    ((JComponent)c).setDoubleBuffered(false);
	}

	Graphics cg = g.create(x, y, w, h);
	try {
	    c.paint(cg);
	}
	finally {
	    cg.dispose();
	}

	if (wasDoubleBuffered && (c instanceof JComponent)) {
	    ((JComponent)c).setDoubleBuffered(true);
	}

	c.setBounds(-w, -h, 0, 0);
public voidpaintComponent(java.awt.Graphics g, java.awt.Component c, java.awt.Container p, int x, int y, int w, int h)
Calls this.paintComponent(g, c, p, x, y, w, h, false).

	paintComponent(g, c, p, x, y, w, h, false);
public voidpaintComponent(java.awt.Graphics g, java.awt.Component c, java.awt.Container p, java.awt.Rectangle r)
Calls this.paintComponent() with the rectangles x,y,width,height fields.

	paintComponent(g, c, p, r.x, r.y, r.width, r.height);
public voidupdate(java.awt.Graphics g)
Shouldn't be called.
private voidwriteObject(java.io.ObjectOutputStream s)

	removeAll();
	s.defaultWriteObject();