* 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}.
*
* @author Hans Muller
*/
public class CellRendererPane extends Container implements Accessible
{
/**
* Construct a CellRendererPane object.
*/
public CellRendererPane() {
super();
setLayout(null);
setVisible(false);
}
/**
* Overridden to avoid propagating a invalidate up the tree when the
* cell renderer child is configured.
*/
public void invalidate() { }
/**
* Shouldn't be called.
*/
public void paint(Graphics g) { }
/**
* Shouldn't be called.
*/
public void update(Graphics g) { }
/**
* 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).<
*/
protected void addImpl(Component x, Object constraints, int index) {
if (x.getParent() == this) {
return;
}
else {
super.addImpl(x, constraints, index);
}
}
/**
* 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.
*/
public void paintComponent(Graphics g, Component c, Container p, int x, int y, int w, int h, boolean shouldValidate) {
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);
}
/**
* Calls this.paintComponent(g, c, p, x, y, w, h, false).
*/
public void paintComponent(Graphics g, Component c, Container p, int x, int y, int w, int h) {
paintComponent(g, c, p, x, y, w, h, false);
}
/**
* Calls this.paintComponent() with the rectangles x,y,width,height fields.
*/
public void paintComponent(Graphics g, Component c, Container p, Rectangle r) {
paintComponent(g, c, p, r.x, r.y, r.width, r.height);
}
private void writeObject(ObjectOutputStream s) throws IOException {
removeAll();
s.defaultWriteObject();
}
/////////////////
// Accessibility support
////////////////
protected AccessibleContext accessibleContext = null;
/**
* 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
*/
public AccessibleContext getAccessibleContext() {
if (accessibleContext == null) {
accessibleContext = new AccessibleCellRendererPane();
}
return accessibleContext;
}
/**
* This class implements accessibility support for the
* CellRendererPane class.
*/
protected class AccessibleCellRendererPane extends AccessibleAWTContainer {
// AccessibleContext methods
//
/**
* Get the role of this object.
*
* @return an instance of AccessibleRole describing the role of the
* object
* @see AccessibleRole
*/
public AccessibleRole getAccessibleRole() {
return AccessibleRole.PANEL;
}
} // inner class AccessibleCellRendererPane
}