📅  最后修改于: 2022-03-11 14:52:05.015000             🧑  作者: Mango
public static class SafeIcon implements Icon {
private Icon wrappee;
private Icon standIn;
public SafeIcon(Icon wrappee) {
this.wrappee = wrappee;
}
@Override
public int getIconHeight() {
return wrappee.getIconHeight();
}
@Override
public int getIconWidth() {
return wrappee.getIconWidth();
}
@Override
public void paintIcon(Component c, Graphics g, int x, int y) {
if (standIn == this) {
paintFallback(c, g, x, y);
} else if (standIn != null) {
standIn.paintIcon(c, g, x, y);
} else {
try {
wrappee.paintIcon(c, g, x, y);
} catch (ClassCastException e) {
createStandIn(e, x, y);
standIn.paintIcon(c, g, x, y);
}
}
}
/**
* @param e
*/
private void createStandIn(ClassCastException e, int x, int y) {
try {
Class> clazz = getClass(e);
JComponent standInComponent = getSubstitute(clazz);
standIn = createImageIcon(standInComponent, x, y);
} catch (Exception e1) {
// something went wrong - fallback to this painting
standIn = this;
}
}
private Icon createImageIcon(JComponent standInComponent, int x, int y) {
BufferedImage image = new BufferedImage(getIconWidth(),
getIconHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics g = image.createGraphics();
try {
wrappee.paintIcon(standInComponent, g, 0, 0);
return new ImageIcon(image);
} finally {
g.dispose();
}
}
/**
* @param clazz
* @throws IllegalAccessException
*/
private JComponent getSubstitute(Class> clazz) throws IllegalAccessException {
JComponent standInComponent;
try {
standInComponent = (JComponent) clazz.newInstance();
} catch (InstantiationException e) {
standInComponent = new AbstractButton() {
};
((AbstractButton) standInComponent).setModel(new DefaultButtonModel());
}
return standInComponent;
}
private Class> getClass(ClassCastException e) throws ClassNotFoundException {
String className = e.getMessage();
className = className.substring(className.lastIndexOf(" ") + 1);
return Class.forName(className);
}
private void paintFallback(Component c, Graphics g, int x, int y) {
g.drawRect(x, y, getIconWidth(), getIconHeight());
g.drawLine(x, y, x + getIconWidth(), y + getIconHeight());
g.drawLine(x + getIconWidth(), y, x, y + getIconHeight());
}
}
////////////////////////////////////////////////////
To use :
icon = new SafeIcon(icon);
BufferedImage image = new BufferedImage(icon.getIconWidth(), icon.getIconHeight(), BufferedImage.TYPE_INT_RGB);
icon.paintIcon(new JPanel(), image.getGraphics(), 0, 0);