问题
I have a JPanel which contains a JToolbar (including few buttons without text) and a JTable and I need to enable/disable (make internal widgets not clickable). I tried this:
JPanel panel = ....;
for (Component c : panel.getComponents()) c.setEnabled(enabled);
but it doesn't work. Is there a better and more generic solution to enable/disable all internal components in a JPanel?
I have partially solved my problem using JLayer starting from the example here http://docs.oracle.com/javase/tutorial/uiswing/misc/jlayer.html:
layer = new JLayer<JComponent>(myPanel, new BlurLayerUI(false));
.....
((BlurLayerUI)layer.getUI()).blur(...); // switch blur on/off
class BlurLayerUI extends LayerUI<JComponent> {
private BufferedImage mOffscreenImage;
private BufferedImageOp mOperation;
private boolean blur;
public BlurLayerUI(boolean blur) {
this.blur = blur;
float ninth = 1.0f / 9.0f;
float[] blurKernel = {
ninth, ninth, ninth,
ninth, ninth, ninth,
ninth, ninth, ninth
};
mOperation = new ConvolveOp(
new Kernel(3, 3, blurKernel),
ConvolveOp.EDGE_NO_OP, null);
}
public void blur(boolean blur) {
this.blur=blur;
firePropertyChange("blur", 0, 1);
}
@Override
public void paint (Graphics g, JComponent c) {
if (!blur) {
super.paint (g, c);
return;
}
int w = c.getWidth();
int h = c.getHeight();
if (w == 0 || h == 0) {
return;
}
// Only create the offscreen image if the one we have
// is the wrong size.
if (mOffscreenImage == null ||
mOffscreenImage.getWidth() != w ||
mOffscreenImage.getHeight() != h) {
mOffscreenImage = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
}
Graphics2D ig2 = mOffscreenImage.createGraphics();
ig2.setClip(g.getClip());
super.paint(ig2, c);
ig2.dispose();
Graphics2D g2 = (Graphics2D)g;
g2.drawImage(mOffscreenImage, mOperation, 0, 0);
}
@Override
public void applyPropertyChange(PropertyChangeEvent pce, JLayer l) {
if ("blur".equals(pce.getPropertyName())) {
l.repaint();
}
}
}
I still have 2 problems:
In the link above events are relative to mouse only. How can I manage the keyboard events?
How can I create a "gray out" effect in place of blur?
回答1:
It requires a recursive call.
import java.awt.*;
import javax.swing.*;
public class DisableAllInContainer {
public void enableComponents(Container container, boolean enable) {
Component[] components = container.getComponents();
for (Component component : components) {
component.setEnabled(enable);
if (component instanceof Container) {
enableComponents((Container)component, enable);
}
}
}
DisableAllInContainer() {
JPanel gui = new JPanel(new BorderLayout());
final JPanel container = new JPanel(new BorderLayout());
gui.add(container, BorderLayout.CENTER);
JToolBar tb = new JToolBar();
container.add(tb, BorderLayout.NORTH);
for (int ii=0; ii<3; ii++) {
tb.add(new JButton("Button"));
}
JTree tree = new JTree();
tree.setVisibleRowCount(6);
container.add(new JScrollPane(tree), BorderLayout.WEST);
container.add(new JTextArea(5,20), BorderLayout.CENTER);
final JCheckBox enable = new JCheckBox("Enable", true);
enable.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent ae) {
enableComponents(container, enable.isSelected());
}
});
gui.add(enable, BorderLayout.SOUTH);
JOptionPane.showMessageDialog(null, gui);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
@Override
public void run() {
new DisableAllInContainer();
}
});
}}
回答2:
I used the following function:
void setPanelEnabled(JPanel panel, Boolean isEnabled) {
panel.setEnabled(isEnabled);
Component[] components = panel.getComponents();
for(int i = 0; i < components.length; i++) {
if(components[i].getClass().getName() == "javax.swing.JPanel") {
setPanelEnabled((JPanel) components[i], isEnabled);
}
components[i].setEnabled(isEnabled);
}
}
回答3:
you can overlay whole Container / JComponent
GlassPaneblock by default MouseEvents, but not Keyboard, required consume all keyevents from ToolKitJLayer(Java7) based onJXLayer(Java6)can't see reason(s) why not works for you
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
public class AddComponentsAtRuntime {
private JFrame f;
private JPanel panel;
private JCheckBox checkValidate, checkReValidate, checkRepaint, checkPack;
public AddComponentsAtRuntime() {
JButton b = new JButton();
//b.setBackground(Color.red);
b.setBorder(new LineBorder(Color.black, 2));
b.setPreferredSize(new Dimension(600, 20));
panel = new JPanel(new GridLayout(0, 1));
panel.add(b);
f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(panel, "Center");
f.add(getCheckBoxPanel(), "South");
f.setLocation(200, 200);
f.pack();
f.setVisible(true);
}
private JPanel getCheckBoxPanel() {
checkValidate = new JCheckBox("validate");
checkValidate.setSelected(false);
checkReValidate = new JCheckBox("revalidate");
checkReValidate.setSelected(true);
checkRepaint = new JCheckBox("repaint");
checkRepaint.setSelected(true);
checkPack = new JCheckBox("pack");
checkPack.setSelected(true);
JButton addComp = new JButton("Add New One");
addComp.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
JButton b = new JButton();
//b.setBackground(Color.red);
b.setBorder(new LineBorder(Color.black, 2));
b.setPreferredSize(new Dimension(400, 10));
panel.add(b);
makeChange();
System.out.println(" Components Count after Adds :" + panel.getComponentCount());
}
});
JButton removeComp = new JButton("Remove One");
removeComp.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
int count = panel.getComponentCount();
if (count > 0) {
panel.remove(0);
}
makeChange();
System.out.println(" Components Count after Removes :" + panel.getComponentCount());
}
});
JButton disabledComp = new JButton("Disabled All");
disabledComp.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
for (Component c : panel.getComponents()) {
c.setEnabled(false);
}
}
});
JButton enabledComp = new JButton("Enabled All");
enabledComp.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
for (Component c : panel.getComponents()) {
c.setEnabled(true);
}
}
});
JPanel panel2 = new JPanel();
panel2.add(checkValidate);
panel2.add(checkReValidate);
panel2.add(checkRepaint);
panel2.add(checkPack);
panel2.add(addComp);
panel2.add(removeComp);
panel2.add(disabledComp);
panel2.add(enabledComp);
return panel2;
}
private void makeChange() {
if (checkValidate.isSelected()) {
panel.validate();
}
if (checkReValidate.isSelected()) {
panel.revalidate();
}
if (checkRepaint.isSelected()) {
panel.repaint();
}
if (checkPack.isSelected()) {
f.pack();
}
}
public static void main(String[] args) {
AddComponentsAtRuntime makingChanges = new AddComponentsAtRuntime();
}
}
回答4:
@Kesavamoorthi if you want to make it more general:
void setPanelEnabled(java.awt.Container cont, Boolean isEnabled) {
cont.setEnabled(isEnabled);
java.awt.Component[] components = cont.getComponents();
for (int i = 0; i < components.length; i++) {
if (components[i] instanceof java.awt.Container) {
setPanelEnabled((java.awt.Container) components[i], isEnabled);
}
components[i].setEnabled(isEnabled);
}
}
来源：https://stackoverflow.com/questions/10985734/java-swing-enabling-disabling-all-components-in-jpanel