问题
I am having issues displaying a wait cursor in my application. Whenever the mouse is above a panel that defines its own cursor, the wait cursor does not appear. If a panel does not change the cursor, the wait cursor appears.
I am attaching a SSCE to accurately explain my problem.
public class BusyCursorTest extends javax.swing.JFrame {
public BusyCursorTest() {
javax.swing.JMenuBar menuBar = new javax.swing.JMenuBar();
javax.swing.JMenu menu = new javax.swing.JMenu(\"Menu\");
javax.swing.JMenuItem wait1 = new javax.swing.JMenuItem(\"Wait 100 ms\");
javax.swing.JMenuItem wait2 = new javax.swing.JMenuItem(\"Wait 250 ms\");
javax.swing.JMenuItem wait3 = new javax.swing.JMenuItem(\"Wait 500 ms\");
javax.swing.JMenuItem wait4 = new javax.swing.JMenuItem(\"Wait 1000 ms\");
menu.add(wait1);
menu.add(wait2);
menu.add(wait3);
menu.add(wait4);
menuBar.add(menu);
setJMenuBar(menuBar);
wait1.addActionListener(getActionListener(this, delayActionListener(100)));
wait2.addActionListener(getActionListener(this, delayActionListener(250)));
wait3.addActionListener(getActionListener(this, delayActionListener(500)));
wait4.addActionListener(getActionListener(this, delayActionListener(1000)));
cursorPanel = new javax.swing.JPanel();
cursorPanel.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseEntered(java.awt.event.MouseEvent e) {
cursorPanel.setCursor(java.awt.Cursor.getPredefinedCursor(java.awt.Cursor.CROSSHAIR_CURSOR));
}
public void mouseExited(java.awt.event.MouseEvent e) {
cursorPanel.setCursor(java.awt.Cursor.getPredefinedCursor(java.awt.Cursor.DEFAULT_CURSOR));
}
});
javax.swing.JTabbedPane tabbedPane = new javax.swing.JTabbedPane();
tabbedPane.addTab(\"Default\", new javax.swing.JPanel());
tabbedPane.addTab(\"Cursor change\", cursorPanel);
getContentPane().add(tabbedPane);
setTitle(\"Cursor test\");
setSize(400, 400);
setDefaultCloseOperation(javax.swing.JFrame.DISPOSE_ON_CLOSE);
setVisible(true);
}
private java.awt.event.ActionListener delayActionListener(final int delay) {
java.awt.event.ActionListener listener = new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent ae) {
try {
Thread.sleep(delay);
} catch (InterruptedException e) {
}
}
};
return listener;
}
public static void main(String[] args) {
new BusyCursorTest();
}
public static java.awt.event.ActionListener getActionListener(final java.awt.Component component,
final java.awt.event.ActionListener originalActionListener) {
java.awt.event.ActionListener actionListener = new java.awt.event.ActionListener() {
public void actionPerformed(final java.awt.event.ActionEvent e) {
java.util.TimerTask timerTask = new java.util.TimerTask() {
public void run() {
originalCursor = component.getCursor();
component.setCursor(java.awt.Cursor.getPredefinedCursor(java.awt.Cursor.WAIT_CURSOR));
}
};
java.util.Timer timer = new java.util.Timer();
try {
timer.schedule(timerTask, DELAY_MS);
originalActionListener.actionPerformed(e);
} finally {
timer.cancel();
component.setCursor(originalCursor);
}
}
};
return actionListener;
}
private javax.swing.JPanel cursorPanel = null;
public static java.awt.Cursor originalCursor = null;
public static final int DELAY_MS = 250;
}
Run the attached SSCE.
When the first tab (\"Default\") is selected, clicking on the 1000ms menu item will show the busy cursor.
When the second tab (\"Cursor change\") is selected, clicking on the 1000ms menu item does not show the busy cursor.
How should I remedy this problem?
I would strongly prefer that my code do not have to take into account any of the panels, as it is immensely difficult for me keep track of which panels may be at the forefront. Also, the events are not always generated due to a mouse click.
What is the recommended workaround so that I can modify the behavior at the top-level container?
回答1:
After searching the internet, I found the answer to my question.
The key is to set the cursor on the glasspane of the frame that contains the component which wants to display a busy cursor. I got the idea from the following articles on the net.
Wait, Cursor, Wait!
An Automatic Wait Cursor: WaitCursorEventQueue
I modified my SSCE to make it work for the case when components inside the frame set their own cursor. Here is the modified SSCE.
public class BusyCursorTest extends javax.swing.JFrame {
private javax.swing.JPanel cursorPanel = null;
public BusyCursorTest() {
javax.swing.JMenuBar menuBar = new javax.swing.JMenuBar();
javax.swing.JMenu menu = new javax.swing.JMenu("Menu");
javax.swing.JMenuItem wait1 = new javax.swing.JMenuItem("Wait 100 ms");
javax.swing.JMenuItem wait2 = new javax.swing.JMenuItem("Wait 250 ms");
javax.swing.JMenuItem wait3 = new javax.swing.JMenuItem("Wait 500 ms");
javax.swing.JMenuItem wait4 = new javax.swing.JMenuItem("Wait 1000 ms");
menu.add(wait1);
menu.add(wait2);
menu.add(wait3);
menu.add(wait4);
menuBar.add(menu);
setJMenuBar(menuBar);
wait1.addActionListener(getActionListener(this, delayActionListener(100)));
wait2.addActionListener(getActionListener(this, delayActionListener(250)));
wait3.addActionListener(getActionListener(this, delayActionListener(500)));
wait4.addActionListener(getActionListener(this, delayActionListener(1000)));
cursorPanel = new javax.swing.JPanel();
cursorPanel.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseEntered(java.awt.event.MouseEvent e) {
cursorPanel.setCursor(java.awt.Cursor.getPredefinedCursor(java.awt.Cursor.CROSSHAIR_CURSOR));
}
public void mouseExited(java.awt.event.MouseEvent e) {
cursorPanel.setCursor(java.awt.Cursor.getPredefinedCursor(java.awt.Cursor.DEFAULT_CURSOR));
}
});
javax.swing.JTabbedPane tabbedPane = new javax.swing.JTabbedPane();
tabbedPane.addTab("Default", new javax.swing.JPanel());
tabbedPane.addTab("Cursor change", cursorPanel);
getContentPane().add(tabbedPane);
setTitle("Cursor test");
setSize(400, 400);
setDefaultCloseOperation(javax.swing.JFrame.DISPOSE_ON_CLOSE);
setVisible(true);
}
private java.awt.event.ActionListener delayActionListener(final int delay) {
java.awt.event.ActionListener listener = new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent ae) {
try {
Thread.sleep(delay);
} catch (InterruptedException e) {
}
}
};
return listener;
}
public static void main(String[] args) {
new BusyCursorTest();
}
public static java.awt.event.ActionListener getActionListener(final javax.swing.JFrame frame,
final java.awt.event.ActionListener originalActionListener) {
java.awt.event.ActionListener actionListener = new java.awt.event.ActionListener() {
public void actionPerformed(final java.awt.event.ActionEvent e) {
java.util.TimerTask timerTask = new java.util.TimerTask() {
public void run() {
originalCursor = frame.getCursor();
startWaitCursor(frame);
}
};
java.util.Timer timer = new java.util.Timer();
try {
timer.schedule(timerTask, DELAY_MS);
originalActionListener.actionPerformed(e);
} finally {
timer.cancel();
stopWaitCursor(frame);
}
}
};
return actionListener;
}
private static void startWaitCursor(javax.swing.JFrame frame) {
frame.getGlassPane().setCursor(java.awt.Cursor.getPredefinedCursor(java.awt.Cursor.WAIT_CURSOR));
frame.getGlassPane().addMouseListener(mouseAdapter);
frame.getGlassPane().setVisible(true);
}
private static void stopWaitCursor(javax.swing.JFrame frame) {
frame.getGlassPane().setCursor(originalCursor);
frame.getGlassPane().removeMouseListener(mouseAdapter);
frame.getGlassPane().setVisible(false);
}
private static java.awt.Cursor originalCursor = null;
private static final java.awt.event.MouseAdapter mouseAdapter = new java.awt.event.MouseAdapter() {
};
public static final int DELAY_MS = 250;
}
回答2:
import java.awt.*;
import java.awt.event.*;
import java.text.SimpleDateFormat;
import java.util.Random;
import javax.swing.*;
import javax.swing.UIManager.LookAndFeelInfo;
import javax.swing.table.*;
public class TableWithTimer implements ActionListener, Runnable {
private static final long serialVersionUID = 1L;
private JFrame frame = new JFrame();
private JScrollPane scroll = new JScrollPane();
private JTable myTable;
private JPanel buttonPanel = new JPanel();
private JButton startButton = new JButton("Start Thread to Update Table");
private JButton stopButton = new JButton("Stop Thread for Update Table");
private JButton newButton = new JButton("Load new Data to Table");
private int count = 0;
private int delay = 3;
private javax.swing.Timer timer = null;
private boolean runProcess;
private int row = 0;
private int column = 0;
private String value = "Amnd";
private int amndValue = 0;
private String valueAt = "";
private SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
private String[] head = {"One", "Two", "Three", "Four", "Five", "Six"};
private String[][] data = new String[25][6];
public TableWithTimer() {
myTable = new TableBackroundPaint0(data, head);
myTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
myTable.setGridColor(Color.gray);
myTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
final TableCellRenderer cellRendener = myTable.getTableHeader().getDefaultRenderer();
myTable.getTableHeader().setDefaultRenderer(new TableCellRenderer() {
@Override
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus, int row, int column) {
JLabel label = (JLabel) cellRendener.getTableCellRendererComponent(
table, value, isSelected, hasFocus, row, column);
label.setBackground(Color.orange);
label.setForeground(Color.darkGray);
label.setFont(new Font("SansSerif", Font.BOLD, 12));
label.setBorder(BorderFactory.createCompoundBorder(label.getBorder(),
BorderFactory.createEmptyBorder(0, 5, 0, 0)));
label.setHorizontalAlignment(SwingConstants.LEFT);
label.setHorizontalAlignment(SwingConstants.CENTER);
if ((label.getText().equals("First")) || (label.getText().equals("Second"))) {
label.setForeground(Color.red);
}
if ((label.getText().equals("Day")) || (label.getText().equals("Month")) || (label.getText().equals("Year"))) {
label.setForeground(Color.blue);
}
if ((label.getText().equals("Time"))) {
label.setForeground(Color.green);
}
return label;
}
});
TableColumnModel cm = myTable.getColumnModel();
for (int column1 = 0; column1 < cm.getColumnCount(); column1++) {
TableColumn colLeft1 = cm.getColumn(column1);
cm.getColumn(column1).setWidth(140);
cm.getColumn(column1).setPreferredWidth(140);
}
//myTable.setFillsViewportHeight(true); // apply paintComponent for whole Viewport
JButton cornerButtonTop = new JButton();
cornerButtonTop.setBackground(scroll.getViewport().getBackground());
JButton cornerButtonBottom = new JButton();
cornerButtonBottom.setOpaque(false);
scroll.setCorner(JScrollPane.UPPER_RIGHT_CORNER, cornerButtonTop);
scroll.setCorner(JScrollPane.LOWER_RIGHT_CORNER, cornerButtonBottom);
scroll.setViewportView(myTable);
scroll.setMinimumSize(new Dimension(600, 400));
scroll.setMaximumSize(new Dimension(900, 600));
scroll.setPreferredSize(new Dimension(850, 430));
frame.add(scroll, BorderLayout.CENTER);
buttonPanel.setLayout(new GridLayout(1, 4, 10, 10));
startButton.addActionListener(this);
startButton.setEnabled(false);
stopButton.addActionListener(this);
stopButton.setEnabled(false);
JButton hideButton = new JButton();
newButton.addActionListener(this);
newButton.setEnabled(false);
buttonPanel.add(startButton);
buttonPanel.add(stopButton);
buttonPanel.add(hideButton);
buttonPanel.add(newButton);
hideButton.setVisible(false);
frame.add(buttonPanel, BorderLayout.SOUTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocation(100, 100);
frame.pack();
frame.setVisible(true);
start();
}
@Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == startButton) {
runProcess = true;
new Thread(this).start();
myTable.requestFocus();
startButton.setEnabled(false);
stopButton.setEnabled(true);
} else if (e.getSource() == stopButton) {
scroll.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
runProcess = false;
startButton.setEnabled(true);
stopButton.setEnabled(false);
newButton.setEnabled(true);
} else if (e.getSource() == newButton) {
runProcess = false;
startButton.setEnabled(true);
stopButton.setEnabled(false);
newButton.setEnabled(false);
addNewData();
}
}
public void addNewData() {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
TableModel model = myTable.getModel();
for (int j = 0; j < model.getRowCount(); j++) {
int column = model.getColumnCount();
for (int i = 0; i < column; i++) {
model.setValueAt("Deleted", j, i);
}
}
startNewData();
}
});
}
private void start() {
scroll.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
timer = new javax.swing.Timer(delay * 100, updateCol());
timer.start();
}
private void startNewData() {
scroll.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
count = 0;
timer = new javax.swing.Timer(1500, updateCol());
timer.start();
}
@Override
public void run() {
scroll.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
count = 0;
Random random = new Random();
while (runProcess) {
row = random.nextInt(myTable.getRowCount());
column = random.nextInt(myTable.getColumnCount());
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
try {
amndValue++;
valueAt = ((myTable.getValueAt(row, column)).toString());
if (!(valueAt.startsWith("A"))) {
count++;
if (count == ((25 * 6))) {
JOptionPane.showMessageDialog(myTable, " Update done ");
scroll.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
runProcess = false;
}
java.util.Date date = new java.util.Date();
String dateTime = sdf.format(date.getTime());
myTable.setValueAt((value + " " + String.valueOf(amndValue) + " at: " + dateTime), row, column);
//myTable.setValueAt(new Integer(1), row, column); // please uncoment for generate misstype error on EDT
myTable.changeSelection(row, column, false, false);
System.out.println("update cycle with value :"
+ (value + " " + String.valueOf(amndValue) + " at: " + dateTime) + ", table row :" + row
+ ", table column " + column);
}
} catch (Exception e) {
runProcess = false;
System.out.println("Error for update JTable cell");
e.printStackTrace();
}
}
});
try {
Thread.sleep(500);
} catch (Exception e) {
e.printStackTrace();
}
}
}
public Action updateCol() {
return new AbstractAction("text load action") {
private static final long serialVersionUID = 1L;
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("updating row " + (count + 1));
TableModel model = myTable.getModel();
int cols = model.getColumnCount();
int row = 0;
for (int j = 0; j < cols; j++) {
row = count;
myTable.changeSelection(row, 0, false, false);
timer.setDelay(200);
Object value = "row " + (count + 1) + " item " + (j + 1);
model.setValueAt(value, count, j);
}
count++;
if (count >= myTable.getRowCount()) {
myTable.changeSelection(0, 0, false, false);
timer.stop();
System.out.println("update cycle completed");
myTable.clearSelection();
startButton.setEnabled(true);
newButton.setEnabled(true);
scroll.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
}
};
}
public static void main(String args[]) {
try {
for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
System.out.println(info.getName());
if ("Nimbus".equals(info.getName())) {
UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (UnsupportedLookAndFeelException e) {
// handle exception
} catch (ClassNotFoundException e) {
// handle exception
} catch (InstantiationException e) {
// handle exception
} catch (IllegalAccessException e) {
// handle exception
}
TableWithTimer tableWithTimer = new TableWithTimer();
}
}
class TableBackroundPaint0 extends JTable {
private static final long serialVersionUID = 1L;
TableBackroundPaint0(Object[][] data, Object[] head) {
super(data, head);
setOpaque(false);
((JComponent) getDefaultRenderer(Object.class)).setOpaque(false);
}
@Override
public void paintComponent(Graphics g) {
Color background = new Color(168, 210, 241);
Color controlColor = new Color(230, 240, 230);
int width = getWidth();
int height = getHeight();
Graphics2D g2 = (Graphics2D) g;
Paint oldPaint = g2.getPaint();
g2.setPaint(new GradientPaint(0, 0, background, width, 0, controlColor));
g2.fillRect(0, 0, width, height);
g2.setPaint(oldPaint);
for (int row : getSelectedRows()) {
Rectangle start = getCellRect(row, 0, true);
Rectangle end = getCellRect(row, getColumnCount() - 1, true);
g2.setPaint(new GradientPaint(start.x, 0, controlColor, (int) ((end.x + end.width - start.x) * 1.25), 0, Color.orange));
g2.fillRect(start.x, start.y, end.x + end.width - start.x, start.height);
}
super.paintComponent(g);
}
}
回答3:
hmmm you code have problem with Concurency in Swing there are two areas
replace Thread.sleep(delay); and java.util.Timer with java.swing.Timer because block EDT
but in other hands there is way how to purposely block EDT (by splungebob from OTN) NOTE: this example against all Swing rulles, and works just in this form and as the example
import java.awt.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
public class DelayedComboBoxDemo implements Runnable {
private JCheckBox chkA = new JCheckBox("A");
private JCheckBox chkB = new JCheckBox("B");
private JCheckBox chkC = new JCheckBox("C");
private JComboBox cboItems = new JComboBox();
private JFrame frame;
public static void main(String[] args) {
SwingUtilities.invokeLater(new DelayedComboBoxDemo());
}
@Override
public void run() {
cboItems.addItem("-");
JPanel p = new JPanel();
p.add(chkA);
p.add(chkB);
p.add(chkC);
p.add(cboItems);
frame = new JFrame("Delayed ComboBox Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(p);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
cboItems.addPopupMenuListener(new PopupMenuListener() {
@Override
public void popupMenuCanceled(PopupMenuEvent e) {
}
@Override
public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
}
@Override
public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
int items = cboItems.getItemCount();
rebuildList();
if (items != cboItems.getItemCount()) {
cboItems.hidePopup();
cboItems.showPopup();
}
}
});
}
private void rebuildList() {
frame.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
Vector<String> items = new Vector<String>();
if (chkA.isSelected()) {
items.add("A");
} else if (chkB.isSelected()) {
items.add("B");
} else if (chkC.isSelected()) {
items.add("C");
} else {
items.add("-");
}
cboItems.setModel(new DefaultComboBoxModel(items));
try {
Thread.sleep(3000); // simulate a long transaction
} catch (InterruptedException ex) {
}
frame.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
}
回答4:
Try setting it on the frame instead of a given component
来源：https://stackoverflow.com/questions/6051755/java-wait-cursor-display-problem