在trigerring setCursor方法后，游标图标不变 [英] Cursor icon does not change after trigerring setCursor method
问题描述
在我的应用程序中有一个 JTable ，具有可调整的标题列。通常，当我将光标移动到表格标题上进行调整大小时，光标图标会改变为调整大小箭头，如< - >。
。
在同一个 Frame 中有一个按钮操作，在执行操作时，忙图标，并在操作完成后使用 Container.setCurosr（Cursor cursor）方法将其更改回默认光标。
有时，如果我将光标移到调整大小的表头上，按钮操作后，光标图标不会更改为调整大小箭头，光标根本不会改变。
更新：附加的示例代码
p> import java.util。*;
import java.awt。*;
import javax.swing。*;
import java.awt.event。*;
public class ColumnResizeIconTest extends JFrame {
JScrollPane scrollPane;
JTable table;
JButton按钮;
public ColumnResizeIconTest（）{
setLayout（new BorderLayout（））;
addComponents（）;
setSize（300,300）;
}
private void addComponents（）{
addButton（）;
addTable（）;
}
private void addButton（）{
button = new JButton（Click Me）;
button.addActionListener（new ActionListener（）{
public void actionPerformed（ActionEvent ae）{
setWaitCursor（）;
for（int i = 0; i <2000; i ++） {
System.out.print（i）;
}
setDefaultCursor（）;
}
}）;
add（button，BorderLayout.NORTH）;
}
private void addTable（）{
scrollPane = new JScrollPane（createTable（））;
add（scrollPane，BorderLayout.CENTER）;
}
private JTable createTable（）{
Object [] [] cellData = {{1-1，1-2，1-3} ，{2-1，2-2，2-3}，{3-1，3-2，3-3}}
String [] columnNames = {column1，column2，column3};
table = new JTable（cellData，columnNames）;
return table;
}
private void setWaitCursor（）{
Container container = getContentPane（）;
setWaitCursor（container）;
}
private void setWaitCursor（Container container）{
for（int iCount = 0; iCount< container.getComponentCount（）; iCount ++）{
Component child =（Component）container.getComponent（iCount）;
if（child instanceof Container）{
setWaitCursor（（Container）child）;
} else {
child.setCursor（new Cursor（Cursor.WAIT_CURSOR））;
}
}
container.setCursor（new Cursor（Cursor.WAIT_CURSOR））;
}
private void setDefaultCursor（）{
Container container = getContentPane（）;
setDefaultCursor（container）;
}
private void setDefaultCursor（Container container）{
for（int iCount = 0; iCount< container.getComponentCount（）; iCount ++）{
Component child =（Component）container.getComponent（iCount）;
if（child instanceof Container）{
setDefaultCursor（（Container）child）;
} else {
child.setCursor（new Cursor（Cursor.DEFAULT_CURSOR））;
}
}
container.setCursor（new Cursor（Cursor.DEFAULT_CURSOR））;
}
public static void main（String [] argv）throws Exception {
ColumnResizeIconTest test = new ColumnResizeIconTest（）;
test.setVisible（true）;
}
}
点击按钮几次并尝试调整大小表列。光标停留在默认光标。
如我在注释中提到的：重新设置/游标，甚至不是单个组件:-)基本问题（在递归游标设置中等待）是假设所有组件都具有默认游标。
正如您在表头上看到的那样，该假设不正确：在该组件上，default是defaultCursor或resizeCursor，取决于鼠标位置。此外，内部光标切换不是很聪明：它不检查状态（从我的头顶部，被一个事实之前的事实 - ）
不完全确定你想要达到什么，所以没有一个具体的解决方案，除了完全删除递归设置，它是太难以正确。选项可能是
- 使glassPane（框架的根窗格）可见，并设置waitCursor
- 在较小的区域上使用JLayer（jdk7）或 JXLayer （jdk6），并在 上设置waitCursor >
- 使用较少侵入的可视化，fi JProgressBar或JXBusyLabel（ SwingX项目）
附录（对于@mKorbel： - ）
这个问题很容易重现， OPs SSCCE（感谢！）：改变addButton方法如下，然后点击按钮，当显示等待光标时，将鼠标移动到标题，然后到另一列（跨越列边框）。这样多次会导致在标题...上的不可预测的游标...
private void addButton（）{
button = new JButton（Click Me）;
final ActionListener off = new ActionListener（）{
@Override
public void actionPerformed（ActionEvent e）{
setDefaultCursor
button.setEnabled（true）;
}
};
button.addActionListener（new ActionListener（）{
public void actionPerformed（ActionEvent ae）{
setWaitCursor（）;
button.setEnabled（false）;
= new Timer（2000，off）;
timer.setRepeats（false）;
timer.start（）;
}
}）;
add（button，BorderLayout.NORTH）;
}
There is a JTable in my application with resizable header columns. Normally when I move the cursor over table header for resizing, the cursor icon changes to resize arrow, like <-->.
But things are different in the following scenario.
There is a button action in the same Frame, and during action performed, I am setting the cursor to busy icon and change it back to default cursor once the action is completed, using Container.setCurosr(Cursor cursor) method.
Sometimes if I move the cursor over table header of resizing, after a button action, the cursor icon does not change to resize arrow, cursor does not change at all.
Can this be considered as a bug in Java Swing or is there a solution for this issue?
Update : Sample code attached
import java.util.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class ColumnResizeIconTest extends JFrame {
JScrollPane scrollPane;
JTable table;
JButton button;
public ColumnResizeIconTest() {
setLayout(new BorderLayout());
addComponents();
setSize(300,300);
}
private void addComponents() {
addButton();
addTable();
}
private void addButton() {
button = new JButton("Click Me");
button.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent ae) {
setWaitCursor();
for(int i=0; i<2000; i++) {
System.out.print(i);
}
setDefaultCursor();
}
});
add(button, BorderLayout.NORTH);
}
private void addTable() {
scrollPane = new JScrollPane(createTable());
add(scrollPane, BorderLayout.CENTER);
}
private JTable createTable() {
Object[][] cellData = { { "1-1", "1-2","1-3" }, { "2-1", "2-2", "2-3" }, { "3-1", "3-2", "3-3" } };
String[] columnNames = { "column1", "column2", "column3" };
table = new JTable(cellData, columnNames);
return table;
}
private void setWaitCursor() {
Container container = getContentPane();
setWaitCursor(container);
}
private void setWaitCursor(Container container) {
for(int iCount = 0; iCount < container.getComponentCount(); iCount++) {
Component child = (Component) container.getComponent(iCount);
if(child instanceof Container) {
setWaitCursor((Container) child);
} else {
child.setCursor(new Cursor(Cursor.WAIT_CURSOR));
}
}
container.setCursor(new Cursor(Cursor.WAIT_CURSOR));
}
private void setDefaultCursor() {
Container container = getContentPane();
setDefaultCursor(container);
}
private void setDefaultCursor(Container container) {
for(int iCount = 0; iCount < container.getComponentCount(); iCount++) {
Component child = (Component) container.getComponent(iCount);
if(child instanceof Container) {
setDefaultCursor((Container) child);
} else {
child.setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
}
}
container.setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
}
public static void main(String[] argv) throws Exception {
ColumnResizeIconTest test = new ColumnResizeIconTest();
test.setVisible(true);
}
}
Click on the button a few times and try to resize the table column. The cursor is stuck with Default cursor.
As already mentioned in my comment: it's not entirely trivial to re-/set the cursors, not even for a single component :-) The base problem (in the recursive cursor setting to wait) is the assumption that all components do have the default cursor.
As you see on the table header, that assumption is not correct: on that component, the "default" is either the defaultCursor or the resizeCursor, depending on mouse location. Additionally, the internal cursor toggling is not very intelligent: it doesn't check for state (from the top of my head, was hit by that fact a while ago :-)
Not entirely sure what you want to reach, so don't have a concrete solution, except dropping the recursive setting entirely, it's too hard to get right. Options might be
- make the glassPane (of the frame's rootpane) visible and set the waitCursor on it
- use JLayer (jdk7) or JXLayer (jdk6) on a smaller area and set the waitCursor on that
- use a less intrusive visualization, f.i. JProgressBar or a JXBusyLabel (in the SwingX project) somewhere
Addendum (for @mKorbel :-)
the problem is easily reproducible, with a little change to the OPs SSCCE (thanks for that!): change the addButton method as below, then click on the button and while the wait cursor is shown, move the mouse into the header and then to another column (across the column border). Doing so several times will lead to unpredicable cursors on the header ...
private void addButton() {
button = new JButton("Click Me");
final ActionListener off = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
setDefaultCursor();
button.setEnabled(true);
}
};
button.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent ae) {
setWaitCursor();
button.setEnabled(false);
Timer timer = new Timer(2000, off);
timer.setRepeats(false);
timer.start();
}
});
add(button, BorderLayout.NORTH);
}
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