我正在使用此实现来创建我的JTree：
https://github.com/imagej/imagej/blob/ee3c360949/ui/swing/util/src/test/java/imagej/util/swing/tree/CheckBoxTreeSample.java
我试图寻找一种在CheckBoxNodeEditor中创建ItemListener的正确方法，然后自己尝试了一些方法，但目前还无法正常工作。我已经为JTree和TreeSelectionListener实现了MouseListener，所以我需要这个itemlistener吗？现在，我的应用程序无需itemlistener，但恐怕以后会用到它。
Kleopatra已经在这篇文章中指出了原始代码的一些错误。另外，克娄巴特拉说动作监听器可以解决问题，所以也许我应该检查一下？ ：
Multiple ITEM_STATE_CHANGED events from jcheckbox in jtree
该论坛中hardwired的帖子有助于为编辑器添加一个以上的侦听器：http://www.java-forums.org/awt-swing/10389-jcheckboxes-jtree-nodes.html
因此，使用hardwire的方法，我可以决定只向面板添加一个侦听器，但是由于每次单击JTree时都会创建一个新的侦听器，因此它仍会引发很多事件？
这是CheckBoxNodeEditor的原始代码（减去节省空间和其他相关类的方法）。如果您同意，我将从此方法的侦听器中删除，而改用我创建的两个侦听器（TreeSelection和MouseListener）：
class CheckBoxNodeEditor extends AbstractCellEditor implements TreeCellEditor {
CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();
public static int clickCount = 0;
ChangeEvent changeEvent = null;
JTree tree;
public CheckBoxNodeEditor(JTree tree) {
this.tree = tree;
}
public Object getCellEditorValue() {
...
}
public Component getTreeCellEditorComponent(JTree tree, Object value,
boolean selected, boolean expanded, boolean leaf, int row) {
System.out.println("getTreeCellEditorComponent method called!");
System.out.println(String.valueOf(clickCount++));
Component editor = renderer.getTreeCellRendererComponent(tree, value,
true, expanded, leaf, row, true);
// editor always selected / focused
ItemListener itemListener = new ItemListener() {
public void itemStateChanged(ItemEvent itemEvent) {
接下来我实际删除的三行：
JCheckBox item = (JCheckBox)itemEvent.getItem();
System.out.println(itemEvent.paramString());
System.out.println("item "+item.getText()+" state Changed!");
if (stopCellEditing()) {
fireEditingStopped();
}
}
};
if (editor instanceof JCheckBox) {
((JCheckBox) editor).addItemListener(itemListener);
}
return editor;
}
}
好的，我看到ItemListener可以控制复选框。因此，实际上每个复选框都分配有自己的侦听器。如何为所有复选框/节点添加一个？
最佳答案
放在一起，toString可以覆盖DefaultXxxXxx中针对non_Vector数组类型的一些方法，可以删除
import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseEvent;
import java.util.EventObject;
import java.util.Vector;
import javax.swing.AbstractCellEditor;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.UIManager;
import javax.swing.event.ChangeEvent;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;
public class JCheckBoxJTreeEditor {
private JFrame frame = new JFrame("CheckBox Tree");
public JCheckBoxJTreeEditor() {
CheckBoxNode accessibilityOptions[] = {
new CheckBoxNode(
"Move system caret with focus/selection changes", false),
new CheckBoxNode("Always expand alt text for images", true)};
CheckBoxNode browsingOptions[] = {
new CheckBoxNode("Notify when downloads complete", true),
new CheckBoxNode("Disable script debugging", true),
new CheckBoxNode("Use AutoComplete", true),
new CheckBoxNode("Browse in a new process", false)};
Vector accessVector = new NamedVector("Accessibility", accessibilityOptions);
Vector browseVector = new NamedVector("Browsing", browsingOptions);
Object rootNodes[] = {accessVector, browseVector};
Vector rootVector = new NamedVector("Root", rootNodes);
JTree tree = new JTree(rootVector);
CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();
tree.setCellRenderer(renderer);
tree.setCellEditor(new CheckBoxNodeEditor(tree));
tree.setEditable(true);
JScrollPane scrollPane = new JScrollPane(tree);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(scrollPane);
frame.setSize(400, 250);
frame.setVisible(true);
}
public static void main(String args[]) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new JCheckBoxJTreeEditor();
}
});
}
}
class CheckBoxNodeRenderer implements TreeCellRenderer {
private JCheckBox leafRenderer = new JCheckBox();
private DefaultTreeCellRenderer nonLeafRenderer = new DefaultTreeCellRenderer();
private Color selectionBorderColor, selectionForeground, selectionBackground,
textForeground, textBackground;
protected JCheckBox getLeafRenderer() {
return leafRenderer;
}
public CheckBoxNodeRenderer() {
Font fontValue;
fontValue = UIManager.getFont("Tree.font");
if (fontValue != null) {
leafRenderer.setFont(fontValue);
}
Boolean booleanValue = (Boolean) UIManager.get("Tree.drawsFocusBorderAroundIcon");
leafRenderer.setFocusPainted((booleanValue != null) && (booleanValue.booleanValue()));
selectionBorderColor = UIManager.getColor("Tree.selectionBorderColor");
selectionForeground = UIManager.getColor("Tree.selectionForeground");
selectionBackground = UIManager.getColor("Tree.selectionBackground");
textForeground = UIManager.getColor("Tree.textForeground");
textBackground = UIManager.getColor("Tree.textBackground");
}
@Override
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected,
boolean expanded, boolean leaf, int row, boolean hasFocus) {
Component returnValue;
if (leaf) {
String stringValue = tree.convertValueToText(value, selected, expanded,
leaf, row, false);
leafRenderer.setText(stringValue);
leafRenderer.setSelected(false);
leafRenderer.setEnabled(tree.isEnabled());
if (selected) {
leafRenderer.setForeground(selectionForeground);
leafRenderer.setBackground(selectionBackground);
} else {
leafRenderer.setForeground(textForeground);
leafRenderer.setBackground(textBackground);
}
if ((value != null) && (value instanceof DefaultMutableTreeNode)) {
Object userObject = ((DefaultMutableTreeNode) value).getUserObject();
if (userObject instanceof CheckBoxNode) {
CheckBoxNode node = (CheckBoxNode) userObject;
leafRenderer.setText(node.getText());
leafRenderer.setSelected(node.isSelected());
}
}
returnValue = leafRenderer;
} else {
returnValue = nonLeafRenderer.getTreeCellRendererComponent(tree, value,
selected, expanded, leaf, row, hasFocus);
}
return returnValue;
}
}
class CheckBoxNodeEditor extends AbstractCellEditor implements TreeCellEditor {
private CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();
private ChangeEvent changeEvent = null;
private JTree tree;
public CheckBoxNodeEditor(JTree tree) {
this.tree = tree;
}
@Override
public Object getCellEditorValue() {
JCheckBox checkbox = renderer.getLeafRenderer();
CheckBoxNode checkBoxNode = new CheckBoxNode(checkbox.getText(), checkbox.isSelected());
return checkBoxNode;
}
@Override
public boolean isCellEditable(EventObject event) {
boolean returnValue = false;
if (event instanceof MouseEvent) {
MouseEvent mouseEvent = (MouseEvent) event;
TreePath path = tree.getPathForLocation(mouseEvent.getX(),
mouseEvent.getY());
if (path != null) {
Object node = path.getLastPathComponent();
if ((node != null) && (node instanceof DefaultMutableTreeNode)) {
DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode) node;
Object userObject = treeNode.getUserObject();
returnValue = ((treeNode.isLeaf()) && (userObject instanceof CheckBoxNode));
}
}
}
return returnValue;
}
@Override
public Component getTreeCellEditorComponent(JTree tree, Object value, boolean selected,
boolean expanded, boolean leaf, int row) {
Component editor = renderer.getTreeCellRendererComponent(tree, value, true,
expanded, leaf, row, true);
ItemListener itemListener = new ItemListener() {
@Override
public void itemStateChanged(ItemEvent itemEvent) {
if (stopCellEditing()) {
fireEditingStopped();
}
}
};
if (editor instanceof JCheckBox) {
((JCheckBox) editor).addItemListener(itemListener);
}
return editor;
}
}
class CheckBoxNode {
private String text;
private boolean selected;
public CheckBoxNode(String text, boolean selected) {
this.text = text;
this.selected = selected;
}
public boolean isSelected() {
return selected;
}
public void setSelected(boolean newValue) {
selected = newValue;
}
public String getText() {
return text;
}
public void setText(String newValue) {
text = newValue;
}
@Override
public String toString() {
return getClass().getName() + "[" + text + "/" + selected + "]";
}
}
class NamedVector extends Vector {
private String name;
public NamedVector(String name) {
this.name = name;
}
public NamedVector(String name, Object elements[]) {
this.name = name;
for (int i = 0, n = elements.length; i < n; i++) {
add(elements[i]);
}
}
@Override
public String toString() {
return "[" + name + "]";
}
}
关于java - CheckBoxNodeTree示例-如何在CheckBoxNodeEditor中正确实现itemlistener？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/19292365/