更改JTree第一个节点的图标 [英] Change icon of the first node of JTree
本文介绍了更改JTree第一个节点的图标的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想只更改 JTree 图标的第一个节点。有一个文件管理器使用 JTree 来显示文件。这是一个示意图。如何更改图标？
I want to change just the first node of a JTree icon. There is a file manager that uses JTree to show files. Here is a schematic example. How can I change the icon?
Back
|->Please wait(this is leaf)
Folder 1
|->file1
file2
file3
Folder 2
|->file1
file2
file3
Folder 3
|->file1
file2
file3
推荐答案
要更改树中条目的外观，请使用 TreeCellRenderer 。 E.G。
To change the appearance of entries in a tree, use a TreeCellRenderer. E.G.
/** A TreeCellRenderer for a File. */
class FileTreeCellRenderer extends DefaultTreeCellRenderer {
private FileSystemView fileSystemView;
private JLabel label;
FileTreeCellRenderer() {
label = new JLabel();
label.setOpaque(true);
fileSystemView = FileSystemView.getFileSystemView();
}
@Override
public Component getTreeCellRendererComponent(
JTree tree,
Object value,
boolean selected,
boolean expanded,
boolean leaf,
int row,
boolean hasFocus) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
File file = (File)node.getUserObject();
label.setIcon(fileSystemView.getSystemIcon(file));
label.setText(fileSystemView.getSystemDisplayName(file));
label.setToolTipText(file.getPath());
if (selected) {
label.setBackground(backgroundSelectionColor);
} else {
label.setBackground(backgroundNonSelectionColor);
}
return label;
}
}
屏幕截图
在Windows上使用原生PLAF。
Screen Shot
Using the native PLAF on Windows.
以下是完整的来源（包括用于获取屏幕截图的渲染器和表模型。
Here is the complete source (including renderer & table model) used to grab that screen shot.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import javax.swing.table.*;
import javax.swing.filechooser.FileSystemView;
import java.io.File;
import java.util.Date;
/**
A basic File Manager. Requires 1.6+ for the Desktop & SwingWorker
classes, amongst other minor things.
Includes support classes FileTableModel & FileTreeCellRenderer.
Neither Delete nor New has been implemented. See commented code for
hints on how to proceed for that functionality.
@TODO Still throws occasional AIOOBEs and NPEs, so some update on
the EDT must have been missed.
@author Andrew Thompson
@version 2011-05-29
@see <a href="https://stackoverflow.com/questions/6147965/change-icon-of-the-first-node-of-jtree/6153182#6153182">Change icon of the first node of JTree</a>
*/
class FileManager {
/** Used to open/edit/print files. */
private Desktop desktop;
/** Provides nice icons and names for files. */
private FileSystemView fileSystemView;
/** Main GUI container */
private JPanel gui;
/** File-system tree. Built Lazily */
private JTree tree;
/** Directory listing */
private JTable table;
private JProgressBar progressBar;
/* File controls. */
private JButton openFile;
private JButton printFile;
private JButton editFile;
private JButton deleteFile;
private JButton newFile;
/* File details. */
private JLabel fileName;
private JTextField path;
private JLabel date;
private JLabel size;
private JCheckBox readable;
private JCheckBox writable;
private JCheckBox executable;
private JCheckBox isDirectory;
private JCheckBox isFile;
/** Table model for File[]. */
private FileTableModel fileTableModel;
private ListSelectionListener listSelectionListener;
private boolean cellSizesSet = false;
/** currently selected File. */
private File currentFile;
private boolean safeMode = true;
public Container getGui() {
if (gui==null) {
gui = new JPanel(new BorderLayout(3,3));
gui.setBorder(new EmptyBorder(5,5,5,5));
fileSystemView = FileSystemView.getFileSystemView();
desktop = Desktop.getDesktop();
DefaultMutableTreeNode root = new DefaultMutableTreeNode();
File[] roots = fileSystemView.getRoots();
for (File fileSystemRoot : roots) {
DefaultMutableTreeNode node = new DefaultMutableTreeNode(fileSystemRoot);
root.add( node );
File[] files = fileSystemView.getFiles(fileSystemRoot, true);
for (File file : files) {
node.add(new DefaultMutableTreeNode(file));
}
}
TreeSelectionListener treeSelectionListener = new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent tse){
DefaultMutableTreeNode node =
(DefaultMutableTreeNode)tse.getPath().getLastPathComponent();
addChildren(node);
setFileDetails((File)node.getUserObject());
}
};
tree = new JTree(root);
tree.setRootVisible(false);
tree.addTreeSelectionListener(treeSelectionListener);
tree.setCellRenderer(new FileTreeCellRenderer());
tree.expandRow(0);
JScrollPane treeScroll = new JScrollPane(tree);
// as per trashgod tip
tree.setVisibleRowCount(15);
Dimension preferredSize = treeScroll.getPreferredSize();
Dimension widePreferred = new Dimension(
250,
(int)preferredSize.getHeight());
treeScroll.setPreferredSize( widePreferred );
JPanel detailView = new JPanel(new BorderLayout(3,3));
fileTableModel = new FileTableModel();
table = new JTable(fileTableModel);
table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
table.setAutoCreateRowSorter(true);
table.setShowVerticalLines(false);
// arbitrary size adjustment to better account for icons
table.setRowHeight( (int)(table.getRowHeight()*1.3) );
listSelectionListener = new ListSelectionListener() {
@Override
public void valueChanged(ListSelectionEvent lse) {
int row = table.getSelectionModel().getLeadSelectionIndex();
setFileDetails( ((FileTableModel)table.getModel()).getFile(row) );
}
};
table.getSelectionModel().addListSelectionListener(listSelectionListener);
JScrollPane tableScroll = new JScrollPane(table);
Dimension d = tableScroll.getPreferredSize();
tableScroll.setPreferredSize(new Dimension((int)d.getWidth(), (int)d.getHeight()/2));
detailView.add(tableScroll, BorderLayout.CENTER);
JPanel fileMainDetails = new JPanel(new BorderLayout(4,2));
fileMainDetails.setBorder(new EmptyBorder(0,6,0,6));
JPanel fileDetailsLabels = new JPanel(new GridLayout(0,1,2,2));
fileMainDetails.add(fileDetailsLabels, BorderLayout.WEST);
JPanel fileDetailsValues = new JPanel(new GridLayout(0,1,2,2));
fileMainDetails.add(fileDetailsValues, BorderLayout.CENTER);
fileDetailsLabels.add(new JLabel("File", JLabel.TRAILING));
fileName = new JLabel();
fileDetailsValues.add(fileName);
fileDetailsLabels.add(new JLabel("Path/name", JLabel.TRAILING));
path = new JTextField(5);
path.setEditable(false);
fileDetailsValues.add(path);
fileDetailsLabels.add(new JLabel("Last Modified", JLabel.TRAILING));
date = new JLabel();
fileDetailsValues.add(date);
fileDetailsLabels.add(new JLabel("File size", JLabel.TRAILING));
size = new JLabel();
fileDetailsValues.add(size);
int count = fileDetailsLabels.getComponentCount();
for (int ii=0; ii<count; ii++) {
fileDetailsLabels.getComponent(ii).setEnabled(false);
}
JToolBar toolBar = new JToolBar();
openFile = new JButton("Open");
openFile.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
try {
desktop.open(currentFile);
} catch(Throwable t) {
JOptionPane.showMessageDialog(
gui,
t.toString(),
t.getMessage(),
JOptionPane.ERROR_MESSAGE
);
}
gui.repaint();
}
});
toolBar.add(openFile);
editFile = new JButton("Edit");
editFile.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
try {
desktop.edit(currentFile);
} catch(Throwable t) {
showThrowable(t);
}
}
});
toolBar.add(editFile);
printFile = new JButton("Print");
printFile.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
try {
desktop.print(currentFile);
} catch(Throwable t) {
showThrowable(t);
}
}
});
toolBar.add(printFile);
// Check the actions are supported on this platform!
openFile.setEnabled(desktop.isSupported(Desktop.Action.OPEN));
editFile.setEnabled(desktop.isSupported(Desktop.Action.EDIT));
printFile.setEnabled(desktop.isSupported(Desktop.Action.PRINT));
toolBar.addSeparator();
deleteFile = new JButton("Delete");
deleteFile.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
if (currentFile==null) {
JOptionPane.showMessageDialog(
gui,
"No file selected for deletion.",
"Select File",
JOptionPane.ERROR_MESSAGE
);
return;
}
if (safeMode) {
safeMessage();
} else {
int result = JOptionPane.showConfirmDialog(
gui,
"Are you sure you want to delete this file?",
"Delete File",
JOptionPane.ERROR_MESSAGE
);
if (result==JOptionPane.OK_OPTION) {
try {
boolean deleted = currentFile.delete();
if (deleted) {
// delete the node..
} else {
JOptionPane.showMessageDialog(
gui,
"The file '" +
currentFile +
"' could not be deleted.",
"Delete Failed",
JOptionPane.ERROR_MESSAGE
);
}
} catch(Throwable t) {
showThrowable(t);
}
}
}
gui.repaint();
}
});
toolBar.add(deleteFile);
final JPanel newPanel = new JPanel(new GridLayout(0,1,3,3));
final JRadioButton newTypeFile = new JRadioButton("New File");
JRadioButton newTypeDirectory = new JRadioButton("New Directory");
ButtonGroup bg = new ButtonGroup();
bg.add(newTypeFile);
bg.add(newTypeDirectory);
final JTextField name = new JTextField(15);
newPanel.add( name );
newPanel.add( newTypeFile );
newPanel.add( newTypeDirectory );
newFile = new JButton("New");
newFile.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae) {
if (currentFile==null) {
JOptionPane.showMessageDialog(
gui,
"No location selected for new file.",
"Select Location",
JOptionPane.ERROR_MESSAGE
);
return;
}
if (safeMode) {
safeMessage();
} else {
int result = JOptionPane.showConfirmDialog(gui, newPanel);
if (result==JOptionPane.OK_OPTION) {
try {
boolean created;
File file = new File( currentFile, name.getText() );
if (newTypeFile.isSelected()) {
created = file.createNewFile();
} else {
created = file.mkdir();
}
if (created) {
// add the new node..
} else {
JOptionPane.showMessageDialog(
gui,
"The file '" +
file +
"' could not be created.",
"Create Failed",
JOptionPane.ERROR_MESSAGE
);
}
} catch(Throwable t) {
showThrowable(t);
}
}
}
gui.repaint();
}
});
toolBar.add(newFile);
JPanel flags = new JPanel(new GridLayout(1,0,4,4));
readable = new JCheckBox("Read");
readable.setEnabled(false);
flags.add(readable);
writable = new JCheckBox("Write");
writable.setEnabled(false);
flags.add(writable);
executable = new JCheckBox("Execute");
executable.setEnabled(false);
flags.add(executable);
isDirectory = new JCheckBox("Directory");
isDirectory.setEnabled(false);
flags.add(isDirectory);
isFile = new JCheckBox("File");
isFile.setEnabled(false);
flags.add(isFile);
//flags.setBorder(new TitledBorder("Flags"));
JPanel fileView = new JPanel(new BorderLayout(3,3));
fileView.add(toolBar,BorderLayout.NORTH);
fileView.add(fileMainDetails,BorderLayout.CENTER);
fileView.add(flags,BorderLayout.SOUTH);
detailView.add(fileView, BorderLayout.SOUTH);
JSplitPane splitPane = new JSplitPane(
JSplitPane.HORIZONTAL_SPLIT,
treeScroll,
detailView);
gui.add(splitPane, BorderLayout.CENTER);
JPanel simpleOutput = new JPanel(new BorderLayout(3,3));
progressBar = new JProgressBar();
simpleOutput.add(progressBar, BorderLayout.EAST);
progressBar.setVisible(false);
gui.add(simpleOutput, BorderLayout.SOUTH);
}
return gui;
}
private void safeMessage() {
String safe =
"This is a test program! " +
"Delete/New have not been enabled. " +
"Recompile with safeMode=false; to enable.";
JOptionPane.showMessageDialog( gui, safe, "Not Enabled", JOptionPane.ERROR_MESSAGE );
}
private void showThrowable(Throwable t) {
JOptionPane.showMessageDialog(
gui,
t.toString(),
t.getMessage(),
JOptionPane.ERROR_MESSAGE
);
gui.repaint();
}
/** Update the table on the EDT */
private void setTableDate(final File[] files) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
table.getSelectionModel().removeListSelectionListener(listSelectionListener);
fileTableModel.setFiles(files);
table.getSelectionModel().addListSelectionListener(listSelectionListener);
int max = table.getRowCount();
if (!cellSizesSet) {
setColumnWidth(0,-1);
setColumnWidth(3,60);
table.getColumnModel().getColumn(3).setMaxWidth(120);
setColumnWidth(4,-1);
setColumnWidth(5,-1);
setColumnWidth(6,-1);
setColumnWidth(7,-1);
cellSizesSet = true;
}
}
});
}
private void setColumnWidth(int column, int width) {
TableColumn tableColumn = table.getColumnModel().getColumn(column);
if (width<0) {
// use the preferred width of the header..
JLabel label = new JLabel( (String)tableColumn.getHeaderValue() );
Dimension preferred = label.getPreferredSize();
width = (int)preferred.getWidth()+10;
}
tableColumn.setPreferredWidth(width);
tableColumn.setMaxWidth(width);
tableColumn.setMinWidth(width);
}
/** Add the files that are contained within the directory of this node. */
private void addChildren(final DefaultMutableTreeNode node) {
SwingWorker worker = new SwingWorker() {
@Override
public String doInBackground() {
tree.setEnabled(false);
progressBar.setVisible(true);
progressBar.setIndeterminate(true);
File file = (File)node.getUserObject();
if ( file.isDirectory() ) {
File[] files = fileSystemView.getFiles(file, true);
if (node.isLeaf()) {
for (File child : files) {
node.add( new DefaultMutableTreeNode(child) );
}
}
setTableDate(files);
}
progressBar.setIndeterminate(false);
progressBar.setVisible(false);
tree.setEnabled(true);
return "done";
}
};
worker.execute();
}
/** Update the File details view with the details of this File. */
private void setFileDetails(File file) {
currentFile = file;
fileName.setIcon(fileSystemView.getSystemIcon(file));
fileName.setText(fileSystemView.getSystemDisplayName(file));
path.setText(file.getPath());
date.setText(new Date(file.lastModified()).toString());
size.setText(file.length() + " bytes");
readable.setSelected(file.canRead());
writable.setSelected(file.canWrite());
executable.setSelected(file.canExecute());
isDirectory.setSelected(file.isDirectory());
isFile.setSelected(file.isFile());
gui.repaint();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
// Significantly improves the look of the output in
// terms of the file names returned by FileSystemView!
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch(Exception weTried) {
}
JFrame f = new JFrame("File Manager");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
FileManager fileManager = new FileManager();
f.setContentPane(fileManager.getGui());
f.pack();
f.setLocationRelativeTo(null);
f.setLocationByPlatform(true);
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
});
}
}
/** A TableModel to hold File[]. */
class FileTableModel extends AbstractTableModel {
private File[] files;
private FileSystemView fileSystemView = FileSystemView.getFileSystemView();
private String[] columns = {
"Icon",
"File",
"Path/name",
"Size",
"Last Modified",
"R",
"W",
"E"
};
FileTableModel() {
this(new File[0]);
}
FileTableModel(File[] files) {
this.files = files;
}
public Object getValueAt(int row, int column) {
File file = files[row];
switch (column) {
case 0:
return fileSystemView.getSystemIcon(file);
case 1:
return fileSystemView.getSystemDisplayName(file);
case 2:
return file.getPath();
case 3:
return file.length();
case 4:
return file.lastModified();
case 5:
return file.canRead();
case 6:
return file.canWrite();
case 7:
return file.canExecute();
default:
System.err.println("Logic Error");
}
return "";
}
public int getColumnCount() {
return columns.length;
}
public Class<?> getColumnClass(int column) {
switch (column) {
case 0:
return ImageIcon.class;
case 3:
return Long.class;
case 4:
return Date.class;
case 5:
case 6:
case 7:
return Boolean.class;
}
return String.class;
}
public String getColumnName(int column) {
return columns[column];
}
public int getRowCount() {
return files.length;
}
public File getFile(int row) {
return files[row];
}
public void setFiles(File[] files) {
this.files = files;
fireTableDataChanged();
}
}
/** A TreeCellRenderer for a File. */
class FileTreeCellRenderer extends DefaultTreeCellRenderer {
private FileSystemView fileSystemView;
private JLabel label;
FileTreeCellRenderer() {
label = new JLabel();
label.setOpaque(true);
fileSystemView = FileSystemView.getFileSystemView();
}
@Override
public Component getTreeCellRendererComponent(
JTree tree,
Object value,
boolean selected,
boolean expanded,
boolean leaf,
int row,
boolean hasFocus) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
File file = (File)node.getUserObject();
label.setIcon(fileSystemView.getSystemIcon(file));
label.setText(fileSystemView.getSystemDisplayName(file));
label.setToolTipText(file.getPath());
if (selected) {
label.setBackground(backgroundSelectionColor);
} else {
label.setBackground(backgroundNonSelectionColor);
}
return label;
}
}
注意
这与已基本相同由trashgod提供，但代码为&屏幕截图。
Note
This is basically the same answer already provided by trashgod, but with code & screen shot.
这篇关于更改JTree第一个节点的图标的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
