向 JTree 句柄添加翻转
Add rollover to JTree handles
我正在尝试对 JTree 的 Collapsed Icon
进行自定义翻转效果。但是,我不确定如何定位单个句柄而不是所有句柄。
如果您 运行 下面的代码,您将看到当您将鼠标悬停在 JTree 的任何句柄、节点或叶上时,所有折叠的句柄都将变为翻转。这是不希望的。那么,当我将鼠标悬停在该句柄上时,如何才能仅更改一个句柄,而最好不要将鼠标悬停在它旁边的节点上?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.plaf.basic.*;
@SuppressWarnings("serial")
public class DirectoryExplorer extends JFrame {
private DirectoryExplorer() {
super("Directory Explorer");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new GridLayout(1, 1));
createPanel();
setSize(800,600);
setVisible(true);
}
private void createPanel() {
JPanel panel = new JPanel(new GridLayout(1, 1));
DefaultMutableTreeNode root = new DefaultMutableTreeNode("Hello");
root.add(new DefaultMutableTreeNode("1"));
root.add(new DefaultMutableTreeNode("2"));
root.add(new DefaultMutableTreeNode("3"));
JTree tree = new JTree();
BasicTreeUI tUI = (BasicTreeUI) tree.getUI();
tUI.setCollapsedIcon(new ImageIcon("resources/closed.png"));
tUI.setExpandedIcon(new ImageIcon("resources/open.png"));
tree.setShowsRootHandles(true);
tree.addMouseMotionListener(new MouseHandler(tree));
panel.add(new JScrollPane(tree));
getContentPane().add(panel);
}
public static void main(String[] args) {
new DirectoryExplorer();
}
private class MouseHandler implements MouseMotionListener {
JTree t = null;
BasicTreeUI tUI = null;
public MouseHandler(JTree tree) {
t = tree;
tUI = (BasicTreeUI) tree.getUI();
}
@Override
public void mouseDragged(MouseEvent e) {
}
@Override
public void mouseMoved(MouseEvent e) {
TreePath selPath = t.getPathForLocation(e.getX(), e.getY());
if(selPath != null)
tUI.setCollapsedIcon(new ImageIcon("resources/rollover.png"));
else
tUI.setCollapsedIcon(new ImageIcon("resources/closed.png"));
t.repaint();
}
}
}
为了获得预期的结果,您需要覆盖 BasicTreeUI.paintExpandControl()
和 BasicTreeUI.MouseHandler.mouseMoved()
。您还需要创建一些方法,例如 setRolloverIcon()
。
一个工作示例可能如下所示
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.net.MalformedURLException;
import java.net.URL;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.plaf.basic.BasicTreeUI;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreePath;
@SuppressWarnings("serial")
public class DirectoryExplorer extends JFrame {
private DirectoryExplorer() {
super("Directory Explorer");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new GridLayout(1, 1));
createPanel();
setSize(800,600);
setVisible(true);
}
private void createPanel() {
JPanel panel = new JPanel(new GridLayout(1, 1));
DefaultMutableTreeNode root = new DefaultMutableTreeNode("Hello");
root.add(new DefaultMutableTreeNode("1"));
root.add(new DefaultMutableTreeNode("2"));
root.add(new DefaultMutableTreeNode("3"));
JTree tree = new JTree();
//UI Stuff//
TreeHandleUI tUI = new TreeHandleUI(tree);
tree.setUI(tUI);
try {
tUI.setCollapsedIcon(new ImageIcon(new URL("https://i.stack.imgur.com/nKJFv.png")));
tUI.setExpandedIcon(new ImageIcon(new URL("https://i.stack.imgur.com/NJvcp.png")));
tUI.setRolloverIcon(new ImageIcon(new URL("https://i.stack.imgur.com/jN6uX.png")));
} catch(MalformedURLException e) {
System.out.println("Bad URL / URLs");
}
////////////
tree.setShowsRootHandles(true);
panel.add(new JScrollPane(tree));
getContentPane().add(panel);
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> new DirectoryExplorer());
}
private class TreeHandleUI extends BasicTreeUI {
///Variables
private JTree t = null;
private Icon rolloverIcon = null;
private boolean rolloverEnabled = false;
private UpdateHandler uH = null;
private boolean isLeftToRight( Component c ) {
return c.getComponentOrientation().isLeftToRight();
}
public TreeHandleUI(JTree tree) {
t = tree;
uH = new UpdateHandler(t);
t.addMouseMotionListener(uH);
}
public void setRolloverIcon(Icon rolloverG) {
Icon oldValue = rolloverIcon;
rolloverIcon = rolloverG;
setRolloverEnabled(true);
if (rolloverIcon != oldValue) {
t.repaint();
}
}
private void setRolloverEnabled(boolean handleRolloverEnabled) {
boolean oldValue = rolloverEnabled;
rolloverEnabled = handleRolloverEnabled;
if (handleRolloverEnabled != oldValue) {
t.repaint();
}
}
@Override
protected void paintExpandControl(Graphics g,
Rectangle clipBounds, Insets insets,
Rectangle bounds, TreePath path,
int row, boolean isExpanded,
boolean hasBeenExpanded,
boolean isLeaf) {
Object value = path.getLastPathComponent();
if (!isLeaf && (!hasBeenExpanded || treeModel.getChildCount(value) > 0)) {
int middleXOfKnob;
if (isLeftToRight(t)) {
middleXOfKnob = bounds.x - getRightChildIndent() + 1;
} else {
middleXOfKnob = bounds.x + bounds.width + getRightChildIndent() - 1;
}
int middleYOfKnob = bounds.y + (bounds.height / 2);
if (isExpanded) {
Icon expandedIcon = getExpandedIcon();
if(expandedIcon != null)
drawCentered(tree, g, expandedIcon, middleXOfKnob, middleYOfKnob );
} else if(isLocationInExpandControl(path, uH.getXPos(), uH.getYPos()) && !isExpanded && rolloverEnabled) {
if(row == uH.getRow()) {
if(rolloverIcon != null)
drawCentered(tree, g, rolloverIcon, middleXOfKnob, middleYOfKnob);
} else {
Icon collapsedIcon = getCollapsedIcon();
if(collapsedIcon != null)
drawCentered(tree, g, collapsedIcon, middleXOfKnob, middleYOfKnob);
}
} else {
Icon collapsedIcon = getCollapsedIcon();
if(collapsedIcon != null)
drawCentered(tree, g, collapsedIcon, middleXOfKnob, middleYOfKnob);
}
}
}
private class UpdateHandler extends BasicTreeUI.MouseHandler {
private JTree t = null;
private int xPos = 0;
private int yPos = 0;
private boolean leftToRight(Component c) {
return c.getComponentOrientation().isLeftToRight();
}
public UpdateHandler(JTree tree) {
t = tree;
}
@Override
public void mouseMoved(MouseEvent e) {
xPos = e.getX();
yPos = e.getY();
t.repaint();
}
public int getXPos() {
return xPos;
}
public int getYPos() {
return yPos;
}
public int getRow() {
return getRowForPath(t, getClosestPathForLocation(t, xPos, yPos));
}
}
}
}
代码将 运行 不下载图像,但它们在下面可用
closed.png
open.png
rollover.png
我正在尝试对 JTree 的 Collapsed Icon
进行自定义翻转效果。但是,我不确定如何定位单个句柄而不是所有句柄。
如果您 运行 下面的代码,您将看到当您将鼠标悬停在 JTree 的任何句柄、节点或叶上时,所有折叠的句柄都将变为翻转。这是不希望的。那么,当我将鼠标悬停在该句柄上时,如何才能仅更改一个句柄,而最好不要将鼠标悬停在它旁边的节点上?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.plaf.basic.*;
@SuppressWarnings("serial")
public class DirectoryExplorer extends JFrame {
private DirectoryExplorer() {
super("Directory Explorer");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new GridLayout(1, 1));
createPanel();
setSize(800,600);
setVisible(true);
}
private void createPanel() {
JPanel panel = new JPanel(new GridLayout(1, 1));
DefaultMutableTreeNode root = new DefaultMutableTreeNode("Hello");
root.add(new DefaultMutableTreeNode("1"));
root.add(new DefaultMutableTreeNode("2"));
root.add(new DefaultMutableTreeNode("3"));
JTree tree = new JTree();
BasicTreeUI tUI = (BasicTreeUI) tree.getUI();
tUI.setCollapsedIcon(new ImageIcon("resources/closed.png"));
tUI.setExpandedIcon(new ImageIcon("resources/open.png"));
tree.setShowsRootHandles(true);
tree.addMouseMotionListener(new MouseHandler(tree));
panel.add(new JScrollPane(tree));
getContentPane().add(panel);
}
public static void main(String[] args) {
new DirectoryExplorer();
}
private class MouseHandler implements MouseMotionListener {
JTree t = null;
BasicTreeUI tUI = null;
public MouseHandler(JTree tree) {
t = tree;
tUI = (BasicTreeUI) tree.getUI();
}
@Override
public void mouseDragged(MouseEvent e) {
}
@Override
public void mouseMoved(MouseEvent e) {
TreePath selPath = t.getPathForLocation(e.getX(), e.getY());
if(selPath != null)
tUI.setCollapsedIcon(new ImageIcon("resources/rollover.png"));
else
tUI.setCollapsedIcon(new ImageIcon("resources/closed.png"));
t.repaint();
}
}
}
为了获得预期的结果,您需要覆盖 BasicTreeUI.paintExpandControl()
和 BasicTreeUI.MouseHandler.mouseMoved()
。您还需要创建一些方法,例如 setRolloverIcon()
。
一个工作示例可能如下所示
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.net.MalformedURLException;
import java.net.URL;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.plaf.basic.BasicTreeUI;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreePath;
@SuppressWarnings("serial")
public class DirectoryExplorer extends JFrame {
private DirectoryExplorer() {
super("Directory Explorer");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new GridLayout(1, 1));
createPanel();
setSize(800,600);
setVisible(true);
}
private void createPanel() {
JPanel panel = new JPanel(new GridLayout(1, 1));
DefaultMutableTreeNode root = new DefaultMutableTreeNode("Hello");
root.add(new DefaultMutableTreeNode("1"));
root.add(new DefaultMutableTreeNode("2"));
root.add(new DefaultMutableTreeNode("3"));
JTree tree = new JTree();
//UI Stuff//
TreeHandleUI tUI = new TreeHandleUI(tree);
tree.setUI(tUI);
try {
tUI.setCollapsedIcon(new ImageIcon(new URL("https://i.stack.imgur.com/nKJFv.png")));
tUI.setExpandedIcon(new ImageIcon(new URL("https://i.stack.imgur.com/NJvcp.png")));
tUI.setRolloverIcon(new ImageIcon(new URL("https://i.stack.imgur.com/jN6uX.png")));
} catch(MalformedURLException e) {
System.out.println("Bad URL / URLs");
}
////////////
tree.setShowsRootHandles(true);
panel.add(new JScrollPane(tree));
getContentPane().add(panel);
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> new DirectoryExplorer());
}
private class TreeHandleUI extends BasicTreeUI {
///Variables
private JTree t = null;
private Icon rolloverIcon = null;
private boolean rolloverEnabled = false;
private UpdateHandler uH = null;
private boolean isLeftToRight( Component c ) {
return c.getComponentOrientation().isLeftToRight();
}
public TreeHandleUI(JTree tree) {
t = tree;
uH = new UpdateHandler(t);
t.addMouseMotionListener(uH);
}
public void setRolloverIcon(Icon rolloverG) {
Icon oldValue = rolloverIcon;
rolloverIcon = rolloverG;
setRolloverEnabled(true);
if (rolloverIcon != oldValue) {
t.repaint();
}
}
private void setRolloverEnabled(boolean handleRolloverEnabled) {
boolean oldValue = rolloverEnabled;
rolloverEnabled = handleRolloverEnabled;
if (handleRolloverEnabled != oldValue) {
t.repaint();
}
}
@Override
protected void paintExpandControl(Graphics g,
Rectangle clipBounds, Insets insets,
Rectangle bounds, TreePath path,
int row, boolean isExpanded,
boolean hasBeenExpanded,
boolean isLeaf) {
Object value = path.getLastPathComponent();
if (!isLeaf && (!hasBeenExpanded || treeModel.getChildCount(value) > 0)) {
int middleXOfKnob;
if (isLeftToRight(t)) {
middleXOfKnob = bounds.x - getRightChildIndent() + 1;
} else {
middleXOfKnob = bounds.x + bounds.width + getRightChildIndent() - 1;
}
int middleYOfKnob = bounds.y + (bounds.height / 2);
if (isExpanded) {
Icon expandedIcon = getExpandedIcon();
if(expandedIcon != null)
drawCentered(tree, g, expandedIcon, middleXOfKnob, middleYOfKnob );
} else if(isLocationInExpandControl(path, uH.getXPos(), uH.getYPos()) && !isExpanded && rolloverEnabled) {
if(row == uH.getRow()) {
if(rolloverIcon != null)
drawCentered(tree, g, rolloverIcon, middleXOfKnob, middleYOfKnob);
} else {
Icon collapsedIcon = getCollapsedIcon();
if(collapsedIcon != null)
drawCentered(tree, g, collapsedIcon, middleXOfKnob, middleYOfKnob);
}
} else {
Icon collapsedIcon = getCollapsedIcon();
if(collapsedIcon != null)
drawCentered(tree, g, collapsedIcon, middleXOfKnob, middleYOfKnob);
}
}
}
private class UpdateHandler extends BasicTreeUI.MouseHandler {
private JTree t = null;
private int xPos = 0;
private int yPos = 0;
private boolean leftToRight(Component c) {
return c.getComponentOrientation().isLeftToRight();
}
public UpdateHandler(JTree tree) {
t = tree;
}
@Override
public void mouseMoved(MouseEvent e) {
xPos = e.getX();
yPos = e.getY();
t.repaint();
}
public int getXPos() {
return xPos;
}
public int getYPos() {
return yPos;
}
public int getRow() {
return getRowForPath(t, getClosestPathForLocation(t, xPos, yPos));
}
}
}
}
代码将 运行 不下载图像,但它们在下面可用
closed.png
open.png
rollover.png