Java 在滚动条上注册侦听器';拇指
我正在使用一个scrollpane设置来使用一个自定义滚动条,除此之外,我还想在滚动条的拇指上安装一个监听器,这样每当鼠标进入拇指区域时,它就可以改变颜色或边框。我搜索了BasicScrollBarUI(由我的自定义scrollbar UI扩展)并找到了installListeners()方法,因此我重写了它并使它为thumb区域调用了一个以上的侦听器 SSCCE:Java 在滚动条上注册侦听器';拇指,java,swing,jscrollpane,mouselistener,jscrollbar,Java,Swing,Jscrollpane,Mouselistener,Jscrollbar,我正在使用一个scrollpane设置来使用一个自定义滚动条,除此之外,我还想在滚动条的拇指上安装一个监听器,这样每当鼠标进入拇指区域时,它就可以改变颜色或边框。我搜索了BasicScrollBarUI(由我的自定义scrollbar UI扩展)并找到了installListeners()方法,因此我重写了它并使它为thumb区域调用了一个以上的侦听器 SSCCE: public class TestScrollBar extends JFrame { public TestScrol
public class TestScrollBar extends JFrame {
public TestScrollBar() {
JPanel innerPanel = new JPanel();
innerPanel.setLayout(new BoxLayout(innerPanel, BoxLayout.Y_AXIS));
for (int i=1; i<=10; i++) {
innerPanel.add(new JLabel("Label "+i));
innerPanel.add(Box.createRigidArea(new Dimension(0, 20)));
}
JScrollPane scrollPane = new JScrollPane(innerPanel);
scrollPane.setPreferredSize(new Dimension(innerPanel.getPreferredSize().width, innerPanel.getPreferredSize().height/2));
scrollPane.getVerticalScrollBar().setUI(new CustomScrollBarUI());
this.setLayout(new BorderLayout());
this.add(Box.createRigidArea(new Dimension(0, 20)), BorderLayout.NORTH);
this.add(Box.createRigidArea(new Dimension(0, 20)), BorderLayout.SOUTH);
this.add(Box.createRigidArea(new Dimension(20, 0)), BorderLayout.EAST);
this.add(Box.createRigidArea(new Dimension(20, 0)), BorderLayout.WEST);
this.add(scrollPane, BorderLayout.CENTER);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
TestScrollBar frame = new TestScrollBar();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
当鼠标从右侧或左侧进入拇指区域时,侦听器可以正常工作,但它并不总是在顶部或底部工作。对于这些侧边,它仅在拇指触摸其中一个按钮时起作用。例如,当滚动条位于最上方时,当鼠标从上方按钮进入拇指区域而不是从下方进入拇指区域时,侦听器仅工作(除了左右侧)。当滚动条触碰减少按钮时,会发生相反的情况(仅适用于右/左/底部,但不适用于顶部)。当拇指在两个按钮之间的某个位置而不触碰任何按钮时,则只有左右两侧起作用。如果运行代码,您可以看到所有这些
我还尝试使用一个现有的监听器(而不是创建我自己的监听器),BasicScrollBarUI.TrackListener,在这里我添加了一个方法,只监听thumb区域,但结果完全相同:
public class CustomScrollBarUI extends BasicScrollBarUI {
@Override
protected TrackListener createTrackListener(){
return new TrackListener();
}
protected class TrackListener extends BasicScrollBarUI.TrackListener {
public void mouseEntered(MouseEvent e) {
currentMouseX = e.getX();
currentMouseY = e.getY();
if (getThumbBounds().contains(currentMouseX, currentMouseY)) {
System.out.println("THUMB");
}
}
}
}
问题是你在听滚动条,这意味着它是拇指和拇指可以移动的区域(轨迹)。因此,mouseEntered方法中的测试条件并不总是正确的。例如,假设拇指位于垂直滚动条的顶部,通过底部输入意味着您将首先输入滚动条轨迹,然后将鼠标移动到拇指区域-->无鼠标输入事件 这是您的代码的一个稍加修改的版本。它主要做的是监听鼠标“移动”事件(通过将您的监听器添加为MouseMotionListener),并按预期工作:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.plaf.basic.BasicScrollBarUI;
public class TestScrollBar extends JFrame {
public static class CustomScrollBarUI extends BasicScrollBarUI {
@Override
protected void installListeners() {
super.installListeners();
CustomListener listener = new CustomListener();
scrollbar.addMouseListener(listener);
scrollbar.addMouseMotionListener(listener);
}
protected class CustomListener extends MouseAdapter {
boolean isInsideThumb = false;
@Override
public void mouseEntered(MouseEvent e) {
handleMouseEvent(e);
}
@Override
public void mouseMoved(MouseEvent e) {
handleMouseEvent(e);
}
@Override
public void mouseExited(MouseEvent e) {
handleMouseEvent(e);
}
private void handleMouseEvent(MouseEvent e) {
if (getThumbBounds().contains(e.getX(), e.getY())) {
if (!isInsideThumb) {
System.out.println("THUMB");
isInsideThumb = true;
}
} else {
if (isInsideThumb) {
System.out.println("OUT OF THUMB");
isInsideThumb = false;
}
}
}
}
}
public TestScrollBar() {
JPanel innerPanel = new JPanel();
innerPanel.setLayout(new BoxLayout(innerPanel, BoxLayout.Y_AXIS));
for (int i = 1; i <= 10; i++) {
innerPanel.add(new JLabel("Label " + i));
innerPanel.add(Box.createRigidArea(new Dimension(0, 20)));
}
JScrollPane scrollPane = new JScrollPane(innerPanel);
scrollPane.setPreferredSize(new Dimension(innerPanel.getPreferredSize().width, innerPanel.getPreferredSize().height / 2));
scrollPane.getVerticalScrollBar().setUI(new CustomScrollBarUI());
this.setLayout(new BorderLayout());
this.add(Box.createRigidArea(new Dimension(0, 20)), BorderLayout.NORTH);
this.add(Box.createRigidArea(new Dimension(0, 20)), BorderLayout.SOUTH);
this.add(Box.createRigidArea(new Dimension(20, 0)), BorderLayout.EAST);
this.add(Box.createRigidArea(new Dimension(20, 0)), BorderLayout.WEST);
this.add(scrollPane, BorderLayout.CENTER);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
TestScrollBar frame = new TestScrollBar();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
导入java.awt.BorderLayout;
导入java.awt.Dimension;
导入java.awt.event.MouseAdapter;
导入java.awt.event.MouseEvent;
导入javax.swing.Box;
导入javax.swing.BoxLayout;
导入javax.swing.JFrame;
导入javax.swing.JLabel;
导入javax.swing.JPanel;
导入javax.swing.JScrollPane;
导入javax.swing.SwingUtilities;
导入javax.swing.plaf.basic.BasicScrollBarUI;
公共类TestScrollBar扩展了JFrame{
公共静态类CustomScrollBarUI扩展了BasicScrollBarUI{
@凌驾
受保护的void installListeners(){
super.installListeners();
CustomListener=新建CustomListener();
scrollbar.addMouseListener(侦听器);
scrollbar.addMouseMotionListener(listener);
}
受保护的类CustomListener扩展了MouseAdapter{
布尔值isInsideThumb=false;
@凌驾
公共无效鼠标事件(鼠标事件e){
handleMouseEvent(e);
}
@凌驾
public void mouseMoved(MouseEvent e){
handleMouseEvent(e);
}
@凌驾
公共无效mouseExited(MouseEvent e){
handleMouseEvent(e);
}
私有无效handleMouseEvent(MouseeEvent e){
if(getThumbBounds().contains(e.getX(),e.getY())){
如果(!isInsideThumb){
System.out.println(“拇指”);
isInsideThumb=真;
}
}否则{
如果(isInsideThumb){
System.out.println(“拇指外”);
isInsideThumb=假;
}
}
}
}
}
公共测试滚动条(){
JPanel innerPanel=新的JPanel();
setLayout(新的BoxLayout(innerPanel,BoxLayout.Y_轴));
对于(int i=1;i当您在轨迹中而不是在拇指中输入鼠标时,鼠标输入被激活。您的代码仅在您在轨迹之外并同时在轨迹上和拇指中输入时有效
改为使用mouseMove事件,您将使其正常工作:
@Override
public void mouseMoved(MouseEvent e) {
currentMouseX = e.getX();
currentMouseY = e.getY();
if (getThumbBounds().contains(currentMouseX, currentMouseY)) {
System.out.println("THUMB");
}
}
也许不能回答您的问题,但您已经了解了AdjustmentListener,那么从理论上讲,转换鼠标点的位置无关紧要,下面是一些有关此问题的示例
@Override
public void mouseMoved(MouseEvent e) {
currentMouseX = e.getX();
currentMouseY = e.getY();
if (getThumbBounds().contains(currentMouseX, currentMouseY)) {
System.out.println("THUMB");
}
}