JLabel ToolTip会干扰MouseListener

本文介绍了JLabel ToolTip会干扰MouseListener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

我有Java Swing应用程序ToolTipMouseTest

I have Java Swing application ToolTipMouseTest

临界线是label.setToolTipText("label" + i);.一旦将其注释掉，只需在控制台上单击标签即可生成2 mousePressed.启用此行后，单击标签将不会产生任何结果.

The critical line is label.setToolTipText("label" + i);. Once it is commented out very click on a label produces 2 mousePressed in console. With this line enabled click on labels would produce nothing.

这是预期的行为还是错误?我的目标是在不禁用MouseListener的情况下显示工具提示.

Is this expected behaviour or a bug? My goal is to show tooltips without disabling MouseListener from working.

几乎是SSCCE，但没有导入:

Almost SSCCE, but without imports:

public class ToolTipMouseTest { public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { new ToolTipMouseTest(); } }); } public ToolTipMouseTest() { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); JLayeredPane lpane = new JLayeredPane() { @Override public Dimension getPreferredSize() { return new Dimension(600,400); } }; MouseAdapter1 mouseAdapter1 = new MouseAdapter1(); lpane.addMouseListener(mouseAdapter1); frame.add(lpane); JPanel panel1 = new JPanel(); panel1.setSize(new Dimension(600, 400)); panel1.setOpaque(false); lpane.add(panel1, JLayeredPane.PALETTE_LAYER); JPanel panel2 = new JPanel(); for (int i = 0; i < 5; i++) { JLabel label = new JLabel("Label " + i); panel2.add(label); label.setToolTipText("label" + i); //HERE!! } JScrollPane spane = new JScrollPane(panel2) { private static final long serialVersionUID = 1L; @Override public Dimension getPreferredSize() { return new Dimension(300, 200); } }; MouseAdapter2 mouseAdapter2 = new MouseAdapter2(); spane.addMouseListener(mouseAdapter2); panel1.add(spane); frame.pack(); frame.setVisible(true); } private class MouseAdapter1 extends MouseAdapter { @Override public void mousePressed (MouseEvent me) { System.out.println("1 mousePressed"); } } private class MouseAdapter2 extends MouseAdapter { @Override public void mousePressed (MouseEvent me) { System.out.println("2 mousePressed"); } } }

推荐答案

它正在按预期工作.让我解释一下原因.

It is working as intended. Let me explain why.

将工具提示添加到任何组件(您的情况下为标签)时，它们会自动从ToolTipManager接收新的鼠标侦听器.这是ToolTipManager类的注册方法:

When you are adding a tooltip to any component (labels in your case) they automatically recieve a new mouse listeners from ToolTipManager. Here is the register method from ToolTipManager class:

public void registerComponent(JComponent component) { component.removeMouseListener(this); component.addMouseListener(this); component.removeMouseMotionListener(moveBeforeEnterListener); component.addMouseMotionListener(moveBeforeEnterListener); component.removeKeyListener(accessibilityKeyListener); component.addKeyListener(accessibilityKeyListener); }

任何组件上至少设置了一个鼠标侦听器时-它会阻止任何鼠标进入/退出/单击/按下/释放事件(如果设置了鼠标移动侦听器，则将鼠标拖动/移动) )从组件层次结构中删除.

When any component has atleast one mouse listener set on it - it will block any mouse enter/exit/click/press/release events (mouse dragged/moved in case there is mouse motion listener set) from going down in the components hierarchy.

在您的情况下-由于设置了工具提示时安装了ToolTipManager侦听器，因此标签阻止了鼠标事件和鼠标运动事件进入分层窗格.

In your case - labels blocking mouse events and mouse motion events from going down to layered pane due to ToolTipManager listeners installed when tooltip is set.

如果您使用变通方法侦听器将事件向下传递，则可以避免这种情况.例如，您可以使用工具提示将该侦听器添加到每个组件，这些提示应向下传递鼠标事件.

This could be avoided if you make a workaround listener with that will pass events down. For example you can add that listener to every component with a tooltip that should pass mouse events down.

这是一个如何完成此操作的小例子:

Here is a small example of how that could be done:

label.addMouseListener ( new MouseAdapter () { public void mousePressed ( MouseEvent e ) { lpane.dispatchEvent ( SwingUtilities.convertMouseEvent ( e.getComponent (), e, lpane ) ); } } );

在这种情况下，事件将传递到分层窗格.无论如何，您甚至可以将它分发到您想要的任何地方(我想您的情况是spane).

In that case event will be passed to layered pane though. Anyway you can dispatch this even anywhere you want (i guess it would be spane in your case).