我对这个问题很感兴趣，并决定制作我自己的小程序，该程序将创建一个主框架/码头和其他可停靠的容器。这些容器将跟随主框架以保持在它们的位置。
所以虽然回答了我想分享我的例子。
至于为什么 OPs 代码不能完美运行，我认为这是因为componentMoved每次移动都会重新触发，因此在可停靠的移动过程中出现了问题。
这是一个小示例，您现在可以将可停靠点添加到主机的北、东、南和/或西。Dockables 保持在其位置的方式由诸如Sticky、Magnetic和Follow Layout之类的布局管理。
Sticky Layout随主框架移动，而 Follow调用可停靠设备移动到主框架位置，Magnetic确实会吸引一定距离内的所有可停靠设备到主框架上指定的最终/停靠点（主框架的东顶部）的给定距离。
它使用 aComponentAdapter/Listener和Swing TimerwithComponent#setLocation(int x,int y)来实现结果。
下面的屏幕截图是 4 个可停靠的（北、西、东和南），中心屏幕是主框架。该类Docker有一个getDockToolbar允许我们添加具有预建停靠和取消停靠按钮的工具栏的能力。
这是代码（下面显示磁性布局）：
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.util.HashMap;
import java.util.Map;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class MagneticFrameAndDialog {
public MagneticFrameAndDialog() {
createAndShowGUI();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new MagneticFrameAndDialog();
}
});
}
private void createAndShowGUI() {
JFrame frame = new JFrame("JFrame (The Docks)");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Docker docker = new Docker();
docker.registerDock(frame);
docker.setLayout(Docker.MAGNETIC_LAYOUT);
//docker.setMagneticFieldSize(250);//default is 150
docker.setComponentMovedReactTime(50);//default is 100
JDialog d1 = createAndShowDialog(300, 300);
d1.setTitle("East Dockable");
JDialog d2 = createAndShowDialog(300, 100);
d2.setTitle("South Dockable");
JDialog d3 = createAndShowDialog(100, 300);
d3.setTitle("West Dockable");
JDialog d4 = createAndShowDialog(300, 100);
d4.setTitle("North Dockable");
docker.registerDockee(d1, Docker.EAST_DOCKED);
docker.registerDockee(d2, Docker.SOUTH_DOCKED);
docker.registerDockee(d3, Docker.WEST_DOCKED);
docker.registerDockee(d4, Docker.NORTH_DOCKED);
frame.add(docker.getDockToolbar(), BorderLayout.SOUTH);
frame.pack();
frame.setVisible(true);
}
private JDialog createAndShowDialog(final int w, final int h) {
JDialog dialog = new JDialog() {
@Override
public Dimension getPreferredSize() {
return new Dimension(w, h);
}
};
dialog.setTitle("Dockable Dialog");
dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
dialog.pack();
dialog.setVisible(true);
return dialog;
}
}
class Docker {
public static final String NORTH_DOCKED = "dock north", SOUTH_DOCKED = "dock south", WEST_DOCKED = " dock west", EAST_DOCKED = "dock east";
public static final String FOLLOW_LAYOUT = "layout follow", STICKY_LAYOUT = "layout sticky", MAGNETIC_LAYOUT = "layout magnetic";
private HashMap<Component, String> dockees = new HashMap<>();
private Timer dockeeMoveTimer;
private ComponentAdapter caDock, caDockee;
private Component dock;
private String layout = STICKY_LAYOUT;
private int MAGNETIC_FIELD_SIZE = 150, movedReactTime = 100;
public Docker() {
initTimers();
initComponentAdapters();
}
public void setLayout(String layout) {
this.layout = layout;
}
void setComponentMovedReactTime(int milis) {
movedReactTime = milis;
}
private void initComponentAdapters() {
caDockee = new ComponentAdapter() {
@Override
public void componentMoved(ComponentEvent ce) {
super.componentMoved(ce);
if (layout.equals(MAGNETIC_LAYOUT)) {
createDockeeMovedTimer();
} else {
iterateDockables();
}
}
private void createDockeeMovedTimer() {
if (dockeeMoveTimer.isRunning()) {
dockeeMoveTimer.restart();
} else {
dockeeMoveTimer.start();
}
}
};
caDock = new ComponentAdapter() {
@Override
public void componentMoved(ComponentEvent ce) {
super.componentMoved(ce);
iterateDockables();
}
@Override
public void componentResized(ComponentEvent ce) {
super.componentResized(ce);
iterateDockables();
}
};
}
private void initTimers() {
dockeeMoveTimer = new Timer(movedReactTime, new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
iterateDockables();
}
});
dockeeMoveTimer.setRepeats(false);
}
private void iterateDockables() {
//System.out.println("Dock will call for Dockees to come");
for (Map.Entry<Component, String> entry : dockees.entrySet()) {
Component component = entry.getKey();
String pos = entry.getValue();
if (!isDocked(component, pos)) {
dock(component, pos);
}
}
}
void registerDock(Component dock) {
this.dock = dock;
dock.addComponentListener(caDock);
}
void registerDockee(Component dockee, String pos) {
dockee.addComponentListener(caDockee);
dockees.put(dockee, pos);
caDock.componentResized(new ComponentEvent(dock, 1));//not sure about the int but w dont use it so its fine for now
}
void deregisterDockee(Component dockee) {
dockee.removeComponentListener(caDockee);
dockees.remove(dockee);
}
void setMagneticFieldSize(int sizeInPixels) {
MAGNETIC_FIELD_SIZE = sizeInPixels;
}
private boolean isDocked(Component comp, String pos) {
switch (pos) {
case EAST_DOCKED:
int eastDockedX = dock.getX() + dock.getWidth();
int eastDockedY = dock.getY();
if (layout.equals(MAGNETIC_LAYOUT)) {
if (comp.getLocation().distance(new Point(eastDockedX, eastDockedY)) <= MAGNETIC_FIELD_SIZE) {
return false;
} else {
return true;
}
} else {
if (comp.getX() == eastDockedX && comp.getY() == eastDockedY) {
// System.out.println("is eastly docked");
return true;
}
}
break;
case SOUTH_DOCKED:
int southDockedX = dock.getX();
int southDockedY = dock.getY() + dock.getHeight();
if (layout.equals(MAGNETIC_LAYOUT)) {
if (comp.getLocation().distance(new Point(southDockedX, southDockedY)) <= MAGNETIC_FIELD_SIZE) {
return false;
} else {
return true;
}
} else {
if (comp.getX() == southDockedX && comp.getY() == southDockedY) {
// System.out.println("is southly docked");
return true;
}
}
break;
case WEST_DOCKED:
int westDockedX = dock.getX() - comp.getWidth();
int westDockedY = dock.getY();
if (layout.equals(MAGNETIC_LAYOUT)) {
if (comp.getLocation().distance(new Point(westDockedX + comp.getWidth(), westDockedY)) <= MAGNETIC_FIELD_SIZE) {
return false;
} else {
return true;
}
} else {
if (comp.getX() == westDockedX && comp.getY() == westDockedY) {
// System.out.println("is southly docked");
return true;
}
}
break;
case NORTH_DOCKED:
int northDockedX = dock.getX() + comp.getHeight();
int northDockedY = dock.getY() - comp.getHeight();
if (layout.equals(MAGNETIC_LAYOUT)) {
if (comp.getLocation().distance(new Point(northDockedX - comp.getHeight(), northDockedY + comp.getHeight())) <= MAGNETIC_FIELD_SIZE) {
return false;
} else {
return true;
}
} else {
if (comp.getX() == northDockedX && comp.getY() == northDockedY) {
// System.out.println("is southly docked");
return true;
}
}
break;
}
return false;
}
private Timer eastTimer = null, southTimer = null, westTimer = null, northTimer = null;
private void dock(final Component comp, String pos) {
//System.out.println("Snapping Dockee back to the dock");
switch (pos) {
case EAST_DOCKED:
int eastDockedX = dock.getX() + dock.getWidth();
int eastDockedY = dock.getY();
if (eastTimer == null) {
eastTimer = getTimer(comp, eastDockedX, eastDockedY);
eastTimer.start();
} else {
if (!eastTimer.isRunning()) {
eastTimer = getTimer(comp, eastDockedX, eastDockedY);
eastTimer.start();
}
}
break;
case SOUTH_DOCKED:
int southDockedX = dock.getX();
int southDockedY = dock.getY() + dock.getHeight();
if (southTimer == null) {
southTimer = getTimer(comp, southDockedX, southDockedY);
southTimer.start();
} else {
if (!southTimer.isRunning()) {
southTimer = getTimer(comp, southDockedX, southDockedY);
southTimer.start();
}
}
break;
case WEST_DOCKED:
int westDockedX = dock.getX() - comp.getWidth();
int westDockedY = dock.getY();
if (westTimer == null) {
westTimer = getTimer(comp, westDockedX, westDockedY);
westTimer.start();
} else {
if (!westTimer.isRunning()) {
westTimer = getTimer(comp, westDockedX, westDockedY);
westTimer.start();
}
}
break;
case NORTH_DOCKED:
int northDockedX = dock.getX();
int northDockedY = dock.getY() - comp.getHeight();
if (northTimer == null) {
northTimer = getTimer(comp, northDockedX, northDockedY);
northTimer.start();
} else {
if (!northTimer.isRunning()) {
northTimer = getTimer(comp, northDockedX, northDockedY);
northTimer.start();
}
}
break;
}
}
private Timer getTimer(final Component comp, int finalX, int finalY) {
Timer t = null;
switch (layout) {
case STICKY_LAYOUT:
t = stickyDockableTimer(comp, finalX, finalY);
break;
case FOLLOW_LAYOUT:
t = followDockableTimer(comp, finalX, finalY);
break;
case MAGNETIC_LAYOUT:
t = followDockableTimer(comp, finalX, finalY);
break;
}
return t;
}
private Timer followDockableTimer(final Component comp, final int finalX, final int finalY) {
Timer t = new Timer(1, new AbstractAction() {
int INCREMENT = 1, DECREMENT = 1;
int x = comp.getX(), y = comp.getY();
@Override
public void actionPerformed(ActionEvent ae) {
//System.out.println(finalX + "," + finalY);
if (x < finalX) {
x += INCREMENT;
} else if (x > finalX) {
x -= DECREMENT;
}
if (y < finalY) {
y += INCREMENT;
} else if (y > finalY) {
y -= DECREMENT;
}
comp.setLocation(x, y);
if (x == finalX && y == finalY) {
if (comp instanceof Window) {
((Window) comp).toFront();
}
((Timer) ae.getSource()).stop();
}
}
});
return t;
}
public JPanel getDockToolbar() {
JPanel panel = new JPanel();
for (Map.Entry<Component, String> entry : dockees.entrySet()) {
final Component component = entry.getKey();
String pos = entry.getValue();
Docker.MyButton jtb = new Docker.MyButton("un-dock" + pos.replace("dock", ""), component, pos);
panel.add(jtb);
jtb.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
Docker.MyButton jtb = (Docker.MyButton) ae.getSource();
String tmp = jtb.getText();
if (tmp.contains("un-dock")) {
jtb.setText(tmp.replace("un-dock", "dock"));
deregisterDockee(jtb.getComponent());
} else {
jtb.setText(tmp.replace("dock", "un-dock"));
registerDockee(jtb.getComponent(), jtb.getDockablePosition());
}
}
});
}
return panel;
}
private Timer stickyDockableTimer(final Component comp, final int finalX, final int finalY) {
Timer t = new Timer(1, new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
comp.setLocation(finalX, finalY);
}
});
t.setRepeats(false);
return t;
}
private class MyButton extends JButton {
private final Component c;
private final String pos;
public MyButton(String text, Component c, String pos) {
super(text);
this.c = c;
this.pos = pos;
}
public Component getComponent() {
return c;
}
public String getDockablePosition() {
return pos;
}
}
}