我正在开发一款Java游戏，并面临以下挑战。
我有2 JPanels，需要在视觉上将形状从一个JPanel拖到另一个GlassPane。我使用JFrame中的GlassPane工作了。当我按下鼠标拖动形状时，mousePressed激活并将形状传递给glassPane。因此，您需要将JPanels mouseAdapter状态从glassPanes mouseAdapter转移到mousePressed。我通过使用Robot类来解决这个问题，它在glassPane被激活后模拟了另一个JPanels mouseAdapter事件。
现在出现问题，这个解决方法仅适用于Windows而不适用于mac osx，在osx上，只要按下鼠标按钮，鼠标就会与mousePressed保持对话。那么有人知道如何在按下鼠标按钮的同时以适当的方式将mouseAdapter状态从一个{{1}}状态转移到另一个{{1}}状态吗？ （释放按钮并再次按下它不是一个选项，因为这会破坏拖动的目的。）
答案 0 :(得分：2)
为什么不将MouseListener仅添加到glasspane，并在mousePressed方法中获取鼠标的位置（Point），然后通过在包含Component的Container上调用getComponentAt（Point p）来获取可拖动组件？然后，您可以将组件放入玻璃板并将其拖动到那里。例如，这是我使用JLayeredPane（类似于使用glasspane）完成此操作的一种方式：DragLabelOnLayeredPane
或者另一个想法：为什么不简单地在拖动的组件上添加MouseAdapter并将其留在组件上？只要您注意相对于屏幕获取鼠标位置并相对于其容器移动组件，您应该没有问题该组件是在contentPane还是在glasspane中。
编辑：或者选择MeBigFatGuy的优秀建议。
编辑2：一个半醉的深夜尝试了一个不那么简短的概念证明概念程序，这个程序只通过将MouseListener添加到玻璃窗格来移动形状。
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.*;
@SuppressWarnings("serial")
public class DragShapesMainPanel extends JPanel {
private static final Dimension RIGHT_PANEL_SIZE = new Dimension(300, 450);
private static final int SHAPE_COUNT = 10;
private static final int SHAPE_WIDTH = 40;
private static final int SHAPE_HEIGHT = SHAPE_WIDTH;
private Shape draggedShape = null;
private DragShapesPanel leftPanel = new DragShapesPanel(Color.blue, Color.black);
private DragShapesPanel rightPanel = new DragShapesPanel(Color.blue, Color.black);
private DragShapesGlassPanel glassPanel = new DragShapesGlassPanel(Color.pink, Color.gray);
private Random random = new Random();
public DragShapesMainPanel() {
setLayout(new GridLayout(1, 0));
setBackground(Color.black);
rightPanel.setPreferredSize(RIGHT_PANEL_SIZE);
leftPanel.setPreferredSize(RIGHT_PANEL_SIZE);
rightPanel.setBorder(BorderFactory.createLineBorder(Color.black, 1));
leftPanel.setBorder(BorderFactory.createLineBorder(Color.black, 1));
add(leftPanel);
add(rightPanel);
MouseAdapter myMouseAdapter = new MyMouseAdapter();
glassPanel.addMouseListener(myMouseAdapter);
glassPanel.addMouseMotionListener(myMouseAdapter);
glassPanel.setOpaque(false);
glassPanel.setVisible(true);
for (int i = 0; i < SHAPE_COUNT; i++) {
leftPanel.addShape(createRandomShape(i));
}
}
private Shape createRandomShape(int i) {
Dimension size = rightPanel.getPreferredSize();
int x = random.nextInt(size.width - SHAPE_WIDTH);
int y = random.nextInt(size.height - SHAPE_HEIGHT);
switch (i % 3) {
case 0:
return new Ellipse2D.Double(x, y, SHAPE_WIDTH, SHAPE_HEIGHT);
case 1:
return new Rectangle2D.Double(x, y, SHAPE_WIDTH, SHAPE_HEIGHT);
case 2:
return new RoundRectangle2D.Double(x, y, SHAPE_WIDTH, SHAPE_HEIGHT, 15, 15);
default:
break;
}
return null;
}
public JPanel getGlassPanel() {
return glassPanel;
}
private class MyMouseAdapter extends MouseAdapter {
Point initialLocation = null;
@Override
public void mousePressed(MouseEvent e) {
if (e.getButton() != MouseEvent.BUTTON1) {
return;
}
Component componentAt = getComponentAt(e.getPoint());
if (!(componentAt instanceof DragShapesPanel)) {
return;
}
initialLocation = e.getPoint();
DragShapesPanel dsPanel = (DragShapesPanel) getComponentAt(initialLocation);
int x = initialLocation.x - dsPanel.getLocation().x;
int y = initialLocation.y - dsPanel.getLocation().y;
Point p = new Point(x, y);
Shape shape = dsPanel.getShapeAtPoint(p);
if (shape == null) {
initialLocation = null;
return;
}
dsPanel.removeShape(shape);
dsPanel.repaint();
int tx = dsPanel.getLocation().x;
int ty = dsPanel.getLocation().y;
draggedShape = AffineTransform.getTranslateInstance(tx, ty).createTransformedShape(shape);
glassPanel.setShape(draggedShape);
glassPanel.repaint();
}
@Override
public void mouseDragged(MouseEvent e) {
if (initialLocation == null) {
return;
}
Point currentLocation = e.getPoint();
int x = currentLocation.x - initialLocation.x;
int y = currentLocation.y - initialLocation.y;
glassPanel.translate(new Point(x, y));
glassPanel.repaint();
}
@Override
public void mouseReleased(final MouseEvent e) {
if (initialLocation == null) {
return;
}
SwingUtilities.invokeLater(new Runnable() {
public void run() {
Component componentAt = getComponentAt(e.getPoint());
if (!(componentAt instanceof DragShapesPanel)) {
return;
}
DragShapesPanel dsPanel = (DragShapesPanel) getComponentAt(e.getPoint());
Point currentLocation = e.getPoint();
int x = currentLocation.x - initialLocation.x;
int y = currentLocation.y - initialLocation.y;
Point dspPoint = dsPanel.getLocation();
int tx = x - dspPoint.x;
int ty = y - dspPoint.y;
draggedShape = AffineTransform.getTranslateInstance(tx, ty).createTransformedShape(
draggedShape);
dsPanel.addShape(draggedShape);
dsPanel.repaint();
initialLocation = null;
glassPanel.setShape(null);
glassPanel.translate(new Point(0, 0));
}
});
}
}
private static void createAndShowUI() {
DragShapesMainPanel dragShapesMain = new DragShapesMainPanel();
JFrame frame = new JFrame("DragShapes");
frame.getContentPane().add(dragShapesMain);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setGlassPane(dragShapesMain.getGlassPanel());
frame.getGlassPane().setVisible(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
@SuppressWarnings("serial")
class DragShapesPanel extends JPanel {
private static final float STROKE_WIDTH = 3;
private static final Stroke SHAPE_STROKE = new BasicStroke(STROKE_WIDTH);
private List<Shape> shapeList = new ArrayList<Shape>();
private Color shapeFillColor;
private Color shapeBorderColor;
public DragShapesPanel(Color fillColor, Color borderColor) {
this.shapeFillColor = fillColor;
this.shapeBorderColor = borderColor;
}
public void addShape(Shape s) {
shapeList.add(s);
}
public void removeShape(Shape s) {
shapeList.remove(s);
}
public Shape getShapeAtPoint(Point p) {
Shape shapeAtPoint = null;
for (int i = shapeList.size() - 1; i >= 0; i--) {
if (shapeList.get(i).contains(p)) {
return shapeList.get(i);
}
}
return shapeAtPoint;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
for (Shape shape : shapeList) {
g2.setColor(shapeFillColor);
g2.fill(shape);
g2.setStroke(SHAPE_STROKE);
g2.setColor(shapeBorderColor);
g2.draw(shape);
}
}
}
@SuppressWarnings("serial")
class DragShapesGlassPanel extends JPanel {
private static final float STROKE_WIDTH = 1.5f;
private static final Stroke SHAPE_STROKE = new BasicStroke(STROKE_WIDTH);
private Shape shape = null;
private Color shapeFillColor;
private Color shapeBorderColor;
private AffineTransform transform = new AffineTransform();
public DragShapesGlassPanel(Color fillColor, Color borderColor) {
this.shapeFillColor = fillColor;
this.shapeBorderColor = borderColor;
}
public void setShape(Shape shape) {
this.shape = shape;
}
public void translate(Point p) {
transform = AffineTransform.getTranslateInstance(p.x, p.y);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (shape == null) {
return;
}
Graphics2D g2 = (Graphics2D) g;
g2.transform(transform);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(shapeFillColor);
g2.fill(shape);
g2.setStroke(SHAPE_STROKE);
g2.setColor(shapeBorderColor);
g2.draw(shape);
}
}