目前，我知道protected void paintComponent(Graphics g) {
super.paintComponent(g);
Rectangle bounds = new Rectangle(0, 0, getWidth(), getHeight());
for (PaintableEntity paintable : paintableEntities) {
Graphics2D g2d = (Graphics2D) g.create();
paintable.paint(g2d, this, bounds);
g2d.dispose();
}
}
模块中的事件import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.ImageObserver;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
/*
You could have entities which can collide which have collision detection
capabilities
Some entities don't need to be painted and may provide things like
visual or audio affects
*/
public interface Entity {
}
public interface MovableEntity extends Entity {
public void update(Rectangle bounds);
}
public interface PaintableEntity extends Entity {
public void paint(Graphics2D g2d, ImageObserver imageObserver, Rectangle bounds);
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new GamePane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class GamePane extends JPanel {
// Could use a single list and filter it, but hay
private List<PaintableEntity> paintableEntities;
private List<MovableEntity> movableEntitys;
private Timer mainLoop;
public GamePane() {
paintableEntities = new ArrayList<>(25);
movableEntitys = new ArrayList<>(25);
paintableEntities.add(new TrackEntity());
CarEntity car = new CarEntity();
paintableEntities.add(car);
movableEntitys.add(car);
mainLoop = new Timer(5, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Rectangle bounds = new Rectangle(0, 0, getWidth(), getHeight());
// Lots of collision detection and other awesome stuff
for (MovableEntity entity : movableEntitys) {
entity.update(bounds);
}
repaint();
}
});
mainLoop.start();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Rectangle bounds = new Rectangle(0, 0, getWidth(), getHeight());
for (PaintableEntity paintable : paintableEntities) {
Graphics2D g2d = (Graphics2D) g.create();
paintable.paint(g2d, this, bounds);
g2d.dispose();
}
}
}
public class CarEntity implements PaintableEntity, MovableEntity {
private int delta = 1;
private int xDelta = 0;
private int yDelta = delta;
private int xPos = 2;
private int yPos = 2;
private int size = 4;
@Override
public void paint(Graphics2D g2d, ImageObserver imageObserver, Rectangle bounds) {
g2d.translate(bounds.x, bounds.y);
g2d.setColor(Color.RED);
g2d.fillRect(xPos - size / 2, yPos - size / 2, size, size);
}
@Override
public void update(Rectangle bounds) {
xPos += xDelta;
yPos += yDelta;
if (xPos + (size / 2) > bounds.x + bounds.width) {
xPos = bounds.x + bounds.width - (size / 2);
xDelta = 0;
yDelta = -delta;
} else if (xPos - (size / 2) < bounds.x) {
xPos = bounds.x + (size / 2);
xDelta = 0;
yDelta = delta;
}
if (yPos + (size / 2) > bounds.y + bounds.height) {
yPos = bounds.y + bounds.height - (size / 2);
xDelta = delta;
yDelta = 0;
} else if (yPos - (size / 2) < bounds.y) {
yPos = bounds.y + (size / 2);
xDelta = -delta;
yDelta = 0;
}
}
}
public class TrackEntity implements PaintableEntity {
@Override
public void paint(Graphics2D g2d, ImageObserver imageObserver, Rectangle bounds) {
g2d.translate(bounds.x, bounds.y);
g2d.setColor(Color.BLUE);
g2d.drawRect(2, 2, bounds.width - 4, bounds.height - 4);
}
}
}
。但是，这只会在面板已经打开后触发。在面板打开之前，我需要一种挂钩模块的方法。我尝试过使用click事件处理程序，但是当你点击标签时，如果标签是浮动的，它就不起作用。
有什么建议吗？
答案 0 :(得分：0)
查看autocomplete example。在该示例中，选项是动态过滤的，但对于选择组件，您可以使用相同的方法动态创建选项。
答案 1 :(得分：0)
为了做我想做的，我设计了一个延迟/异步加载选择控件。
基本上，我在选择并获得所需的选项的同时，给选择项添加了一个带有加载微调器的临时虚拟选项，然后将它们分为选择项。