我需要屏幕虚拟操纵杆解决方案来控制外部设备-购物车。我的程序是用Java / Swing编写的，并且可以在带有电阻式触摸屏的Windows加固平板电脑上工作。 Swing中没有x-y滑块控件，无法通过Google找到它，因此可能我需要从头开始编写它。现在的问题是：编写这种控件的最佳方法是什么？我本来打算放置两个JSlider控件，一个水平和第二个垂直控件，并制作自定义拇指，但是我担心这会给我带来麻烦，因为它实际上是一个hack。也许只是从头开始写？也许有一个现有的解决方案？
我将通过拇指拖动并触摸最终的拇指位置来使用它。
参考方案
例如
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Stroke;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class SimpleJoystickDemo extends JFrame {
//I think that orginally made by @HFOE
private int displayWidth = 340;
private int displayHeight = 550;
private final Point position;
public SimpleJoystickDemo() {
super("SimpleJoystickDemo");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(displayWidth, displayHeight);
setLocationRelativeTo(null);
position = new Point();
SimpleJoystick myJoystick = new SimpleJoystick(150, position, 100);
add(myJoystick, BorderLayout.PAGE_END);
Drawing drawing = new Drawing(position);
add(drawing);
}
public static void main(final String[] args) {
Runnable gui = new Runnable() {
@Override
public void run() {
new SimpleJoystickDemo().setVisible(true);
}
};
SwingUtilities.invokeLater(gui);
}
private class Drawing extends JPanel {
private static final long serialVersionUID = 1L;
private final Point position;
public Drawing(Point position) {
this.position = position;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(Color.RED);
g2.fillOval(160 + position.x, 160 - position.y, 15, 15);
}
}
}
class SimpleJoystick extends JPanel {
private static final long serialVersionUID = 1L;
//Maximum value for full horiz or vert position where centered is 0:
private int joyOutputRange;
private float joySize; //joystick icon size
private float joyWidth, joyHeight;
private float joyCenterX, joyCenterY; //Joystick displayed Center
//Display positions for text feedback values:
private int textHorizPos, textVertPos;
private int fontSpace = 12;
private float curJoyAngle; //Current joystick angle
private float curJoySize; //Current joystick size
private boolean isMouseTracking;
private boolean leftMouseButton;
private int mouseX, mouseY;
private Stroke lineStroke = new BasicStroke(10, BasicStroke.CAP_ROUND,
BasicStroke.JOIN_ROUND);
private final Point position;
public SimpleJoystick(final int joyOutputRange,
final Point position, final int joySize) {
this.joyOutputRange = joyOutputRange;
this.position = position;
this.joySize = joySize;
joyWidth = joySize;
joyHeight = joyWidth;
setPreferredSize(new Dimension((int) joyWidth + 250,
(int) joyHeight + 80));
joyCenterX = getPreferredSize().width / 2;
joyCenterY = getPreferredSize().height / 2;
this.joySize = joyWidth / 2;
setBackground(new Color(226, 226, 226));
MouseAdapter mouseAdapter = new MouseAdapter() {
@Override
public void mouseMoved(final MouseEvent e) {
mouseCheck(e);
}
@Override
public void mousePressed(final MouseEvent e) {
leftMouseButton = SwingUtilities.isLeftMouseButton(e);
mouseCheck(e);
}
};
addMouseMotionListener(mouseAdapter);
addMouseListener(mouseAdapter);
}
private void mouseCheck(final MouseEvent e) {
mouseX = e.getX();
mouseY = e.getY();
float dx = mouseX - joyCenterX;
float dy = mouseY - joyCenterY;
if (leftMouseButton) {
isMouseTracking = true;
} else {
isMouseTracking = false;
}
if (isMouseTracking) {
curJoyAngle = (float) Math.atan2(dy, dx);
curJoySize = (float) Point.distance(mouseX, mouseY,
joyCenterX, joyCenterY);
} else {
curJoySize = 0;
}
if (curJoySize > joySize) {
curJoySize = joySize;
}
position.x = (int) (joyOutputRange * (Math.cos(curJoyAngle)
* curJoySize) / joySize);
position.y = (int) (joyOutputRange * (-(Math.sin(curJoyAngle)
* curJoySize) / joySize));
SwingUtilities.getRoot(SimpleJoystick.this).repaint();
}
@Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(Color.LIGHT_GRAY);
g2.fillOval((int) (joyCenterX - joyWidth / 2),
(int) (joyCenterY - joyHeight / 2),
(int) joyWidth, (int) joyHeight);
//rotate and draw joystick line segment:
Graphics2D g3 = (Graphics2D) g2.create();
g3.translate(joyCenterX, joyCenterY);
g3.rotate(curJoyAngle);
g3.setColor(Color.GRAY);
g3.setStroke(lineStroke);
g3.drawLine(0, 0, (int) curJoySize, 0);
g3.dispose();
//
g2.setColor(Color.GRAY);
g2.fillOval((int) joyCenterX - 10, (int) joyCenterY - 10, 20, 20);
textHorizPos = 50;
textVertPos = (int) (joyCenterY - 50);
g2.drawString("Horizont:", textHorizPos, textVertPos);
textHorizPos += (4 * fontSpace);
g2.drawString(String.valueOf(position.x), textHorizPos, textVertPos);
textHorizPos = 50;
textVertPos += 12;
g2.drawString("Vertical :", textHorizPos, textVertPos);
textHorizPos += (4 * fontSpace);
g2.drawString(String.valueOf(position.y), textHorizPos, textVertPos);
}
}
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