java swing - paint jcomponent

Question

我嘗試使chord鍵盤模擬。 我無法解決鍵盤中的KeyboardButtons沒有繪製的原因。我在Keyboard中有更多的KeyboardButtons。鼠標正確聽取，但多邊形不繪。

當我調用鍵盤的paintComponent（）中的每個KeyboardButton的繪畫時，多邊形都被繪製，但不會改變mousePressed上的顏色。

Keyboard.java

package keyboard; 


import java.awt.Color; 
import java.awt.Graphics; 
import java.awt.Point; 
import java.awt.Polygon; 
import java.awt.event.MouseEvent; 
import java.awt.event.MouseListener; 
import javax.swing.JComponent; 
import javax.swing.JPanel; 

public class Keyboard extends JPanel implements MouseListener{ 

    Point[] leftFingers; 
    Point leftCenter = new Point(300, 600); 
    KeyboardButton[] buttons; 

    public Keyboard(Point left1, Point left2, Point left3, Point left4, Point left5) { 
    leftFingers = new Point[5]; 
    leftFingers[0] = left1; 
    leftFingers[1] = left2; 
    leftFingers[2] = left3; 
    leftFingers[3] = left4; 
    leftFingers[4] = left5; 
    buttons = registerKeys(); 
    addMouseListener(this); 
    } 

    public KeyboardButton[] registerKeys() { 
    Polygon[] polygons = generateKeyPolygons(calculateBordersOfKeys(leftFingers)); 
    KeyboardButton[] buttons = new KeyboardButton[5]; 
    for (int i = 0; i < polygons.length; i++) { 
     buttons[i] = new KeyboardButton(polygons[i]); 

    } 
    return buttons; 
    } 

    private Point[] calculateBordersOfKeys(Point[] fingers) { 
    Point[] centers = calculateCentersBetweenEachTwoFingers(fingers); 
    Point[] result = new Point[6]; 

    result[0] = calculateCentralSymmetry(centers[0], fingers[0]); 
    System.arraycopy(centers, 0, result, 1, centers.length); 
    result[5] = calculateCentralSymmetry(centers[3], fingers[4]); 
    return result; 
    } 

    @Override 
    protected void paintComponent(Graphics g) { 
    super.paintComponent(g); 
    g.setColor(Color.red); 
    g.drawOval(leftCenter.x - 25, leftCenter.y - 25, 50, 50); 

    for (int i = 0; i < leftFingers.length; i++) { 
     g.drawOval(leftFingers[i].x, leftFingers[i].y, 10, 10); 

    } 
    } 


    private Polygon[] generateKeyPolygons(Point[] borders) { 
    Polygon[] polygons = new Polygon[5]; 
    for (int i = 0; i < borders.length - 1; i++) { 
     Polygon p = new Polygon(); 
     p.addPoint(leftCenter.x, leftCenter.y); 
     p.addPoint(borders[i].x, borders[i].y); 
     p.addPoint(borders[i + 1].x, borders[i + 1].y); 
     polygons[i] = p; 
    } 

    return polygons; 
    } 

    private Point[] calculateCentersBetweenEachTwoFingers(Point[] fingers) { 
    Point[] centers = new Point[4]; 
    for (int i = 0; i < fingers.length - 1; i++) { 
     centers[i] = new Point(((fingers[i].x + fingers[i + 1].x)/2), ((fingers[i].y + fingers[i + 1].y)/2)); 
    } 
    return centers; 
    } 

    private Point calculateCentralSymmetry(Point toReflected, Point center) { 
    Point reflection = new Point(); 

    if (toReflected.x > center.x) { 
     reflection.x = center.x - Math.abs(center.x - toReflected.x); 
    } else { 
     reflection.x = center.x + Math.abs(center.x - toReflected.x); 
    } 

    if (toReflected.y > center.y) { 
     reflection.y = center.y - Math.abs(center.y - toReflected.y); 
    } else { 
     reflection.y = center.y + Math.abs(center.y - toReflected.y); 
    } 

    return reflection; 
    } 

    public void mouseClicked(MouseEvent e) { 

    } 

    public void mousePressed(MouseEvent e) { 
    for (KeyboardButton button : buttons) { 
     button.checkMousePosition(e); 
    } 
    } 

    public void mouseReleased(MouseEvent e) { 
    for (KeyboardButton button : buttons) { 
     button.checkMousePosition(e); 
    } 
    } 

    public void mouseEntered(MouseEvent e) { 

    } 

    public void mouseExited(MouseEvent e) { 

    } 


} 

KeyboardButton.java

package keyboard; 

import java.awt.Color; 
import java.awt.Graphics; 
import java.awt.Polygon; 
import java.awt.event.*; 
import javax.swing.JComponent; 
import javax.swing.JPanel; 

public class KeyboardButton extends JComponent { 

    Polygon polygon; 
    boolean isActive; 
    final Color ACTIVE_COLOR = Color.red; 
    final Color INACTIVE_COLOR = Color.blue; 

    public KeyboardButton(Polygon p) { 
    polygon = p; 
    } 

    public void checkMousePosition(MouseEvent e) { 
    if (polygon.contains(e.getX(), e.getY())) { 
     setState(true); 
    } 
    } 

    @Override 
    protected void paintComponent(Graphics g) { 
    super.paintComponent(g); 
    g.setColor(isActive ? ACTIVE_COLOR : INACTIVE_COLOR); 
    g.drawPolygon(polygon); 
    } 

    void setState(boolean state) { 
    isActive = state; 
    System.out.println(this.hashCode()); 
    repaint(); 

    } 
} 

Answer 1

據我所知道的，KeyboardButton組件沒有被加入到Keyboard。所以，當他們調用repaint()時，它不起作用，因爲它們不是視圖層次結構的一部分。