我正在创建一个音乐/绘图应用程序，您可以使用鼠标自由绘制线条，并且TrackBar水平通过它并读取线条并使用x和y坐标来修改音乐。
TrackBar类是JPanel，而DrawBoard类是我在Frame中添加的JPanel。但是哪一个是最重要的是将展示的，我想要的是他们两个都展示，并TrackBar传递到绘制的线上。下面是这3个类的源代码，并取出了一些不实用的代码：
我添加它们的MainFrame类（使用当前设置TrackBar没有出现，但绘图板出现，因为它重叠了它）：
public class MainFrame extends JFrame {
public static ColourToolbar colourBar;
public static TrackBar tb;
public MainFrame(){
super("VIPE by Prestige WorldWide");
// Top colour toolbar for tones
colourBar = new ColourToolbar();
this.getContentPane().add(colourBar, BorderLayout.NORTH);
// This class ImagePanel is a JPanel which I overite the paintCOmponent to have background
ImagePanel bg = new ImagePanel();
bg.setLayout(new BorderLayout());
Dimension size = getPreferredSize();
size.setSize(1024,800); //w, h
bg.setPreferredSize(size);
this.getContentPane().add(bg, BorderLayout.CENTER);
// I add the TrackBar to the ImagePanel since its the Background
tb = new TrackBar();
bg.add(tb, BorderLayout.CENTER);
// I add the drawing board but It will overlap the Trackbar
DrawBoard dboard = new DrawBoard();
bg.add(dboard, BorderLayout.CENTER);
// The control toolbar where the settings and control buttons are.
Toolbar toolBar = new Toolbar();
this.getContentPane().add(toolBar, BorderLayout.SOUTH);
}
public static void main(String[] args){
MainFrame frame = new MainFrame();
frame.setBackground(Color.WHITE);
frame.setSize(1024,768);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
//frame.pack();
frame.setVisible(true);
}
}
现在是TrackBar类：
public class TrackBar extends JPanel{
private TrackBarAction tba = new TrackBarAction(this);
public static int TIME = 9;
public Timer t = new Timer(TIME, tba);
public static double x = 0, y = 0, velX = 1.0, velY = 0;
private int SKIP = 120;
public TrackBar(){
this.setOpaque(false);
}
@Override
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g;
//g2d.drawRect((int)x, (int)y, 10, 800);
Rectangle2D r2d = new Rectangle2D.Double(x, y, 8.0, 800.0); // x,x, w, h
g2d.setPaint(Color.DARK_GRAY);
g2d.fill(r2d);
g2d.draw(r2d);
}
public void reset(){
t.stop();
x = 0;
y = 0;
velX = 0.5;
velY = 0;
this.repaint();
}
public void skipForward(){
if(x+SKIP <= 1024){
x += SKIP;
} else {
x = 1024 - x;
}
this.repaint();
}
public void skipBackwards(){
if(x-SKIP >= 0){
x -= SKIP;
} else {
x = 0;
}
this.repaint();
}
}
现在是DrawBoard类：
public class DrawBoard extends JPanel implements MouseListener, MouseMotionListener{
(..)
public Color currentColor;
public static boolean eraser = false;
private int xX1, yY1;
public DrawBoard(){
Graphics2D g2d = bImage.createGraphics();
g2d.dispose();
Dimension size = getPreferredSize();
size.setSize(1024,800); //w, h
setPreferredSize(size);
//status = new JLabel("default");
//add(status, BorderLayout.SOUTH);
addMouseListener(this);
addMouseMotionListener(this);
imgLabel = new JLabel(new ImageIcon(bImage)) {
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
paintInLabel(g);
}
};
imgLabel.setOpaque(false);
setOpaque(false);
add(imgLabel, BorderLayout.CENTER);
}
private void paintInLabel(Graphics g) {
if(!eraser){
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(getColor()); // this colour is when mouse is pressed
g2d.setStroke(new BasicStroke(STROKESIZE));
if (points.size() < 1) {
return;
}
for (int i = 1; i < points.size(); i++) {
int x1 = points.get(i - 1).x;
int y1 = points.get(i - 1).y;
int x2 = points.get(i).x;
int y2 = points.get(i).y;
g2d.drawLine(x1, y1, x2, y2);
}
}
}
// Where the drawing happens
@Override
public void mousePressed(MouseEvent e) {
//status.setText("you pressed down the mouse");
if(!eraser){
xX1 = e.getX();
yY1 = e.getY();
points.add(e.getPoint());
}
}
@Override
public void mouseDragged(MouseEvent e) {
//status.setText("you draged the mouse");
Graphics2D g2d = bImage.createGraphics();
// this is the eraser code
if(eraser){
//Graphics2D g2d = bImage.createGraphics();
System.out.println("eraser = true");
System.out.println("Stroke = " + STROKESIZE);
g2d.setComposite(AlphaComposite.Clear);
g2d.setColor(new Color(0, 0, 0, 0));
g2d.drawRect(e.getX(), e.getY(), STROKESIZE, STROKESIZE);
g2d.fillRect(e.getX(), e.getY(), STROKESIZE, STROKESIZE);
// g2d.setColor(c);
imgLabel.repaint();
}else {
//g2d.setComposite();
points.add(e.getPoint());
System.out.println("point = " + e.getPoint());
imgLabel.repaint();
}
}
@Override
public void mouseReleased(MouseEvent e) {
//status.setText("you release the mouse click");
if(!eraser){
Graphics2D g2d = bImage.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(getColor()); // this is the final colour
g2d.setStroke(new BasicStroke(STROKESIZE));
if (points.size() >= 2) {
for (int i = 1; i < points.size(); i++) {
int x1 = points.get(i - 1).x;
int y1 = points.get(i - 1).y;
int x2 = points.get(i).x;
int y2 = points.get(i).y;
g2d.drawLine(x1, y1, x2, y2);
}
}
g2d.dispose();
points.clear();
imgLabel.repaint();
}
//imgLabel.repaint();
}
// End of where the drawing happens
public void clearDrawBoard() {
}
private Color getColor() {
return ColourToolbar.selectedColor;
}
private void setColor(Color col){
this.currentColor = col;
}
@Override
public void mouseClicked(MouseEvent e) {
//throw new UnsupportedOperationException("Not supported yet.");
}
}
答案 0 :(得分：4)
BorderLayout只能有一个组件为每个组件添加5个位置。通过将DrawPanel添加到中心位置，您可以有效地删除TrackPanel。
相反，将TrackBar的布局管理器设置为BorderLayout并将DrawPanel添加到它。
您也可以使用JLayeredPane，但管理变得更加复杂