我正在使用Swing制作GUI，并希望使用相对定位配置Graphics2D对象。我想这样做，当我调整窗口大小时，对象重新绘制在相对于初始锚位置的新位置（可能在某处的左上角）。我曾尝试使用布局管理器来执行此操作，但它不会影响实际绘图，因为这些点几乎是硬编码的。
最好的方法是什么？谁能提供一个很好的例子？感谢。
这是我自包含的例子：
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
public class DrawPanelMain extends JPanel {
public static final double version = 0.0;
private JPanel btnPanel = new JPanel();
private JPanel switchPanel = new JPanel();
private JScrollPane switchPanelScrollPane = new JScrollPane(switchPanel);
//private JPanel[] panelArray = new JPanel[3];
DrawEllipses drawEllipses = new DrawEllipses(POINT_LIST);
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
initializePointList();
createAndShowGui();
}
});
}
public static java.util.List<Point> POINT_LIST = new ArrayList<>();
/*
* This loop will initialize POINT_LIST with the set of points for drawing the ellipses.
* The for each loop initializes points for the top row and the second for loop draws the
* right triangle.
*/
private static void initializePointList() {
int ellipsePointsYCoordinate[] = {140, 200, 260, 320, 380, 440, 500, 560, 620};
int ellipsePointsXCoordinate[] = {140, 200, 260, 320, 380, 440, 500, 560, 620, 680};
int xx = 80;
for (int aXt : ellipsePointsXCoordinate) {
POINT_LIST.add(new Point(aXt, xx));
}
for (int i = 0; i < ellipsePointsYCoordinate.length; i++) {
for (int j = i; j < ellipsePointsYCoordinate.length; j++) {
POINT_LIST.add(new Point(ellipsePointsXCoordinate[i], ellipsePointsYCoordinate[j]));
}
}
}
public DrawPanelMain() {
switchPanel.setBorder(BorderFactory.createLoweredSoftBevelBorder());
switchPanel.setBackground(Color.DARK_GRAY);
switchPanel.add(drawEllipses);
switchPanelScrollPane.setPreferredSize(new Dimension(600,600));
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
// first column
c.gridx = 0;
add(switchPanelScrollPane, c);
// second column
c.gridx = 1;
// first row
c.gridy = 0;
// second row
c.gridy = 1;
c.gridx = 0;
add(btnPanel, c);
btnPanel.add(new JButton(new AddSwitchAction("Add Switch Panel")));
}
public static void createAndShowGui() {
JFrame frame = new JFrame("RF Connection Panel " + version);
frame.setLayout(new BorderLayout());
frame.add(new DrawPanelMain());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(false);
//frame.setLocationRelativeTo(null);
frame.pack();
frame.setVisible(true);
}
/*
* AddSwitchAction will add a new pane to the tabbedPane when the add switch button is clicked
*/
private class AddSwitchAction extends AbstractAction {
public AddSwitchAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
@Override
public void actionPerformed(ActionEvent e) {
String title = "Switch ";
DrawEllipses tabComponent = new DrawEllipses(POINT_LIST);
switchPanel.add(title, tabComponent);
}
}
}
@SuppressWarnings("serial")
class DrawEllipses extends JPanel {
private final int PREF_W = 750; //Window width
private final int PREF_H = 750; //Window height
private final int OVAL_WIDTH = 30;
private static final Color INACTIVE_COLOR = Color.RED;
private static final Color ACTIVE_COLOR = Color.green;
private java.util.List<Point> points;
private java.util.List<Ellipse2D> ellipses = new ArrayList<>();
private Map<Ellipse2D, Color> ellipseColorMap = new HashMap<>();
/*
* This method is used to populate "ellipses" with the initialized ellipse2D dimensions
*/
public DrawEllipses(java.util.List<Point> points) {
this.points = points;
for (Point p : points) {
int x = p.x - OVAL_WIDTH / 2;
int y = p.y - OVAL_WIDTH / 2;
int w = OVAL_WIDTH;
int h = OVAL_WIDTH;
Ellipse2D ellipse = new Ellipse2D.Double(x, y, w, h);
ellipses.add(ellipse);
ellipseColorMap.put(ellipse, INACTIVE_COLOR);
}
MyMouseAdapter mListener = new MyMouseAdapter();
addMouseListener(mListener);
addMouseMotionListener(mListener);
}
/*
* paintComponent is used to paint the ellipses
*/
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g); // paints the background
setBackground(Color.DARK_GRAY);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
for (Ellipse2D ellipse : ellipses) {
g2.setColor(ellipseColorMap.get(ellipse));
g2.fill(ellipse);
g2.setColor(Color.BLACK);
g2.setStroke(new BasicStroke(2));
g2.draw(ellipse);
}
/*
* Set the font characteristics, color, and draw the row labels.
*/
g.setFont(new Font("TimesRoman", Font.BOLD, 18));
g.setColor(Color.BLACK);
//Along the top row
g.drawString("External Port", 10, 50);
g.drawString("1", 135, 50);
g.drawString("2", 195, 50);
g.drawString("3", 255, 50);
g.drawString("4", 315, 50);
g.drawString("5", 375, 50);
g.drawString("6", 435, 50);
g.drawString("7", 495, 50);
g.drawString("8", 555, 50);
g.drawString("9", 615, 50);
g.drawString("10", 672, 50);
//Along the Y-axis
g.drawString("Radio 2", 40, 145);
g.drawString("3", 90, 205);
g.drawString("4", 90, 265);
g.drawString("5", 90, 325);
g.drawString("6", 90, 385);
g.drawString("7", 90, 445);
g.drawString("8", 90, 505);
g.drawString("9", 90, 565);
g.drawString("10", 90, 625);
//Along the X-Axis
g.drawString("1", 135, 670);
g.drawString("2", 195, 670);
g.drawString("3", 255, 670);
g.drawString("4", 315, 670);
g.drawString("5", 375, 670);
g.drawString("6", 435, 670);
g.drawString("7", 495, 670);
g.drawString("8", 555, 670);
g.drawString("9", 615, 670);
//Draws a 3DRect around the top row of ellipse2D objects
g2.setColor(Color.lightGray);
g2.draw3DRect(120, 60, 580, 40, true);
g2.draw3DRect(121, 61, 578, 38, true);
g2.draw3DRect(122, 62, 576, 36, true);
}
/*
* MouseAdapter is extended for mousePressed Event that detects if the x, y coordinates
* of a drawn ellipse are clicked. If the color is INACTIVE it is changed to ACTIVE and
* vice versa.
*/
private class MyMouseAdapter extends MouseAdapter {
@Override
/*
* When mousePressed event occurs, the color is toggled between ACTIVE and INACTIVE
*/
public void mousePressed(MouseEvent e) {
Color c;
for (Ellipse2D ellipse : ellipses) {
if (ellipse.contains(e.getPoint())) {
c = (ellipseColorMap.get(ellipse) == INACTIVE_COLOR) ? ACTIVE_COLOR : INACTIVE_COLOR;
ellipseColorMap.put(ellipse, c);
}
}
repaint();
}
}
/*
* This method will set the dimensions of the JFrame equal to the preferred H x W
*/
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
/*
* Used for button click action to change all ellipses to ACTIVE_COLOR
*/
public void activateAll(){
for (Ellipse2D ellipse : ellipses){
ellipseColorMap.put(ellipse, ACTIVE_COLOR);
}
repaint();
}
/*
* Used for button click action to change all ellipses to INACTIVE_COLOR
*/
public void deactivateAll(){
for (Ellipse2D ellipse : ellipses){
ellipseColorMap.put(ellipse, INACTIVE_COLOR);
}
repaint();
}
}
答案 0 :(得分：3)
正如我之前建议的那样，如果你想要相对定位，那么你需要在每次绘画时（或调整组件大小时）计算相对位置。
基本上你知道宽度方向你有10个圆形，你想要每个30像素绘制一个标签，固定宽度为100个。这意味着你的最小宽度为400像素。
当然这是不合理的，因为你想要在每个圆圈之间留一个间隙，所以你需要决定你的首选差距是什么，再乘以9来确定你的真实最小尺寸。看起来你有大约30像素的间隙，这是另一个270像素，给出了一个670像素的首选大小。
所以问题是当宽度大于670时你会怎么做？你是增加差距还是留在30？
更难的情况是当宽度小于670时，您现在需要将间隙调整得更小，降低到某个最小值。
确定要使用的水平间隙后，您将对垂直间隙进行相同的分析。
现在，当您进行绘画时，您将获得起始位置，并且您绘制的每一行都会因您的垂直间隙而增加。并且行上的每个圆圈都会增加水平间隙。
我从未尝试过，但我相信您可以使用Ellipse的setFrame(...)方法动态移动其位置。所以当你进行绘画时，椭圆将不在正确的位置，它应该正确响应鼠标事件。
所以基本上你是在为Graphics编写自己的自定义布局管理器。
第二种方法是使用真实的组件而不是自定义绘画。
您可以轻松创建自定义图标来表示圆圈。那么也许你可以使用JToggleButton。然后，您可以通过切换按钮和两个不同颜色的图标来处理更改颜色的逻辑。
现在困难的部分。我以前从未尝试过，但我相信你可以使用Spring Layout。
SpringLayout将组件相对于彼此定位。它还包含＆＃34;弹簧＆＃34;在组件之间允许间隙增长/缩小。
我认为这是两种方法。