JPanel 사각형 만들기

Question

여러 하위 구성 요소가있는 JPanel이있는 경우 부모 크기가 조정되는 방법에도 불구하고 JPanel이 사각형으로 유지되도록하려면 어떻게해야합니까? 다음 코드에서 변형을 시도했지만 서브 컴포넌트도 사각형이되지는 않습니다.

public void paint(Graphics g){ 
    if(this.isSquare()){ 
     Dimension d = this.getSize(); 
     if(d.height > d.width){ 
      this.setSize(d.width, d.width); 
     } else { 
      this.setSize(d.height, d.height); 
    } 
    super.paint(g); 
} 

여기에 SSCCE가 있습니다.

포함하는 상위 :

import javax.swing.JFrame; 

public class TestFrame extends JFrame{ 

    public TestFrame(){ 
     this.add(new TestPanel()); 
    } 

    public static void main(String[] args){ 
     TestFrame tf = new TestFrame(); 

     tf.setSize(500, 500); 
     tf.setVisible(true); 
    } 
} 

되어야 하는지를 사각형 인 JPanel :

import java.awt.BorderLayout; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.Graphics; 

import javax.swing.JLabel; 
import javax.swing.JPanel; 
import javax.swing.border.LineBorder; 


public class TestPanel extends JPanel{ 
    private boolean isSquare; 

    public TestPanel(){ 
     this.setSquare(true); 
     this.setLayout(new BorderLayout()); 

     JLabel panel1 = new JLabel(); 
     panel1.setBorder(new LineBorder(Color.RED, 4)); 
     panel1.setBackground(Color.CYAN); 

     JLabel panel2 = new JLabel(); 
     panel2.setBorder(new LineBorder(Color.BLUE, 4)); 
     panel2.setBackground(Color.CYAN); 


     this.setBorder(new LineBorder(Color.GREEN, 4)); 
     this.setBackground(Color.CYAN); 

     this.add(panel1, BorderLayout.WEST); 
     this.add(panel2, BorderLayout.EAST); 
    } 

    public void paint(Graphics g){ 
     if(this.isSquare()){ 
      Dimension d = this.getSize(); 
      if(d.height > d.width){ 
       this.setSize(d.width, d.width); 
      } else { 
       this.setSize(d.height, d.height); 
      } 
      super.paint(g); 
     } 
    } 

    private boolean isSquare() { 
     return isSquare; 
    } 

    private void setSquare(boolean isSquare) { 
     this.isSquare = isSquare; 
    } 
} 

Answer 1

import java.awt.*; 
import javax.swing.*; 
import javax.swing.border.EmptyBorder; 

public class SoSquare { 

    public static void main(String[] args) { 
     Runnable r = new Runnable() { 

      @Override 
      public void run() { 
       // the GUI as seen by the user (without frame) 
       // A single component added to a GBL with no constraint 
       // will be centered. 
       JPanel gui = new JPanel(new GridBagLayout()); 

       gui.setBackground(Color.WHITE); 

       SquarePanel p = new SquarePanel(); 
       p.setBackground(Color.red); 
       gui.add(p); 

       JFrame f = new JFrame("Demo"); 
       f.add(gui); 
       // Ensures JVM closes after frame(s) closed and 
       // all non-daemon threads are finished 
       f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); 
       // See http://stackoverflow.com/a/7143398/418556 for demo. 
       f.setLocationByPlatform(true); 

       // ensures the frame is the minimum size it needs to be 
       // in order display the components within it 
       f.pack(); 
       f.setSize(400,100); 
       // should be done last, to avoid flickering, moving, 
       // resizing artifacts. 
       f.setVisible(true); 
      } 
     }; 
     // Swing GUIs should be created and updated on the EDT 
     // http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html 
     SwingUtilities.invokeLater(r); 
    } 
} 

/** 
* A square panel for rendering. NOTE: To work correctly, this must be the only 
* component in a parent with a layout that allows the child to decide the size. 
*/ 
class SquarePanel extends JPanel { 

    @Override 
    public Dimension getPreferredSize() { 
     Dimension d = super.getPreferredSize(); 
     Container c = getParent(); 
     if (c != null) { 
      d = c.getSize(); 
     } else { 
      return new Dimension(10, 10); 
     } 
     int w = (int) d.getWidth(); 
     int h = (int) d.getHeight(); 
     int s = (w < h ? w : h); 
     return new Dimension(s, s); 
    } 
} 

Answer 2

은 성분의 바람직한/최소/최대 크기를 존중하는 레이아웃 관리자를 이용한다. getPreferred/Minimum/MaximumSize 메서드를 재정 의하여 원하는 크기로 되돌립니다.

import java.awt.BorderLayout; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.EventQueue; 
import java.awt.GridBagLayout; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JPanel; 
import javax.swing.UIManager; 
import javax.swing.UnsupportedLookAndFeelException; 
import javax.swing.border.LineBorder; 

public class SqaurePaneTest { 

    public static void main(String[] args) { 
     new SqaurePaneTest(); 
    } 

    public SqaurePaneTest() { 
     EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
       } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { 
       } 

       JFrame frame = new JFrame("Testing"); 
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
       frame.setLayout(new GridBagLayout()); 
       frame.add(new TestPane()); 
       frame.pack(); 
       frame.setLocationRelativeTo(null); 
       frame.setVisible(true); 
      } 
     }); 
    } 

    public class TestPane extends JPanel { 

     public TestPane() { 
      setLayout(new BorderLayout()); 
      add(new JLabel("Look ma, I'm a square", JLabel.CENTER)); 
      setBorder(new LineBorder(Color.GRAY)); 
     } 

     @Override 
     public Dimension getMinimumSize() { 
      return getPreferredSize(); 
     } 

     @Override 
     public Dimension getMaximumSize() { 
      return getPreferredSize(); 
     } 

     @Override 
     public Dimension getPreferredSize() { 
      return new Dimension(200, 200); 
     } 
    } 

} 

또는 같은 일이