避免在零布局中重疊組件

Question

我在擴展JComponent的類中有一個空佈局，以便可以在我所需的座標中添加組件。但我也不希望某些組件重疊。任何想法，我怎麼能做到這件事？通過使用任何其他佈局？其實我想要FlowLayout的一些功能。有什麼辦法嗎？

Answer 1

您可能需要實現自己的佈局管理器，例如像這樣：

public class NonOverlappingLayout implements LayoutManager 
{ 
    @Override 
    public void addLayoutComponent (String name, Component comp) 
    { 
     // Do nothing 
    } 

    @Override 
    public void removeLayoutComponent (Component comp) 
    { 
     // Do nothing 
    } 

    @Override 
    public Dimension preferredLayoutSize (Container parent) 
    { 
     int count = parent.getComponentCount(); 
     Rectangle [] r = new Rectangle [count]; 

     for (int i = 0; i < count; i++) 
     { 
      Component c = parent.getComponent (i); 
      if (c.isVisible()) 
       r [i] = c.getBounds(); 
      else r [i] = new Rectangle (0, 0, 0, 0); 
     } 

     r = doLayout (r); 

     Rectangle result = new Rectangle (0, 0, 0, 0); 
     for (int i = 0; i < count; i++) 
     { 
      result = result.union (r [i]); 
     } 

     return result.getSize(); 
    } 

    @Override 
    public Dimension minimumLayoutSize (Container parent) 
    { 
     return preferredLayoutSize (parent); 
    } 

    @Override 
    public void layoutContainer (Container parent) 
    { 
     int count = parent.getComponentCount(); 
     Rectangle [] r = new Rectangle [count]; 

     for (int i = 0; i < count; i++) 
     { 
      Component c = parent.getComponent (i); 
      if (c.isVisible()) 
       r [i] = c.getBounds(); 
      else r [i] = new Rectangle (0, 0, 0, 0); 
     } 

     r = doLayout (r); 

     int minX = 0; 
     int minY = 0; 
     for (int i = 0; i < count; i++) 
     { 
      minX = Math.min (minX, r [i].x); 
      minY = Math.min (minY, r [i].y); 
     } 

     for (int i = 0; i < count; i++) 
     { 
      r [i].translate (-minX, -minY); 
      Component c = parent.getComponent (i); 
      if (c.isVisible()) 
       c.setBounds (r [i]); 
     } 
    } 

    public Rectangle [] doLayout (Rectangle [] initialPositions) 
    { 
     int count = initialPositions.length; 
     Rectangle [] result = new Rectangle [count]; 
     for (int i = 0; i < count; i++) 
      result [i] = new Rectangle (initialPositions [i]); 

     boolean intersection; 

     do 
     { 
      intersection = false; 

      for (int i = 0; i < count; i++) 
      { 
       int xf = 0; 
       int yf = 0; 

       Rectangle r1 = result [i]; 

       for (int j = 0; j < count; j++) 
       { 
        Rectangle r2 = result [j]; 

        if (i != j && r1.intersects (r2)) 
        { 
         if (r1.x * 2 + r1.width < r2.x * 2 + r2.width) 
          xf -= 1; 
         else 
          xf += 1; 

         if (r1.y * 2 + r1.height < r2.y * 2 + r2.height) 
          yf -= 1; 
         else 
          yf += 1; 

         intersection = true; 
        } 
       } 

       if (xf > 0) result [i].x += 1; 
       else if (xf < 0) result [i].x -= 1; 

       if (yf > 0) result [i].y += 1; 
       else if (yf < 0) result [i].y -= 1; 
      } 
     } while (intersection); 

     return result; 
    } 

    public static void main (String [] args) 
    { 
     JFrame frame = new JFrame(); 
     frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().setLayout (new NonOverlappingLayout()); 

     Random r = new Random(); 
     for (int i = 0; i < 100; i++) 
     { 
      JButton b = new JButton(); 
      b.setBounds (r.nextInt (780), r.nextInt (580), 20, 20); 
      frame.getContentPane().add (b); 
     } 
     frame.getContentPane(); 

     frame.pack(); 
     frame.setVisible (true); 
    } 
}