griddedpanel.java

来自「这是JFrame的一些例子(chapter4)。可以参考一下。想要做GUI的人不」· Java 代码 · 共 165 行

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

/**
* A simple helper class that provides various easy to understand methods
* that lays out the components using the GridBagLayout.
*
* @author James Tan
*/
public class GriddedPanel extends JPanel
{
    private GridBagConstraints constraints;
    // define some default constraints values
    private static final int C_HORZ = GridBagConstraints.HORIZONTAL;
    private static final int C_NONE = GridBagConstraints.NONE;
    private static final int C_WEST = GridBagConstraints.WEST;
    private static final int C_WIDTH = 1;
    private static final int C_HEIGHT = 1;

    /**
    * Creates a grid bag layout panel using a default insets constraints.
    */
    public GriddedPanel()
    {
        this( new Insets( 2, 2, 2, 2 ) );
    }

    /**
    * Creates a grid bag layout panel using the specified insets
    * constraints.
    */
    public GriddedPanel( Insets insets )
    {
        super( new GridBagLayout() );
        // creates the constraints object and set the desired
        // default values
        constraints = new GridBagConstraints();
        constraints.anchor = GridBagConstraints.WEST;
        constraints.insets = insets;
    }

    /**
    * Adds the component to the specified row and col.
    */
    public void addComponent( JComponent component, int row, int col )
    {
        addComponent( component, row, col, C_WIDTH,
                      C_HEIGHT, C_WEST, C_NONE );
    }

    /**
    * Adds the component to the specified row and col that spans across
    * a specified number of columns and rows.
    */
    public void addComponent( JComponent component, int row, int col,
                              int width, int height )
    {
       addComponent( component, row, col, width, height, C_WEST, C_NONE );
    }

    /**
    * Adds the component to the specified row and col that anchors at
    * the specified position.
    */
    public void addAnchoredComponent( JComponent component, int row,
                                      int col, int anchor )
    {
       addComponent( component, row, col, C_WIDTH, C_HEIGHT, anchor, C_NONE );
    }

    /**
    * Adds the component to the specified row and col that spans across
    * a specified number of columns and rows that anchors at the specified
    * position.
    */
    public void addAnchoredComponent( JComponent component, int row, int col,
                                      int width, int height, int anchor )
    {
       addComponent( component, row, col, width, height, anchor, C_NONE );
    }

    /**
    * Adds the component to the specified row and col filling the column
    * horizontally.
    */
    public void addFilledComponent( JComponent component, int row, int col )
    {
        addComponent( component, row, col, C_WIDTH, C_HEIGHT, C_WEST, C_HORZ );
    }

    /**
    * Adds the component to the specified row and col with the specified
    * filling direction.
    */
    public void addFilledComponent( JComponent component, int row, int col,
                                    int fill )
    {
       addComponent( component, row, col, C_WIDTH, C_HEIGHT, C_WEST, fill );
    }

    /**
    * Adds the component to the specified row and col that spans across
    * a specified number of columns and rows with the specified filling
    * direction.
    */
    public void addFilledComponent( JComponent component, int row, int col,
                                    int width, int height, int fill )
    {
       addComponent( component, row, col, width, height, C_WEST, fill );
    }
    
    /**
    * Adds the component to the specified row and col that spans across
    * a specified number of columns and rows with the specified filling
    * direction and an anchoring position.
    */
    public void addComponent( JComponent component, int row, int col,
                              int width, int height, int anchor, int fill )
    {
       // sets the constraints object
       constraints.gridx = col;
       constraints.gridy = row;
       constraints.gridwidth = width;
       constraints.gridheight = height;
       constraints.anchor = anchor;
       double weightx = 0.0;
       double weighty = 0.0;
       
       // only use the extra horizontal or vertical spaces if the component
       // spans more than one column or/and row.
       if( width > 1 )
       {
          weightx = 1.0;
       }
       if( height > 1 )
       {   
          weighty = 1.0;
       }

       switch( fill )
       {
           case GridBagConstraints.HORIZONTAL:
               constraints.weightx = weightx;
               constraints.weighty = 0.0;
               break;
           case GridBagConstraints.VERTICAL:
               constraints.weighty = weighty;
               constraints.weightx = 0.0;
               break;
           case GridBagConstraints.BOTH:
               constraints.weightx = weightx;
               constraints.weighty = weighty;
               break;
           case GridBagConstraints.NONE:
               constraints.weightx = 0.0;
               constraints.weighty = 0.0;
               break;
           default:
               break;
       }
       constraints.fill = fill;
       add( component, constraints );
    }
}