src/tim/prune/gui/GuiGridLayout.java

   1 package tim.prune.gui;
   2
   3 import java.awt.GridBagConstraints;
   4 import java.awt.GridBagLayout;
   5 import java.awt.Insets;
   6
   7 import javax.swing.JComponent;
   8 import javax.swing.JPanel;
   9
  10 /**
  11  * Class to make it easier to use GridBagLayout for a non-equal-width layout
  12  * Default is two columns but can handle more
  13  */
  14 public class GuiGridLayout
  15 {
  16         private GridBagLayout _layout = null;
  17         private GridBagConstraints _constraints = null;
  18         private JPanel _panel = null;
  19         private int _numColumns = 0;
  20         private double[] _colWeights = null;
  21         private boolean[] _rightAligns = null;
  22         private int _x = 0;
  23         private int _y = 0;
  24
  25         /**
  26          * Constructor
  27          * @param inPanel panel using layout
  28          */
  29         public GuiGridLayout(JPanel inPanel)
  30         {
  31                 // Default is two columns, with more weight to the right-hand one; first column is right-aligned
  32                 this(inPanel, null, null);
  33         }
  34
  35         /**
  36          * Constructor
  37          * @param inPanel panel using layout
  38          * @param inColumnWeights array of column weights
  39          * @param inAlignRights array of booleans, true for right alignment, false for left
  40          */
  41         public GuiGridLayout(JPanel inPanel, double[] inColumnWeights, boolean[] inAlignRights)
  42         {
  43                 _panel = inPanel;
  44                 _layout = new GridBagLayout();
  45                 _constraints = new GridBagConstraints();
  46                 _colWeights = inColumnWeights;
  47                 _rightAligns = inAlignRights;
  48                 if (_colWeights == null || _rightAligns == null || _colWeights.length != _rightAligns.length
  49                         || _colWeights.length < 2)
  50                 {
  51                         _colWeights = new double[] {0.5, 1.0};
  52                         _rightAligns = new boolean[] {true, false};
  53                 }
  54                 _numColumns = _colWeights.length;
  55                 _constraints.weightx = 1.0;
  56                 _constraints.weighty = 0.0;
  57                 _constraints.ipadx = 10;
  58                 _constraints.ipady = 1;
  59                 _constraints.insets = new Insets(1, 5, 1, 5);
  60                 // Apply layout to panel
  61                 _panel.setLayout(_layout);
  62         }
  63
  64         /**
  65          * Add the given component to the grid
  66          * @param inComponent component to add
  67          */
  68         public void add(JComponent inComponent)
  69         {
  70                 _constraints.gridx = _x;
  71                 _constraints.gridy = _y;
  72                 _constraints.weightx = _colWeights[_x];
  73                 // set anchor
  74                 _constraints.anchor = (_rightAligns[_x]?GridBagConstraints.LINE_END:GridBagConstraints.LINE_START);
  75                 _layout.setConstraints(inComponent, _constraints);
  76                 // add to panel
  77                 _panel.add(inComponent);
  78                 // work out next position
  79                 _x++;
  80                 if (_x >= _numColumns) {
  81                         nextRow();
  82                 }
  83         }
  84
  85         /**
  86          * Go to the next row of the grid
  87          */
  88         public void nextRow()
  89         {
  90                 _x = 0;
  91                 _y++;
  92         }
  93 }