CS535 Object-Oriented Programming & Design
Fall Semester, 1996
Doc 28, AWT Gridbag

1. References

Doc 28, AWT Gridbag Slide # 1

Doc 28, AWT Gridbag Slide # 2

Column and row positions of the upper left hand corner of the component to be added

Number of columns and rows the component will occupy

REMAINDER

RELATIVE

Determines if component fills the entire area

HORIZONTAL

VERTICAL

NONE

BOTH

If the component does not fill the entire space, anchor indicates where if will be placed

Margin around the outside of a component

Added to the minimum size of the component

How much of available space should the component take

Doc 28, AWT Gridbag Slide # 3

class  GridBagExample  extends Frame  {
   public GridBagExample( int  width, int height ) {
      setTitle( "Grid Bag" );
      resize( width, height );
      GridBagLayout aLayout = new GridBagLayout();
      GridBagConstraints constraints = new GridBagConstraints();
      setLayout( aLayout );
      
      constraints.gridx = 0;      // Start column
      constraints.gridy = 0;      // Start row
      
      constraints.gridwidth = 2;   // Num. of columns wide
      constraints.gridheight = 1;   // Num. of rows high

      constraints.weighty = 100;
      constraints.weightx = 100;
      
      constraints.anchor = GridBagConstraints.CENTER;
      constraints.fill = GridBagConstraints.NONE;
      
      Button none = new Button( "none" );
      aLayout.setConstraints( none, constraints );
      
      constraints.gridy = 1;
      constraints.fill = GridBagConstraints.HORIZONTAL;

      Button horz = new Button( "horz" );
      aLayout.setConstraints( horz, constraints );

      constraints.gridy = 2;
      constraints.fill = GridBagConstraints.BOTH;

      Button both = new Button( "both" );
      aLayout.setConstraints( both, constraints );

      constraints.gridy = 3;
      constraints.fill = GridBagConstraints.VERTICAL;

      Button vert = new Button( "vert" );
      aLayout.setConstraints( vert, constraints );

      add( none );      add( both );
      add( horz );      add( vert );
      show();
   }
}
Doc 28, AWT Gridbag Slide # 4

Doc 28, AWT Gridbag Slide # 5

class  GridBagExample  extends Frame  {
   public GridBagExample( int  width, int height ) {
      setTitle( "Grid Bag" );
      resize( width, height );
      GridBagLayout aLayout = new GridBagLayout();
      GridBagConstraints constraints = new GridBagConstraints();
      setLayout( aLayout );
      
      constraints.gridx = 0;      // Start column
      constraints.gridy = 0;      // Start row
      
      constraints.gridwidth = 1;   // Num. of columns wide
      constraints.gridheight = 1;   // Num. rows high

      constraints.weighty = 100;
      constraints.weightx = 100;
      
      constraints.anchor = GridBagConstraints.CENTER;
      constraints.fill = GridBagConstraints.NONE;
      
      Button center = new Button( "center" );
      aLayout.setConstraints( center, constraints );
      
      constraints.gridx = 1;
      constraints.anchor = GridBagConstraints.WEST;

      Button west = new Button( "west" );
      aLayout.setConstraints( west, constraints );

      constraints.gridx = 2;
      constraints.anchor = GridBagConstraints.NORTHWEST;

      Button nwest = new Button( "nwest" );
      aLayout.setConstraints( nwest, constraints );

      constraints.gridx = 3;
      constraints.anchor = GridBagConstraints.NORTHEAST;

      Button neast = new Button( "neast" );
      aLayout.setConstraints( neast, constraints );

      add( center );      add( nwest );
      add( west );      add( neast );
      show();
   }
}
Doc 28, AWT Gridbag Slide # 6

Doc 28, AWT Gridbag Slide # 7

class GridBagExample extends Frame {
   public GridBagExample( int  width, int height ) {
      setTitle( "Insets" );
      resize( width, height );
      GridBagLayout aLayout = new GridBagLayout();
      GridBagConstraints constraints = new GridBagConstraints();
      setLayout( aLayout );
      
      constraints.gridwidth = 1;   // Num. of columns wide
      constraints.gridheight = 1;   // Num. rows high

      int top = 10;            int bottom = 20;
      int left = 12;            int right = 0;
      
      constraints.insets = new Insets( top, left , bottom, right );
      
      constraints.fill = GridBagConstraints.BOTH;
      constraints.weighty = 100;
      constraints.weightx = 100;

      constraints.gridx = 2;
      constraints.gridy = 0;
      Button one = new Button( "one" );
      aLayout.setConstraints( one, constraints );
      
      constraints.gridx = 1;
      Button two = new Button( "two" );
      aLayout.setConstraints( two, constraints );

      constraints.gridx = 0;
      Button three = new Button( "three" );
      aLayout.setConstraints( three, constraints );

      add( one );         add( two );
      add( three );
      show();
   }
}
Doc 28, AWT Gridbag Slide # 8

      int top = 10;            int bottom = 20;
      int left = 12;            int right = 0;
      
      constraints.insets = new Insets( top, left , bottom, right );

Doc 28, AWT Gridbag Slide # 9