package org.drools.examples.conway.ui;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import javax.swing.ImageIcon;
import org.drools.examples.conway.Cell;
import org.drools.examples.conway.CellGrid;
import org.drools.examples.conway.CellState;
/**
* @author <a href="mailto:brown_j@ociweb.com">Jeff Brown</a>
*/
public class CellGridCanvas extends Canvas {
private static final long serialVersionUID = 1L;
private static final Color BACKGROUND_COLOR = Color.gray;
private static final Color GRID_COLOR = CellGridCanvas.BACKGROUND_COLOR.brighter();
private Image offScreenImage;
private Image backgroundImage;
private final int cellSize;
private final CellGrid cellGrid;
private final Image liveCellImage = new ImageIcon( CellGridCanvas.class.getResource( "/org/drools/examples/conway/liveCellImage.gif" ) ).getImage();
/**
* Constructs a CellGridCanvas.
*
* @param cellGrid
* the GoL cellgrid
*/
public CellGridCanvas(final CellGrid cellGrid) {
this.cellGrid = cellGrid;
this.cellSize = this.liveCellImage.getWidth( this );
setBackground( CellGridCanvas.GRID_COLOR );
addMouseListener( new MouseAdapter() {
/**
* Invoked when a mouse button has been pressed on a component.
*/
public void mousePressed(final MouseEvent e) {
toggleCellAt( e.getX(),
e.getY() );
}
} );
addMouseMotionListener( new MouseMotionAdapter() {
public void mouseDragged(final MouseEvent e) {
final Cell cell = getCellAtPoint( e.getX(),
e.getY() );
if ( cell != null ) {
cellGrid.updateCell( cell, CellState.LIVE );
repaint();
}
}
} );
}
private void toggleCellAt(final int x,
final int y) {
final Cell cell = getCellAtPoint( x,
y );
if ( cell != null ) {
if ( cell.getCellState() == CellState.LIVE ) {
this.cellGrid.updateCell( cell, CellState.DEAD );
} else {
this.cellGrid.updateCell( cell, CellState.LIVE );
}
repaint();
}
}
private Cell getCellAtPoint(final int x,
final int y) {
Cell cell = null;
final int column = x / this.cellSize;
final int row = y / this.cellSize;
final int numberOfColumns = this.cellGrid.getNumberOfColumns();
final int numberOfRows = this.cellGrid.getNumberOfRows();
if ( column >= 0 && column < numberOfColumns && row >= 0 && row < numberOfRows ) {
cell = this.cellGrid.getCellAt( row,
column );
}
return cell;
}
/**
* Use double buffering.
*
* @see java.awt.Component#update(java.awt.Graphics)
*/
public void update(final Graphics g) {
final Dimension d = getSize();
if ( (this.offScreenImage == null) ) {
this.offScreenImage = createImage( d.width,
d.height );
}
paint( this.offScreenImage.getGraphics() );
g.drawImage( this.offScreenImage,
0,
0,
null );
}
/**
* Draw this generation.
*
* @see java.awt.Component#paint(java.awt.Graphics)
*/
public void paint(final Graphics g) {
// Draw grid on background image, which is faster
final int numberOfColumns = this.cellGrid.getNumberOfColumns();
final int numberOfRows = this.cellGrid.getNumberOfRows();
if ( this.backgroundImage == null ) {
final Dimension d = getSize();
this.backgroundImage = createImage( d.width,
d.height );
final Graphics backgroundImageGraphics = this.backgroundImage.getGraphics();
// draw background (MSIE doesn't do that)
backgroundImageGraphics.setColor( getBackground() );
backgroundImageGraphics.fillRect( 0,
0,
d.width,
d.height );
backgroundImageGraphics.setColor( CellGridCanvas.BACKGROUND_COLOR );
backgroundImageGraphics.fillRect( 0,
0,
this.cellSize * numberOfColumns - 1,
this.cellSize * numberOfRows - 1 );
backgroundImageGraphics.setColor( CellGridCanvas.GRID_COLOR );
for ( int x = 1; x < numberOfColumns; x++ ) {
backgroundImageGraphics.drawLine( x * this.cellSize - 1,
0,
x * this.cellSize - 1,
this.cellSize * numberOfRows - 1 );
}
for ( int y = 1; y < numberOfRows; y++ ) {
backgroundImageGraphics.drawLine( 0,
y * this.cellSize - 1,
this.cellSize * numberOfColumns - 1,
y * this.cellSize - 1 );
}
}
g.drawImage( this.backgroundImage,
0,
0,
null );
// draw populated cells
for ( int row = 0; row < numberOfRows; row++ ) {
for ( int column = 0; column < numberOfColumns; column++ ) {
final Cell cell = this.cellGrid.getCellAt( row,
column );
if ( cell.getCellState() == CellState.LIVE ) {
g.drawImage( this.liveCellImage,
column * this.cellSize,
row * this.cellSize,
this );
}
}
}
}
/**
* This is the preferred size.
*
* @see java.awt.Component#getPreferredSize()
*/
public Dimension getPreferredSize() {
final int numberOfColumns = this.cellGrid.getNumberOfColumns();
final int numberOfRows = this.cellGrid.getNumberOfRows();
return new Dimension( this.cellSize * numberOfColumns,
this.cellSize * numberOfRows );
}
/**
* This is the minimum size (size of one cell).
*
* @see java.awt.Component#getMinimumSize()
*/
public Dimension getMinimumSize() {
return new Dimension( this.cellSize,
this.cellSize );
}
}