pilecanvas.java

一些JAVA的小程序

// CS 582 - Fall 1996 - OSU
// Jean-Guy Speton

import java.awt.*;

// Risk-specific widget to display Cards in a Pile.
class PileCanvas extends Canvas
{
  // The maximum number of "top" cards to display.
  private final static int MAX_CARDS_SHOWN = 5;

  private Risk risk;
  
  public PileCanvas(Risk risk)
  {
    this.risk = risk;
    setBackground(Color.white);
  }

  // AWT methods.

  // Toggle a card's selected state, unless doing so would result in
  // more than 3 selected cards.
  public boolean mouseDown(Event event, int x, int y)
  {
    int i = x / (size().width / MAX_CARDS_SHOWN);
    Pile pile = risk.getCurrentPlayer().getPile();
    int numSelected = 0;

    for (int j = 0; j < MAX_CARDS_SHOWN; j++) {
      if (j < pile.size()) {
	if (pile.cardAt(j).isSelected()) {
	  numSelected++;
	}
      }
    }

    if (i < pile.size()) {
      if (pile.cardAt(i).isSelected() || (numSelected < 3)) {
	pile.cardAt(i).toggleSelected();
	repaint();
      }
    }

    risk.checkCardSet();
    
    return true;
  }
  
  public void paint(Graphics g)
  {
    Pile pile = risk.getCurrentPlayer().getPile();
    Dimension d = size();
    int cardWidth = d.width / MAX_CARDS_SHOWN;
    int cardHeight = d.height - 1;

    for (int i = 0; i < MAX_CARDS_SHOWN; i++) {
      if (i == pile.size()) {
	break;
      }

      Card c = pile.cardAt(i);
      c.paint(g, cardWidth * i, 0, cardWidth, cardHeight);
    }
  }
}