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

// Allows a user to stack (and un-stack) wood.
public class RecWoodPile extends WindowController implements ActionListener {

  // dimensions of wood to be stacked
  private static final int WOOD_WIDTH = 100;
  private static final int WOOD_HT = 10;

  // the stacking displacement
  private static final int STACKING_DISP = 26;

  // the stack of wood
  private StackInterface woodStack;

  // buttons that allow a user to select a mode (stacking or unstacking)
  private JButton stackButton, unStackButton;

  // the x and y locations of the next item of wood to be stacked
  private static final int WOOD_X = 100;
  private int y = 340;

  // an image of wood
  private Image woodImage;

  public void begin() {
    // create the user interface components

    stackButton = new JButton("Stack 'em");
    unStackButton = new JButton("Unstack 'em");

    JPanel buttonPanel = new JPanel();
    buttonPanel.add(stackButton);
    buttonPanel.add(unStackButton);

    getContentPane().add(buttonPanel, BorderLayout.SOUTH);

    // add listeners
    stackButton.addActionListener(this);
    unStackButton.addActionListener(this);

    woodImage = getImage("wood5.jpg");

    // the stack is initially empty
    woodStack = new EmptyStack();
  }

  public void actionPerformed(ActionEvent e) {
    if (e.getSource() == stackButton) {
      // put a new piece of wood on the stack
      VisibleImage wood = new VisibleImage(woodImage, WOOD_X, y, canvas);
      woodStack = new NonEmptyStack(wood, woodStack);
      y = y - STACKING_DISP;
    } else {
      // only remove a piece of wood if stack is not empty
      if (!woodStack.isEmpty()) {
        VisibleImage wood = woodStack.getFirst();
        wood.removeFromCanvas();
        woodStack = woodStack.getRest();
        y = y + STACKING_DISP;
      }
    }
  }
}