// Drawing.java
// Class that stores a drawing as an ordered list of Shape objects.

// Written by THC for CS 5 Lab Assignment 3.

import java.util.ArrayList;
import java.awt.*;

public class Drawing {
  private ArrayList<Shape> shapes;    // the ordered list of Shape objects
  private Color currentColor;         // current default color

  // Constructor creates an empty list of Shape objects and saves the
  // default color.
  public Drawing(Color initialColor) {
    shapes = new ArrayList<Shape>();
    currentColor = initialColor;
  }

  // Set the default color.
  public void setColor(Color c) {
    currentColor = c;
  }

  // Return the default color.
  public Color getColor() {
    return currentColor;
  }

  // Add a Shape to the front of the list.
  public void add(Shape s) {
    shapes.add(0, s);
  }

  // Have each Shape in the list draw itself.
  // Draws from back to front, so that Shapes in the front overlay Shapes
  // in the back.
  public void draw(Graphics page) {
    for (int i = shapes.size() - 1; i >= 0; i--)
      shapes.get(i).draw(page);
  }

  // Return a reference to the first Shape in the drawing (from front to back)
  // that contains Point p. If no Shape contains p, return null.
  public Shape getFrontmostContainer(Point p) {
    for (int i = 0; i < shapes.size(); i++)
      if (shapes.get(i).containsPoint(p))
        return shapes.get(i);

    return null;
  }

  // Given a reference to a Shape, remove it from the drawing if it's there.
  public void remove(Shape s) {
    int index = shapes.indexOf(s); // where in the ArrayList it is
    if (index >= 0) // is it in the ArrayList?
      shapes.remove(index); // yes, remove it
  }

  // Given a reference to a Shape, move it to the front of the drawing
  // if it's actually in the drawing.
  public void moveToFront(Shape s) {
    int index = shapes.indexOf(s); // where in the ArrayList it is
    if (index >= 0) { // is it in the ArrayList?
      shapes.remove(index); // yes, remove it from where it is...
      shapes.add(0, s); // ...and add it to the front
    }
  }

  // Given a reference to a Shape, move it to the back of the drawing
  // if it's actually in the drawing.
  public void moveToBack(Shape s) {
    int index = shapes.indexOf(s); // where in the ArrayList it is
    if (index >= 0) { // is it in the ArrayList?
      shapes.remove(index); // yes, remove it from where it is...
      shapes.add(s); // ...and add it to the back
    }
  }

  // Make a Shape replace the Shape currently at the front of the drawing.
  public void replaceFront(Shape s) {
    if (shapes.size() > 0) { // is the drawing nonempty?
      shapes.remove(0); // yes, remove the front Shape...
      shapes.add(0, s); // ...and put in the replacement
    }
  }
}