Computer Science 120
Introduction to Programming
Spring 2012, Siena College
Drag4ShirtsArrayList Demo
A working demo of Drag4ShirtsArrayList will appear below. Click inside the applet to interact with it.
Drag4ShirtsArrayList BlueJ Project
Click here to download a BlueJ project for Drag4ShirtsArrayList.
Drag4ShirtsArrayList Source Code
The Java source code for Drag4ShirtsArrayList is below. Click on a file name to download it.
import objectdraw.*;
import java.awt.*;
import java.util.ArrayList;
/*
* Example Drag4ShirtsArrayList
*
* Drag a shirt around window, given choice of red shirt, blue shirt,
* green shirt, and yellow shirt, but now stored in an ArrayList.
*
* Jim Teresco, Siena College, CSIS 120, Spring 2012
*
* $Id: template.java 1777 2012-01-04 01:43:52Z terescoj $
*/
public class Drag4ShirtsArrayList extends WindowController {
// starting location of t-shirt
private static final int ITEM_LEFT = 75;
private static final int ITEM_TOP = 50;
private static final int SND_OFFSET = 150;
// T-shirts on the screen
private ArrayList<TShirt> shirts;
// The piece of laundry to be moved.
private TShirt selectedShirt;
// Previously noted position of mouse cursor
private Location lastPoint;
// Whether user is actually dragging a shirt
private boolean dragging;
// display the shirts, store them in an ArrayList
public void begin() {
// first, construct our ArrayList that can hold TShirt objects
shirts = new ArrayList<TShirt>();
// now, create each shirt and add it to the ArrayList
TShirt shirt = new TShirt(ITEM_LEFT, ITEM_TOP, canvas);
shirt.setColor(Color.red);
shirts.add(shirt);
shirt = new TShirt(ITEM_LEFT + SND_OFFSET, ITEM_TOP, canvas);
shirt.setColor(Color.blue);
shirts.add(shirt);
shirt = new TShirt(ITEM_LEFT, ITEM_TOP + SND_OFFSET, canvas);
shirt.setColor(Color.green);
shirts.add(shirt);
shirt = new TShirt(ITEM_LEFT + SND_OFFSET, ITEM_TOP + SND_OFFSET, canvas);
shirt.setColor(Color.yellow);
shirts.add(shirt);
selectedShirt = shirt; // last created shirt "on top" at start (it has to
// be one of them, doesn't really matter which)
}
// Whenever the mouse is pressed, note its location
// and which (if any) shirt the mouse is on.
public void onMousePress(Location point) {
lastPoint = point;
// start out assuming that we are not on top of any shirt, which
// means we will not be dragging.
dragging = false;
// test the selected shirt (which is on top) first.
if (selectedShirt.contains(point)) {
dragging = true;
} else {
// otherwise, look at each shirt in the ArrayList in turn, see if
// it contains the point. If we find one, we set it as the
// selected shirt so it will be dragged around and set dragging to true
for (int shirtNum = 0; shirtNum < shirts.size(); shirtNum++) {
TShirt shirt = shirts.get(shirtNum);
if (shirt.contains(point)) {
selectedShirt = shirt;
dragging = true;
selectedShirt.sendToFront();
}
}
}
}
// If mouse is dragged, move the selected shirt with it
// If didn't press mouse on a shirt, do nothing
public void onMouseDrag(Location point) {
if (dragging) {
selectedShirt.move(point.getX() - lastPoint.getX(),
point.getY() - lastPoint.getY());
lastPoint = point;
}
}
// move all shirts back to starting positions when mouse leaves window
public void onMouseExit(Location point) {
for (int shirtNum = 0; shirtNum < shirts.size(); shirtNum++) {
shirts.get(shirtNum).reset();
}
dragging = false;
}
}
import objectdraw.*;
import java.awt.*;
/*
* Example Drag2Shirts
*
* A class that defines a graphical type that looks a bit
* like a t-shirt.
*
* Jim Teresco, Siena College, CSIS 120, Spring 2011
* Based on example from Williams College CSCI 134
*
* $Id: TShirt.java 1576 2011-03-24 04:32:40Z terescoj $
*/
public class TShirt {
/* constant for overall size of the T-shirt */
private static final double SIZE = 120;
/* other constants defined relative to SIZE */
private static final double SLEEVE_WIDTH = SIZE;
private static final double SLEEVE_HEIGHT = 0.2 * SIZE;
private static final double BODY_WIDTH = 0.6 * SIZE;
private static final double BODY_HEIGHT = (0.65) * SIZE;
private static final double BODY_INSET = 0.2 * SIZE;
private static final double NECK_WIDTH = 0.3 * SIZE;
private static final double NECK_HEIGHT = 0.06 * SIZE;
private static final double NECK_INSET = 0.35 * SIZE;
private double startX, startY; // the initial location of the shirt
// Rectangles that form a border around the shirt
private FramedRect sleeveTrim, bodyTrim;
private FramedOval neckTrim;
// Rectangles that form the interior color of the shirt
private FilledRect body, sleeves;
private FilledOval neck;
/*
* Create a new T-shirt with its upper left corner at (x,y) and with
* a width of size.
*/
public TShirt(double x, double y, DrawingCanvas canvas) {
// create boundary rectangles
sleeveTrim = new FramedRect(x,
y + NECK_HEIGHT / 2,
SLEEVE_WIDTH,
SLEEVE_HEIGHT,
canvas);
bodyTrim = new FramedRect(x + BODY_INSET,
y + NECK_HEIGHT / 2,
BODY_WIDTH,
BODY_HEIGHT,
canvas);
// create interior rectangles
sleeves = new FilledRect(x + 1,
y + NECK_HEIGHT / 2 + 1,
SLEEVE_WIDTH - 1,
SLEEVE_HEIGHT - 1,
canvas);
body = new FilledRect(x + BODY_INSET + 1,
y + NECK_HEIGHT / 2 + 1,
BODY_WIDTH - 1,
BODY_HEIGHT - 1,
canvas);
// give it a neck hole
neck =
new FilledOval(x + NECK_INSET, y, NECK_WIDTH, NECK_HEIGHT, canvas);
neckTrim =
new FramedOval(x + NECK_INSET, y, NECK_WIDTH, NECK_HEIGHT, canvas);
// set the interior to white
body.setColor(Color.white);
neck.setColor(Color.white);
sleeves.setColor(Color.white);
// remember the starting location for re-set
startX = x;
startY = y;
}
/*
* Move the t-shirt by specified offsets.
*/
public void move(double xOffset, double yOffset) {
body.move(xOffset, yOffset);
neck.move(xOffset, yOffset);
sleeves.move(xOffset, yOffset);
bodyTrim.move(xOffset, yOffset);
sleeveTrim.move(xOffset, yOffset);
neckTrim.move(xOffset, yOffset);
}
/*
* Returns true if the t-shirt contains the point;
* false otherwise
*/
public boolean contains(Location pt) {
return bodyTrim.contains(pt) || sleeveTrim.contains(pt) || neck.contains(pt);
}
/*
* Change color of t-shirt to newColor.
*/
public void setColor(Color newColor) {
body.setColor(newColor);
neck.setColor(newColor);
sleeves.setColor(newColor);
}
/*
* Put t-shirt in front of other objects on canvas.
*/
public void sendToFront() {
bodyTrim.sendToFront();
sleeveTrim.sendToFront();
body.sendToFront();
neck.sendToFront();
sleeves.sendToFront();
neckTrim.sendToFront();
}
/*
* Move the t-shirt to a new upper-left coordinate position.
*/
public void moveTo(double x, double y) {
double dx = x - sleeves.getX();
double dy = y - neck.getY();
this.move(dx, dy);
}
/*
* Move t-shirt back to starting position.
*/
public void reset() {
this.moveTo(startX, startY);
}
}