very interesting. -
Is that the same as polymorphism?
I tried to do the same thing [having an ArrayList of different classes] with interface, but that wasn’t a good experience, because I had a lot of same methods inside all classes using the interface. Is inheritance different and better?
Thank you!
Chrisir
interface example
(side question: why do I have still a switch() there, is it inevitable? switch() is evil)
// Demo for Drawing Program with ArrayList
// for mouse is on item / drag
final float hotSpotSize = 22; // radius
// Help text
final String helpText =
"Use 0,1,2, click mouse, use Backspace and 'c'.\n"
+ "Use right mouse to drag previous items. \nWhen you hold an item (right mouse button) use cursor to change size and rotation, use DEL to remove.";
// shapes / items
ArrayList<Shape> listShapes = new ArrayList();
// the type we add
int currentShapeToGenerate = 0;
// current shape we are adding (from currentShapeToGenerate)
String[] texts = {
"circle",
"square",
"triangle"
};
// mouse drag
boolean hold = false;
int i_hold=0;
// -----------------------------------------------------------------------------------------------
// Core funcs
void setup() {
size(1000, 700);
}
void draw() {
background(0);
// display all
displayShapes();
// drag
dragItem();
// show when mouse is on Hot Spot
showSmallRedCircleOnHotSpot();
// text
showText();
}
// -----------------------------------------------------------------------------------------------
// Input funcs
void mousePressed() {
if (mouseButton == LEFT) { // ----------------------------------
Shape newShape = null ;
switch( currentShapeToGenerate ) {
case 0:
newShape = new shapeCircle (mouseX, mouseY);
break;
case 1:
newShape = new shapeSquare (mouseX, mouseY);
break;
case 2:
newShape = new shapeTriangle (mouseX, mouseY);
break;
}//switch
// add
if (newShape!=null) {
listShapes.add(newShape);
} //if
//
} else {
// right mouse button --------------------------------
// search the item to drag
int i=0;
for (Shape currentShape : listShapes) {
if ( currentShape.underMouse() ) {
// store the item to drag
hold=true;
i_hold=i;
return;
}
i++;
}
}
}//func
void mouseReleased() {
hold = false;
}
void keyPressed() {
// get keys:
// these first keys apply always ---
if (key=='0'||key=='1'||key=='2') {
currentShapeToGenerate=int(key+"");
} else if (key==ESC) {
key=0;//kill Esc
} else if (key==BACKSPACE) {
// delete last item
if (listShapes.size()>0)
listShapes.remove(listShapes.size()-1);
} else if (key=='c') {
listShapes.clear();
} else if ( hold && keyCode == DELETE ) { // these following keys only apply when we hold a shape ---
listShapes.remove(i_hold);
hold=false;
} else if ( hold && keyCode == LEFT ) {
listShapes.get(i_hold).incAngle();
} else if ( hold && keyCode == RIGHT ) {
listShapes.get(i_hold).decAngle();
} else if ( hold && keyCode == UP ) {
listShapes.get(i_hold).incSize();
} else if ( hold && keyCode == DOWN ) {
listShapes.get(i_hold).decSize();
}
//
}// func
// --------------------------------------------------------------------------------------------
// Other funcs
void displayShapes() {
stroke(0);
int i=0;
for (Shape currentShape : listShapes) {
// set color (hold / not hold)
fill(255); // White = not hold
if (hold && i==i_hold) {
fill(255, 0, 0); // Red = hold
}
// display
currentShape.display();
// currentShape.move();
i++;
}//for
}
void dragItem() {
if (hold) {
listShapes.get(i_hold).setX(mouseX);
listShapes.get(i_hold).setY(mouseY);
}//if
}
void showSmallRedCircleOnHotSpot() {
for (Shape currentShape : listShapes) {
if (currentShape.underMouse()) {
// display the empty red circle
currentShape.showSmallRectCircle();
return;
}//if
}//for
}
void showText() {
fill(255);
text (helpText
+ "\n"
+ "curent > "
+ texts[ currentShapeToGenerate ], 17, 17);
}
// =============================================================================================
// not called directly
interface Shape {
void display();
void move();
float getX();
float getY();
void setX(float x_);
void setY(float y_);
void incAngle();
void decAngle();
void incSize();
void decSize();
boolean underMouse();
void showSmallRectCircle();
} //interface
// =============================================================================================
class shapeCircle implements Shape {
float x = 50;
float y = 50;
float angle;
float size1=25;
shapeCircle(float x_, float y_) {
x=x_;
y=y_;
}
void move() {
x = x + random(-1, 1);
}
void display() {
fill(255);
ellipse(x, y, size1, size1);
}
Shape copy() {
return new shapeCircle(x, y);
}
// ------------------------------------------------
float getX() {
return x;
}
float getY() {
return y;
}
void setX(float x_) {
x=x_;
}
void setY(float y_) {
y=y_;
}
void incAngle() {
angle+=0.01;
}
void decAngle() {
angle-=0.01;
}
void incSize() {
size1+=1;
}
void decSize() {
size1-=1;
}
boolean underMouse() {
return
dist(mouseX, mouseY, x, y)<hotSpotSize;
}
void showSmallRectCircle() {
// display the empty red circle
noFill();
stroke(255, 0, 0);
circle(x, y, hotSpotSize);
}
} //class
// =============================================================================================
class shapeSquare implements Shape {
float x = 50;
float y = 50;
float angle=0;
float size1 = 25;
shapeSquare(float x_, float y_) {
x=x_;
y=y_;
}
void move() {
y = y + random(-1, 1);
}
void display() {
rectMode(CENTER);
push();
translate(x, y);
rotate(angle);
rect(0, 0, size1, size1);
pop();
//reset
rectMode(CORNER); // default mode
}
// ------------------------------------------------
float getX() {
return x;
}
float getY() {
return y;
}
void setX(float x_) {
x=x_;
}
void setY(float y_) {
y=y_;
}
void incAngle() {
angle+=0.01;
}
void decAngle() {
angle-=0.01;
}
void incSize() {
size1+=1;
}
void decSize() {
size1-=1;
}
boolean underMouse() {
return
dist(mouseX, mouseY, x, y)<hotSpotSize;
}
void showSmallRectCircle() {
// display the empty red circle
noFill();
stroke(255, 0, 0);
circle(x, y, hotSpotSize);
}
} //class
// =============================================================================================
class shapeTriangle implements Shape {
float x = 50;
float y = 50;
float angle;
float size1=25;
shapeTriangle(float x_, float y_) {
x=x_;
y=y_;
}
void move() {
y = y + random(-1, 1);
}
void display() {
push();
translate(x, y);
rotate(angle);
triangle(0, 0,
0-size1, 0,
0, 0+size1);
pop();
}
// ------------------------------------------------
float getX() {
return x;
}
float getY() {
return y;
}
void setX(float x_) {
x=x_;
}
void setY(float y_) {
y=y_;
}
void incAngle() {
angle+=0.01;
}
void decAngle() {
angle-=0.01;
}
void incSize() {
size1+=1;
}
void decSize() {
size1-=1;
}
boolean underMouse() {
return
dist(mouseX, mouseY, x, y)<hotSpotSize;
}
void showSmallRectCircle() {
// display the empty red circle
noFill();
stroke(255, 0, 0);
circle(x, y, hotSpotSize);
}
} //class
//
Thank you so much 
I didn’t have the time to work on it until now I hope tomorrow I will be able to do so and maybe new questions will arise.