racket/collects/htdch/Examples/draw-multiple-canvas.ss
2006-07-28 14:44:41 +00:00

45 lines
1.1 KiB
Scheme

import draw.*;
import colors.*;
import geometry.*;
class Example {
Canvas create(int w, int h, Color bg) {
Canvas c = new Canvas(w,h);
boolean tstC = c.show();
boolean tstCDraw = c.drawRect(new Posn(0,0),w,h,bg);
return c;
}
}
class Example1 extends Example {
Canvas c = create(100,200,new Black());
Canvas d = create(200,100,new White());
boolean tst = c.close();
String result = "the white 200 x 100 canvas is visible; the black one has disappeared";
}
class Example2 extends Example {
Canvas c = create(100,200,new Blue());
Canvas d = create(200,100,new Red());
boolean tst = d.close();
String result = "the blue canvas is visible; the green one has disappeared";
}
class Example3 extends Example {
Canvas c = create(100,100,new Green());
String sc = "a green 100 x 100 canvas pops up";
Canvas d = create(200,200,new Black());
String sd = "a black 200 x 200 canvas pops up";
boolean tst = c.close();
String st = "the green screen has disappeared";
boolean tst2 = c.show();
String result = "the black canvas is visible; a second white one (of 100 x 100) is visible";
}