package draw; public class Canvas { private int width = 0; private int height = 0; public Canvas(int width, int height) { this.width = width; this.height = height; } // these two are cheats: protected native boolean copy(); protected native boolean stop(); // I need to figure out how to accomplish these two things, especially stop, // directly at the Scheme level w/o going thru the Java layer. public native boolean show(); public native boolean close(); public native boolean drawCircle(Posn p, int r, Color c); public native boolean drawDisk(Posn p, int r, Color c); public native boolean drawRect(Posn p, int width, int height, Color c); public native boolean drawLine(Posn p0, Posn p1, Color c); public native boolean drawString(Posn p, String s); public native boolean clearCircle(Posn p, int r, Color c); public native boolean clearDisk(Posn p, int r, Color c); public native boolean clearRect(Posn p, int width, int height, Color c); public native boolean clearLine(Posn p0, Posn p1, Color c); }