Transcript Drawing Gizmo Example - University of Wisconsin–La Crosse

Programming Language Features
• Syntax
• Semantics
Syntax Diagram
Syntax Diagram
Syntax Diagram
Syntax Diagram
Syntax Diagram
Syntax Diagram
Syntax Diagram
Syntax Diagram
Syntax Diagram
Drawing Gizmo Example
// Example program with parameters that displays a T
// The T is drawn by the method drawT
public class Driver {
private DrawingGizmo pencil;
public void drawT() {
//Draws a letter T
//PRE: Assumes the current position of the pen is the
// leftmost postion of the top of the T and the direction
// of the pen is 0 degrees
//POST: The method leaves the pen at the rightmost
// position of the top of the T and the direction of the
// pen is 0 degrees
pencil.draw();
pencil.turnBy(90);
pencil.moveBy(80);
Drawing Gizmo Example
//Move the pen to the middle of the top of the T
pencil.dontDraw();
pencil.turnBy(-180);
pencil.moveBy(40);
//Draw the vertical part of the T
pencil.draw();
pencil.turnBy(-90);
pencil.moveBy(120);
//Move pen to the rightmost position of the top of the T
//leave the direction of the pen at 0 degrees
pencil.dontDraw();
pencil.turnBy(180);
pencil.moveBy(120);
pencil.turnBy(90);
pencil.moveBy(40);
pencil.turnBy(-90);
}
Drawing Gizmo Example
public Driver() {
pencil = new DrawingGizmo();
//Move the pen to the left
pencil.dontDraw();
pencil.turnBy(-90);
pencil.moveBy(80);
pencil.turnBy(90);
drawT();
}
}