I really need some help with this, we have to create an animation in java for a class but I'm only in the first year and don't even understand it all properly yet, yet they refuse to help us with it because it is an assignment. I have the drawing part down but I added a wait1second method and cannot get the thing to compile and don't know why, nor do I know how to make things loop so it will be a constant animation :(
Please help.
import element.*;
import java.awt.Color;
publicclass DrawingAssignment2
{
publicstaticvoid main(String args[])
{
}
publicstaticvoid wait1second()
// post: pause for one second
{
long now = System.currentTimeMillis();
long then = now + 1000; // one second of milliseconds
while (System.currentTimeMillis() < then)
{
// Do Nothing
}
DrawingWindow d = new DrawingWindow(300,600);
//Borders 1
d.setForeground(Color.red); //sets drawing colour to red.
Rect Border1 = new Rect (5,10,10,580); //sets coordinates for rectangle
d.draw(Border1); //draws rectangle
d.fill(Border1); //fills rectangle with current colour
//Border 2
Rect Border2 = new Rect (5,580,290,10);
d.draw(Border2);
d.fill(Border2);
//Border 3
Rect Border3 = new Rect (5,10,290,10);
d.draw(Border3);
d.fill(Border3);
//Border 4
Rect Border4 = new Rect (285,10,10,580);
d.draw(Border4);
d.fill(Border4);
wait1Second();
//------------------------------------------------------------
d.clear(Border1);
d.clear(Border2);
d.clear(Border3);
d.clear(Border4);
//------------------------------------------------------------
//Borders 5
d.setForeground(Color.blue); //sets drawing colour to red.
Rect Border5 = new Rect (5,10,10,580); //sets coordinates for rectangle
d.draw(Border5); //draws rectangle
d.fill(Border5); //fills rectangle with current colour
//Border 6
Rect Border6 = new Rect (5,580,290,10);
d.draw(Border6);
d.fill(Border6);
//Border 7
Rect Border7 = new Rect (5,10,290,10);
d.draw(Border7);
d.fill(Border7);
//Border 8
Rect Border8 = new Rect (285,10,10,580);
d.draw(Border8);
d.fill(Border8);
wait1Second();
//------------------------------------------------------------
d.clear(Border5);
d.clear(Border6);
d.clear(Border7);
d.clear(Border8);
//------------------------------------------------------------
//Borders 9
d.setForeground(Color.yellow); //sets drawing colour to red.
Rect Border9 = new Rect (5,10,10,580); //sets coordinates for rectangle
d.draw(Border9); //draws rectangle
d.fill(Border9); //fills rectangle with current colour
//Border 10
Rect Border10 = new Rect (5,580,290,10);
d.draw(Border10);
d.fill(Border10);
//Border 11
Rect Border11 = new Rect (5,10,290,10);
d.draw(Border11);
d.fill(Border11);
//Border 12
Rect Border12 = new Rect (285,10,10,580);
d.draw(Border12);
d.fill(Border12);
//------------------------------------------------------------
d.clear(Border9);
d.clear(Border10);
d.clear(Border11);
d.clear(Border12);
//------------------------------------------------------------
//Car Body
d.setForeground(Color.red);
d.moveTo(30,130);
d.lineTo(30,100);
d.lineTo(50,100);
d.lineTo(100,70);
d.lineTo(160,70);
d.lineTo(210,100);
d.lineTo(250,110);
d.lineTo(280,130);
d.lineTo(30,130);
//Windows
d.setForeground(Color.blue);
d.moveTo(170,77);
d.lineTo(170,100);
d.lineTo(210,100);
//Wheels
d.setForeground(Color.black);
Circle wheel1 = new Circle (60,130,20);
d.fill(wheel1);
Circle wheel2 = new Circle (220,130,20);
d.fill(wheel2);
//Lights
d.setForeground(Color.yellow);
Rect rearl = new Rect(10,110,35,35); // lights
Text t = new Text ("A new sports car!!",90,540);
Text t2 = new Text ("Driving over all Terrain!",90,560);
d.draw(t);
d.draw(t2);
d.draw(new Rect(t.left(),t.top(),t.width(),t.height()));
}
}
1. Where are you getting the elemnts Package from?
2. you have defind your method as wait1second() with a simple "s" and when invokeing it calling with a capital "S" like wait1Second();
3. You seems to be calling the wait1second() inside that method itself. Its looks to me as a recursive call and I dont see a terminating condition and you might get a stack overflow error.
4. Where do you have these Circle and Rect classes? Are they in the element package?
SOrry again but what would be a terminating condition? I added additional brackets but the drawing classes stopped working instead as if i had shut off the elements package.
Waiting one second by hogging the CPU in a do-nothing while loop is a very bad thing to do.
Have a look at the java.util.Timer class; it is pretty easy to use and using it instead of this wait1second() stuff will give you a much better design. What you do is tell the timer how often to run a task (like drawing one frame of an animation), then it will call that task at each interval.
Essentially, your class will have a run() method. Each time it is called, it draws the next step in the animation.
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