Question

Hi
I work with netbeans.
I have written a code which has two classes (1) Demo (2) mainFrame which extends javax.swing.JFrame

at first, my mainFrame will be run and it will show a panel that you can put some points on it and then when you click a button ; the dimension of all points will be store in a list , then I will send this list to Demo class because I have to put the points in an order that you can draw a line between each two points respectively.
I have two problems here :

1. I have that list <listOfPoints> ,how can I send this list to mainFrame class for drawing lines without making a new object of the mainFrame class?

2. I should work with paint method?
   please help me by some code example in java (with netbeans)

   Totally :

   I have a lot of points' dimension in my list ,I want to traverse my list in the i.e., paint method and draw line between each pi and pi+1.how can I do this?
   

thanks

Answer 1

Google: netbeans java drawline

first answer

search

Graphics gg = buffImg.createGraphics();
        gg.setColor(Color.MAGENTA);
        gg.drawLine(10,10,buffImg.getWidth()-buffImg.getWidth()/10,

http://wws2.uncc.edu/tpw/tpwJavaNtebeansTutorial/index.html

regarding your question about drawing a list of points

void drawList(Graphics gg, List points){
   MyPointClass prev p = null;
   for(MyPointClass p : points){
       if(prevp != null){
           gg.drawLine(prevp.x, prevp.y, p.x, p.y);
       }
       prev = p;
    }
}

And if you don’t feel like passing object from one frame to the other male drawList static and then you can do MyClassContainingDrawLineMethod.drawList(gg, points);