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The code in Listing 24 :

  • Creates the JPanel object, and sets its layout property to GridLayout.
  • Creates the requisite number of objects of the MyCanvas class (which extends Canvas), setting the background colors of the panels alternately towhite and gray.
  • Adds the MyCanvas objects to the cells in the grid. (Note that the constructor for each MyCanvas object receives an integer that specifies itsposition in the stack of MyCanvas objects. We will see how that information is used later.)

More routine construction code

The code in Listing 25 is simply more routine code required to:

  • Finish the construction of the GUI object
  • Set its location and size on the screen
  • Make it visible

Once again, I will let the comments serve as the explanation for this code.

Listing 25. More routine construction code.
//Add the sub-assemblies to the // frame. Set its location, size,// and title, and make it visible. getContentPane().add(ctlPnl,"South"); getContentPane().add(canvasPanel,"Center"); setBounds(0,0,frmWidth,frmHeight);setTitle("Graph01, " + "Copyright 2002, " +"Richard G. Baldwin"); setVisible(true);//Set to exit on X-button click setDefaultCloseOperation(EXIT_ON_CLOSE); //Get and save the size of the// plotting surface width = canvases[0].getWidth(); height = canvases[0].getHeight();

Force a repaint

As you will see later, the actual plotting behavior of this program is defined by the code in an overridden version of the paint method in the MyCanvas class. I will discuss that code in some detail later.

One way to cause the code in the overridden paint method to be executed is to call the repaint method on a reference to a MyCanvas object.

The code in Listing 26 calls the repaint method on each MyCanvas object in sequence, to guarantee that they are properly painted when the GUI object first becomes visible.

Listing 26. Force a repaint.
for(int cnt = 0; cnt<number; cnt++){ canvases[cnt].repaint(); }//end for loop}//end constructor

Similar code will be used again later to cause the graphs to be repainted each time the user presses the Graph button in the bottom right corner of Figure 1 .

End of the constructor

The code in Listing 26 also ends the constructor for the GUI object. When the constructor finishes execution, the GUI appears on the screen with all plotting areas properly painted.

Re-plotting the data

[link] shows the beginning of the event handler that is registered on the button to cause the functions to be re-plotted.

Beginning of the re-plot code.
public void actionPerformed( ActionEvent evt){//Re-instantiate the object that // provides the datatry{ if(args != null){data = (GraphIntfc01)Class. forName(args).newInstance();}else{ data = new junk();}//end else }catch(Exception e){//Known to be safe at this point. // Otherwise would have aborted// earlier. }//end catch

The purpose of the event handler is to cause the functions to be re-plotted after the user changes the plotting parameters.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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