paint error, with a simple boolean

[PRW56]

its extremely odd, to me anyway, i tried to put a section of the paint method, thats in a frame, into a conditional so that it only executes the first time, to cut down on the flickering when the animation happens, but the paint methods inside it dont execute, when i put in system.out.println to test it, it executes but nothing else in the conditional. i used this method in an applet and it worked, i dont know why...

here is code:

import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class CFrame extends Fram implements ActionListener
{
Image image1,image2;
Button b = new Button("Enter");
Button show = new Button("Show Answer");
Button reset = new Button("RESET");
TextField entry = new TextField("",5);
Timer timer = new Timer();
int xloc=180,x=0,yloc=490,rate;
boolean first=false,q=true;
Font big = new Font("Serif",Font.BOLD,40);
Label ans = new Label("Correct answer is: d(theta)/dt = 1 rad/sec");
Label tryt = new Label("");
Label rr = new Label("Related Rates");
boolean att=false, cor = false;;
CFrame()
{
super("CFRAME");
setSize(1000,850);
setLayout(null);
add(b);
add(show);
add(entry);
add(rr);
add(reset);
reset.addActionListener(this);
reset.setBounds(50,130,60,30);
b.setBounds(630,50,60,30);
b.addActionListener(this);
show.setBounds(630,100,80,40);
show.addActionListener(this);
entry.setBounds(710,50,60,25);
rr.setBounds(25,25,250,100);
rr.setFont(big);
rr.setBackground(Color.BLUE);
setVisible(true);
setBackground(Color.BLUE);
//System.out.print(b.getX());
//repaint();
//start();
}
public void paint(Graphics g)
{
Toolkit tool = Toolkit.getDefaultToolkit();
image2 = tool.getImage("E:\\programmin\\WhiteBook\\pics\\ax is.jpg");
g.drawImage(image2,50,150,this);
image2 = tool.getImage("E:\\programmin\\WhiteBook\\pics\\bo lt.jpg");
g.drawImage(image2,110,470,this);
image2 = tool.getImage("E:\\programmin\\WhiteBook\\pics\\wo rk.jpg");
g.drawImage(image2,400,500,this);
g.setFont(big);
//g.setColor(Color.BLACK);
//g.drawString("Related Rates",25,25);
if(first==true)
{

// here is conditional that im talking about

if(q==true)
{
//System.out.print(b.getX());
//image1 = tool.getImage("E:\\programmin\\WhiteBook\\pics\\bo lt.jpg");
//System.out.print(":gjdfgjkl");
//g.drawImage(image1,900,985,this);
g.fillOval(900,980,50,50);
q=false;
}
g.setColor(Color.YELLOW);
g.fillOval(xloc,yloc,25,25);
if(x>=52)
{
g.setColor(Color.RED);
g.drawLine(485,500,xloc,yloc+12);
}
//g.setColor(Color.BLACK);
//g.drawLine(500,200,xloc,yloc+25);
try
{
if(x<50)
{
xloc+=5;
//yloc-=x^2;
++x;
Thread.sleep(10);
}
if(x>=50&&x<77)
{
xloc+=10;
yloc-=(x-49)^2;
++x;
Thread.sleep(100);
}
if(x==77)
{
//g.setColor(Color.MAGENTA);
//g.drawLine(485,500,xloc,yloc+12);
if(att==false)
{
add(ans);
ans.setBounds(330,150,180,30);
ans.setForeground(Color.RED);
g.setColor(Color.GREEN);
g.drawArc(340,450,200,200,90,-38);
++x;
}
else
{
if(cor==true)
{
add(tryt);
tryt.setBounds(330,150,180,30);
g.setColor(Color.GREEN);
g.drawArc(340,450,200,200,90,-38);
++x;
}
else
{
add(tryt);
tryt.setBounds(330,150,180,30);
add(ans);
ans.setBounds(330,150,180,30);
g.setColor(Color.GREEN);
if(Integer.parseInt(entry.getText())>1)
{
g.drawArc(340,450,200,200,90,-45);
System.out.print(b.getX());
}
else
{
if(Integer.parseInt(entry.getText())<1)
{
g.drawArc(340,450,200,200,90,-25);
System.out.print(b.getX());
}
}
++x;
}
}

}
}
catch(InterruptedException e)
{
}
if(x<78)
repaint();
}

}
public void start()
{
timer.schedule(new TimerTask()
{
public void run()
{
xloc-=5;
repaint();
//System.out.println("hey");
timer.cancel();
}
},500,500);

}
public void actionPerformed(ActionEvent e)
{
String buttonClicked=e.getActionCommand();
if(buttonClicked.equals("Enter"))
{
att=true;
if(1==Integer.parseInt(entry.getText()))
{
tryt.setText("Correct");
first=true;
cor=true;
repaint();
}
else
{
tryt.setText("InCorrect");
first=true;
repaint();
}
}
else
{
if(buttonClicked.equals("Show Answer"))
{
first=true;
repaint();
}
else
{
if(buttonClicked.equals("RESET"))
{
first=false;
remove(tryt);
remove(ans);
xloc=180;
yloc=490;
x=0;
repaint();
}
}
}
//System.out.println("hey");
//rate=Integer.parseInt(entry.getText());
//first=true;
//repaint();
}
}

[KevinWorkman]

Some advice:

When posting code, use the code tags to preserve formatting. And make sure you paste your actual code in SSCCE form (what's a Fram?) without any extra code.

Don't do any loading inside your painting code.

Don't call Thread.sleep inside your painting code.

[PRW56]

sorry for not explaining fram is my window adapter, what do you mean by add tags, and why not do those two things

[KevinWorkman]

I mean surround your code with code tags to preserve the formatting.

And you shouldn't do those things because it ties up the EDT, which will result in terrible things, including the symptom you described.

[PRW56]

while i bing EDT can you tell me how to tag the code, i did it the first time i did a post by accident (on other thread)...

[KevinWorkman]

EDT = Event Dispatching Thread. It's where things like event handlers and Swing code (including painting) gets called. So if you do something that takes a long time on the EDT (like reading files), then the EDT stops responding- which prevents your program from responding to events or handling painting, which will cause the flickering behavior you described, as well as other symptoms. One of the reasons Java has a bad rep amongst the uneducated for being slow is because novice programmers deal with the EDT wrong and cause their program to freeze up or appear laggy.

And you should have a little button in the advanced editor that automatically wraps the selection in code tags. It does this:

System.out.println("ooh look how pretty");

[PRW56]

//ok ill try wraping... anyway should i move the loading stuff to the constructor and try to actionPerformed, what would be the most efficient?

import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class CFrame extends Fram implements ActionListener
{
Image image1,image2;
Button b = new Button("Enter");
Button show = new Button("Show Answer");
Button reset = new Button("RESET");
TextField entry = new TextField("",5);
Timer timer = new Timer();
int xloc=180,x=0,yloc=490,rate;
boolean first=false,q=true;
Font big = new Font("Serif",Font.BOLD,40);
Label ans = new Label("Correct answer is: d(theta)/dt = 1 rad/sec");
Label tryt = new Label("");
Label rr = new Label("Related Rates");
boolean att=false, cor = false;;
CFrame()
{
super("CFRAME");
setSize(1000,850);
setLayout(null);
add(b);
add(show);
add(entry);
add(rr);
add(reset);
reset.addActionListener(this);
reset.setBounds(50,130,60,30);
b.setBounds(630,50,60,30);
b.addActionListener(this);
show.setBounds(630,100,80,40);
show.addActionListener(this);
entry.setBounds(710,50,60,25);
rr.setBounds(25,25,250,100);
rr.setFont(big);
rr.setBackground(Color.BLUE);
setVisible(true);
setBackground(Color.BLUE);
//System.out.print(b.getX());
//repaint();
//start();
}
public void paint(Graphics g) 
{
Toolkit tool = Toolkit.getDefaultToolkit();
image2 = tool.getImage("E:\\programmin\\WhiteBook\\pics\\ax is.jpg");
g.drawImage(image2,50,150,this);
image2 = tool.getImage("E:\\programmin\\WhiteBook\\pics\\bo lt.jpg");
g.drawImage(image2,110,470,this);
image2 = tool.getImage("E:\\programmin\\WhiteBook\\pics\\wo rk.jpg");
g.drawImage(image2,400,500,this);
g.setFont(big);
//g.setColor(Color.BLACK);
//g.drawString("Related Rates",25,25);
if(first==true)
{

// here is conditional that im talking about

if(q==true)
{
//System.out.print(b.getX());
//image1 = tool.getImage("E:\\programmin\\WhiteBook\\pics\\bo lt.jpg");
//System.out.print(":gjdfgjkl");
//g.drawImage(image1,900,985,this);
g.fillOval(900,980,50,50);
q=false;
}
g.setColor(Color.YELLOW);
g.fillOval(xloc,yloc,25,25);
if(x>=52)
{
g.setColor(Color.RED);
g.drawLine(485,500,xloc,yloc+12);
}
//g.setColor(Color.BLACK);
//g.drawLine(500,200,xloc,yloc+25);
try
{
if(x<50)
{
xloc+=5;
//yloc-=x^2;
++x;
Thread.sleep(10);
}
if(x>=50&&x<77)
{
xloc+=10;
yloc-=(x-49)^2;
++x;
Thread.sleep(100);
}
if(x==77)
{
//g.setColor(Color.MAGENTA);
//g.drawLine(485,500,xloc,yloc+12);
if(att==false)
{
add(ans);
ans.setBounds(330,150,180,30);
ans.setForeground(Color.RED);
g.setColor(Color.GREEN);
g.drawArc(340,450,200,200,90,-38);
++x;
}
else
{
if(cor==true)
{
add(tryt);
tryt.setBounds(330,150,180,30);
g.setColor(Color.GREEN);
g.drawArc(340,450,200,200,90,-38);
++x;
}
else
{
add(tryt);
tryt.setBounds(330,150,180,30);
add(ans);
ans.setBounds(330,150,180,30);
g.setColor(Color.GREEN);
if(Integer.parseInt(entry.getText())>1)
{
g.drawArc(340,450,200,200,90,-45);
System.out.print(b.getX());
}
else
{
if(Integer.parseInt(entry.getText())<1)
{
g.drawArc(340,450,200,200,90,-25);
System.out.print(b.getX());
}
}
++x;
}
}

}
}
catch(InterruptedException e)
{
}
if(x<78)
repaint();
}

}
public void start() 
{
timer.schedule(new TimerTask() 
{
public void run() 
{
xloc-=5;
repaint();
//System.out.println("hey");
timer.cancel();
}
},500,500);

}
public void actionPerformed(ActionEvent e)
{
String buttonClicked=e.getActionCommand();
if(buttonClicked.equals("Enter"))
{
att=true;
if(1==Integer.parseInt(entry.getText()))
{
tryt.setText("Correct");
first=true;
cor=true;
repaint();
}
else
{
tryt.setText("InCorrect");
first=true;
repaint();
}
}
else
{
if(buttonClicked.equals("Show Answer"))
{
first=true;
repaint();
}
else
{
if(buttonClicked.equals("RESET"))
{
first=false;
remove(tryt);
remove(ans);
xloc=180;
yloc=490;
x=0;
repaint();
}
}
}
//System.out.println("hey");
//rate=Integer.parseInt(entry.getText());
//first=true;
//repaint();
}
}

[KevinWorkman]

Do you really not use indentation in your code? And yes, you still have to move the loading out of your paint method. And you still have to get rid of those calls to Thread.sleep(). These are what's causing your problems, so we can't really proceed until you fix them.

[PRW56]

i actually do but at the time that i tried wrapping i only coppied and pasted the first post, if u wnat me to re-re-post the code i will, also what's ur take on when to use threads or timer?

[KevinWorkman]

i actually do but at the time that i tried wrapping i only coppied and pasted the first post, if u wnat me to re-re-post the code i will, also what's ur take on when to use threads or timer?

You can edit any of your previous posts to format the code correctly, no need to re-re-post the code.

And whether you use a Timer or a Thread is a separate question. Either way, you should should NOT call Thread.sleep() while on the EDT.

[PRW56]

yeah i figured out i could do that immediately after... but yeah i get that i shouldnt use that method in this case, im just curious what you think is the optimum time to use timer and/or threads?

[KevinWorkman]

yeah i figured out i could do that immediately after... but yeah i get that i shouldnt use that method in this case, im just curious what you think is the optimum time to use timer and/or threads?

My general rule of thumb- use a Swing Timer until you have a reason not to.

[PRW56]

What would be a reason not to use a swing timer?

[DarrylBurke]

What would be a reason not to use a swing timer?

One I can think of is when you require a timing accuracy greater than javax.swing.Timer can provide. Another could be when you want a fixed delay from the end of one action to the beginning of the next. There could be others.

db

[PRW56]

That makes sense, but it is also why i despise using swing. The only things i have been taught were from a book around ten years old, and in said book it only used the word swing two pages, 1 being the index. Swing's methods seem to simplify what you would normally have to do when using the older classes from java.util, but when I use them I run into... unusual problems.

[DarrylBurke]

That makes sense, but it is also why i despise using swing. The only things i have been taught were from a book around ten years old, and in said book it only used the word swing two pages, 1 being the index. Swing's methods seem to simplify what you would normally have to do when using the older classes from java.util, but when I use them I run into... unusual problems.

Ah. And do you also drive a stick-shift that you have to hand-crank to start the engine?

db

[PRW56]

No i take a horse-drawn buggy, only way to get to town after all, I can't afford the steam powered computers they have.