Paul Chamsay

I guess for now I would have to say desktop applications.

I have finished studying HFJ and I'm wondering what book I should tackle next. I basically want to expand my knowledge in java and have a "working knowledge" in it and maybe contribute to open-source as well soon. I have basic knowledge in C++, VB.net, and HTML/CSS if that matters..

Hi,

I'm just wondering what's the difference of doing this:

class IceCream { public static void main(String[] args) { new IceCream().go(); } }

as opposed to this

class IceCream { public static void main(String[] args) { IceCream ic = new IceCream(); ic.go(); } }

Are there any performance implications? Which "style" is more recommended? Thanks!

Ah, you're a genius Ulf, thanks a lot!

I never thought of actually creating two move objects .. I kept on thinking how to identify which thread is going to call the run() method

Hi Ulf, I really tried to think of some differentiating logic but I just can't figure out how the run method will know which for loop to run .. If I'm not mistaken, you were trying to tell me to do something like this where there are two threads but only one job (run method).

Runnable Job = new Move(this, appWidth); anim = new Thread(Job); anim2 = new Thread(Job);

Any clues? I really appreciate your help.

Does it make sense if I do a setName() on those two threads then do something like:


if (getName() == "somename") excute for loop for image else execute for loop for string

Is that what you meant?

I have additional codes inside the for loop of Move2

Something like:

if (image == picture[1]) image == picture[2];

Where I switch images. Do you think I should still combine though?

Hi, I worked on it again tonight and this is what I have:

import javax.swing.*; import java.awt.*; import java.applet.AudioClip; public class Test2Threads extends JApplet implements Runnable { private Thread anim, anim2, music; private int appWidth, xCoorImage, xCoorString, yCoor; Image currentImage; private String title; private AudioClip sound; public void init() { setBackground(Color.WHITE); title = "Computers"; sound = getAudioClip(getCodeBase(), "tune.au"); } public void start() { currentImage = getImage(getCodeBase(), "air.gif"); appWidth = getWidth(); yCoor = getHeight() / 2; Runnable Job = new Move(this, appWidth); Runnable Job2 = new Move2(this, appWidth); anim = new Thread(Job); anim2 = new Thread(Job2); music = new Thread(this); anim.start(); anim2.start(); music.start(); } public void stop() { sound.stop(); } public void paint(Graphics g) { g.setFont(new Font("TimesRoman", Font.BOLD, 30)); g.setColor(Color.BLUE); g.clearRect(0, 0, appWidth, getHeight()); g.drawImage(currentImage, xCoorImage, yCoor /2, this); g.drawString(title, xCoorString, yCoor); } public void run() { sound.loop(); } public void setImageX(int x) { xCoorImage = x; } public void setStringX(int x) { xCoorString = x; } } class Move implements Runnable { Test2Threads parent; int appWidth; public Move (Test2Threads parent, int appWidth) { this.parent = parent; this.appWidth = appWidth; } public void run() { while (true) { for (int i = 0; i < appWidth; i+=15) { parent.setImageX(i); parent.repaint(); try { Thread.sleep(100); } catch (InterruptedException e) { } } } } } class Move2 implements Runnable { Test2Threads parent; int appWidth; public Move2 (Test2Threads parent, int appWidth) { this.parent = parent; this.appWidth = appWidth; } public void run() { while (true) { for (int i = appWidth; i > 0 - appWidth; i-= 15) { parent.setStringX(i); parent.repaint(); try { Thread.sleep(100); } catch (InterruptedException e) { } } } } }

I'm curious about the music thread though.. Is it okay if it's like that or should a separate thread be created for it? I'm thinking that I have too many classes for a small task like this ..

Also, I would like to know if the code has good OO design? Thanks!

Thanks Ulf! Works great!

import javax.swing.*; import java.awt.*; public class Test2Threads extends JApplet { private Thread anim; private int appWidth, xCoor, yCoor; private String title; public void init() { setBackground(Color.WHITE); title = "Computers"; } public void start() { appWidth = getWidth(); yCoor = getHeight() / 2; Runnable Job = new Move(this, appWidth); anim = new Thread(Job); anim.start(); } public void paint(Graphics g) { g.setFont(new Font("TimesRoman", Font.BOLD, 30)); g.setColor(Color.BLUE); g.clearRect(0, 0, appWidth, getHeight()); g.drawString(title, xCoor, yCoor); } public void setX(int x) { xCoor = x; } } class Move implements Runnable { Test2Threads parent; int appWidth; public Move (Test2Threads parent, int appWidth) { this.parent = parent; this.appWidth = appWidth; } public void run() { while (true) { for (int i = 0; i < appWidth; i+= 15) { parent.setX(i); parent.repaint(); try { Thread.sleep(100); } catch (InterruptedException e) { } } } } }

Thanks! So I got started on this.. This is what I have so far:

import javax.swing.*; import java.awt.*; public class Test2Threads extends JApplet { Thread anim; int appWidth, xCoor, yCoor; String title; public void init() { setBackground(Color.WHITE); title = "Computers"; } public void start() { Runnable Job = new Move(); anim = new Thread(Job); anim.start(); appWidth = getWidth(); yCoor = getHeight() / 2; } public void paint(Graphics g) { g.setFont(new Font("TimesRoman", Font.BOLD, 30)); g.setColor(Color.BLUE); g.clearRect(0, 0, appWidth, getHeight()); g.drawString(title, xCoor, yCoor); } } class Move extends Test2Threads implements Runnable { public void run() { while (true) { for (int i = 0; i < appWidth; i+= 15) { xCoor = i; repaint(); try { Thread.sleep(1000); } catch (InterruptedException e) { } } } } }

I can't get it to work using that way.. Any ideas why? It doesn't move at all.. Also, I'm not sure how to have 2 threads going on the same time. I'm planning to create 1 more class..

Also, is it possible to have a paint method that does something different from another paint method?

Hi,

First of all, I'm sorry if this is the wrong forum to post my problem. I wasn't sure if it would fit better in the threads forum or here or the beginner's ..

I have this task of animating 2 strings and one image in an Applet.

Basically what the 2 strings would do is move from left to the right of the screen and the image will move from right to left, all at the same time.

My question is, do I use 3 threads in my applet so those 2 strings and the image will move accordingly all at the same time?

Thanks!

Ah, thanks!

Nathe, there's a better solution than going through each item in the list.

Michael explained it in his previous post:

it can be done that way, with listeners, but you would need to add a listener to each list,
in case a quantity was clicked (or make the quantity lists not selectable).

alternative, in setting their selection models the same is only 2 lines of code.

Assignment instructions if I'm not mistaken is to have the dvdlist and blueray list not selectable.

Since you're using a listener for the movieslist, listbox01.getSelectedIndex() will return the exact index of the movie selected.

See if you can improve that code to 2-3 lines without any loops.

Hello everyone,

Just wondering what the difference is between ImageIcon and Image?

Is ImageIcon used only for JApplets?

Thanks

ran into another problem ..

What I did was I passed an object of FruitStock inside FruitStockTester to FruitQuery's constructor when I initialized it.

If I'm not mistaken, since I'm passing by reference, changes in the object made inside FruitQuery class will be 'seen' by FruitStockTester.

Problem is since I passed the object to the constructor, is there anyway for other methods inside FruitQuery class to change the object?

What I did was I did something like this:

FruitStock object = new FruitStock(); public class FruitQuery { FruitQuery (FruitStock obj) { object = obj; } public void setStock (int a) { object.setStock(a); } }

changes aren't seen by FruitStockTester .. Any help with this ?

EDIT: I understand that obj can be passed around but my program is an frame and changes to obj are supposed to be made through events ..