I am trying to create a swing app that is a quiz. I need the jLabel to change on a button click but when I click the button, the app locks up. Can someone point me in the right direction?
My button click code is below:
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String[] questions = {"test0","test1","test2","test3","test4","test5","test6"};
String[] answers = {"","","","","","",""};
int i = 0;
do {
jLabel2.setText(questions[i]);
index.setText(String.valueOf(i));
if (txtAnswer.getText().toLowerCase().equals(answers[i].toLowerCase())) {
i++;
jLabel2.setText(questions[i]);
}
else {
add(lblWrong);
}
}
while(i < 7);
}
I am getting a warning that the evt parameter has not been used, could this be a problem?
Thank you
You don't want the do while loop. It's trapping you in the button press method as if you get an answer wrong you keep entering the else and can't leave it, stopping the app from working. Replace it with an if statement checking if i < 7.
In the else condition of your loop, you don't add 1 to i at all - therefore you can potentially end up in the situation where it's never incremented, thus it will be an infinite loop (locking your program up.)
Related
I'm trying to do a memory game using "cards" all works fine but I need to know when the user win the game to display a message but I can't figure out how to do that? How can I check using a condition if all the buttons are .setEnabled(false)? Or should I compare all the buttons using a loop?
I hope you can help me.
Since you have cartas as an array. You should just iterate through a loop to see if all cards are set to false.
for(int x =0; x< cartas.length;x++)
{
if(cartas[x].isEnabled()) //enabled
{
break; //a button is still enabled so cancel loop
}
else if(x == cartas.length-1&& !cartas[x].isEnabled())
{
//All cards have been disabled. Do Something.
}
}
Therefore, the method
isEnabled();
allows you to check if all buttons are
.setEnabled(false);
I know this sounds very basic, but I never really learned how to do this.
I know about for loops where you can just use for example:
for(int i=0; i<=10; i++)
System.out.println(i);
But that just prints out numbers from 0 to 10 with a gap of 1...which isn't what I'm looking for.
I'm looking for some code where the program starts at a value and adds 1 (or another number) whenever the a button is clicked.
I already have the code for the button and everything, but I have an empty ActionListener as I don't know what to place inside it.
In the ActionListener actionPerformed method write the following code:
public void actionPerformed(ActionEvent event)
{
if(event.getSource() == button_name)
{
count_variable += 1;
}
}
Just add something like this.
int counter = 0;
JButton button = new JButton(" Click me ");
//Add action listener to button
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
//Execute when button is pressed
counter++;
}
});
This will make counter++ execute whenever the button is pressed. If you want another number, say 10, then just replace counter++ with counter+=10
**disclaimer**
Make sure that counter is accessible inside of ActionPerformed. You can do this by making it a field variable of an encapsulating class, making it a mutable object, and many other ways.
Hi I'm new to stackoverflow so bear with me if I make mistakes.
I'm making this Java Simon Says Game for a class project. It works by a random number generator for each sequence#. I show the sequence through doClick() but remove the actionlisteners beforehand and add it afterwards.
The problem is the buttons won't unpress or unarm until all other buttons have been pressed. I've tried using thread.sleep to put a delay between each if...else statements yet it only stays pressed for longer. I've tried updating the gui through repaint(), revalidate(), updateUI() within the try... catch of the thread.sleep but that didn't work either.
I've realized this issue is mainly cosmetic because when I tried implementing setPressed or setArmed it said it wasn't being pressed but it looked pressed.
Here is the code snippet in it's most simplest form without thread.sleep or my previous attempts in comments.
public void sequence2() //This is where the issue happens. The buttons won't unpress until every button has been pressed.
{
level.setText(" Level 2"); //Level indicator
Green.removeActionListener(Listener);
Red.removeActionListener(Listener);
Yellow.removeActionListener(Listener);
Blue.removeActionListener(Listener);
if(sequence1 == 1)
{
Green.doClick(300); //Programmatically clicks the button
}
else if(sequence1 == 2)
{
Red.doClick(300);
}
else if(sequence1 == 3)
{
Yellow.doClick(300);
}
else if(sequence1 == 4)
{
Blue.doClick(300);
}
if(sequence2 == 1)
{
Green.doClick(300);
}
else if(sequence2 == 2)
{
Red.doClick(300);
}
else if(sequence2 == 3)
{
Yellow.doClick(300);
}
else if(sequence2 == 4)
{
Blue.doClick(300);
}
Green.addActionListener(Listener);
Red.addActionListener(Listener);
Yellow.addActionListener(Listener);
Blue.addActionListener(Listener);
}
I'm very new to java so I'm not skilled in multithreading or working on the Event Dispatch Thread for that manner. But if that's the only solution I'll need some more help with that.
I have the full code in a zip file with previous attempts commented out if that will help.
https://drive.google.com/file/d/0Bxg4WleC9jD2VFhoZmZBNjV6Vkk/view?usp=sharing
Invoking doClick() may be an awkward choice for this, as it uses a Timer internally. Instead, use a JToggleButton, which will allow you to control each button's appearance based on its selected state using setSelected(). A complete example is shown in the game Buttons. In the ActionListener of your Swing Timer, select the current button, play its note and increment the sequence index. When all notes have been played, unselect all the buttons.
Addendum: Can you show how you implement the timer?
In outline, given a suitable list of toggle buttons:
private static final int MAX = 4;
List<JToggleButton> buttons = new ArrayList<JToggleButton>(MAX);
private int i;
The timer's listener might look like this:
#Override
public void actionPerformed(ActionEvent e) {
Object src = e.getSource();
JToggleButton b = buttons.get(i);
if (i > MAX) { // reset i and all the buttons
for (JToggleButton b : buttons) {
b.setSelected(false);
}
timer.stop();
i = 0;
} else {
b.setSelected(true);
// play tone i
i++;
}
}
A toggle button's item listener should update the button's appearance as indicated by its state:
#Override
public void itemStateChanged(ItemEvent e) {
JToggleButton b = (JToggleButton) e.getItem();
if (b.isSelected()) {
// change icon, color etc.
} else {
// restore icon, color etc.
}
}
I am a beginner in java, I want to know is there any possible way to control a loop by clicking a button? I am creating a GUI, and it's supposed to run 10 times in the loop. Is there a way that I could have a button on the screen so that when the user presses, then it goes to the next iteration? Because currently everything just runs and executes once.
In your java class, you should define an attribute and each time you click on the button you add 1 to this attribute and do the action.
define an attribute in your class;
public int i = 0;
and create a button to be clicked on:
private void clickMeButtonActionPerformed(java.awt.event.ActionEvent evt) {
// code your action here:
this.i++;
}
You could have the loop wait for the button click, and then once it loops 10 times break the loop.
You can use javaFX it's gonna replace javaswing very soon anyways plus it's cooler.
import javafx.scene.control.button
Button button = new Button("control");
int i = 0;
button.setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent e) {
i++;
label.setText("i increased");
}
});
i have a problem with my code. I think that my problem is easy,but i have compiled for 3 days without good results. I have three images. They are put on screen one-one each time. User choose from 4 button if image's side is up, down, right or left. Also, i want to understand if user was wrong and then i will count errors. When user make 3 errors then the game will stop. I have shown code below. Please help me if you have any good idea.
The problem is that at the first loop,run right.It goes at the first if. After that it do the loop and then it does not go to second if.
if it is more helpful,some details:
i want to make a programma that it will show to user an image.This image has 4 sides (up,down,right,left).When the image is at "up side",user has to click on up button,when the image is at "down side",user has to click on down button etc. User can do 3 errors max. At first,program show the image at right side,if user clicks on right button then i want to show the "second image" at left side.If user does not at left side,then i want to add an error(error++) and after it shows the third image at up side etc. I hope it is more helpful to understand. If you can't please let me know.
My program is at Netbeans,java.
Thank you
public void actionPerformed(ActionEvent e)
{
while(errors<3)
{
image.setIcon(createImageIcon("visual1" + e.getActionCommand() + ".PNG"));
if (k==1)
{
if(e.getSource() == right_button)
{
image.setIcon(createImageIcon("visual2" + e.getActionCommand() + ".PNG"));
}
}
else if ( k==2 )
{
if(e.getSource() == left_button )
{
image.setIcon(createImageIcon("visual3" + e.getActionCommand() + ".PNG"));
}
}
else if (k==3 )
{
if(e.getSource() == up_button)
{
System.out.print("if3");
}
}
else
{
errors++;
}
k=k+1;
}
}
You should consider calling Repaint and Invalidate, right after you update your GUI like this -
mainframe.repaint();
mainframe.invalidate();
here mainframe is your JFrame object.
A problem I see with your while loop is that it is at risk of getting stuck in an infinite loop, since the variable used as an exit criterion is only updated some of the time, in an else block. I think you should re-arrange your logic:
Get rid of that while loop as it will only cause trouble. It is useful for a linear command line program but not for an event-driven GUI program like yours.
Read in all images and create all ImageIcons in the class constructor, and store them in variables. There's no need to re-read the images multiple times (unless they're huge).
Instead of using a while loop, increment the error variable in your method above, and then write the method so that it will change behaviors depending on the value of error (depending on the state of the class).
e.g.,
// somewhere in your code create your icons
Icon rightIcon = ......;
Icon leftIcon = .....;
Icon upIcon = .....;
Icon downIcon = .....;
// elsewhere in your code
public void actionPerformed(ActionEvent e) {
if (errors >= 3) {
// notify user of error
return; // end this method
}
// check if current icon matches image
// if so, change icon
// if not increment error
}
Note that an enum Direction {UP, DOWN, LEFT, RIGHT} and a Map<Direction, Icon> could be helpful here.