For class I'm working on my first GUI application. It's just a simple image viewer with four buttons: Previous, Next, Stop, Play. Previous and Next work fine, but honestly I don't even know how to begin working on the slideshow part (Play & Stop). I know there's a timer class that would probably be handy for controlling the speed as the images change...but I'm not sure what kind of logic is typically used to cycle through the images. Can anyone point me in the right direction, my brain is a little fried at this point :0
I've included my code below. I'm new to this, so hopefully people won't be too critical of my technique. If it matters, I'm working in eclipse.
here's my code so far:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.TimerTask;
public class ImageGallery extends JFrame
{
private ImageIcon myImage1 = new ImageIcon ("Chrysanthemum.jpg");
private ImageIcon myImage2 = new ImageIcon ("Desert.jpg");
private ImageIcon myImage3 = new ImageIcon ("Jellyfish.jpg");
private ImageIcon myImage4 = new ImageIcon ("Penguins.jpg");
JPanel ImageGallery = new JPanel();
private ImageIcon[] myImages = new ImageIcon[4];
private int curImageIndex=0;
public ImageGallery ()
{
ImageGallery.add(new JLabel (myImage1));
myImages[0]=myImage1;
myImages[1]=myImage2;
myImages[2]=myImage3;
myImages[3]=myImage4;
add(ImageGallery, BorderLayout.NORTH);
JButton PREVIOUS = new JButton ("Previous");
JButton PLAY = new JButton ("Play");
JButton STOP = new JButton ("Stop");
JButton NEXT = new JButton ("Next");
JPanel Menu = new JPanel();
Menu.setLayout(new GridLayout(1,4));
Menu.add(PREVIOUS);
Menu.add(PLAY);
Menu.add(STOP);
Menu.add(NEXT);
add(Menu, BorderLayout.SOUTH);
//register listener
PreviousButtonListener PreviousButton = new PreviousButtonListener ();
PlayButtonListener PlayButton = new PlayButtonListener ();
StopButtonListener StopButton = new StopButtonListener ();
NextButtonListener NextButton = new NextButtonListener ();
//add listeners to corresponding componenets
PREVIOUS.addActionListener(PreviousButton);
PLAY.addActionListener(PlayButton);
STOP.addActionListener(StopButton);
NEXT.addActionListener(NextButton);
}
public static void main (String [] args)
{
ImageGallery frame = new ImageGallery();
frame.setSize(490,430);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
}
class PreviousButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if(curImageIndex>0 && curImageIndex <= 3)
{ ImageGallery.remove(0);
curImageIndex=curImageIndex-1;
ImageIcon TheImage= myImages[curImageIndex];
ImageGallery.add(new JLabel (TheImage));
ImageGallery.validate();
ImageGallery.repaint();
}
else
{
ImageGallery.remove(0);
ImageGallery.add(new JLabel (myImage1));
curImageIndex=0;
ImageGallery.validate();
ImageGallery.repaint();
}
}
}
class PlayButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
// *need help here*//
}
}
class StopButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
// *need help here*//
}
}
class NextButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if(curImageIndex>=0 && curImageIndex < 3)
{ ImageGallery.remove(0);
curImageIndex = curImageIndex + 1;
ImageIcon TheImage= myImages[curImageIndex];
ImageGallery.add(new JLabel (TheImage));
ImageGallery.validate();
ImageGallery.repaint();
}
else
{
ImageGallery.remove(0);
ImageGallery.add(new JLabel (myImage4));
curImageIndex=3;
ImageGallery.validate();
ImageGallery.repaint();
}
}
}
}
Why complicating simple things,
I think that this is job for CardLayout and for slideshow is there Swing Timer
put images as Icon to the JLabel
This example shows a start/stop button that controls a javax.swing.Timer. Instead of replacing the label each time, just update the label's Icon, as suggested by #mKorbel and shown here.
You need use a thread for the slideshow. You can use a flag in the run method for continue with the show or stop if this flag change, for example, a boolean var. One example you can see in http://java.sun.com/developer/technicalArticles/Threads/applet/.
These are some guidelines that might get you started:
First you will need a separate thread to control the changing images. I suggest you write a class that implements TimerTask. Override the run() method in this class. In this run method you should put the functionality to change the current image being displayed (similar to what you did in the next and previous function).
In the actionPerformed() method for the play button you will need to create an instance of a Timer class and start your timer using the scheduleAtFixedRate(TimerTask task, long delay, long period) method (other methods in this class may be used as well, scheduleAtFixedRate() seem more appropriate though).
For the stop you will then need to add enough functionality to stop the running timer using the cancel() method in the Timer class
Related
Goal
What I want to do is to set a MouseListener on a Panel when click on a Button1.
Then I want to click on another Button that changes the MouseListener code to do something else.
Example of application
Click on JButton1 -> add MouseListener that change a JLabel background color to red.
Click on JButton2 -> DOESNT ADD a new MouseListener, but change the first one to set the JLabel text to "hello world"
What I can't do
I don't know how to modify an UNIQUE MouseListener.
What I tried
I tried to set an jButton.actionPerformed( new jLabel1.addMouseListener()) for each button, but they create two instance of MouseListener.
I don't want to set one MouseListener for several JButtons, but several JButton changing the status of my MouseListener.
Thanks alot :)
Better to give the JLabel a MouseListener from the get-go, but give it boolean if-blocks that will turn on or off functionality depending on the state of class boolean fields. In your button ActionListeners, simply change the state of these boolean fields. For example in the code below, the boolean flag labelListenerOn is toggled on or off in the first JButton's ActionListener. The JLabel's MouseListener checks the state of this variable and changes the labels background color if the flag is true only. Similarly for the other boolean flag and other ActionListener:
import java.awt.Color;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.*;
public class ButtonListener extends JPanel {
private static final String TURN_ON_MOUSE = "Turn On Mouse";
private static final String TURN_OFF_MOUSE = "Turn Off Mouse";
private JButton button1 = new JButton(TURN_ON_MOUSE);
private JButton button2 = new JButton("Button 2");
private JLabel label1 = new JLabel("Label 1");
private MouseListener labelListener = new LabelListener();
private boolean labelListenerOn = false;
private boolean labelChangeText = false;
public ButtonListener() {
label1.setOpaque(true);
label1.addMouseListener(labelListener);
button1.addActionListener(e -> {
if (labelListenerOn) {
labelListenerOn = false;
((JButton) e.getSource()).setText(TURN_ON_MOUSE);
} else {
labelListenerOn = true;
((JButton) e.getSource()).setText(TURN_OFF_MOUSE);
}
});
button2.addActionListener(e -> {
labelChangeText = true;
});
add(button1);
add(button2);
add(label1);
}
private class LabelListener extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
Color labelColor = label1.getBackground();
if (labelListenerOn) {
if (labelColor.equals(Color.RED)) {
label1.setBackground(null);
} else {
label1.setBackground(Color.RED);
}
// label1.repaint(); // per Rob Camick's comment, this is not necessary
}
if (labelChangeText) {
label1.setText("Hello World");
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
private static void createAndShowGui() {
ButtonListener mainPanel = new ButtonListener();
JFrame frame = new JFrame("ButtonListener");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
}
If you want to get fancy, look up M-V-C for "model-view-controller", where you separate the program logic (here the state of the boolean flags) from the program view code (the Swing GUI code), usually in their own classes, and then use a master class to hook all the components up. This would add an additional layer of indirection and complexity, and would be over-kill in this situation, but in large programs, and especially in programs that are likely going to be updated, changed and grown, this will actually reduce complexity in the long run, and make the program much more "scalable" -- easier to grow and modify. Again, I do not recommend that you do this here, but do look it over for possible future use.
I am still new to using Swing and creating GUIs in Java. I was working on a simple test code where the color of a button changes to a random color when it is pressed. Although it works, every time I press the button, it minimizes the previous window and opens a new one and they keep piling up. How will I make it so that this does not happen? Does this occur because I am creating an object in the actionPerformed method? The reason why I have made an object there is to link the Swing class with the separate Action class I have made in order to manipulate the button variable.
Therefore, my two questions are:
How can I prevent multiple windows from appearing and instead have them replace each other?
Is there a way to utilize ActionListener within the same class and would it make things easier?
Any help is greatly appreciated!
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.*;
public class Swing extends JFrame{
private JFrame f;
private JLabel l;
private JButton b;
private JPanel p;
public Swing(){
test();
}
//*
public JFrame getJFrame(){
return f;
}
public JLabel getJLabel(){
return l;
}
public JButton getJButton(){
return b;
}
public JPanel getJPanel(){
return p;
}
//*
public void test(){
// Frame Setup
f = new JFrame("Frame");
f.setVisible(true);
f.setSize(500, 500);
f.setResizable(true);
f.setDefaultCloseOperation(EXIT_ON_CLOSE);
//
// Panel Setup
p = new JPanel();
p.setVisible(true);
//
// Other
b = new JButton("Button");
l = new JLabel("Label");
b.addActionListener(new Action());
//
// Additions
p.add(b);
p.add(l);
f.add(p); // ***
//
}
public static void main(String[] args){
Swing swing = new Swing();
swing.test();
}
}
final class Action implements ActionListener{
public void actionPerformed(ActionEvent e){
Swing swingObject = new Swing(); //
JButton button = swingObject.getJButton(); //
button.setBackground(randomColor());
}
public Color randomColor(){
Random rn = new Random();
ArrayList<Color> color = new ArrayList<Color>();
color.add(Color.BLUE);
color.add(Color.GREEN);
color.add(Color.RED);
color.add(Color.YELLOW);
color.add(Color.PINK);
color.add(Color.CYAN);
color.add(Color.ORANGE);
color.add(Color.MAGENTA);
int s = color.size();
int random = rn.nextInt(s);
return color.get(random);
}
}
From your listener, you're executing
Swing swingObject = new Swing();
This does what it should do: create a new Swing JFrame. You don't want a new JFrame, so don't call its constructor. From the listener, simply get the button that fired the event, and change its color:
JButton button = (JButton) e.getSource();
button.setBackground(randomColor());
You could also pass the button to modify when creating the listener:
class Action implements ActionListener{
private JButton buttonToUpdate;
public Action(JButton buttonToUpdate) {
this.buttonToUpdate = buttonToUpdate;
}
public void actionPerformed(ActionEvent e){
buttonToUpdate.setBackground(randomColor());
}
}
And, to create it:
b = new JButton("Button");
b.addActionListener(new Action(b));
Very new to Java, but I am slowly picking my way through things. So please be kind. I understand most things I've tried so far, and built a version of the following that uses console output, but now I'm trying to make a GUI. I tried the netbeans GUI maker, but it created so much new code that when I tried to pick through it, I got lost. I'm much better at learning by piecing new things together myself, not having an IDE generate a ton of code and then attempt to find where I want to work.
I am trying to build an window that has a list with three choices on the left side, a button in the middle that confirms your choice, and an answer output on the right. Once the button is pressed, the input from the list is read and is converted into a corresponding answer. As of right now, all I get is "We recommend... null" after selecting an option in the list. The button appears to do nothing at the moment.
I have used tutorials, hacked up others' code from online, and referenced a few books, but I'm stuck.
Here is what I have:
package diffguidegui;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class DiffGuideGUI extends JPanel implements ListSelectionListener {
private JList resultsTabList;
private DefaultListModel listModel;
private static final String recommendString = "Recommend a Option";
private JButton recommendButton;
private String recommendOutput;
final JLabel output = new JLabel("We recommend..." + recommendOutput);
//build list
public DiffGuideGUI () {
super(new BorderLayout());
listModel = new DefaultListModel();
listModel.addElement("A");
listModel.addElement("B");
//create the list and put it in the scroll pane
resultsTabList = new JList(listModel);
resultsTabList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
resultsTabList.setSelectedIndex(0);
//listener for user input
resultsTabList.addListSelectionListener(this);
resultsTabList.setVisibleRowCount(2);
JScrollPane listScrollPane = new JScrollPane(resultsTabList);
//build the button at the bottom to fire overall behavior
recommendButton = new JButton(recommendString);
recommendButton.setActionCommand(recommendString);
recommendButton.addActionListener(new RecommendListener());
//create a panel that uses Boxlayout for the button
JPanel buttonPane = new JPanel();
buttonPane.setLayout(new BoxLayout(buttonPane, BoxLayout.LINE_AXIS));
buttonPane.add(recommendButton);
//create a panel that uses Boxlayout for the label
JPanel outputPane = new JPanel();
outputPane.setLayout(new BoxLayout(outputPane, BoxLayout.LINE_AXIS));
outputPane.add(output);
add(listScrollPane, BorderLayout.WEST);
add(buttonPane, BorderLayout.CENTER);
add(outputPane, BorderLayout.EAST);
}
//build listener class
class RecommendListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
//build in logic for choice made here
String resultsTabChoice;
resultsTabChoice = (String)resultsTabList.getSelectedValue();
if( resultsTabChoice.equals("A")) {
recommendOutput = "One";}
else {recommendOutput = "Two";}
}
}
public void valueChanged(ListSelectionEvent e) {
if(e.getValueIsAdjusting() == false) {
if(resultsTabList.getSelectedIndex() == -1) {
recommendButton.setEnabled(false);
} else {
recommendButton.setEnabled(true);
}
}
}
//Create GUI and show it
private static void createAndShowGUI() {
JFrame frame = new JFrame("Recommend Window");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//create and set up content pane
JComponent newContentPane = new DiffGuideGUI();
newContentPane.setOpaque(true);
frame.setContentPane(newContentPane);
//display the window
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
The button appears to do nothing at the moment.
It does something. It calculates the value for your recommendOutput varable. But you never output this value.
try the following:
//build listener class
class RecommendListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
//build in logic for choice made here
String resultsTabChoice;
resultsTabChoice = (String)resultsTabList.getSelectedValue();
if( resultsTabChoice.equals("A")) {
recommendOutput = "One";}
else {recommendOutput = "Two";}
System.out.println(recommendOutput); // <-###################
}
}
This should print the value to stdout
To put the value into your label try this instead:
output.setText(recommendOutput);
where do you set the text for the JLabel? It says "We recommend NULL" because recommenedOutput is null when the object is created. I dont see
output.setText("We recommend "+value) anywhere. You probably need output.invalidate() also. Try putting setText(String text)/invalidate() in the RecommendListener.actionPerformed() method.
output.setText("We recommend A");
output.invalidate();
I am trying to program an applet that has four buttons, all of which play a short audio file. The goal is to try and have the user successfully click the buttons any number of times, therefore creating a beat. Here is my attempt:
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import javax.swing.*;
public class drumKit extends JApplet
{
private JButton snareButton;
private JButton hiHatButton;
private JButton bassButton;
private JButton cymbalsButton;
private AudioClip snare;
private AudioClip hiHat;
private AudioClip bass;
private AudioClip cymbals;
public void init()
{
setLayout (new FlowLayout());
sampleButtons();
snare = getAudioClip(getDocumentBase(), "Snare.wav");
hiHat = getAudioClip(getDocumentBase(), "HiHat.wav");
bass = getAudioClip(getDocumentBase(), "Kick.wav");
cymbals = getAudioClip(getDocumentBase(), "Crash.wav");
}
private void sampleButtons()
{
snareButton = new JButton("Snare");
hiHatButton = new JButton("Hi Hat");
bassButton = new JButton("Kick");
cymbalsButton = new JButton("Cymbals");
snareButton.addActionListener(new ButtonListener());
hiHatButton.addActionListener(new ButtonListener());
bassButton.addActionListener(new ButtonListener());
cymbalsButton.addActionListener(new ButtonListener());
add(snareButton);
add(hiHatButton);
add(bassButton);
add(cymbalsButton);
}
private class ButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if (e.getSource() == snareButton)
snare.play();
if (e.getSource() == hiHatButton)
hiHat.play();
if (e.getSource() == bassButton)
bass.play();
if (e.getSource() == cymbalsButton)
cymbals.play();
}
}
}
The problem is, when I click the buttons, nothing plays. I referred to the solutions listed here, a window pops up preventing any further interactions with the applet. Sorry, a bit of a newbie here.
//Thanks for your help.
When you say "applet or GUI" I think you really mean applet or application--they are both GUIs. I'm not really familiar with AudioClip, but if it works as easy as it seems, then all you need to do is change your JApplet to a JPanel, then create a main method which creates a JFrame and set its content pane to your JPanel:
disclaimer: This code has not been tested and probably contains complilation errors (I will correct anything pointed out).
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import javax.swing.*;
public class drumKit extends JPanel implements ActionListener
{
private final JButton snareButton;
private final JButton hiHatButton;
private final JButton bassButton;
private final JButton cymbalsButton;
private final AudioClip snare;
private final AudioClip hiHat;
private final AudioClip bass;
private final AudioClip cymbals;
public drumKit()
{
super();
// create buttons
snareButton = new JButton("Snare");
hiHatButton = new JButton("Hi Hat");
bassButton = new JButton("Kick");
cymbalsButton = new JButton("Cymbals");
// setup audio clips
snare = getAudioClip(getDocumentBase(), "Snare.wav");
hiHat = getAudioClip(getDocumentBase(), "HiHat.wav");
bass = getAudioClip(getDocumentBase(), "Kick.wav");
cymbals = getAudioClip(getDocumentBase(), "Crash.wav");
// set layout
setLayout (new FlowLayout());
// add this action listener to the buttons and add to this panel
sampleButtons();
}
private void sampleButtons()
{
// add this as the each button's action listener
snareButton.addActionListener(this);
hiHatButton.addActionListener(this);
bassButton.addActionListener(this);
cymbalsButton.addActionListener(this);
// add each button to this panel
this.add(snareButton);
this.add(hiHatButton);
this.add(bassButton);
this.add(cymbalsButton);
}
public void actionPerformed(ActionEvent e)
{
if (e.getSource() == snareButton)
snare.play();
else if (e.getSource() == hiHatButton)
hiHat.play();
else if (e.getSource() == bassButton)
bass.play();
else if (e.getSource() == cymbalsButton)
cymbals.play();
}
/**
* main method creates a frame which contains this custom panel
* and displays it.
*/
public static void main(String ...args){
// set the look and feel to the system's look and feel
try{
UIManager.setLookAndFeel(
UIManager.getSystemLookAndFeelClassName());
}catch(Exception e){
// if this fails, who cares, the look and feel will be Java's
// just continue
}
// create frame and make sure that when you close the frame the
// program exits!
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// create your panel, set it to the frame's content pane,
// then show the frame
final JPanel panel = new drumKit();
frame.setContentPane(panel);
frame.setVisible(true);
// resize the frame to be the preferred size of your panel
frame.pack();
}
If you cannot read the files, then I would suggest putting in the fully qualified path name rather than just "Snare.wav" (for example) which looks in the current CLASSPATH directory (which for eclipse, I believe is the project directory).
anyone know or have an idea as to why my button disappears after i resize the applet?
this is my code:
import java.awt.event.*;
import javax.swing.*;
import acm.program.*;
public class button extends ConsoleProgram {
public void init(){
hiButton = new JButton("hi");
add(hiButton, SOUTH);
addActionListeners();
}
public void actionPerformed(ActionEvent e){
if(hiButton == e.getSource()){
println("hello") ;
}
}
private JButton hiButton;
}
I'm not sure if it is a good Idea to redefine the init-method. When I have a look at http://jtf.acm.org/javadoc/student/acm/program/ConsoleProgram.html I would expect that you have implement only the run-method. Overriding init without calling super.init() Looks strange to me.
Maybe I would be better to derive from JApplet directly for your first steps in Applet programming.
Assuming that
your ConsoleProgram extends (directly or indirectly) JApplet
You declared SOUTH as a static final variable that has the value BorderLayout.SOUTH (otherwise your code doesn't compile)
The code should work, no need to repaint (unless you would like to do some application-specific optimization). I just copied and pasted your code (by expliciting the two assumptions above), I see the applet and the button doesn't disappear on resize.
Anyway there are few "not good" things in the code:
First of all, a naming convention issue: the class name should be "Button" with the first letter capitalized (on top of that, it's a poor name for an Applet)
Second, action listeners should be attached before adding the component;
Third, as Oracle doc suggests here, the code that builds the GUI should be a job that runs on the event dispatcher thread. You can do that by wrapping the build gui code in a Runnable using a SwingUtilities.invokeAndWait(Runnable()
Have you tried calling super.init() at the start of your init() method?
Try explicitly using a layout for your Console and then use relative positioning.
To re-size a button in Applet:
public class Button extends JApplet implements ActionListener {
private JButton button;
public void init() {
Container container = getContentPane();
container.setLayout(null);
container.setBackground(Color.white);
button = new JButton("Press Me");
button.setSize(getWidth()/2,20);
button.setLocation(getWidth()/2-button.getSize().width/2, getHeight()/2-button.getSize().height/2);
container.add(button);
button.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
int width = (button.getSize().width == getWidth()/2) ? getWidth()/4 : getWidth()/2;
int height = button.getSize().height;
button.setSize(width,height);
button.setLocation(getWidth()/2-width/2, getHeight()/2-height/2);
}
}
To re-size a button in JFrame:
public class Button extends JFrame implements ActionListener {
private JButton button;
public Button(String title) {
Container container = getContentPane();
container.setLayout(null);
container.setBackground(Color.white);
setTitle(title);
setSize(400,400);
button = new JButton("Press Me");
button.setSize(getWidth()/2,20);
button.setLocation(getWidth()/2-button.getSize().width/2,
getHeight()/2-button.getSize().height/2);
container.add(button);
button.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
int width = (button.getSize().width == getWidth()/2) ? getWidth()/4 : getWidth()/2;
int height = button.getSize().height;
button.setSize(width,height);
button.setLocation(getWidth()/2-width/2, getHeight()/2-height/2);
}
public static void main(String[] args) {
Button button = new Button("Test");
button.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
button.setVisible(true);
}
}
Have you declared the repaint method...???
You are using swing. It needs to have declared a repaint.
Please define a custom repaint mwthod