how to identify dynamically created jbutton actions - java

I create two jbuttons in one panel(can be Box).i create same panel dynamically several times in same frame.so if two panels created dynamically those button make with same variable name.But i want to identify buttons one by one for put actions.how to identify dynamically created buttons one by one?
button creating code
public class Jscrollpanetest extends JFrame {
JScrollPane scrollPane;
Box box;
private static int panelCount = 0;
public Jscrollpanetest() {
setPreferredSize(new Dimension(200, 400));
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
scrollPane = new JScrollPane();
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scrollPane.getVerticalScrollBar().setUnitIncrement(15);
box = Box.createVerticalBox();
scrollPane.getViewport().add(box);
this.add(scrollPane);
this.pack();
this.setLocationRelativeTo(null);
this.setVisible(true);
Timer t = new Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent ae) {
box.add(new TestPanel(), box.size());
scrollPane.validate();
}
});
t.setRepeats(true);
t.start();
}
public class TestPanel extends JPanel {
int myId = panelCount++;
public TestPanel() {
this.setLayout(new GridBagLayout());
this.setBorder(BorderFactory.createBevelBorder(1));
JButton up = new JButton("^");
JLabel rate = new JLabel("1");
JButton down = new JButton("^");
JLabel label = new JLabel("" + myId);
label.setHorizontalAlignment(JLabel.CENTER);
label.setVerticalAlignment(JLabel.CENTER);
this.setMaximumSize(new Dimension(1000, 200));
this.setPreferredSize(new Dimension(1000, 100));
this.add(label);
this.add(up);
this.add(rate);
this.add(down);
}
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
Jscrollpanetest testScrollPane = new Jscrollpanetest();
}
});
}
}

If use and dynamic created ActionListener there will be no problem. So each button will have its own ActionListener.
If using a common ActionListener must add tags to each button as extend JButton.

Related

JPanel won't update

I've hit a problem in getting a JPanel to update.
My simple program uses a custom JPanel which displays a label and a textfield. A Jbutton on the main panel is used to replace the JPanel with a new JPanel. The initial panel shows up fine but when the button is pressed the panel is not updated with a new MyPanel. I can tell that a new object is being created as count is being incremented.
public class SwingTest extends JFrame{
private JPanel mp;
private JPanel vp;
private JButton button;
public static void main(String[] args) {
SwingTest st = new SwingTest();
}
public SwingTest() {
vp = new MyPanel();
mp = new JPanel(new BorderLayout());
mp.add(vp, BorderLayout.CENTER);
button = new JButton("Change");
button.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent ae) {
vp = new MyPanel();
vp.revalidate();
}
});
mp.add(button, BorderLayout.SOUTH);
this.add(mp);
this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
setLocationRelativeTo(null);
setSize(250, 150);
pack();
setVisible(true);
}
}
and my custom panel....
public class MyPanel extends JPanel{
private JLabel label;
private JTextField tf;
static int count = 0;
public MyPanel(){
count++;
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
setPreferredSize(new Dimension(400, 200));
c.gridx = 0;
c.gridy = 0;
label = new JLabel(String.valueOf(count));
tf = new JTextField(10);
add(label,c);
c.gridx = 1;
add(tf, c);
}
}
You state:
A Jbutton on the main panel is used to replace the JPanel with a new JPanel.
And yet this code:
button.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent ae) {
vp = new MyPanel();
vp.revalidate();
}
});
and yet this code does not do this at all. All it does is change the JPanel referenced by the vp variable, but has absolutely no effect on the JPanel that is being displayed by the GUI, which suggests that you're confusing reference variable with reference or object. To change the JPanel that is displayed, you must do exactly this: add the new JPanel into the container JPanel into the BorderLayout.CENTER (default) position, then call revalidate() and repaint() on the container.
e.g.,
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
// vp = new MyPanel();
// vp.revalidate();
mp.remove(vp); // remove the original MyPanel from the GUI
vp = new MyPanel(); // create a new one
mp.add(vp, BorderLayout.CENTER); // add it to the container
// ask the container to layout and display the new component
mp.revalidate();
mp.repaint();
}
});
Or better still -- use a CardLayout to swap views.
Or better still -- simply clear the value held by the JTextField.
For more on the distinction between reference variable and object, please check out Jon Skeet's answer to this question: What is the difference between a variable, object, and reference?

Java Button disappears after clicking

I'm trying to add a button using an JOptionPane in another button, but after I clicked the original button just keeps disappearing.
I've tried adding the JPanel manually instead of using 'handPanelNPC.getHandPanel()' by iterating through the handPanel.buttons but it stil wont work. I've checked the ArrayList size and it is already inserted properly.
LayoutTesting.java
public class LayoutTesting extends JFrame{
HandPanel handPanelNPC = new HandPanel();
public LayoutTesting(HandPanel handPanel, int type){
Container pane = getContentPane();
if (type==1){
handPanelNPC = handPanel;
}
pane.setLayout(new BorderLayout());
pane.add(handPanelNPC.getHandPanel(), BorderLayout.NORTH);
validate();
repaint();
}
public LayoutTesting(){
Container pane = getContentPane();
pane.setLayout(new BorderLayout());
pane.add(handPanelNPC.getHandPanel(), BorderLayout.NORTH);
}
}
HandPanel.java
public class HandPanel implements ActionListener{
JFrame frame = null;
JPanel panel = new JPanel();
ArrayList<JButton> buttons = new ArrayList<JButton>();
public HandPanel(){
addNewButton();
panel.setLayout(new FlowLayout());
panel.add(buttons.get(0));
}
public JComponent getHandPanel(){
panel = new JPanel();
for(int i=0; i<buttons.size(); i++){
JButton button = buttons.get(i);
panel.add(button);
}
return panel;
}
public void addNewButton(){
JButton button = new JButton();
button.setPreferredSize(new Dimension(40,58));
button.addActionListener(this);
buttons.add(button);
}
public void actionPerformed(ActionEvent e) {
String[] options = {"Summon", "Set", "Add Card"};
int messageType = JOptionPane.QUESTION_MESSAGE;
int code = JOptionPane.showOptionDialog(
frame,
"What would you like to do?",
"Card Name",
0, messageType, null,
options, options[1]);
if (code==2){
addNewButton();
LayoutTesting frame = new LayoutTesting(this, 1);
}
}
}
Main.java
public class Main extends JFrame{
public static void main(String[] args){
LayoutTesting frame = new LayoutTesting();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 300);
frame.setVisible(true);
}
}
You have too many odd things happening in your code to give a simple answer.
Try debugging your own code by looking at this line in HandPanel.java:
LayoutTesting frame = new LayoutTesting(this, 1);
What does it really do? Now remove that line and the button will not disappear. Now try and work out what that line was doing, and why the button disappeared.
Also 'panel.add(buttons.get(0));' does nothing because there is never a button in the array when you make that call (You add the button afterwards in another method).
Here is a rough working demo that lets you add as many new cards as you want to the first frame, and each card has a button that will let you summon a new card.
public class LayoutTesting extends JFrame{
Container pane;
//Add card when button is pressed:
public void addCard(){
Container card = new JPanel();
card.setBackground(Color.red);
JButton newButton = addNewButton();
newButton.setBackground(Color.red);
card.add(newButton);
pane.add(card);
revalidate();
repaint();
}
//Setup window and add button:
public LayoutTesting(){
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 300);
setVisible(true);
setLayout(new FlowLayout());
pane = new JPanel();
pane.setLayout(new GridBagLayout());
JButton firstButton = addNewButton();
firstButton.setBackground(Color.green);
add(pane);
add(firstButton);
}
//Create button and action listener:
public JButton addNewButton(){
JButton button = new JButton();
button.setPreferredSize(new Dimension(40, 58));
button.addActionListener(new java.awt.event.ActionListener(){
#Override
public void actionPerformed(java.awt.event.ActionEvent evt){
buttonAction(evt);
}
});
return button;
}
//Action fer each button:
public void buttonAction(ActionEvent e) {
String[] options = {"Summon", "Set", "Add Card"};
int messageType = JOptionPane.QUESTION_MESSAGE;
int code = JOptionPane.showOptionDialog(
this,
"What would you like to do?",
"Card Name",
0, messageType, null,
options, options[1]);
if (code==2){
addCard();
}
}
}

Combinations of Classes

Hey everyone, I want to combine my classes and get it in
only one frame. Now I have 2 classes and I don't know how to group them.
The JSlider.
public class JSliderExample extends JFrame {
JSlider jsHorizontal;
JTextField jtf1;
public JSliderExample() {
jsHorizontal = new JSlider(JSlider.HORIZONTAL, 0, 100, 50);
jtf1 = new JTextField(15);
jtf1.setEditable(false);
jtf1.setText("Horizontal value is " + jsHorizontal.getValue());
JPanel panel = new JPanel();
panel.setBackground(Color.WHITE);
panel.add(jsHorizontal);
panel.setBackground(Color.WHITE);
panel.add(jtf1);
panel.setBackground(Color.WHITE);
getContentPane().add(panel, BorderLayout.CENTER);
getContentPane().add(panel, BorderLayout.SOUTH);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(300, 400, 400, 300);
setVisible(true);
setBackground(Color.WHITE);
}
class JSliderHandler implements ChangeListener {
public void stateChanged(ChangeEvent ce) {
jtf1.setText("value is " + jsHorizontal.getValue());
}
}
And there are my buttons
.
public void createGUI() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout());
JButton button2 = new JButton("PLAY");
button2.setActionCommand("Button PLAY was pressed!");
panel.add(button2);
textField = new JTextField();
textField.setColumns(23);
panel.add(textField);
ActionListener actionListener = new TestActionListener();
button1.addActionListener(actionListener);
button2.addActionListener(actionListener);
button3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
textField.setText(e.getActionCommand());
}
});
getContentPane().add(panel);
setPreferredSize(new Dimension(320, 100));
}
public class TestActionListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
textField.setText(e.getActionCommand());
}
}
In the end of programm I see 2 frames that consist of 2 classes.
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
TestFrame frame = new TestFrame();
frame.pack();
JSliderExample frame1 = new JSliderExample();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
If you don't want to see 2 JFrames, then don't create 2 JFrames. Why not make JPanels with all your classes above and not JFrames, and then in your main method, add your JPanels to the JFrame created within main. Simple.
So for example, instead of having JSliderExample extend JFrame, change it's name to SliderPanel and have it extend JPanel, and likewise with your JButton program. Then your main method could look something like:
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
// your JSlider example class **that extends JPanel**
SliderPanel sliderPanel = new SliderPanel();
// your JButton example class **that extends JPanel**
ButtonPanel buttonPanel = new ButtonPanel():
JFrame frame = new JFrame("My GUI");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(sliderPanel, BorderLayout.PAGE_START);
frame.add(buttonPanel, BorderLayout.CENTER);
frame.pack();
frame.setLocationRelativeTo(null); // center GUI if you want
frame.setVisible(true);
}
});
}

BorderLayout not working JFrame

For some reason I can't get the BorderLayout to set the way it's supposed to. Just would like to know where I'm going wrong.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ColorFactory extends JFrame
{
final int width = 500;
final int height = 300;
private JPanel buttonPanel;
private JPanel radioButtonPanel;
private JLabel msgChangeColor;
public ColorFactory()
{
setTitle("Color Factory");
setSize(width, height);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
createTopPanel();
add(buttonPanel, BorderLayout.NORTH);
createBottomPanel();
add(radioButtonPanel, BorderLayout.SOUTH);
msgChangeColor = new JLabel("Top buttons change the panel color and bottom radio buttons change the text color.");
add(msgChangeColor, BorderLayout.CENTER);
pack();
}
private void createTopPanel()
{
buttonPanel = new JPanel();
setLayout(new FlowLayout());
JButton redButton = new JButton("Red");
redButton.setBackground(Color.RED);
redButton.addActionListener(new ButtonListener());
redButton.setActionCommand("R");
JButton orangeButton = new JButton("Orange");
orangeButton.setBackground(Color.ORANGE);
orangeButton.addActionListener(new ButtonListener());
orangeButton.setActionCommand("O");
JButton yellowButton = new JButton("Yellow");
yellowButton.setBackground(Color.YELLOW);
yellowButton.addActionListener(new ButtonListener());
yellowButton.setActionCommand("Y");
buttonPanel.add(redButton);
buttonPanel.add(orangeButton);
buttonPanel.add(yellowButton);
}
private void createBottomPanel()
{
radioButtonPanel = new JPanel();
setLayout(new FlowLayout());
JRadioButton greenRadioButton = new JRadioButton("Green");
greenRadioButton.setBackground(Color.GREEN);
greenRadioButton.addActionListener(new RadioButtonListener());
greenRadioButton.setActionCommand("G");
JButton blueRadioButton = new JButton("Blue");
blueRadioButton.setBackground(Color.BLUE);
blueRadioButton.addActionListener(new RadioButtonListener());
blueRadioButton.setActionCommand("B");
JButton cyanRadioButton = new JButton("Cyan");
cyanRadioButton.setBackground(Color.CYAN);
cyanRadioButton.addActionListener(new RadioButtonListener());
cyanRadioButton.setActionCommand("C");
radioButtonPanel.add(greenRadioButton);
radioButtonPanel.add(blueRadioButton);
radioButtonPanel.add(cyanRadioButton);
}
private class ButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String actionColor = e.getActionCommand();
if(actionColor.equals("R"))
{
buttonPanel.setBackground(Color.RED);
radioButtonPanel.setBackground(Color.RED);
}
if(actionColor.equals("O"))
{
buttonPanel.setBackground(Color.ORANGE);
radioButtonPanel.setBackground(Color.ORANGE);
}
if(actionColor.equals("Y"))
{
buttonPanel.setBackground(Color.YELLOW);
radioButtonPanel.setBackground(Color.YELLOW);
}
}
}
private class RadioButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String actionTextColor = e.getActionCommand();
if(actionTextColor.equals("G"))
{
msgChangeColor.setForeground(Color.GREEN);
}
if(actionTextColor.equals("B"))
{
msgChangeColor.setForeground(Color.BLUE);
}
if(actionTextColor.equals("C"))
{
msgChangeColor.setForeground(Color.CYAN);
}
}
}
public static void main(String[] args)
{
ColorFactory run = new ColorFactory();
run.setVisible(true);
}
}
The problem is you are changing the layout manager for the frame when you create your top and bottom panels...
private void createTopPanel() {
buttonPanel = new JPanel();
setLayout(new FlowLayout()); // <--- This is call setLayout on the frame
This is why it's dangerous to...
Extend from something like JFrame directly...
Dynamically build components
It's all to easy to lose context and start effecting components you didn't actually want to...
Another problem (besides the one posted by MadProgrammer) is that you add your components to the JFrame itself.
You should add content to the content pane of the frame which you can get by calling JFrame.getContentPane().
Example:
JFrame f = new JFrame("Test");
Container c = f.getContentPane();
c.add(new JButton("In Center"), BorderLayout.CENTER);
c.add(new JButton("At the Bottom"), BorderLayout.SOUTH);
c.add(new JButton("At the Top"), BorderLayout.NORTH);
c.add(new JButton("On the Left"), BorderLayout.WEST);
c.add(new JButton("On the Right"), BorderLayout.EAST);
You can set/change the content panel by calling JFrame.setContentPane(). The default content panel already has BorderLayout so you don't even need to change it nor to set a new panel.

positioning jpanel at the bottom

I want to position the JPanel that contains the send button and the textfield (and right now uses a flowlayout) at the bottom of the JTextArea (The white area).
How can I achieve this?
public GUI()
{
mainWindow = new JFrame("Chat GUI");
lowerPanel = new JPanel(new FlowLayout());
usersPanel = new JPanel(new GridLayout(GRIDLAYOUT_ROWS, GRIDLAYOUT_COLS));
users = new JList(data);
usersPanel.add(users);
sendButton = new JButton("Send");
textField = new JTextField(TEXTFIELD_WIDTH);
textArea = new JTextArea(TEXTAREA_HEIGHT, TEXTAREA_WIDTH);
textArea.setEditable(false);
}
private void addButtonListener(JButton b) {
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
}
});
}
public void createGUI() {
addButtonListener(sendButton);
lowerPanel.add(sendButton);
lowerPanel.add(textField);
mainWindow.add(users);
mainWindow.add(textArea);
mainWindow.add(lowerPanel);
mainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainWindow.setVisible(true);
mainWindow.setLayout(new FlowLayout());
mainWindow.pack();
}
You Will have Layout :
this.add(buttonPanel,BorderLayout.SOUTH);
see this answer

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