How to check if a jframe is opened? - java

My code below create a new array and sends it to chat(jFrame).
String info1[]=new String[3];
// username , userid , userid2 are variables
info1[0]=username4;
info1[1]=""+userid;
info1[2]=""+userid2;
chat.main(info1);
But i need to modify this code to work such a way that it , if the chat jframe was opened,
then dont open a new jFrame .But instead open a new tab in chat jframe . The code for chat frame is :
private void formWindowActivated(java.awt.event.WindowEvent evt) {
JScrollPane panel2 = new JScrollPane();
JTextArea ta=new JTextArea("");
ta.setColumns(30);
ta.setRows(19);
panel2.setViewportView(ta);
jTabbedPane1.add("Hello", panel2);
}

I wonder if you shouldn't be using JDialogs instead of JFrames, if the window is dependent on another window.
A solution is to use a class field to hold a reference to the window (JFrame or JDialog) and checking if it is null or visible, and if so, then lazily create/open the window,
public void newChat(User user) {
if (chatWindow == null) {
// create chatWindow in a lazy fashion
chatWindow = new JDialog(myMainFrame, "Chat", /* modality type */);
// ... set up the chat window dialog
}
chatWindow.setVisible(true);
addTabWithUser(user);
}
but that's about all I can say based on the information provided. If you need more specific help, then you will need to provide more information.

If using JFrames it can be simply done like this:
if (Frame1.component != null) {
Frame1 is opened
} else if (Frame2.component == null) {
Frame2 is closed
}
Component ex.JTextField, JComboBox etc.

Related

Passing an object from one JFrame to another [duplicate]

I have two Jframes where frame1 has some text fields and when a button on frame1 is clicked, I open another JFrame which contains a search box and a JTable containing search results.
When I click on a result row on JTable, I want that particular values to be reflected in the frame1 text fields.
I tried passing the JFrame1's object as a parameter but I have no clear idea on how to achieve this.
Any help would be highly appreciated.
Thanks
First of all, your program design seems a bit off, as if you are using a JFrame for one of your windows where you should in fact be using a JDialog since it sounds as if one window should be dependent upon the other.
But regardless, you pass references of GUI objects the same as you would standard non-GUI Java code. If one window opens the other (the second often being the dialog), then the first window usually already holds a reference to the second window and can call methods off of it. The key often is when to have the first window call the second's methods to get its state. If the second is a modal dialog, then the when is easy -- immediately after the dialog returns which will be in the code immediately after you set the second dialog visible. If it is not a modal dialog, then you probably want to use a listener of some sort to know when to extract the information.
Having said this, the details will all depend on your program structure, and you'll need to tell us more about this if you want more specific help.
For a simple example that has one window open another, allows the user to enter text into the dialog windows JTextField, and then places the text in the first window's JTextField, please have a look at this:
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class WindowCommunication {
private static void createAndShowUI() {
JFrame frame = new JFrame("WindowCommunication");
frame.getContentPane().add(new MyFramePanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
// let's be sure to start Swing on the Swing event thread
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
class MyFramePanel extends JPanel {
private JTextField field = new JTextField(10);
private JButton openDialogeBtn = new JButton("Open Dialog");
// here my main gui has a reference to the JDialog and to the
// MyDialogPanel which is displayed in the JDialog
private MyDialogPanel dialogPanel = new MyDialogPanel();
private JDialog dialog;
public MyFramePanel() {
openDialogeBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openTableAction();
}
});
field.setEditable(false);
field.setFocusable(false);
add(field);
add(openDialogeBtn);
}
private void openTableAction() {
// lazy creation of the JDialog
if (dialog == null) {
Window win = SwingUtilities.getWindowAncestor(this);
if (win != null) {
dialog = new JDialog(win, "My Dialog",
ModalityType.APPLICATION_MODAL);
dialog.getContentPane().add(dialogPanel);
dialog.pack();
dialog.setLocationRelativeTo(null);
}
}
dialog.setVisible(true); // here the modal dialog takes over
// this line starts *after* the modal dialog has been disposed
// **** here's the key where I get the String from JTextField in the GUI held
// by the JDialog and put it into this GUI's JTextField.
field.setText(dialogPanel.getFieldText());
}
}
class MyDialogPanel extends JPanel {
private JTextField field = new JTextField(10);
private JButton okButton = new JButton("OK");
public MyDialogPanel() {
okButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
okButtonAction();
}
});
add(field);
add(okButton);
}
// to allow outside classes to get the text held by the JTextField
public String getFieldText() {
return field.getText();
}
// This button's action is simply to dispose of the JDialog.
private void okButtonAction() {
// win is here the JDialog that holds this JPanel, but it could be a JFrame or
// any other top-level container that is holding this JPanel
Window win = SwingUtilities.getWindowAncestor(this);
if (win != null) {
win.dispose();
}
}
}
You'd do a very similar technique to get information out of a JTable.
And again, if this information doesn't help you, then please tell us more about your program including showing us some of your code. The best code to show is a small compilable example, an SSCCE similar to what I've posted above.

How to transfer an answer to another jframe? [duplicate]

I have two Jframes where frame1 has some text fields and when a button on frame1 is clicked, I open another JFrame which contains a search box and a JTable containing search results.
When I click on a result row on JTable, I want that particular values to be reflected in the frame1 text fields.
I tried passing the JFrame1's object as a parameter but I have no clear idea on how to achieve this.
Any help would be highly appreciated.
Thanks
First of all, your program design seems a bit off, as if you are using a JFrame for one of your windows where you should in fact be using a JDialog since it sounds as if one window should be dependent upon the other.
But regardless, you pass references of GUI objects the same as you would standard non-GUI Java code. If one window opens the other (the second often being the dialog), then the first window usually already holds a reference to the second window and can call methods off of it. The key often is when to have the first window call the second's methods to get its state. If the second is a modal dialog, then the when is easy -- immediately after the dialog returns which will be in the code immediately after you set the second dialog visible. If it is not a modal dialog, then you probably want to use a listener of some sort to know when to extract the information.
Having said this, the details will all depend on your program structure, and you'll need to tell us more about this if you want more specific help.
For a simple example that has one window open another, allows the user to enter text into the dialog windows JTextField, and then places the text in the first window's JTextField, please have a look at this:
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class WindowCommunication {
private static void createAndShowUI() {
JFrame frame = new JFrame("WindowCommunication");
frame.getContentPane().add(new MyFramePanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
// let's be sure to start Swing on the Swing event thread
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
class MyFramePanel extends JPanel {
private JTextField field = new JTextField(10);
private JButton openDialogeBtn = new JButton("Open Dialog");
// here my main gui has a reference to the JDialog and to the
// MyDialogPanel which is displayed in the JDialog
private MyDialogPanel dialogPanel = new MyDialogPanel();
private JDialog dialog;
public MyFramePanel() {
openDialogeBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openTableAction();
}
});
field.setEditable(false);
field.setFocusable(false);
add(field);
add(openDialogeBtn);
}
private void openTableAction() {
// lazy creation of the JDialog
if (dialog == null) {
Window win = SwingUtilities.getWindowAncestor(this);
if (win != null) {
dialog = new JDialog(win, "My Dialog",
ModalityType.APPLICATION_MODAL);
dialog.getContentPane().add(dialogPanel);
dialog.pack();
dialog.setLocationRelativeTo(null);
}
}
dialog.setVisible(true); // here the modal dialog takes over
// this line starts *after* the modal dialog has been disposed
// **** here's the key where I get the String from JTextField in the GUI held
// by the JDialog and put it into this GUI's JTextField.
field.setText(dialogPanel.getFieldText());
}
}
class MyDialogPanel extends JPanel {
private JTextField field = new JTextField(10);
private JButton okButton = new JButton("OK");
public MyDialogPanel() {
okButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
okButtonAction();
}
});
add(field);
add(okButton);
}
// to allow outside classes to get the text held by the JTextField
public String getFieldText() {
return field.getText();
}
// This button's action is simply to dispose of the JDialog.
private void okButtonAction() {
// win is here the JDialog that holds this JPanel, but it could be a JFrame or
// any other top-level container that is holding this JPanel
Window win = SwingUtilities.getWindowAncestor(this);
if (win != null) {
win.dispose();
}
}
}
You'd do a very similar technique to get information out of a JTable.
And again, if this information doesn't help you, then please tell us more about your program including showing us some of your code. The best code to show is a small compilable example, an SSCCE similar to what I've posted above.

MDI Application in java

I am making a MDI application in java using netbeans.
the issue is that i have two buttons: Add employee and search employee. When i click Add employee, the internal frame for add employee opens up in the desktop pane, and when i click search employee it gets behind the earlier frame and is not visible until i exit the first frame. I want that if desktop pane is not empty then earlier internal frame should be disposed on click of the other button. Plese help me out
This is the code: Here JP is variable name for desktop pane.
private void BAddEmpActionPerformed(java.awt.event.ActionEvent evt) {
o=new EntryEmp();
JP.add(o);
o.setVisible(true);
}
private void BSearchEmpActionPerformed(java.awt.event.ActionEvent evt) {
Employee_search ob1=new Employee_search();
JP.add(ob1);
ob1.setVisible(true);
}
I think you should be able to set the first panes visibility to false:
private void BSearchEmpActionPerformed(java.awt.event.ActionEvent evt) {
Employee_search ob1=new Employee_search();
JP.add(ob1);
ob1.setVisible(true);
if (o != null && o.getVisible == true){
o.setVisible(false);
//and possibly kill it:
o = null;
}
After you've added the new JInternalFrame and made it visible call JInternalFrame#toFront

jInternalFrame not brought to the front

I have a JDesktopPane which contains a number of JInternalFrames. The first time I press one button to visible jinternalframe1 and second button to visible jinternalframe2, it appear above the main window without problems. However, if I press one of the buttons to Reopen jinternalframe1 or jinternalframe2, they are not brought in front of the main window... EDIT: actually, i can't do anything with jinternalframe on a button click...i can only click once on the button and then no operation can be perform on the jinternalframe through the button..why it doesn't work!!
this is the coding of button1...
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt)
{
jinternalframe1 frame1 = new jinternalframe1();
try {
if(Allow.flag == false) {
desktopPane.add(frame1);
frame1.setVisible(true);
Allow.flag = true;
} else if(Allow.flag == true) {
frame1.setSelected(true);
}
} catch(PropertyVetoException e) {
System.out.println(e);
}
}
Allow.java
public class Allow {
static boolean flag = false;
}
Every time you click on the button you create a new JInternalFrame object, but you only ever add the first internal frame that you create to the desktop pane.
Don't keep creating new internal frame objects. I would guess you should only create the internal frame if your "frame1" variable is null.
If you need more help then post a proper SSCCE that demonstrates the problem.

How would I use a button in Java to open an existing frame in the same package?

I have a bunch of jFrames in the same package. How would I go about opening all of them using buttons from one "Master Frame".
i.e, Master Frame named "Bob" has a bunch of buttons then will allow me to open jFrames that have already been created.
In your event handler, do newFrame.setVisible(true);
You could use this technique. I'm using it to set visible, but you could also use it for creation.
Map<String,Frame> myFrames = new HashMap<String,Frame>();
buttonForFrameA.setActionCommand("FRAME_A");
buttonForFrameB.setActionCommand("FRAME_B");
myFrames.put("FRAME_A",aFrame);
myFrames.put("FRAME_B",bFrame);
public void actionPerformed(ActionEvent e) {
if(e.getActionCommand().startsWith("FRAME_") {
for(Frame frame : myFrames.values())
frame.setVisible(false);
Frame selectedFrame = myFrames.get(e.getActionCommand());
if(selectedFrame != null) selectedFrame.setVisible(true);
}

Categories