Java - How to "unhide" a JFrame - java

I am quite new to Java, but familiar with native Android dev so bear with me xD. I created an application that creates a JFrame. Then I set the closeOperation to: setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);.
It performs as expected, the frame is hidden and this is what I want (when I close). I need the application to keep on running (only once instance), because I am running a thread in the background that is performing an operation.
My actionListener on my button in my JFrame currently does this: setVisible(false);
My question is this, how can I maximize the JFrame again after it has been hidden? Would it be possible to display the frame when the user clicks on the minimized application in the task bar? Is there some type of listener that I need to implement?
Thanks in advance, any advice will be appreciated
UPDATE
For this solution to work correctly you need to do the following. Also have a look at XtremeBaumer's answer for this to make sense.
On JFrame creation setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);.
When you want to minimize the app (on click possibly) frame.setState(Frame.ICONIFIED);.
When you want to maximize the app again frame.setState(Frame.NORMAL); in windowDeiconified event.
One last thing, if you want to also minimize your app when the user clicks on the exit button (red x) add this to the windowClosing event frame.setState(Frame.ICONIFIED);.

this.addWindowListener(new WindowListener(){
#Override
public void windowActivated(WindowEvent e) {
}
#Override
public void windowClosed(WindowEvent e) {
}
#Override
public void windowClosing(WindowEvent e) {
setState(Frame.ICONIFIED)
}
#Override
public void windowDeactivated(WindowEvent e) {
}
#Override
public void windowDeiconified(WindowEvent e) {
this.setVisible(true);
//this should be what you want
}
#Override
public void windowIconified(WindowEvent e) {
}
#Override
public void windowOpened(WindowEvent e) {
}
});
i hope this solves your question. add it to your JFrame

Related

How to make an action only when my Frame disappear on the screen in Java?

I need to take a screenshot of an area of my screen, to make that i use "Robot" in Java. But if the user place the windows in the area, the windows will be on the screenshot instead of the background.
I tried to solve my problem by placing a :
myframe.setVisible(false);
But when i look the screenshot the windows appear on it. I thought it was because the windows didn't have enough time to disappear or because the render of the screen wasn't updated yet, so i tried different things like using:
repaint();
Or by placing a
try{}finally{}
block to be sure that the actions in the try block have been finished.
But no one of these solution works. These is other ways in my mind but they looks globally bad because they use functions to wait.
So is there a good solution to my problem?
You could use window listener to fire the screen shot when window is closing:
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class MainFrame extends JFrame implements WindowListener {
public MainFrame() {
super("Test Frame");
JLabel displayMsg = new JLabel(" Close window");
getContentPane().add(displayMsg);
addWindowListener(this);
setSize(400, 300);
setVisible(true);
}
#Override
public void windowClosing(WindowEvent e) {
System.out.println("WindowListener method called: windowClosing.");
//add you screen capture code here
}
//--Not used
#Override
public void windowClosed(WindowEvent e) {
//do nothing
}
#Override
public void windowOpened(WindowEvent e) {
//do nothing
}
#Override
public void windowIconified(WindowEvent e) {
//do nothing
}
#Override
public void windowDeiconified(WindowEvent e) {
//do nothing
}
#Override
public void windowActivated(WindowEvent e) {
//do nothing
}
#Override
public void windowDeactivated(WindowEvent e) {
//do nothing
}
public void windowGainedFocus(WindowEvent e) {
//do nothing
}
public void windowLostFocus(WindowEvent e) {
//do nothing
}
public static void main(String[] args) {
new MainFrame();
}
}
Use SwingUtilities.invokeLater() to take the actual screenshot. Not 100% sure, but I think that myframe.setVisible(false); doesn't become effective till the program flow goes back to the event dispatching loop.
EDIT:
instead of
useRobotToMakeScreenshot();
write
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
useRobotToMakeScreenshot();
}
}
(of course, you have to replace useRobotToMakeScreenshot() with the actual call to the method that does the screenshooting thing)

Java Swing feedback button on a tablet touch screen

Is it possible obtain a feedback from JButton in a Java Swing application on a tablet?
I am using Windows 8 and if I switch a physical mouse to the device, motion feedback from JButton is in the typical way, but if I use a finger, the feedback disappears.
I have tried overriding methods customizing my inherited JButtons, and a estended etc., but I haven't hoped the goal... I guess it is related with when we touch the screen with a mouse, you only click a point on the screen, but if you touches with a finger, there are several pixels selected.
Any idea?
Thank you so so much!
Im not entirely sure what you mean by feedback, but I THINK the answer to the question your asking is no. Swing was never designed for that sort of interface. However if the feedback you are referring to is something like the button highlighting and swelling when clicked, this is usually something that should happen on its own. If as I suspect you are referring to a hover action being performed when youtouch but dont 'tap' the button, then there is likely no way for you to control that. As an alternative, if your application is not yet mature, you may want to consider switching from swing to JavaFX which uses CSS to give you a large amount of control over things like this.
I've got an acceptable solution. I will try to explain it as simple and complete as possible.
First of all, you have to use a JButton extended class like these:
import java.awt.Color;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
/**
* Customized <code>JButton</code> to obtained a feedback user experience of movement.
* #author Gabriel Moreno.
*/
public class FeedbackTouchScreenButton extends JButton {
public FeedbackTouchScreenButton() {
super();
this.addMouseListener(new MouseListener() {
#Override
public void mouseClicked(final MouseEvent e) {
new Thread(new Runnable() {
#Override
public void run() {
Color bg = e.getComponent().getBackground();
e.getComponent().setBackground(Color.BLUE); // For example
try {
Thread.sleep(100);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
e.getComponent().setBackground(bg);
}
}).start();
} // mouseClicked()
#Override
public void mouseEntered(MouseEvent e) {}
#Override
public void mouseExited(MouseEvent e) {}
#Override
public void mousePressed(MouseEvent e) {}
#Override
public void mouseReleased(MouseEvent e) {}
});
} // FeedbackTouchScreenButton()
} // FeedbackTouchScreenButton
When you customize the action performed of the concerned button, you will have to throw (carefully) another thread. For example:
// ---
btnExample.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(final java.awt.event.ActionEvent evt) {
new Thread(new Runnable() {
#Override
public void run() {
btnExampleActionPerformed(evt);
} // run()
}).start();
}
});
// ---
This example apparently works. But actually only it seems... :-)
The reason is because on the tablet screen the 'onPressed' state of the component doesn't works with a finger like with a mouse pointer.
THE KEY: 'onClick' = 'onPressed' + 'onRelease'.
And 'onClick' is correctlty done on the touch screen. It is the moment when the trick is done, when you release your finger from the device.

Java - MousePress Hold and Release event listener

hello is there a way mouse even that can Hold the mouse and release cause I can't find it on google.
so for example this image..
When the jTextBox is **** when he click the button, he see the words oops...
then after he release the click of mouse the jTextBox will back to **** again
I know this code already but the mouseevent is I only don't know
Yes. You will want to implement the MouseListener interface with a new class and add this new Listener against your button with the following;
button.addMouseListener(new YourMouseListener());
An example custom MouseListener might look like this.
class YourMouseListener implements MouseListener {
#Override
public void mouseClicked(MouseEvent e) {
}
#Override
public void mousePressed(MouseEvent e) {
// Insert code to show password
}
#Override
public void mouseReleased(MouseEvent e) {
// Insert code to hide password again
}
#Override
public void mouseEntered(MouseEvent e) {
}
#Override
public void mouseExited(MouseEvent e) {
}
}
I hope this helps.
You'll need a Robot object. This can do things as follows:
robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
The Mousebutton is pressed until you do this:
robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
This should do what you want.

how to call a method before exit in jframe with java

i tried like they answered in this question
How can save some Objects, directly after the User has closed the Applications JFrame, but before the Program exits?
but the frame won't close
i wrote the following but it's the same thing, the frame wont close .
#Override
public void windowClosed(WindowEvent e) {
dispose();
setVisible(false);
System.exit(0);
}
#Override
public void windowClosing(WindowEvent e) {
dispose();
setVisible(false);
System.exit(0);
}
you can add shutdown hook in general to do work just before the jvm exits, no need for these listeners.
Shutdown Hook
If you want to do it by listener, use the windowClosedEvent:
#Override
public void windowClosed(WindowEvent e) {
save();
}
By default the last frame exits the application, unless you did not set the default close operation to anything other than DISPOSE_ON_CLOSE.

How can I Listen for Keyboard input without Text Field Java

I am working on a Java application and interfacing with an RFID reader that acts as a keyboard input device.
The application will be used for employee time tracking, so the employee should not see the code that his/her RFID tag contains.
Currently, the application opens a jFrame that asks the employee to scan their tag. This is where I would like to listen for the keyboard input.
All of the RFID tags are 10 digits, so I would like to use some kind of regex to detect when a card is scanned if possible.
If someone could point me in the right direction, or contribute some code I would be grateful.
Thanks in advance.
UPDATE:
I was able to read the input of the scanner by adding the following to the constructor of my JFrame.
addKeyListener(new KeyListener(){
#Override
public void keyPressed(KeyEvent e){ System.out.print(e.getKeyChar());}
#Override
public void keyReleased(KeyEvent e) { }
#Override
public void keyTyped(KeyEvent e) { }
});
So it is now confirmed that the Reader is just standard Keyboard input.
Here is an example of what I get for a tag: 0006459027
Now, the big question is, how do I take the characters that I got, and detect that it is a 10 digit string, and from there trigger an event to open a new frame?
First, I'd see if the RFID reader is triggering an ActionEvent to be fired when the tag is scanned. This would be the simplest approach.
Failing that, you would need to attach a DocumentListener to the fields underlying document and monitor for changes.
You'll need to decide how best to interrupt the results (as you're likely to get each letter of the RFID at a time). You could monitor the length of the document or have a javax.swing.Timer which triggers after a short delay (you'd reset the timer on each update event triggered by the DocumentListener)
Check out
JTextField.addActionListener
JTextField.getDocument().addDocumentListener
I'd suggest taking a look at DocumentFilter as well, but your interested in the final result, not modifying it.
UPDATED with DocumentListener Example
// In the classes variable decleration section...
private JTextField rfidField;
// In the classes constructor or UI init method...
rfidField = new JTextField(12);
rfidField.getDocument().addDocumentListener(new DocumentListener() {
public void handleUpdate(DocumentEvent e) {
if (e.getDocument().getLength() == 10) {
System.out.println("Trigger me happy...");
SwingUtilities.invokeLater(new Runnable() {
public void run() {
rfidField.setText(null);
}
});
}
}
#Override
public void insertUpdate(DocumentEvent e) {
handleUpdate(e);
}
#Override
public void removeUpdate(DocumentEvent e) {
handleUpdate(e);
}
#Override
public void changedUpdate(DocumentEvent e) {
handleUpdate(e);
}
});
// Now don't forget to add the field to your forms container ;)
//////
One of things I would be do when you "trigger" the code event is, once you've read it from the text field, is clear the text field (JTextField.setText(null)) - IMHO
If the RFID reader acts as a keyboard input device, try with key events:
JFrame frame = new JFrame();
// frame setup
frame.addKeyListener(new KeyAdapter(){
public void KeyPressed(KeyEvent ke)
{
System.out.println(ke);
}
});
Otherwise you have to check which kind of event it fires.
I was in a similar situation but with a bar-code scanner.
I really worked hard on a custom DocumentListener that would take care of all scenarios, and none of it worked.
Out of desperation, I added an ActionListener and it then worked very well.
Here is a code snap-shot :
try {
txtStockItemRef.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
System.out.println(txtStockItemRef.getText());
DatabaseManager.peformStockItemLookupByBarcodeRef(txtStockItemRef.getText());
}
});
} catch(Exception exc) {
LiveCityRetailTools.handleExceptionWithUserMessage(exc);
}

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