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Swing mouseEntered strange behavior

I have a jframe with some JComponents, with some mouseListener. My aim is to show a little jframe with a specified text, when the mouse enter on a jlabel, and to show off it when the mouse is exited.
Jframe is supposed to be shown near the mouse.
Anyway that does not happen, and the programm behaves in a very strange way.
Why?
the bug
That's my code
package finestrina;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class finestra implements MouseListener{
private JFrame finestra = new JFrame();
private JFrame pagina = new JFrame();
private JButton submit1 = new JButton("press");
private JTextField text = new JTextField();
finestra(){
pagina.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pagina.setSize(500, 500);
JPanel cont = new JPanel();
cont.setLayout(new GridLayout(3,4));
JLabel label = new JLabel();
label.setText("ON MOUSEROVER THIS");
cont.add(label);
label.addMouseListener(this);
submit1.addMouseListener(this);
text.addMouseListener(this);
cont.add(submit1);
cont.add(text);
pagina.add(cont);
pagina.setVisible(true);
finestra.setUndecorated(true);
}
#Override
public void mouseClicked(MouseEvent arg0) {}
#Override
public void mouseEntered(MouseEvent event) {
if(event.getSource() instanceof JLabel){
JLabel event_casted = (JLabel)event.getSource();
if(event_casted.getText().equals("ON MOUSEROVER THIS")){
Point punto = event.getLocationOnScreen();
punto.setLocation(punto.getX()+20, punto.getY()+20);
JLabel littlelabel = new JLabel();
littlelabel.setText("your mouse is on the jlabel");
finestra.add(littlelabel);
finestra.setLocation(punto);
finestra.setSize(100,100);
finestra.setVisible(true);
}
}
}
#Override
public void mouseExited(MouseEvent event) {
if(event.getSource() instanceof JLabel){
JLabel event_casted = (JLabel)event.getSource();
if(event_casted.getText().equals("ON MOUSEROVER THIS")){
finestra.setVisible(false);
}
}
}
#Override
public void mousePressed(MouseEvent event) {
}
#Override
public void mouseReleased(MouseEvent arg0) {}
public static void main(String[] args0){
new finestra();
};
}

There are a number of (possible) issues
The GridLayout will cause the component to occupy most of the space of the container, which might cause the window to "appear" to popup earlier then you expect
finestra.add(event_casted); is causing the label to be removed from it's current parent container (the main window), as a component can only belong to a single container
It would, generally be better to use the tooltip support provided by the API. Maybe have a look at How to Use Tool Tips, remember, they can also support HTML.
If that's not functionality what you want, then maybe a JPopupMenu might be better

Search bar for JPanel text

I have wrote a java program, it has a CardLayout with a JPanel for each card.
The JPanel contains long text, I just need to implement a little "search bar" that just search for specified text on the viewed JPanel.
It simply has to highlight the searched text inside the JPanel.
In order to make it clearer, I'm talking about something like the Chrome's of Firefox's search bar (ctrl-f) but that works just for one JPanel in my program.
Here is a picture.
Is it possible? How can I do that?
Thanks

Easiest way is to create a small search JPanel that is positioned above your text JPanel. Both JPanels would be inside of another JPanel. I'd use a JTextField and a JButton, because I like the user in control of when to search.
Here's one of my GUI's with a search JPanel.
And here's the code to create the search JPanel. Note that I used a JPanel. You only extend Swing components when you want to override one of the component methods.
package gov.bop.cobol.paragraph.structure.view;
import gov.bop.cobol.paragraph.structure.model.ParagraphStructureModel;
import gov.bop.cobol.paragraph.structure.thread.SearchActionThread;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class SearchPanel {
protected JPanel panel;
protected JTextField findTextField;
protected ParagraphStructureFrame frame;
protected ParagraphStructureModel model;
public SearchPanel(ParagraphStructureFrame frame,
ParagraphStructureModel model) {
this.frame = frame;
this.model = model;
createPartControl();
}
protected void createPartControl() {
panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.X_AXIS));
panel.setBorder(BorderFactory.createEmptyBorder(6, 6, 6, 6));
JLabel findLabel = new JLabel("Search:");
panel.add(findLabel);
panel.add(Box.createRigidArea(new Dimension(6, 0)));
findTextField = new JTextField(30);
panel.add(findTextField);
panel.add(Box.createRigidArea(new Dimension(6, 0)));
JButton findButton = new JButton("Search");
findButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
String s = findTextField.getText().toUpperCase().trim();
if (!s.equals("")) {
findTextField.setText(s);
Thread thread = new Thread(new SearchActionThread(frame,
model, s));
thread.start();
}
}
});
panel.add(findButton);
}
public JPanel getPanel() {
return panel;
}
}

Java / Swing / WebcamCapture : When I disable a JLabel, an other image appears

I come to you because I have a strange issue, for which I don't find any solution...
I build an application using a webcam, in order to take some photographs.
I use WebcamCapture to do that, and I don't encounter any issues with it.
The only "weird" thing that happens is the following :
I use a JDialog in which I make photograph. In its JFrame parent, I display those photographs in JLabel.
Then, i need to disable those JLabel, and I do that by calling a method which disable all components. The weird thing is, when I disable JLabel, the JLabel display the last image capture by the webcam. Not the last photographs, but really the last captured image.
It's seems that BufferedImage (used by WebcamPanel) are linked to the issue.
Here is the SSCE :
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.border.Border;
import com.github.sarxos.webcam.Webcam;
import com.github.sarxos.webcam.WebcamPanel;
#SuppressWarnings("serial")
public class CameraFrame extends JFrame implements ActionListener{
public Webcam webcam;
Boolean enabled = true;
CameraFrame frame;
private JButton btnSaveVerso;
private JLabel lblVerso;
private JButton btnEnable;
private JButton btnQuit;
private JPanel mainPanel;
private WebcamPanel streamPanel;
public static void main(String[] args){
CameraFrame frame = new CameraFrame();
frame.setVisible(true);
}
public CameraFrame() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
setLocationRelativeTo(null);
setResizable(false);
setMinimumSize(new Dimension(800, 600));
setPreferredSize(new Dimension(800,600));
buildPanel();
setContentPane(mainPanel);
}
});
}
public void buildPanel() {
mainPanel = new JPanel();
mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.PAGE_AXIS));
Border blackline = BorderFactory.createLineBorder(Color.black, 1, true);
webcam = Webcam.getDefault();
webcam.open();
streamPanel = new WebcamPanel(webcam);
streamPanel.setPreferredSize(new Dimension(webcam.getViewSize()));
streamPanel.setMaximumSize(new Dimension(webcam.getViewSize()));
btnSaveVerso = new JButton("Take pic");
btnSaveVerso.setActionCommand("take");
btnSaveVerso.addActionListener(this);
lblVerso = new JLabel("Here will be the pic taken by the camera");
lblVerso.setBorder(blackline);
btnEnable = new JButton("Disable");
btnEnable.setActionCommand("disable");
btnEnable.addActionListener(this);
btnQuit = new JButton("Quit");
btnQuit.setActionCommand("quit");
btnQuit.addActionListener(this);
mainPanel.add(streamPanel);
mainPanel.add(btnSaveVerso);
mainPanel.add(lblVerso);
mainPanel.add(btnEnable);
mainPanel.add(btnQuit);
}
#Override
public void actionPerformed(final ActionEvent e) {
Thread newThread = new Thread(){
public void run(){
if(e.getActionCommand().equals("take")){
ImageIcon icon = new ImageIcon(webcam.getImage().getScaledInstance(100, 150, Image.SCALE_SMOOTH ));
lblVerso.setIcon(new ImageIcon(icon.getImage()));
lblVerso.revalidate();
lblVerso.repaint();
}
else if(e.getActionCommand().equals("disable")){
if(enabled){
lblVerso.setEnabled(false);
enabled = false;
btnEnable.setText("Enable");
}
else{
lblVerso.setEnabled(true);
enabled = true;
btnEnable.setText("Disable");
}
}
}
};
newThread.run();
if(e.getActionCommand().equals("quit")){
webcam.close();
this.setVisible(false);
}
}
}
I hope you will compile it without issues. Don't forget to link the librairies.
Thanks in advance

I finally resolved the problem : you simply need to close the webcam after each pictures, as follows :
BufferedImage picture = webcam.getImage();
webcam.close();
webcam.open();
... Do what you need with picture
(You don't even need to convert BufferedImage picture in an other type.)

Need Help in debugging a simple swing app using JLayeredPane

I am trying to develop a swing application which looks like the following :-
(The demo for this application can be found here)
The black square moves as the cursor is moved .The ComboBox entry selects the topmost layer in the stack,above which the square will appear during movement but below the remaining next top layers.
I have completed it nearly but the black square(image) is vibrating when mouse is moved (motion is not smooth) and also its motion is confined to small area and it is not moving over complete layered pane.Also there is no effect of changing settings in ComboBox or CheckBox.
Here is the code :-
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class JLayeredPaneDemo implements ActionListener, MouseMotionListener{
private String layerString[]={"Red(0)","Yellow(1)","Blue(2)","Green(3)","Orange(4)"};
private Color layerColors[]={Color.RED,Color.YELLOW,Color.BLUE,Color.GREEN,Color.ORANGE};
JComboBox jcb;
JCheckBox jcheck;
JLayeredPane layeredPane;
ImageIcon img;
JLabel cursor;
public static void main(String args[])
{
SwingUtilities.invokeLater(new Runnable(){public void run(){new JLayeredPaneDemo();}});
}
public JLayeredPaneDemo()
{
JFrame frame=new JFrame("JLayeredPane Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridLayout(2,1));
frame.add(createControlPanel());
//frame.add(Box.createRigidArea(new Dimension(0, 10)));
frame.add(createLayeredPane());
try
{
img=new ImageIcon(ImageIO.read(new File("src/watermark.png")));
}catch(IOException e){System.out.println("ERROR LOADING IMAGE :"+ e);}
cursor=new JLabel(img);
cursor.setBounds(45,45,img.getIconWidth(),img.getIconHeight());
cursor.addMouseMotionListener(this);
layeredPane.add(cursor,new Integer(2),0);
frame.pack();
frame.setVisible(true);
}
public JPanel createControlPanel()
{
JPanel panel=new JPanel();
panel.setBorder(BorderFactory.createTitledBorder("Select the Settings"));
jcb=new JComboBox(layerString);
jcb.setSelectedIndex(0);
jcb.setActionCommand("LAYER_SETTING");
jcb.addActionListener(this);
jcheck=new JCheckBox();
jcheck.setSelected(true);
jcheck.setActionCommand("FRONT_BACK");
jcheck.addActionListener(this);
panel.add(jcb);
panel.add(jcheck);
return panel;
}
public JLayeredPane createLayeredPane()
{
layeredPane=new JLayeredPane();
layeredPane.setBorder(BorderFactory.createTitledBorder("Layered Pane : Move Your Mouse"));
layeredPane.setPreferredSize(new Dimension(300,310));
Point origin=new Point(20,20);
int offset=35;
for(int i=0;i<layerString.length;i++)
{
JLabel label=createColoredLabel(layerString[i],layerColors[i],origin);
layeredPane.add(label,new Integer[i]);
origin.x+=offset;
origin.y+=offset;
}
return layeredPane;
}
private JLabel createColoredLabel(String str,Color color,Point origin)
{
JLabel label =new JLabel(str);
label.setVerticalAlignment(JLabel.TOP);
label.setHorizontalAlignment(JLabel.CENTER);
label.setOpaque(true);
label.setBackground(color);
label.setForeground(Color.BLACK);
label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
label.setBounds(origin.x,origin.y,100,100);
return label;
}
public void actionPerformed(ActionEvent e)
{
String cmd=e.getActionCommand();
if(cmd.equals("LAYER_SETTING"))
{
int position=jcheck.isSelected() ? 0 :1;
layeredPane.setLayer(cursor,jcb.getSelectedIndex(),position);
}
else if(cmd.equals("FRONT_BACK"))
{
if(jcheck.isSelected())
layeredPane.moveToFront(cursor);
else
layeredPane.moveToBack(cursor);
}
}
#Override
public void mouseDragged(MouseEvent e) {
// TODO Auto-generated method stub
//Do nothing
}
#Override
public void mouseMoved(MouseEvent e) {
// TODO Auto-generated method stub
cursor.setLocation(e.getX(),e.getY());
}
}
Please Help me to find the problem.

Your mouseMoved() implementation no longer applies the offsets used in the original; you'll need to supply them based on the geometry of the Icon used in your cursor.
//Adjustments to put Duke's toe at the cursor's tip.
private static final int XFUDGE = 40;
private static final int YFUDGE = 57;
...
//Make Duke follow the cursor.
public void mouseMoved(MouseEvent e) {
dukeLabel.setLocation(e.getX()-XFUDGE, e.getY()-YFUDGE);
}
Addendum: I don't understand why I didn't get any error when I used the wrong brackets? Can anyone point out the reason, please.
layeredPane.add(label,new Integer(i));
Because the language defines an array as an Object, the compiler chose the matching available add() method:
public void add(Component comp, Object constraints);

There are two silly mistakes which consumed my 11 precious hours.
1)I set actionListener for 'cursor' instead of layeredPane and that's why the movement was confined to a small area.
2)Secondly,i wrote layeredPane.add(label,new Integer[i]); instead of layeredPane.add(label,new Integer(i)); .(Notice the square brackets).

How to display different components in a JFrame?

I am very new to Java AWT. My question header must seem ridiculous to you, sorry about that. In my application I have three buttons which display different threads when clicked on. Now I want to add maybe a button or checkboxes or choicelist, etc when clicked on a particular button. For eg, if I click on yes button, it should display a choice list, something like that. How do I achieve something like that? Here is my code so far:
import java.awt.Button;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class AppWindow extends Frame implements ActionListener{
String keymsg = "Test message";
String mousemsg = "Nothing";
int mouseX=30, mouseY=30;
String msg;
public AppWindow(){
//addKeyListener(new MyKeyAdapter(this));
//addMouseListener(new MyMouseAdapter(this));
addWindowListener(new MyWindowAdapter());
}
public void paint(Graphics g){
g.drawString(msg, 150, 100);
}
//Here the window is created:
public static void main(String args[]){
AppWindow appwin = new AppWindow();
appwin.setSize(new Dimension(300,200));
appwin.setTitle("My first AWT Application");
appwin.setLayout(new FlowLayout(FlowLayout.LEFT));
appwin.setVisible(true);
Button yes,no,maybe;
yes = new Button("yes");
no = new Button("no");
maybe = new Button("maybe");
appwin.add(yes);
appwin.add(no);
appwin.add(maybe);
yes.addActionListener(appwin);
no.addActionListener(appwin);
maybe.addActionListener(appwin);
}
#Override
public void actionPerformed(ActionEvent ae) {
// TODO Auto-generated method stub
String str = ae.getActionCommand();
if(str.equals("yes")){
msg = "You pressed Yes";
}
if(str.equals("no")){
msg = "You pressed No";
}
if(str.equals("maybe")){
msg = "You pressed Maybe";
}
repaint();
}
}
class MyWindowAdapter extends WindowAdapter {
public void windowClosing(WindowEvent we){
System.exit(0);
}
}

Points describing what you should be doing :
As already mentioned by others, better to use Swing over AWT, since Swing is more advanced.
As much as possible, always try to Paint on top of a JPanel or a
JComponent, instead of Painting right on top of your JFrame, by
overriding the paintComponent(Graphics g) method of the said
JComponent/JPanel
Never call setVisible(true) on the JFrame until and unless it's
size has been established. So in general terms, this has to be the
last call, once you are done adding components to the JFrame and
the size of the JFrame has been realized by the LayoutManager.
Inside your actionPerformed(...), instead of writing all if
statement blocks, you should adhere to the if-else if statement
blocks. The benefit of this, over the former is that, at any given
time, only one event will be fired, hence once the said condition is
satisfied, you don't want your code to keep checking other
conditions, which in general is really not a good programming
practice, IMHO.
MOST IMPORTANT THING : Never make calls like pack()/setVisible(...) from within the main method, such calls belong
to the Event Dispatch Thread, and must be done on the same. Please
read Concurrency in Swing for more detail.
Have a look at the example program, for better understanding.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ComponentExample
{
private CustomPanel drawingBoard;
private JPanel contentPane;
private JButton yesButton;
private JButton noButton;
private JButton maybeButton;
private JComboBox cbox;
private ActionListener buttonAction = new ActionListener()
{
#Override
public void actionPerformed(ActionEvent ae)
{
JButton button = (JButton) ae.getSource();
if (cbox.isShowing())
contentPane.remove(cbox);
if (button == yesButton)
{
drawingBoard.setText("You Pressed YES.");
contentPane.add(cbox, BorderLayout.PAGE_END);
}
else if (button == noButton)
drawingBoard.setText("You Pressed NO.");
else if (button == maybeButton)
drawingBoard.setText("You Pressed MAYBE.");
/*
* revalidate()/repaint() is needed
* when the JComponent is added or
* removed from the already
* visible Container.
*/
contentPane.revalidate();
contentPane.repaint();
}
};
public ComponentExample()
{
cbox = new JComboBox(
new String[]{"I GOT IT"
, "I STILL HAD DOUBT"});
}
private void displayGUI()
{
JFrame frame = new JFrame("Component Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
contentPane = new JPanel();
contentPane.setOpaque(true);
contentPane.setBackground(Color.DARK_GRAY);
contentPane.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(5, 5));
JPanel buttonPanel = new JPanel();
buttonPanel.setOpaque(true);
buttonPanel.setBackground(Color.WHITE);
yesButton = new JButton("YES");
yesButton.addActionListener(buttonAction);
noButton = new JButton("NO");
noButton.addActionListener(buttonAction);
maybeButton = new JButton("MAY BE");
maybeButton.addActionListener(buttonAction);
buttonPanel.add(yesButton);
buttonPanel.add(noButton);
buttonPanel.add(maybeButton);
contentPane.add(buttonPanel, BorderLayout.PAGE_START);
drawingBoard = new CustomPanel();
contentPane.add(drawingBoard, BorderLayout.CENTER);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new ComponentExample().displayGUI();
}
});
}
}
class CustomPanel extends JPanel
{
private String msg;
public CustomPanel()
{
msg = "";
setOpaque(true);
setBackground(Color.WHITE);
}
public void setText(String msg)
{
this.msg = msg;
repaint();
}
#Override
public Dimension getPreferredSize()
{
return (new Dimension(300, 300));
}
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawString(msg, getWidth() / 3, getHeight() / 3);
}
}

I don't know if I have understood the question well but... couldn't you create those elements and call their setVisible(boolean) methods to make them not visible at first, and them make them visible when user pushes buttons?