I have a left Panel with multiples Jlabels which i use them as buttons to change a Main Panel's content which is layouted with a CardLayout.
I cant work perfectly with these events:
mouseEntered : to make highlight effect to the jlabel
mouseExited : to take off the highlight effect.
mouseClicked : to change the content of the main Panel and start some threads
The problem here that can't found an event or a method tell me that another Jlabel has been clicked so i can stop my threads started in the mouseClicked event,
OR
an event or method tell me that a JPanel in the CardLayout has been displayed or hidden.
Your problem is not finding an appropriate event. I think you are doing this using a visual GUI builder and expect to solve everything out-of-the-box. It's not going to work that way, you will need to write some real code. For example, write a method that you will call from the mouse click listener of each of the three JLabels. Thus you will have arranged for this method to be called for each JLabel click. Then in the method do the appropriate handling. This is just a rough outline, you haven't provided much detail to give any further advice.
It sounds like you need FocusEvents and FocusListeners. These are supported by all JComponents like JPanel, JLabel, and JButton, such as by calling addFocusListener();
Basically a FocusListener can tell you when a JComponent gains focus (such as by clicking on the JComponent) and when it looses focus (such as by clicking on a different JComponent).
Refer to http://docs.oracle.com/javase/1.4.2/docs/api/java/awt/event/FocusListener.html for further information
Related
I have a panel with 6 JButtons and an empty JLabel on the bottom. I want the JLabel to display a description of whichever button I hover over with the mouse through mouseEntered() method.
Is there any sort of method equivalent to getActionCommand() for MouseEvent? I figure if the program is able see which button's string I'm hovering over then I'll be able to change the JLabel.
Edit:
If there is no equivalent method, which doesn't seem to be from what I understand from the docs, is there a way I can use the mouseEntered method for multiple buttons?
I figured I can use getSource to specify which button it's hovering over. Pretty much does exactly what I want it to do.
Learning GUIs for an assignment, and would appreciate some advice...no code, for the aforementioned reason.
I have a programme with a JFrame, and a single JPanel, that contains methods that take keyboard input using the KeyEvent class.
My class that extends JPanel, has the following in it:
setFocusable(true);
requestFocus();
I've since modified the programme, to include a second JPanel (to add a control panel to the right containing 4 JButtons).
The problem is that the keyboard input no longer works on the first JPanel when I run the programme (it did before).
The keyboard input on the right JPanel only works before the second JPanel has been added to the programme. If I remove the second JPanel, keyboard input works, when it is there it doesn't....
I realised that I had setFocusable(true); and requestFocus(); in both panels, so I deleted it from the second panel (with the JButtons), but it still doesn't work. I sense it's a focus issue.....any advice?
Do I need to look at KeyBindings (don't know what this is yet, but a few similar threads suggest it)....
We can't tell you what is wrong based on two lines of code. We have no idea what panel1 and panel2 do or what components they contain.
My class that extends JPanel, has the following in it:
A couple of problems with that:
You should NOT be using the requestFocus() method. Read the API for that method and it will tell you the appropriate method to use.
Even if you do use the appropriate method, you can't use that method in the constructor of a class. Requesting focus on a component can only be done to visible components on a GUI.
Do I need to look at KeyBindings
Yes, Swing has newer and better API's than AWT. In AWT you didn't have a choice. In Swing you should be using Key Bindings. All Swing components do use Key Bindings and Actions. One of the main reasons is you don't have the focus issue.
Start by reading the Swing tutorial for Swing basics. There are sections on:
How to Use Key Bindings
How to Use Actions to get you started.
A Key Binding is simply the process of mapping a KeyStroke to an Action.
Also, in the future, when you ask a question post a proper SSCCE that demonstrates the problem.
If you mean with "pass back and force" that the focus should move on tab keypress between those two, use a FocusTraversalPolicy where you define who should get focus in which order.
When you click on a button, that button receives the keyboard focus. If you want the focus to revert back to the first JPanel, then you should add an ActionListener to each button, and in the actionPerformed() method of the listener just add the line:
firstPanel.requestFocusINnWindow();
I have something like this...
Its a bunch of JLabels within JPanels inside a
--JFrame
--JPanel
--Set<JPanel>
--JLabel object contained in each JPanel object cotained in the set
I want to create an external panel/frame so that each time I hover over each individual JPanel, a new frame/panel pops up giving me some data. This will essentially overlap over the JFrame.
Its pretty brief but I just need some guidance as to what I need to look up.
Maybe you can just use JToolTip. When the mouse hovers over the label for a couple of seconds it will display automatically. See the section from the Swing tutorial on How to Use Tool Tips.
Or if you want something more complicated use a MouseListener. On mouseEntered() you can display a JPopupMenu or an undecorated JDialog.
You can start by reading the Swing tutorial on How to Write a Mouse Listener.
I am using three JButtons in my swing application. When I click on each button, the corresponding data (formatted in JTable with JScrollPane) will display on JPanel.
Problem: when I resize the JFrame, the JPanel is replacing with default button (the button which i was clicked first) information instead of current JButton information.
My sample code:
jbutton1.addActionListener(this);
jbutton2.addActionListener(this);
public void actioPerformed(ActionEvent e){
if(e.getActionCommand.equals("button1"))
JPanel.add(table1);
}
if(e.getActionCommand.equals("button2"))
JPanel.add(table1);
}.......
Resizing the JPanel will not suddenly replace components or add other components to the panel.
My best guess (and it is a guess due to the limited information in the question) is that none of your buttons actually work and just show the wrong information.
The code you posted only contains an add without any revalidation of the layout. Consult the javadoc of the Container#add method. When you resize, the layout gets revalidated and you see what is actually contained in the JPanel.
Possible solutions:
Call invalidate and repaint on your panel as well in your ActionListener
Use a CardLayout to switch between the different components
I personally prefer the CardLayout option, but it might depend a bit on the situation.
Note that in the code you posted, you add table1 for both buttons. Might be a copy-paste problem, or a problem with your actual code.
I was unable express problem clearly.Sorry for your inconvenience.
JPanel.removeAll() method has fixed my problem.
I added this method before adding any new component to JPanel. That fixes JPanel unexpected behavior.
i have mouselisteners on multiple jpanels. I need to detect if the mouse is pressed when it enters on a different jpanel than the one the event has started from. how can i do that?
Either listen on a JPanel that includes the others or see if using Drag and Drop might suit your needs better.