I'm working on a GUI assignment and I encountered a problem that I cannot figure out. I have a JFrame with multiple JPanels, one of those JPanels contains a CardLayout with multiple JPanels. Since we are more people working on the project we decided to make a separate class (that extends JPanel) for each panel that's gonna be inside the CardLayout.
The problem is accessing components of the JFrame from the JPanel classes.
To give you an example, I have a JLabel somewhere in the JFrame that serves as a status bar and I want to change the text of the status bar when a button is pressed on the SaleMain panel (a class SaleMain that extends JPanel, contained in the CardLayout).
Another example, inside another panel EditCustomer (also a JPanel class, included in the CardLayout), I'd like to have a button with an action listener that will change the current panel (the one containing the button) to a different panel from the CardLayout.
Hope I made it as clear as possible, thank you guys in advance for helping me :)
The model / view / controller pattern (MVC) is useful for creating a GUI. By separating your model from your view, you can concentrate on one part of your GUI at a time.
You create a model for your GUI that contains the information you want to present on your GUI.
I have a JLabel somewhere in the JFrame that serves as a status bar and I want to change the text of the status bar when a button is pressed on the SaleMain panel
Put the text in your model, and in the action listener for the button, you have the text put in the status bar.
I'd like to have a button with an action listener that will change the current panel (the one containing the button) to a different panel from the CardLayout.
Then do so. The action listener is a controller that can change the view.
Take a look at my article, Dice Game, to see how a Java Swing application implements the MVC pattern and JPanel switching.
Related
I'm new to Java and actually designing the GUI for an application.
My main is a JFrame with 5 buttons and 1 panel which will have the "content", for the first button for example, I've designed a Jframe which has a JTabbedPane.
Now I would like to know how can I incorporate the content from that frame to the "content" panel when clicking on the button ?
I tried to use .add but I get:
java.lang.IllegalArgumentException: adding a window to a container
(seems we can't add Jframe to Jpanel).
I also tried the setVisible way but it doesn't meet what I need since it will hide the panel completely and I will get a tiny window with the buttons.
![Jframe content][1]
![Main Jframe with buttons and Jpanel to show the jframe content][2]
The code is generated by netbeans, and I forgot to mention that I did research on adding a Jframe into another Jframe but here isn't my problem at all.
I tried by changing the Jframe by JInternalFrame but clicking on button doesn't do anything.
Button has
contentPanel.add(new GestionUtilisateur());
So basically when you click on the "Gestion Utilisateur" button for example, you get that JTabbedPane that has to appear in the content area (which is blank here)
You should not be putting JFrames inside JPanels. If you have multiple panels you would like to display, depending on something like a button, look in to LAYOUTS.
In particular, it sounds like a CardLayout would work well for your needs. CardLayouts allow you to swap which panel is displayed in a frame by bringing it to the "front" of a list of panels. This would let you display your JTabbedPane on one button click, then click another to change the content pane.
JFrame can not be added in a JPanel.
use JInternalFrame
Make and hold references to JPanels containing your content. A JFrame is really just that, it's a frame (though you can add a single component to it).
You can't add a JFrame to a JPanel. If you want multiple components to be visible use layouts such as BorderLayout, GridBag, etc. Check out some of the Swing layout tutorials here.
Content should be designed as JPanel (you can design it with drag&drop just like JFrame) but if you really have to put a JFrame to JPanel for some reason, you can do it by
myJPanel.add(myJFrame.getContentPane());
however i would suggest modification of your program.
I'm working on a game and I am using a CardLayout to switch between different JPanels in the same JFrame.
Problem: I have a helpPanel that I can go to pushing a button in the main-menuPanel and pushing a button in the gamePanel.
What I want:
I want to be able to place a JButton in my helpPanel that (when pressed) goes back to the main-menuPanel or the gamePanel (depending if you came from the main-menuPanel or from the gamePanel).
What I've tried: I've tried using the actionlistener in combination with .previous(container parent) but that only takes me back to the JPanel that was added to the CardLayout in the position previous to the helpPanel. I've also tried nesting the actionListeners to try and get different situations but that didn't work.
What I searched: I've searched for solutions in other Questiones but it's always about switching between 2 different JPanels in stead of 3.
Can anyone help me please? I find it to be a very difficult situation.
Read the section from the Swing tutorial on How to Use Card Layout. It shows you how to switch between cards by specifying a String that identifies the card to display.
I have been working on a game menu recently(which you'll see bits and pieces of here), and one way to do it is to have a common ActionListener for all the panel's buttons within. then set their action commands to have specific Strings.
in this example, overallgame is the master CardLayout panel. GAME, CREDITS, and MAIN-MENU are String constants used to title panels inside the overallgame panel
ActionListener listener=new ActionListener()
{public void actionPerformed(ActionEvent e){
if(e.getActionCommand().equals("start")){
//dummyframe.add(newgame);
//mainmenupanel=null;
CardLayout layout=(CardLayout)(overallgame.getLayout());//retrieves the overall layout
layout.show(overallgame, GAME);//uses it to switch to main game panel
newgame.requestFocus(true);//need to redirect focus to the game rather than original main menu
dummyframe.repaint();
}
else if(e.getActionCommand().equals("show credits")){
CardLayout layout=(CardLayout)(overallgame.getLayout());
layout.show(overallgame, CREDITS);
}
else if(e.getActionCommand().equals("switch to main")){
CardLayout layout=(CardLayout)(overallgame.getLayout());
layout.show(overallgame, MAIN_MENU);
}
else if(e.getActionCommand().equals("show chapter panel")){
CardLayout layout=(CardLayout)(overallgame.getLayout());
layout.show(overallgame, CHAPTERSTART);
}
else{
JOptionPane.showMessageDialog(null, "hey");
}
}
};
as you can see, the above ActionCommands used are specific Strings. you can set a JButton to have an ActionCommand like "start" with a line like this(with using my pre-defined listener, that will switch to panel with my in-progress game)
, causing the NewGame JButton to have an ActionEvent with the ActionCommand, "start" whenever clicked.
NewGame.setActionCommand("start");
to make a panel have a title that can be used by the CardLayout, you have to define the name when adding the panel to the CardLayout. this line adds a JPanel called mainmenupanel to my overallgame JPanel, and then allows the overallgame panel to refer to it with the String constant MAIN_MENU.
overallgame.add(mainmenupanel, MAIN_MENU);
as you can see, conditionally analyzing your pre-set ActionCommands on an overridden ActionListener to then use the CardLayout to show a particular JPanel is a good way to do what you want.
Hope this helps!(I just did this recently too, so I was at a loss for a while, too).
feel free to comment to ask questions if I wasn't completely clear
So I have created this JFrame window which has a lot of items like JLabel, JComboBox JTextField etc… At the bottom it has a "next" JButton.
I want that when a user clicks the next button, everything on the screen should be removed and replaced with stuffs from other class that I have created.
I only manage to open a new JFrame window whenever I click the next button. Can somebody please tell me how to remove all items from the screen and replace them with items from another class.
Thanks. I am a newbie so please give me the easiest way possible.
This sounds like a job for CardLayout
You could create a base panel in the BorderLayout.SOUTH position of your JFrame that would have your navigation buttons and have a number of panels added to your main panel being managed by CardLayout.
See Creating Wizard Dialogs with Java Swing
While the systematic thing for it is using CardLayout, you can imitate it if you don't want to learn how to use it!!
Create a Panel, add all items except the next button to this panel. Use BorderLayout to put the panel on top of the next button in the frame.
Now when the user press the next button you remove the panel (jframe.remove(panel)). create a new JPanel and add it using the BorderLayout again on top of the next button.
I generate a bunch of JPanels and then pass them into a class that extends JFrame. How do I add an indefinite number of JPanels to this JFrame. I was also reading about JScrollPane should I incorporate this somehow into the design?
Example Code:
class foo extends JPanel
{
//generate JPanels
}
class bar extends JFrame
{
//grab some amount of foo classes and put them into this JFrame and show it
}
Also is there anything I need to watch out for when showing this JFrame?
Thanks
How do I add an indefinite number of JPanels to this JFrame?
CardLayout, JDesktopPane/JInternalFrame, JTabbedPane, JScrollPane - there are a number of options.
Also is there anything I need to watch out for when showing this JFrame?
(shrugs)
Construct and show GUI components on the EDT.
pack() the GUI before setting the position and calling setVisible(true).
Don't rely on the default layouts of content panes.
Don't implement custom painting in a top level container.
..
JFrame -> JScrollPane -> fathers JPanel then you'll decide which of LayoutManager will lay your bunch of JPanels, by defalut FlowLayout, don't forget to play with PreferedSize for childsPanels
I am learning java and building one project to test basics.
I have one menu item FILE and then sub menu item like
1)Front
2)Admin
3)Booking
I have separate gui made in separate files but i want that they should be visible in one area , with click on submenus
I am using swing , JmenuBar . Also the other guis are using Jframe
I have separate gui made in separate files but i want that they should be visible in one area
Most applications should only ever have a single JFrame, which indeed is your requirement since you want the separate GUI to be visible in the same area.
Therefore your other GUI, should not extend JFrame but instead should extend JPanel. Then you can just use a CardLayout on your real GUI to swap the panels in/out depending on which panel is selected from your menu. All these basic are covered in the Swing tutorial. I guess you would start with the section on:
How to Use Card Layout
How to Use Menus
Other people have already talked about ActionListeners and stuff, so that's half of the problem. The other half is how to actually deal with the multiple windows. I would probably not use one JFrame per different GUI, given that the spirit of the JFrame suggests you should only have one instance of it per application. Instead, I would look at using either JDialog or JInternalFrame. I'm not sure what you mean by
...should be visible in one area...
but JInternalFrame will allow you to implement something like a multiple document interface, where all the sub-GUIs would be contained within the frame of the main UI. JDialog would be give you independent windows like JFrame does.
If with "they should be visible in one area" you mean modal, then you should change all your JFrames to JDialogs and leave only the JFrame that contains your main-menu.
To do this, you need an ActionListener for each of the menu items. Then have each listener pass the instance of the JFrame you want to a method that controls where you want to position the window and show it.
//Make menu items
JMenuItem font = new JMenuItem();
font.addActionListener(new ActionListener() {
showWindow(new FontFrame());
});
JMenuItem admin = new JMenuItem();
admin.addActionListener(new ActionListener() {
showWindow(new AdminFrame());
});
...
//define frame handling method
void showWindow(JFrame f) {
...
f.setVistible(true);
}