CardLayout - How to use previous() and next() using NetBeans GUI Builder? - java

Here is what I tried:
Dragged some JPanels onto a JFrame (using NetBeans inspector window).
In JFrame constructor, made all JPanels invisible using .setVisible(false), except the one I want to show first.
It works and I can easily go from one to another by using some buttons with actionPerformed and adding .setVisible(false) to the current card and .setVisible(true) to the one I want to see.
What I wanted to do now is to use CardLayout previous() and next(), similar to a browser's back/forward. I also would like to reach to a panel from different places, i.e., two panels can link to the same one, so previous panel wouldn't always be the same.
I tried using the following code in an actionPerformed inside JFrame class:
CardLayout cardLayout = (CardLayout) this.getLayout();
cardLayout.previous(this);
However, it doesn't work. What am I missing? Is this supposed to do what I'm looking for?

As you have set the layout of your JFrame to CardLayout, you will need to use the parent container when using its next() & previous() methods. For JFrame the parent container is the content pane. So change:
cardLayout.previous(this);
to
cardLayout.previous(getContentPane());

Declare a variable String previousCard in your JPanel. When you go from CardA to CardB set previousCard variable to "CardA" or whatever the card's name is. So after setting this for all transitions from one card to other, the back buttons will always do the same thing.
cardLayouot.show(getContentPane(), previousCard);

Related

Open elements and struct of jFrame in another like a menu

i have 5 jFrames in my java project. And i want to make like a Main Menu.
I mean, i want that the program starts with a jFrame and when i click a button insteand of open the jFrame, all the elements like labels, buttons and tables are being shown in my principal jFrame.
And if i click other button the main frame will clean and charge other jframe.
It is possible? im programming with java jdk 8 and netbeans.
Thanks
Edit:
I think who marked duplicate didn't understand my question. I don't want to open or close the frame, or other frames, I want to load the structure and components of several in the same frame. Please read my question before you start complain that is duplicated
i have 5 jFrames in my java project.
And that's a problem.
And i want to make like a Main Menu. I mean, i want that the program starts with a jFrame and when i click a button insteand of open the jFrame, all the elements like labels, buttons and tables are being shown in my principal jFrame. And if i click other button the main frame will clean and charge other jframe.
Yes this can be solved by getting the contentPane (usually a JPanel) from the JFrame whose content you want to display within the currently displayed JFrame, and making it the contentPane of the displayed JFrame, for example:
// create the new JFrame, the one whose content you wish to display
NewJFrame newJFrame = new NewJFrame();
// get its contentPane
Container newContentPane = newJFrame.getContentPane();
// add this content pane into the displayed JFrame
displayedJFrame.setContentPane(newContentPane);
// revalidate and repaint the JFrame so that its new data is well displayed
displayedJFrame.revalidate();
displayedJFrame.repaint();
// displayedJFrame.pack(); // and you might need to do this if sizes are way off
But this extra gymnastics is bulky, prone to bugs and unnecessary. You are painting yourself in a corner by having your class extend JFrame, forcing you to create and display JFrames, when often more flexibility is called for. In fact, I would venture that most of the Swing GUI code that I've created and that I've seen does not extend JFrame, and in fact it is rare that you'll ever want to do this. More commonly your GUI classes will be geared towards creating JPanels, which can then be placed into JFrames or JDialogs, or JTabbedPanes, or swapped via CardLayouts, wherever needed. This will greatly increase the flexibility of your GUI coding.
For this situation what I recommend is that you do that, that your GUI classes create JPanels, and that you add the ones that you want to swap to a JPanel that uses a CardLayout. And then whenever you want to show a different "card", call show(...) on the CardLayout object, passing in the JPanel that uses it, as well as the String key that was used when adding the "card" JPanel to the CardLayout-using JPanel. This is all well-explained in the CardLayout Tutorials.
Other useful links:
For rationale on why to avoid manually swapping please see: What's so special about CardLayout vs manual adding/removal of JPanels?
For using a CardLayout to help control a "multi-page" application with multiple classes, please see: How to Integrate Multi-page Java Desktop Application from Multiple GUI Classes

JPanel data getting changed on mouse click

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.

how to start, developing swing based application with few panels with next buttons for each

I'm new to java.I'm creating a swing based UI. I've created 2 frames, each one in separate .java file inside same package.
These two frames represents 2 screens (panels) of application. When Next button in first frame is clicked, it should move to second frame.
When I checked, these two classes are having main method, I think it should be correct way for creating applications. there should be only one main method.
When Next is clicked, I'm trying to make setVisible(false) for main panel of first frame and setVisible(true) for main panel of second frame. But this cannot be done, since the panels within a class are private. Any resolution for the above problem?
As I'm beginner, Can somebody suggest me in how to start up with these kind of applications? what are the guidelines that need to be followed? And please help me in finding documentation related to starting up with the development of such applications.
After going through the answers, My comments are:
I used the following code to go to next panel from first panel, but didn't worked.
private void gotoNextPanel(){
// jPanelFirstScreen.setVisible(false);
JPanelSecondScreen jpanelSecondScreen= new JPanelSecondScreen();
jpanelSecondScreen.setVisible(true);
UpgradeUtilityGUI upgradeUtilityGUI = new UpgradeUtilityGUI();
upgradeUtilityGUI.removeAll();
validate();
repaint();
// upgradeUtilityGUI.add(jpanelSecondScreen);
upgradeUtilityGUI.getContentPane().add(jpanelSecondScreen, "card2");
jpanelSecondScreen.setVisible(true);
validate();
repaint();
}
I'm using netbeans, and 've added two panels to the cardlayout of frame. And when I use the above code to change panels, Nothing is happening, the first panel is still appearing. Can somebody tell me, how to write code for moving from one panel to another when both the panels 've been added to cardlayout of jFrame ?
Use a CardLayout, as shown here (and one frame) as mentioned by others.
When Next is clicked, I'm trying to make setVisible(false) for main panel of first frame and setVisible(true) for main panel of second frame. But this cannot be done, since the panels within a class are private. Any resolution for the above problem?
Make the panels public access level and they will be available from other packages.
One problem in that code snippet is implied by the line:
UpgradeUtilityGUI upgradeUtilityGUI = new UpgradeUtilityGUI();
It goes out of scope before ever being added to a container. Also, their should be no need to remove anything when adding a new card to the layout, and no need to call repaint().
If your application is as simple as having only two panels you shouldn't create two JFrames. You should create a JFrame with two JPanel each of them contains the neccessary information for you. If you are ready with your first panel you can call setVisible(false) on it, and call setVisible(true) on the 2nd frame. It is the one of the most easy-to-understand solution.
But, it only depends on you if it is good for you or you would like to use some more detailed solution.
Don't use two or more JFrames, nor with separated and compiled Jar files, this is road to the hell, better would be look at CardLayout,
What you should do is have a single JFrame for the application, then you add and remove JPanels as you want to move between screens.
Each of your JPanels should basically have the following...
1. A JButton called "Next"
2. A ButtonListener for each button, that tells the JFrame to load panel2, panel3, etc.
As part of the ButtonListener, you basically just want to call something like JFrame.removeAll() to remove the existing panel, then JFrame.add(JPanel) to add the next panel.
By having 1 JFrame, you also only have 1 main() method.

Deleting a JPanel inside a JPanel... inside a JPanel

I am trying to make a slideshow-like application in Java using NetBeans.
I have a JFrame (the main window) and inside it are two buttons (back and next) for navigation, and a JPanel (mainPanel) which acts as holder of the 'slides' of the app. I am also using custom JPanel (SlidePanel) objects which are then placed inside the mainPanel. Some of these SlidePanel objects have JPanels within them.
Now, I've been able to place these SlidePanel objects inside the mainPanel and also navigate through them (for example, if I click the next button, SlidePanel 1 would be replaced by SlidePanel 2, or if I click the back button, SlidePanel 2 would be replaced by SlidePanel 1.) I've done this by using the removeAll(), revalidate(), and repaint() methods.
The problem starts here. The third SlidePanel object contains a JPanel inside it. What happens when you get to the third SlidePanel, it works fine. But from there, if you click the back button (which takes you back to SlidePanel 2), the JPanel from SlidePanel 3 remains on the screen, with the components inside SlidePanel 2 adjusted to fit the mainPanel.
What should I do to fix this?
EDIT: Thank you very much to all those who answered. I tried CardLayout on a dummy project and it worked fine. Now, all I have to do is add it to the original one. Thanks again. :)
I suggest to use CardLayout for that, rather as add and remove JPanels on the Runtime example for CardLayout and together with your idea could be here
I suggest you use a different layout manager (e.g. CardLayout); let the layout manager worry about juggling it's components.

Need to create a WIZARD on Netbeans (jDialog vs CardLayout)?

I would like to create a "wizard" on a JDialog using the CardLayout, triggered by user pressing the New button from the menubar. In Netbeans I have created a JDialog through which I have a series of jPanels in CardLayout format. In my "New" menu item I wrote the following code to initiate the jDialog as follows,
CardLayout cl = (CardLayout) jDialogNew.getLayout();
cl.preferredLayoutSize(jDialogNew);
cl.show(jDialogNew, "card1");
However, the compiler comes up with the following error,
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException:
java.awt.BorderLayout cannot be cast to java.awt.CardLayout
If anyone is out there that can take me through creating a wizard on "Netbeans" I'd be eternally grateful
Your jDialogNew has a BorderLayout set as its layout and and not a CardLayout, meaning that when you call getLayout() to try to fit it into a variable that cant hold a BorderLayout an exception is thrown. The classes are different so you cannot cast from one to another, causing a ClassCastException.
A possible solution to this is to set your own layout for the jDialogNew. I dont have code infront of me so I cant check myself, but try looking for a method like setLayout(), and pass in a new layout of your choice.
you can do with following
create JFrame -> Add "CARD LAYOUT"
add JPanels to project. Design JPanels. Customize init code of JFrame. Insert JPanels with this.add(jpanel name). for all jpanels setVisible(false) - then setVisible true which jpanel you want to start with.
The way I did it in Netbeans was very easy! All I had to do was to was to introduce a separate JFrame in my resources package (being a part of my overall package) and in that JFrame I created a JPanel with the CardLayout, under which I created all my other JPanels relating to that top JPanel. Now having the JFrame I could set my fixed canvas plus everything else I needed to construct and activate my CardLayout "Wizard" dialogue box! Then I had to call the new JFrame from with my application whenever the event was triggered. It made life a whole lot easier and it works just great!

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