I am creating a Java applet, and I am trying to add a JFrame to it. I am calling:
add(new MyJFrameSubclass());
But when I launch the application, my JFrame isn't shown until I resize the window.
This may be too elementary of a suggestion, but sticking in a validate() or repaint() can sometimes solve problems that seem complicated.
A simple fix is to add a frame.show(); after you add your JFrame, I had the same issue and this seemed to help, the frame being the name of your JFrame.
JFrame and JApplet are both top-level containers. Instead of trying to have both containers present at once, put your content in a lightweight container such as JPanel; then add that JPanel to either a JFrame (for local use) or a JApplet (for the browser). This example shows the approach.
Related
I am now writing code simple GUI that's for start the game window. I only need Do you want to start game message and start button on the window. But I have a confusing concepts for the JFrame and JPanel. Actually, I thought I need to add JPanel to JFrame to add the other components such as JLabel, JButton,...etc. But I realized I don't actually need JPanel. I can just add the components simply use add(button), add(label) to JFrame. So why I need JPanel. And I think JFrame doesn't need JPanel but JPanel need JFrame. Am I understand correctly?
No, not always. A simple graphical user interface may be implemented by just adding components "directly" to a JFrame. But in order to get more flexibility, you would always use JPanels. For example, to employ different layouts in different parts of the GUI, to group certain components together, etc.
A JFrame is backed by a JRootPane, a part of which is a contentPane.
(image from Oracle Javadoc)
When you add components to a JFrame, you are really adding them to the content pane, e.g.: frame.getContentPane().add(Component).
A JFrame is a common starting scene of a Swing GUI application, while a JPanel is intended to be put in another scene (container). Since both content pane and a JPanel inherit from the same class (Container) you may use them in a similar manner, as far as adding components to them goes.
Do I need JPanel always?
No. Well, unless you need a Swing GUI. Then yes.
Another answer replied words to the effect. "No, you can add components direct to a frame" What they missed was that components added to a JFrame are added to the content pane (automatically). The content pane is a JPanel.
Having said that:
I (and many others) would recommend designing an app based around a main content panel, then adding that panel to a top-level container as needed. The top level container might be a JFrame, JWindow, JDialog, JOptionPane ..
What prompted the question? A JPanel is a very 'light weight' container (in more ways than one). A GUI can contain 1000s and not be burdened by doing so. Of course, that's a rare requirement, but just saying .. use panels as needed and don't worry about it.
I not able to getting the proper JinternalFrame. In my application in main JFrame I have one disktopPane that contains GridLayout.
When I call JInternalFrame by click on button I am getting that internalFrame, but that fix to a particular Grid box only, and I am not able to maximize the InternalFrame.
How can I solve the probleam?
below is my GUI:
I am doing Code through NetBeans.
How Can I fix this issue ?
Don't use a jdesktoppane. Use a normal JFrame with a JPanel with your components and the gridbaglayout.
For the windows floating above the main JFrame use new JFrame's with setAlwaysOnTop(true) and make sure they have your main JFrame as root.
I'm trying to reuse a JPanel inside a JDialog instead of replicating another JPanel that has the exact features. I tried removing and adding the component to the JDialog, but it's not working as I expected. What is the recommended approach to this issue?
write a class "myFeaturesJPanel" that extends jPanel having the needed features. then just add a own instance to your popUpPanel and your original panel
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 am new to Java, started learning swing and have a problem with resizing a JPanel inside a JFrame. I am following this tutorial:
http://vincentramdhanie.blogspot.com/2009/11/cardlayout-with-netbeans.html
because ultimately I am learning each of the different layouts and have come to the CardLayout now. In the above, there is a JPanel being used for a status panel. That is what I want to do as well, but when I drag a JPanel onto my blank JForm it takes up all the space and I don't see any resizing handles for it like I would if I were using a .NET panel. Changing preferredSize in the properties window also does nothing. What am I missing here? I feel like a complete noob for asking such a basic question but I really can't find any way to resize this thing.. :-|
EDIT:
I forgot to mention; I am using NetBeans IDE
You can't resize the JComponent because you've select CardLayout. The CardLayout can holds/manages one or more components that share the same display space.
What you need to read documentation and good tutorials.