I have two JPanels that needs to add a JPanel into it, however only the last added JPanel does it show the JPanel. As shown below:
holderPanel1.add(dataPanel);
holderPanel2.add(dataPanel);
only holderPanel2 shows the dataPanel, but holderPanel1 does not show.
UI Components (such as JPanel) are the underline representation of things you see on the screen (location, parent, sub-components etc.), so each panel that you see on the screen has to have a separate underline representation, so you cannot add a panel to two different panels, you need to create two separate panels.
Related
I'm having trouble getting my JButtons to appear where I want. For some reason all my buttons are appearing in the middle of the Panel when I want it to appear flushed with the top of the Panel, centered. I've tried manipulating different layout positioning such as BorderLayout.NORTH and GridBagConstraints.NORTH however I do not know if I utilizing it on the right components.
Currently my code has A Frame holding a JLayeredPane holding a JSplitPane with two JPanels in it so it has gotten quite confusing.
Do you have any suggestions on how I can get the buttons to appear on the top of the Panel?
I currently have the panel using a GridBagLayout
Read the section from the Swing tutorial on How to Use GridBagLayout for a working example and information about the constraints used by the layout manager.
For some reason all my buttons are appearing in the middle of the Panel
Specifically read the section on the weightx/y constraints, which states that the components will clump together in the center unless you use non-zero values.
I want to design a jFrame where there are three jButtons and a set of three jpanels one above the other. When we call a jPanel from the respective jButton , that pane will be displayed. It would appear to the user as if the same portion of the jFrame is displaying the content to be shown on clicking each jButton.But when i am trying to set the jPanels one above the other, they are being shown side by side thus elongating the jFrame horizontally. What should i do to put one jPanel over the other? Any other idea than jPanel which should do the work i intend to do would also be help !!
Your behavior sounds like you are using a FlowLayout. This will not "layer" anything. Instead us a CardLayout, which does exactly what you are trying to accomplish. You call method like show, next, and previous to navigate the panels. See How to Use CardLayout for more details.
Also there are probably hundreds of other examples here on so. Go through the cardlayout questions.
[Tip: navigate the different tabs like "votes" and "frequent" to filter to some of the better posts]
Here's one that uses the show() method to switch between two panels by name.
I have a UI requirement in java swing wherein I need to achieve the below:
The 2 buttons on the top are placed in a JPanel. I need to draw a line through the center of that panel, upto the beginning of the 2 buttons. The panel below is a container of panels arranged in a card layout. As and when the button is clicked, the card is switched showing another panel.
So in all respects this looks like a JTabbedPane, with one difference, the tabs are buttons arranged in the center of the tabbed pane. I need this difference for the UI I am building.
As of now, the buttons and card layout panel, looks like the below
As you can see, the buttons and panels appear and look separate, instead it would be nice if they are made to appear like they represent one unit.
As you can see, the buttons and panels appear and look separate, instead it would be nice if they are made to appear like they represent one unit.
Put the Border around the outer panel. That is use a panel with a BorderLayout. This panel can have a LineBorder. Then you add your button panel to the NORTH and the panel with the CardLayout to the CENTER.
The line won't be drawn through the buttons but the buttons and panel will appear like they represent on unit.
So I am working on a GUI application using the swing framework. In short, I have 3 JPanels that act as different views of my application. Now the problem is that no matter the order I add the JPanels to my JFrame, only the final JPanel I add resizes when I switch to that view.
Some relevant bits of code:
When creating the window, I first create each individual JPanel, and add it to the JFrame:
JPanel newPanel = new SomeClassExtendingJPanel();
this.jframe.add(newPanel);
Next, whenever I switch between views of the application, I hide the panel that is currently active:
jframe.validate();
jframe.repaint();
oldPanel.setVisible(false);
And then activate the to be shown panel:
jframe.validate();
jframe.repaint();
newPanel.setVisible(true);
Does anyone know what could be wrong?
To resize the JFrame with each swap, you could call pack() on it, but this is kludgy having a GUI resize all the time. A better solution is to use the mechanism that Swing has for swapping views -- a CardLayout. This will size the container to the largest dimension necessary to adequately display all of the "card" components.
Check out the CardLayout tutorial and the CardLayout API for more on this.
JFrame's ContentPane has implemented BorderLayout by Default, and there is possible to put only one JComponents to the one Area,
you have to change used LayoutManager or put another JPanels to the other Areas
In short, my need is to have a background Image in my java app, and upon some event, create some other graphics on top of that image.
I was thinking I would use a JPanel to draw the background image in, add it at to my JFrame the start of program, and then add other JPanels on top of that upon certain events. The problem is Swing gives the JPanels added first the highest Z index, so what should be my background is showing up on top of everything.
Is there any way to control the Z index/order of the JPanels, or am I going about this completely wrong?
You can use the setComponentZOrder() to handle Z-Order in your application.
Resources :
JavaDoc - Container.setComponentZOrder
oracle.com - Mixing heavy and light components
Sounds strange to add mutiple JPanels and use z-order. I would suggest you either simple add ONE JPanel with the paintComponent(Graphics g) method overwritten, where you draw the correct image according to your events.
Or use the CardLayout, and add JLabels (with different images), then when your event triggers, use
CardLayout cl = (CardLayout)getLayout();
cl.show(this, "card3");
to show the correct JLabel.
The JLayeredPane is designed for just this purpose. It allows you to control the Z-order of components.
I was thinking I would use a JPanel to
draw the background image in, add it
at to my JFrame the start of program,
Sounds reasonable.
and then add other JPanels on top of
that upon certain events. The problem
is Swing gives the JPanels added first
the highest Z index, so what should be
my background is showing up on top of
everything.
Adding a panel to a panel is just like adding another component to the panel. The child component will be painted on top of the parent panel. There is no need to play around with Z-Order.
The key is to set a layout manager on the panel with the image. Then each panel you add to the image panel must be made non-opaque so that the background image will be painted.
Maybe the Background Panel can help you out. It automatically makes any component added directly to the panel non-opaque.