I'm trying to create a pretty simple application that has a JSplitPane (which is divided into a JTabbedPane and a JPanel) above a status bar panel. I want to use a simple layout (i.e. BoxLayout, FlowLayout, or BorderLayout), but I've tried and they all give me the same error. I've simplified the code as much as possible to show the error.
The error is that there should only be 2 regions in the main box layout (the frame): a top (with the JSplitPane, which has the black border) and a bottom (with the JPanel status bar). However, when I add the status bar, a third region is created in the upper left that contains nothing. Any ideas on how to get rid of it?
public static void main(String[] args) {
JFrame frame = new JFrame("Application");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.Y_AXIS));
// Create left side of the application
JTabbedPane tabby = new JTabbedPane(JTabbedPane.LEFT);
// Create right side of the application
JPanel rightPanel = new JPanel(new BorderLayout());
// Create the status bar at the bottom
JPanel statusBar = new JPanel(new BorderLayout());
JPanel statusBarPanel = new JPanel();
statusBarLabel = new JLabel("Status Bar");
statusBarPanel.add(statusBarLabel);
parent.add(statusBarPanel);
JSplitPane mainPain = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, tabby, rightPanel);
frame.add(mainPain);
frame.add(statusBar);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
I'm trying to create a pretty simple application that has a JSplitPane (which is divided into a JTabbedPane and a JPanel) above a status bar panel.
Normally you would just use the default BorderLayout of the frame and then do:
frame.add(splitPane, BorderLayout.CENTER);
frame.add(statusBar, BorderLayout.PAGE_END);
A status bar is typically one or more labels that display information so they are display in a fixed size at the bottom.
The other panel will then contain the main components of the application. These components will then get any extra space available to the frame as it is resized.
but I've tried and they all give me the same error
parent.add(statusBarPanel);
The variable "parent" doesn't exist. Get rid of it. Add the status bar to the frame as shown above.
not sure if thats it, but it seems, like you add 2 Panels when adding the Statusbar.
You got a statusBarPanel which is added to "parent", and statusBar, which is added to the frame itself. Maybe thats your 3rd Panel.
Related
So I'm writing a program in which I wish to have a single JFrame containing a JPanel header in a separate colour and directly underneath have a grid of buttons in a separate JPanel. So far my program works perfectly except for the fact that the header String isn't showing up in the NORTH panel. Instead I'm getting a box containing the set background colour with a small grey box in the centre. I'm wondering if I didn't set the size of the panel correctly?
I have heard this can be accomplished using JLabel, but when I tried to do this, it would not show the background colour that I had set.
So, could anyone please show me how to achieve the following either with the JPanel (preferably because I would like to know how it works and what I'm missing) or with JLabel: filling that little grey box in the middle of the header with a String.
Here is my code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Example {
public static void main(String[] args) {
// Initialize a panel for the header, and mainGrid which will contain buttons
JPanel panel = new JPanel();
JPanel header = new JPanel();
JPanel mainGrid = new JPanel();
// Initialize the header
DisplayPanel message = new DisplayPanel();
header.setBackground(Color.ORANGE);
header.add(message);
// Initialize the mainGrid panel
mainGrid.setLayout(new GridLayout(2,2,2,2));
mainGrid.add(new JButton("1"));
mainGrid.add(new JButton("2"));
mainGrid.add(new JButton("3"));
mainGrid.add(new JButton("4"));
// Add the two subpanels to the main panel
panel.setLayout(new BorderLayout());
panel.add(header, BorderLayout.NORTH); // The issue is this panel isn't displaying the String created in DisplayPanel
panel.add(mainGrid, BorderLayout.CENTER);
// Add main panel to JFrame
JFrame display = new JFrame("Test");
display.setContentPane(panel);
display.setSize(200,100);
display.setLocation(500,200);
display.setVisible(true);
display.setResizable(false);
display.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private static class DisplayPanel extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawString("header" , 20, 20); // The string I want to be displayed
}
}
}
I would very much appreciate anyone's help or input as I have only been studying Java for a few months and this is my first post. Thank you in advance.
Also, any general tips on writing that you may have would be greatly appreciated.
I'm wondering if your problem is that you're nesting your message JPanel inside of the header JPanel, and the container header JPanel uses the JPanel default FlowLayout. Thus the component it holds won't expand on its own and will remain trivially small.
Consider either giving the header JPanel a BorderLayout so that message expands inside of it, or
use a JLabel to show your text, not a JPanel's paintComponent method. The JLabel should size itself to be big enough to show its text. If you do this and want it to show a background color, all you have to do is call setOpaque(true) on your JLabel, and you're set.
Actually, if you nest the JLabel, then there's no need to make it opaque. Just do this:
JPanel header = new JPanel();
JPanel mainGrid = new JPanel();
JLabel message = new JLabel("Header", SwingConstants.CENTER);
header.setBackground(Color.ORANGE);
header.setLayout(new BorderLayout());
header.add(message);
I would highly recommend using a GUI builder WYSIWYG IDE, like NetBeans, where you can easily drag and drop components to where they need to be. If you're doing any sort of complex GUI layout, it can be madness (and in my opinion, nonsensical) trying to write and maintain the code.
The layout your trying to implement would be trivial in NetBeans.
I am trying to display 2 panels that I have created in separate files one at the top and one at the bottom of my GUI with a button group between them. However, the window is only displaying one panel or the button group at a time. The panels and button group are displaying properly but only the last one added to the frame is being displayed at any given execution.
Here is the current code without any layouts...
package UserGUI;
import javax.swing.*;
import java.awt.*;
public class RealFrame extends JFrame {
JButton Close = new JButton("Close");
JButton Proceed = new JButton("Proceed");
AuthorPanel header = new AuthorPanel();
FreeSpacePanel disk = new FreeSpacePanel();
public RealFrame() {
super();
ButtonGroup Ops = new ButtonGroup();
Ops.add(Close);
Ops.add(Proceed);
JPanel OPS = new JPanel();
OPS.add(Close);
OPS.add(Proceed);
add(disk);
add(OPS);
add(header);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500,500);
setVisible(true);
}
}
JFrame uses a BorderLayout by default, so when you do...
add(disk);
add(OPS);
add(header);
You're adding each component to the same location (the CENTRE position), but the BorderLayout will only layout the last one added.
Instead, you should use something more like...
add(disk, BorderLayout.NORTH);
add(OPS);
add(header, BorderLayout.SOUTH);
See How to Use Borders for more details
add(disk);
add(OPS);
add(header);
The default layout manager of the content pane of the JFrame is a BorderLayout. If you don't specify a constraint then the component is added to the BorderLayout.CENTER. Only one component can be added to the CENTER so the only the last component is displayed.
Try:
add(disk, BorderLayout.NORTH);
add(OPS, BorderLayout.CENTER);
add(header, BorderLayout.SOUTH);
to see the difference.
Or try another layout manager on the frame. See How to Use Layout Manager for more information.
I have a simple problem when I want to add tabs in my jpanel. The alignment of the tabs get horizontal instead of vertical, wich looks like crap =/.
It looks like this:
If I discard the panel instead and add the tabbedPane directly to the frame, everything works fine.
If you uncomment the three lines of code and remove the getContentPane().add(jtp); you can reproduce my probleme.
working Code:
public class TabbedPane extends JFrame
{
public TabbedPane()
{
setTitle("Tabbed Pane");
setSize(300, 300); // set size so the user can "see" it
JTabbedPane jtp = new JTabbedPane();
// JPanel panel = new JPanel();//uncomment all three lines
// panel.add(jtp);
// getContentPane().add(panel);
getContentPane().add(jtp);//remove me
JPanel jp1 = new JPanel();// This will create the first tab
JPanel jp2 = new JPanel();// This will create the second tab
JLabel label1 = new JLabel();
label1.setText("This is Tab 1");
jp1.add(label1);
jtp.addTab("Tab1", jp1);
jtp.addTab("Tab2", jp2);
JButton test = new JButton("Press");
jp2.add(test);
setVisible(true); // otherwise you won't "see" it
}
public static void main(String[] args)
{
TabbedPane tab = new TabbedPane();
}
}
Thanks a lot!
If I discard the panel instead and add the tabbedPane directly to the frame, everything works fine.
The default layout of JPanel is FlowLayout, which "lets each component assume its natural (preferred) size." The default layout of JFrame is BorderLayout, the CENTER of which ignores preferred size. In either case, invoking setSize() precludes the layout from functioning initially; re-size the frame to see the effect. Instead, use pack(), which "Causes this Window to be sized to fit the preferred size and layouts of its subcomponents."
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
setVisible(true); // otherwise you won't "see" it
There are many things I would change in that code, starting with the recommendations of #trashgod. OTOH this is the minimal change needed in order to stretch the tabbed pane to the width/height of the parent container.
// give the panel a layout that will stretch components to available space
JPanel panel = new JPanel(new GridLayout());//uncomment all three lines
panel.add(jtp);
getContentPane().add(panel);
//getContentPane().add(jtp);//remove me
For more details see this answer.
Well firstly you can try this:
JPanel panel = new JPanel();//uncomment all three lines
panel.setLayout(new GridLayout());
JPanel jp1 = new JPanel();// This will create the first tab
JPanel jp2 = new JPanel();// This will create the second tab
JLabel label1 = new JLabel();
label1.setText("This is Tab 1");
jp1.add(label1);
jtp.addTab("Tab1", jp1);
jtp.addTab("Tab2", jp2);
JButton test = new JButton("Press");
jp2.add(test);
getContentPane().add(jtp);
and in the main:
TabbedPane tab = new TabbedPane();
tab.pack();
tab.setVisible(true);
May I suggest using MigLayout to set layouts, it will make your life easier. Hope it helps.
Try GridbagLayout. Once you have mastered it, you can design UI of any sort with this layout.
I agree with prasanth regarding the use of GridBagLayout
I have gone through this problem once and I solved it by adding the JTabbedPaneto the panel via GridBagLayout, make sure you add the JTabbedPane using the ipadx and ipady according to your requirements in your GridBagConstraints object
e.g.
JPanel myPanel=new JPanel();
myPanel.setLayout(new GridBagLayout());
JTabbedPane jTP=new JTabbedPane();
jTP.add("Tab1",new JPanel());//substitute your component instead of "new JPanel"
GridBagConstraints myConstraints=new GridBagConstraints();
myConstraints.ipadx=400;//streches the component being added along x axis - 200 px on both sides
myConstraints.ipady=600;//streches the component being added along y axis - 200 px on both sides
myPanel.add(jTP,myConstraints);
You can adjust both these properties according to what is perfect for your need
After much searching, I hope this will bring me an answer.
Ok, I have a JFrame, which has a a JPanel across the top, and one across the bottom. It also has one on the side, which contains a JScrollPane. The top and bottom panels should remain a consistent size with the window resizing, but the side panel should change vertically. Unfortunately, no scrollbar shows up at all when the JScrollPane has too many items. Rather, the entire window is enlarged, pushing the bottom panel and all excess within the JScrollPane off-screen.
I have been using MigLayout, but if I need to use another layout for the side panel I can. Here is my most recent failed iteration of code.
This is where I add the JScrollPane:
public MenuPanel(){
this.setLayout(new BorderLayout());
innerPanel = new InnerPanel();
jsp = new JScrollPane(innerPanel,
JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
this.add(jsp, BorderLayout.CENTER);
}
This is inside the main window:
private void addSideSelectionPane() {
side = new SelectionPanel();
this.add(side, "wmax 200, growy");
}
And here is the code where I create the main window:
public InsWindow(){
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setExtendedState( this.getExtendedState()| java.awt.Frame.MAXIMIZED_BOTH );
this.setLayout(new MigLayout("debug, nogrid, fill", "[grow, fill]", "[pref!]10[grow, fill]"));
this.addTestLabel();
this.addSideSelectionPane();
this.addMainWindow();
this.addBottomPanel();
this.setVisible(true);
}
I have a JPanel subclass on which I add buttons, labels, tables, etc. To show on screen it I use JFrame:
MainPanel mainPanel = new MainPanel(); //JPanel subclass
JFrame mainFrame = new JFrame();
mainFrame.setTitle("main window title");
mainFrame.getContentPane().add(mainPanel);
mainFrame.setLocation(100, 100);
mainFrame.pack();
mainFrame.setVisible(true);
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
But when I size the window, size of panel don't change. How to make size of panel to be the same as the size of window even if it was resized?
You can set a layout manager like BorderLayout and then define more specifically, where your panel should go:
MainPanel mainPanel = new MainPanel();
JFrame mainFrame = new JFrame();
mainFrame.setLayout(new BorderLayout());
mainFrame.add(mainPanel, BorderLayout.CENTER);
mainFrame.pack();
mainFrame.setVisible(true);
This puts the panel into the center area of the frame and lets it grow automatically when resizing the frame.
You need to set a layout manager for the JFrame to use - This deals with how components are positioned. A useful one is the BorderLayout manager.
Simply adding the following line of code should fix your problems:
mainFrame.setLayout(new BorderLayout());
(Do this before adding components to the JFrame)
If the BorderLayout option provided by our friends doesnot work, try adding ComponentListerner to the JFrame and implement the componentResized(event) method. When the JFrame object will be resized, this method will be called. So if you write the the code to set the size of the JPanel in this method, you will achieve the intended result.
Ya, I know this 'solution' is not good but use it as a safety net.
;)
From my experience, I used GridLayout.
thePanel.setLayout(new GridLayout(a,b,c,d));
a = row number, b = column number, c = horizontal gap, d = vertical gap.
For example, if I want to create panel with:
unlimited row (set a = 0)
1 column (set b = 1)
vertical gap= 3 (set d = 3)
The code is below:
thePanel.setLayout(new GridLayout(0,1,0,3));
This method is useful when you want to add JScrollPane to your JPanel. Size of the JPanel inside JScrollPane will automatically changes when you add some components on it, so the JScrollPane will automatically reset the scroll bar.
As other posters have said, you need to change the LayoutManager being used. I always preferred using a GridLayout so your code would become:
MainPanel mainPanel = new MainPanel();
JFrame mainFrame = new JFrame();
mainFrame.setLayout(new GridLayout());
mainFrame.pack();
mainFrame.setVisible(true);
GridLayout seems more conceptually correct to me when you want your panel to take up the entire screen.