I've tried a lot of different ways, but I will explain two and what was happening (no error messages or anything, just not showing up like they should or just not showing up at all):
First, I created a JPanel called layout and set it as a BorderLayout. Here is a snippet of how I made it look:
JPanel layout = new JPanel();
layout.setLayout(new BorderLayout());
colorChoice = new JLabel("Choose your color: ");
layout.add(colorChoice, BorderLayout.NORTH);
colorBox = new JComboBox(fireworkColors);
colorBox.addActionListener(this);
layout.add(colorBox, BorderLayout.NORTH);
In this scenario what happens is they don't show up at all. It just continues on with whatever else I added.
So then I just tried setLayout(new BorderLayout()); Here is a snippet of that code:
setLayout(new BorderLayout());
colorChoice = new JLabel("Choose your color: ");
add(colorChoice, BorderLayout.NORTH);
colorBox = new JComboBox(fireworkColors);
colorBox.addActionListener(this);
add(colorBox, BorderLayout.NORTH);
In this scenario they are added, however, the width takes up the entire width of the frame and the textfield (not shown in the snippet) takes up basically everything else.
Here is what I have tried:
setPreferredSize() & setSize()
Is there something else that I am missing? Thank you.
I also should note that this is a separate class and there is no main in this class. I only say this because I've extended JPanel instead of JFrame. I've seen some people extend JFrame and use JFrame, but I haven't tried it yet.
You created a JPanel, but didn't add it to any container. It won't be visible until it is added to something (a JFrame, or another panel that is in a frame somewhere up the hierarhcy)
You added two components to the same position in the BorderLayout. The last one added is the one that will occupy that position.
Update:
You do not need to extend JFrame. I never do, instead I always extend JPanel. This makes my custom components more flexible: they can be added in another panel, or they can be added to a frame.
So, to demonstrate the problem I will make an entire, small, program:
public class BadGui
{
public static void main(String[] argv)
{
final JFrame frame = new JFrame("Hello World");
final JPanel panel = new JPanel();
panel.add(new JLabel("Hello"), BorderLayout.NORTH);
panel.add(new JLabel("World"), BorderLayout.SOUTH);
frame.setVisible(true);
}
}
In this program I created a panel, but did not add it to anything so it never becomes visible.
In the next program I will fix it by adding the panel to the frame.
public class FixedGui
{
public static void main(String[] argv)
{
final JFrame frame = new JFrame("Hello World");
final JPanel panel = new JPanel();
panel.add(new JLabel("Hello"), BorderLayout.NORTH);
panel.add(new JLabel("World"), BorderLayout.SOUTH);
frame.getContentPane().add(panel);
frame.setVisible(true);
}
}
Note that in both of these, when I added something to the panel, I chose different layout parameters (one label I put in 'North' and the other in 'South').
Here is an example of a JPanel with a BorderLayout that adds a JPanel with a button and label to the "North"
public class Frames extends JFrame
{
public Frames()
{
JPanel homePanel = new JPanel(new BorderLayout());
JPanel northContainerPanel = new JPanel(new FlowLayout());
JButton yourBtn = new JButton("I Do Nothing");
JLabel yourLabel = new JLabel("I Say Stuff");
homePanel.add(northContainerPanel, BorderLayout.NORTH);
northContainerPanel.add(yourBtn);
northContainerPanel.add(yourLabel);
add(homePanel);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setLocationRelativeTo(null);
setExtendedState(JFrame.MAXIMIZED_BOTH);
setTitle("Cool Stuff");
pack();
setVisible(true);
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(Frames::new);
}
}
The below suggestion is assuming that your extending JFrame.
Testing
First of all, without seeing everything, theres always a numerous amount of things you can try.
First off, after you load everything, try adding this in (Again, assuming your extending JFrame:
revalidate();
repaint();
I add this into my own Swing projects all the time, as it refreshes and checks to see that everything is on the frame.
If that doesn't work, make sure that all your JComponent's are added to your JPanel, and ONLY your JPanel is on your JFrame. Your JFrame cannot sort everything out; the JPanel does that.
JPanel window = new JPanel();
JButton button = new JButton("Press me");
add(window);
window.add(button); // Notice how it's the JPanel that holds my components.
One thing though, you still add your JMenu's and what-not through your JFrame, not your JPanel.
Related
Well, actually I have a Layout problem in java Swing. I simply want to add a JPanel on the bottom of a Frame - a coding snipplet that might be done with every web based language in about 5 Minutes. Not so in Java. I tried to add a jPanel to a jFrame, that Contains a jContentPane, set the size of the jPanel to what I need and to repaint and revalidate the jFrame, as well as setting the LayOutManager to null.
Java shows me in this case a full-width jPanel, that fills my whole jFrame.
Therefore I tried another approach: I divided my jPanel in a fully transparent jPanel on top and a 20%opaque jPanel on the bottom. Still it didn't work out as expected.
Since then I tried to resize the child jPanels of my new Panel and the Panel as well and tried to repaint and revalidate the jFrame. Without any effect.
Despite of my efforts, java still shows me a full sized 20%opaque jPanel on the whole jFrame, that now contains another 20%opaque jPanel on Top.
I know that this whole problem is caused by the LayoutManager, Java useless per Default. However, it is not an option to set the LayoutManager to null or even change the LayoutManager of our jFrame, because that would lead us to refactor the whole functionality of our tiny app we worked on for several weeks.
public void showUndoPanel() {
System .out.println("Show Undo Panel");
JPanel myPanel = new JPanel(null);
JPanel glassPanel = new JPanel();
JPanel ContentPanel = new JPanel();
JLabel myJLabel = new JLabel("Great Job!");
myPanel.setBackground(new Color(255,122,122,100));
glassPanel.setSize(650, 550);
glassPanel.setBackground(new Color(255,122,122,100));
myPanel.add(glassPanel);
ContentPanel.setSize(650, 30);
ContentPanel.setBackground(new Color(255,122,122,20));
ContentPanel.add(myJLabel);
myPanel.revalidate();
myPanel.repaint();
undoPanel = myPanel;
myJFrame.add(undoPanel);
myJFrame.revalidate();
}
What I expected:
What it actually does:
Well, I solved the problem by using a BoxLayoutManager and a RigidArea. In case if anyone else may encounter that problem again in the future, I decided to provide the code for this simple solution.
public void showUndoPanel() {
System .out.println("Show Undo Panel");
JPanel myPanel = new JPanel(null);
JPanel glassPanel = new JPanel();
JPanel ContentPanel = new JPanel();
JLabel myJLabel = new JLabel("Great Job!");
myPanel.setBackground(new Color(255,255,255,0));
myPanel.setLayout(new BoxLayout(myPanel, BoxLayout.PAGE_AXIS));
glassPanel.setSize(650, 650);
glassPanel.setBounds(0,0,650,550);
glassPanel.setBackground(new Color(255,122,122,0));
myPanel.add(glassPanel);
myPanel.add(Box.createRigidArea(new Dimension(0,450)));
ContentPanel.setSize(650, 30);
ContentPanel.setBounds(0,750,650,30);
ContentPanel.setBackground(new Color(255,122,122,20));
ContentPanel.add(myJLabel);
myPanel.add(ContentPanel);
myPanel.revalidate();
myPanel.repaint();
undoPanel = myPanel;
myJFrame.add(undoPanel);
myJFrame.revalidate();
}
Now it behaves as expected:
BorderLyout would make it easier to implement.
Note the comments in the following mre:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Main {
private static JFrame myJFrame;
public static void main(String[] args) {
myJFrame = new JFrame();
myJFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
myJFrame.setLocationRelativeTo(null);
showUndoPanel();
myJFrame.pack();
myJFrame.setVisible(true);
}
public static void showUndoPanel() {
JPanel myPanel = new JPanel();
myPanel.setBackground(new Color(255,255,255,0));
myPanel.setLayout(new BorderLayout());
JPanel glassPanel = new JPanel(); //uses FlowLayout by default
//glassPanel.setSize(650, 650); //use preferred size
glassPanel.setPreferredSize(new Dimension(650, 650));
//glassPanel.setBounds(0,0,650,550); //no need to set bounds. bounds are set by the layout manager
glassPanel.setBackground(new Color(255,122,122,0));
myPanel.add(glassPanel, BorderLayout.CENTER);
JPanel contentPanel = new JPanel(); //uses FlowLayout by default
//contentPanel.setSize(650, 30);//use preferred size
contentPanel.setPreferredSize(new Dimension(650, 30));
//contentPanel.setBounds(0,750,650,30); //no need to set bounds. bounds are set by the layout manager
contentPanel.setBackground(new Color(255,122,122,20));
JLabel myJLabel = new JLabel("Great Job!");
contentPanel.add(myJLabel);
myPanel.add(contentPanel, BorderLayout.SOUTH);
myJFrame.add(myPanel);
}
}
I have a class that extends JFrame and works by adding in 2 panels with BoxLayout buttons, and one JTabbedPane in the center which displays graphs.
I want one of the buttons to remove all current components in the frame and add new ones.
Here are the methods used.
private void createAndShowGraphs() {
ImageIcon createImageIcon(lsuLettersPath); //simple png file to fill one tab
final JTabbedPane jtp = new JTabbedPane();
JLabel iconLabel = new JLabel();
iconLabel.setOpaque(true);
jtp.addTab(null, icon, iconLabel);
//Here is where the errors begin
JPanel menu = new JPanel();
menu.setLayout(new BoxLayout(menu, BoxLayout.Y_AXIS));
//I want this button to remove all components currently in the JFrame and replace them with new components specified in the createAndShowIntro() method
menu.add(new JButton(new AbstractAction("Intro Pane") {
public void actionPerformed(ActionEvent e) {
//I've also tried putting removeAll in the Intro method
removeAll();
createAndShowIntro();
}
}));
add(jtp, BorderLayout.CENTER);
add(menu, BorderLayout.WEST);
pack();
setVisible(true);
}
private void createAndShowIntro() {
System.out.println("Made it to Intro");
//all I want is a blank JLabel with the String "test" to show up
JPanel test = new JPanel();
test.setLayout(new BorderLayout());
JLabel label = new JLabel();
label.setText("test");
label.setHorizontalAlignment(SwingConstants.CENTER);
label.setVerticalAlignment(SwingConstants.CENTER);
test.add(label);
add(test, BorderLayout.CENTER);
test.revalidate();
label.revalidate();
validate();
test.repaint();
label.repaint();
repaint();
pack();
setVisible(true);
}
When I call createAndShowGraphs() in main() and then hit the 'Intro' button, everything freezes and nothing is actually removed. I know it makes it the Intro method because of the "Made it to Intro" string output to the terminal.
I've tried all kinds of combinations of invalidate(), validate(), revalidate(), repaint() on the labels and on the frame itself. Really frustrated because I don't know how else I'm going to be able to display 3 different screens to switch back and forth between while only actually displaying one at a time.
Thanks for your time.
What kind of layout should I use to create a page Like this:
It should be resizable
It has two main panels Right and Left?
Extra space will be given to the 'Main Text' text area, and extra height will be given to the button panel while centering them.
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class EndOfLineButtonLayout {
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
// the GUI as seen by the user (without frame)
JPanel gui = new JPanel(new BorderLayout());
gui.setBorder(new EmptyBorder(2, 3, 2, 3));
JPanel textPanel = new JPanel(new BorderLayout(5,5));
textPanel.add(new JScrollPane(new JTextArea("Top Text",3,20)),
BorderLayout.PAGE_START);
textPanel.add(new JScrollPane(new JTextArea("Main Text",10,10)));
gui.add(textPanel, BorderLayout.CENTER);
JPanel buttonCenter = new JPanel(new GridBagLayout());
buttonCenter.setBorder(new EmptyBorder(5,5,5,5));
JPanel buttonPanel = new JPanel(new GridLayout(0,1,5,5));
for (int ii=1; ii<6; ii++) {
buttonPanel.add(new JButton("Button " + ii));
}
// a component added to a GBL with no constraint will be centered
buttonCenter.add(buttonPanel);
gui.add(buttonCenter, BorderLayout.LINE_END);
JFrame f = new JFrame("Demo");
f.add(gui);
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See http://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
You can use gridbag layout, try using netbeans, I have tried it and found really usefull.
Once you create it with netbeans you can use the same and build infact any kind of layout.
best of luck with other solutions.
p.s. border layout is perfect for your requirement, but I mentioned this just in case you would like to do lot more .
I would use BorderLayout.
Create Three JPanels and add them to a JFrame as follows:
public class YourClass extends JFrame{
//code here
this.setLayout(new BorderLayout());
this.add(TopPanel, BorderLayout.NORTH);
this.add(RightPanel, BorderLayout.EAST);
this.add(MainPanel, BorderLayout.CENTER);
this.pack();
this.setVisible(true);
The two main panels would be placed inside a main JPanel using a BorderLayout. The left panel would be placed using BorderLayout.CENTER, and the right panel would be placed using BorderLayout.LINE_END.
The left panel would use a BoxLayout, Y axis to separate the two JPanels within the left panel.
The right buttons panel would use a GridBagLayout. This sizes the buttons the same and allows you to use Insets to add some spacing to the buttons.
The buttons would be spaced from the top to the bottom of the right buttons panel. If you want all the buttons towards the top of the right buttons panel, you would put the right buttons panel inside of another JPanel using a FlowLayout.
I am trying to place a JPanel on top of another JPanel which contains a JTextArea and a button and i want to the upper apnel to be transparent. I have tried it by making the setOpaque(false) of the upper panel. but it is not working. Can anyone help me to get through this? Thanks in advance!
public class JpanelTest extends JPanel
{
public JpanelTest()
{
super();
onInit();
}
private void onInit()
{
setLayout(new BorderLayout());
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.add(new JTextArea(100,100),BorderLayout.CENTER);
panel.add(new JButton("submit"),BorderLayout.SOUTH);
JPanel glass = new JPanel();
glass.setOpaque(false);
add(panel,BorderLayout.CENTER);
add(glass,BorderLayout.CENTER);
setVisible(true);
}
public static void main(String args[])
{
new JpanelTest();
}
}
Indeed, it would be useful to tell the reason why you want panels one over another.
Starting with your code, and changing it a lot, I got it to work, but it might not do what you expect...
import java.awt.*;
import javax.swing.*;
public class Test extends JFrame
{
public Test()
{
super();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500, 200);
onInit();
setVisible(true);
}
private void onInit()
{
JLayeredPane lp = getLayeredPane();
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.add(new JTextArea(), BorderLayout.CENTER);
panel.add(new JButton("Submit"), BorderLayout.SOUTH);
panel.setSize(300, 150); // Size is needed here, as there is no layout in lp
JPanel glass = new JPanel();
glass.setOpaque(false); // Set to true to see it
glass.setBackground(Color.GREEN);
glass.setSize(300, 150);
glass.setLocation(10, 10);
lp.add(panel, Integer.valueOf(1));
lp.add(glass, Integer.valueOf(2));
}
public static void main(String args[])
{
// Schedule a job for the event-dispatching thread:
// creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new Test();
}
});
}
}
If totally transparent, well, it is like it isn't here! When opaque, it just covers some of the GUI, but doesn't prevent mouse clicks, for example.
1) there are a few ways, there no issue to put JPanel, with covering full JFrames/JPanel area or only part of Rectangle / Dimension that returns JFrames/JPanel
use JLayer(Java7) based on JXLayer (Java6)
use GlassPane
use JViewport
use OverlayLayout
use transucent JDialog / JWindow
2) everything depends of if you want to protect against mouse and key events from the top layer to bottom, or not (to avoiding redispatch events from - to and vice versa)
Check out this tutorial on using Swing Root Panes.
The glass pane is useful when you want to be able to catch events or paint over an area that already contains one or more components. For example, you can deactivate mouse events for a multi-component region by having the glass pane intercept the events. Or you can display an image over multiple components using the glass pane.
I am writing a class where I want to be able to add an unknown number of panels to another JPanel in a vertical BoxLayout. theses panels each consist of a label as a title and another panel. I want the panels that are added to all be located at the top of the panel (in this case Gui) so I added vertical glue at the bottom. I had everything working as expected until I needed to redo some of the code in order to place the main panel (represented by gui) in a scrollpane. for the sake of simplicity I was able to duplicate my problem in the following code. when run you will notice that the glue does not take the empty space but it is rather divided between the other panels. I have set a size for the jframe rather then used .pack() to illustrate the point.
public class Gui extends JFrame {
public Gui() {
getContentPane().setLayout(new BoxLayout(getContentPane(), BoxLayout.PAGE_AXIS));
getContentPane().add(new Panel());
getContentPane().add(new Panel());
getContentPane().add(new Panel());
getContentPane().add(new Panel());
getContentPane().add(Box.createVerticalGlue());
}
public class Panel extends JPanel{
public Panel(){
this.setLayout(new BorderLayout());
this.add(new JLabel("Title"), BorderLayout.NORTH);
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
this.add(panel);
panel.add(new JButton("button"));
}
}
public static void main (String[] args){
Gui g = new Gui();
g.setSize(240, 320);
g.setLocationRelativeTo(null);
g.setVisible(true);
g.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
If you invoke this.setBorder(BorderFactory.createLineBorder(Color.BLACK)) within the Panel class and panel.setBorder(BorderFactory.createLineBorder(Color.RED)) on the nested JPanel, you'll see that there is no "empty space" between those components.
EDIT
By replacing the layout manager of Panel with BoxLayout, you'll get the following -
To be honest, you'll just need to play around with your layout managers. I recommend you read Laying Out Components Within a Container before you proceed any further with Swing.