I hava an JButton and want to position to the bottom left of an JPanel. This is my code:
panel = new JPanel(new FlowLayout(FlowLayout.LEFT));
panel.setPreferredSize(new Dimension(130, 300));
panel.add(jlabel1);
panel.add(jlabel2);
panel.add(button, BorderLayout.SOUTH);
Later in the code, I update the Jlabels (if it matters):
panel.remove(jlabel1);
panel.remove(jlabel2);
//Some other code
panel.add(jlabel1)
panel.add(jlabel2)
Through all this, I want the JButton to stay in the bottom of the JPanel. How can I fix this? Nothing happens with the BorderLayout.SOUTH. Thanks.
The short answer is that BorderLayout.SOUTH isn't doing anything because the panel to which you are adding button doesn't have a BorderLayout.
Check out the Java Tutorials section on layout managers for a better explanation
https://docs.oracle.com/javase/tutorial/uiswing/layout/index.html
Meanwhile, this code (made up on-the-spot and completely untested) should give you some ideas about the direction you need to go:
panel = new JPanel(new BorderLayout());
panel.setPreferredSize(new Dimension(130, 300));
JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
buttonPanel.add(button);
panel.add(buttonPanel, BorderLayout.SOUTH);
JPanel labelPanel = newJPanel(new FlowLayout(FlowLayout.LEFT));
labelPanel.add(jLabel1);
labelPanel.add(jLabel2);
panel.add(labelPanel, BorderLayout.CENTER));
Related
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
JPanel topPanel = new JPanel(new FlowLayout());
.....
JPanel centrePanel = new JPanel(new FlowLayout(10, 0));
........
JScrollPane scrollPane = new JScrollPane(table);
scrollPane.setPreferredSize(new Dimension(100, 160));
centrePanel.add(glListScrollPane);
........
........
JPanel bottomPanel = new JPanel();
bottomPanel.setLayout(new GridLayout(0, 2));
......
........
panel.add(topPanel, BorderLayout.CENTER);
panel.add(centrePanel, BorderLayout.CENTER);
panel.add(bottomPanel, BorderLayout.CENTER);
frame.add(panel);
frame.add(standardButtonPanel);
public void lockScreen(boolean editable) {
standardButtonPanel.button1.setVisible(editable);
......
}
When doing edit and un-edit. the panel is changing its position a little bit.
I have used BoxLayout as I wanted to have the components have there own size and users can resize the screen also.
Is there any other approach? Where I can fix the layout problem?
Instead of using setVisible, try using setEnabled as it dosent hide the button (hence does not affect the UI) but makes it so that the end-user cannot press the button.
I have this Java JFrame class, in which I want to use a boxlayout, but I get an error saying java.awt.AWTError: BoxLayout can't be shared. I've seen others with this problem, but they solved it by creating the boxlayout on the contentpane, but that is what I'm doing here. Here's my code:
class EditDialog extends JFrame {
JTextField title = new JTextField();
public editDialog() {
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setTitle("New entity");
getContentPane().setLayout(
new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(title);
pack();
setVisible(true);
}
}
Your problem is that you're creating a BoxLayout for a JFrame (this), but setting it as the layout for a JPanel (getContentPane()). Try:
getContentPane().setLayout(
new BoxLayout(getContentPane(), BoxLayout.PAGE_AXIS)
);
I've also found this error making this:
JPanel panel = new JPanel(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
The JPanel isn't initialized yet when passing it to the BoxLayout. So split this line like this:
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
This will work.
I think that one important thing to highlight from the previous answers is that the BoxLayout's target (the first parameter) should be the same Container that the setLayout method is being called upon as in the following example:
JPanel XXXXXXXXX = new JPanel();
XXXXXXXXX.setLayout(new BoxLayout(XXXXXXXXX, BoxLayout.Y_AXIS));
If you're using the layout on a JFrame like:
JFrame frame = new JFrame();
frame.setLayout(new BoxLayout(frame, BoxLayout.Y_AXIS));
frame.add(new JLabel("Hello World!"));
The control is actually being added to the ContentPane so it will look like it's 'shared' between the JFrame and the ContentPane
Do this instead:
JFrame frame = new JFrame();
frame.setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.Y_AXIS));
frame.add(new JLabel("Hello World!"));
I recently started working with Java and I am not too sure how to put my BoxedLayout Panel in the middle of my `JFrame. At the moment, I have the following:
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
JLabel quizLabel = new JLabel("Java Quiz",SwingConstants.CENTER);
quizLabel.setForeground(Color.BLUE);
quizLabel.setFont(new Font("Arial", Font.BOLD, 20));
quizLabel.setOpaque(true);
panel.add(quizLabel);
JLabel newLineLabel = new JLabel(" ",SwingConstants.CENTER);
newLineLabel.setOpaque(true);
panel.add(newLineLabel);
JLabel createdByLabel = new JLabel("Created By",SwingConstants.CENTER);
createdByLabel.setOpaque(true);
panel.add(createdByLabel);
JLabel nameLabel = new JLabel("XXX",SwingConstants.CENTER);
nameLabel.setOpaque(true);
panel.add(nameLabel);
contentPane.add(panel, BorderLayout.CENTER);
contentPane is taken from my frame. This gives me the following output:
I want the three labels inside the panel to appear in the middle of the Frame.
Because it is the only panel on the screen, the BoxLayout will fill the entire frame and thus depending on how your JComponents are created in the panel, it will show it like that on the frame too.
What I would do if I were you, is created a BorderLayout as a container for your BoxLayout.
This way, you can set your BoxLayout as the center of the Borderlayout.
See if this code works:
//This will fill your frame
JPanel containerPanel = new JPanel(new BorderLayout());
contentPane.add(containerPanel);
//this is the BoxPanel you wnat your components to be organized in
JPanel boxPanel = new JPanel(new BoxLayout());
//Add all your components to the boxPanel
//add your panel with all the components to the container panel
containerPanel.add(boxPanel, BorderLayout.CENTER);
The easiest way is to use a GridBagLayout. Using the default constraints a single component will be centered in the panel:
//contentPane.add(panel, BorderLayout.CENTER);
contentPane.setLayout( new GridBagLayout() );
contentPane.add(panel, new GridBagConstraints());
I've searched a fair amount and I cannot locate a good, simple answer to this problem.
I want a box layout (superPanel), which contains an upper and lower JPanel (mainPanel and footerPanel). The upper will contain further JPanels (leftPanel and rightPanel).
Consider the code below, I find that when I resize the window, the mainPanel gets larger, and so does the footer. The footer should always stay the same size, below the mainPanel, at the bottom of the frame.
frame = new JFrame("Frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel container = new JPanel();
container.setLayout(new BoxLayout(container, BoxLayout.Y_AXIS));
JPanel superPanel = new JPanel();
JPanel mainPanel = new JPanel();
JPanel leftPanel = new JPanel();
JPanel rightPanel= new JPanel();
JPanel footerPanel = new JPanel();
footerPanel.setBackground(Color.GREEN);
mainPanel.setBackground(Color.RED);
mainPanel.add(leftPanel);
mainPanel.add(rightPanel);
mainPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
leftPanel.add(new JButton("left"));
rightPanel.add(new JButton("right"));
footerPanel.add(new JButton("footer"));
container.add(mainPanel);
container.add(footerPanel);
frame.add(container);
frame.pack();
frame.setVisible(true);
Anybody know why this is occurring? If you run this you'll see that red and green both grow in size as the window is resized. What I want to see is the red getting larger, while the green remains the same size.
Glue doesn't work, and I don't want to have to use GridBagLayout unless I have to (please explain why I should if need be)
Thanks
When you want a "main" section and side sections which don't change size, you usually want a BorderLayout:
container.setLayout(new BorderLayout());
container.add(mainPanel, BorderLayout.CENTER);
container.add(footerPanel, BorderLayout.PAGE_END);
Try to use GridBagLayout with fill.BOTH, weightx = 1 and weighty = 1 for the main panel and fill.NONE, weightx = 0 and weighty = 0 for the footer panel or use Miglayout which is really easy and with it you can do all what you want.
BorderLayout is what you want on your container, adding the mainPanel to the center and footerPanel to the south. Try the following changes on your code:
frame = new JFrame("Frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel container = new JPanel();
container.setLayout(new BorderLayout()); // Use BorderLayout instead of BoxLayout
JPanel superPanel = new JPanel();
JPanel mainPanel = new JPanel();
JPanel leftPanel = new JPanel();
JPanel rightPanel = new JPanel();
JPanel footerPanel = new JPanel();
footerPanel.setBackground(Color.GREEN);
mainPanel.setBackground(Color.RED);
mainPanel.add(leftPanel);
mainPanel.add(rightPanel);
mainPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
leftPanel.add(new JButton("left"));
rightPanel.add(new JButton("right"));
footerPanel.add(new JButton("footer"));
container.add(mainPanel, BorderLayout.CENTER); // Add mainPanel to the central area
container.add(footerPanel, BorderLayout.SOUTH); // Add footePanel to the bottom
frame.add(container);
frame.pack();
frame.setVisible(true);
The BorderLayout determines that a component added to the CENTER area will expand both horizontally and vertically to follow the container. The SOUTH area can only expand horizontally while EAST and WEST can only expand vertically. Keep in mind that every layout manager class has its own rules on how to divide the container space among components and how they are resized.
I have this Java JFrame class, in which I want to use a boxlayout, but I get an error saying java.awt.AWTError: BoxLayout can't be shared. I've seen others with this problem, but they solved it by creating the boxlayout on the contentpane, but that is what I'm doing here. Here's my code:
class EditDialog extends JFrame {
JTextField title = new JTextField();
public editDialog() {
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setTitle("New entity");
getContentPane().setLayout(
new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(title);
pack();
setVisible(true);
}
}
Your problem is that you're creating a BoxLayout for a JFrame (this), but setting it as the layout for a JPanel (getContentPane()). Try:
getContentPane().setLayout(
new BoxLayout(getContentPane(), BoxLayout.PAGE_AXIS)
);
I've also found this error making this:
JPanel panel = new JPanel(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
The JPanel isn't initialized yet when passing it to the BoxLayout. So split this line like this:
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
This will work.
I think that one important thing to highlight from the previous answers is that the BoxLayout's target (the first parameter) should be the same Container that the setLayout method is being called upon as in the following example:
JPanel XXXXXXXXX = new JPanel();
XXXXXXXXX.setLayout(new BoxLayout(XXXXXXXXX, BoxLayout.Y_AXIS));
If you're using the layout on a JFrame like:
JFrame frame = new JFrame();
frame.setLayout(new BoxLayout(frame, BoxLayout.Y_AXIS));
frame.add(new JLabel("Hello World!"));
The control is actually being added to the ContentPane so it will look like it's 'shared' between the JFrame and the ContentPane
Do this instead:
JFrame frame = new JFrame();
frame.setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.Y_AXIS));
frame.add(new JLabel("Hello World!"));