I have a JPanel with FlowLayout that I'm dynamically filling with identical components (JButtons in the MWE). The JPanel is inside a JScrollPane. As I add components, I'd like them to fill left to right, kicking down to the next row once the top row would become wider than the JScrollPane.
My problem is that FlowLayout is instead widening the JPanel ad nauseum, to which the JScrollPane responds by adding a horizontal scroll. How do I prevent this?
Edit: I've seen WrapLayout; I was hoping for a solution within standard Java since I'm using NetBeans GUI Builder for my application.
MWE based on this answer:
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JPanel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.*;
import javax.swing.JScrollPane;
public class MWE extends JFrame implements ActionListener {
JPanel panel;
JScrollPane pane;
public MWE() {
super("Add component on JFrame at runtime");
setLayout(new BorderLayout());
this.panel = new JPanel();
this.pane = new JScrollPane();
this.panel.setLayout(new FlowLayout(FlowLayout.LEFT));
this.pane.setViewportView(this.panel);
add(pane, BorderLayout.CENTER);
JButton button = new JButton("CLICK HERE");
add(button, BorderLayout.SOUTH);
button.addActionListener(this);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500, 500);
setVisible(true);
}
public void actionPerformed(ActionEvent evt) {
this.panel.add(new JButton("Button"));
this.panel.revalidate();
validate();
}
public static void main(String[] args) {
MWE mwe = new MWE();
}
}
Try setting a preferred size for the panel :
this.panel.setPreferredSize(new Dimension(500, 500));
Related
I have a problem using BorderLayout, but first of all, here is my GUI setup:
As you can see, I have 3 different components inside my JFrame. Adding the JMenu and JList works fine. But my JPanel should have a fixed size so I want to prevent my BorderLayout from stretching the panel. I tried everything, setPreferredSize() setMinimumSize() setMaximumSize() setSize() but again the layout stretches my panel to fit to the frame. (The panel is added to the frame using BorderLayout.CENTER).
Is there any way to prevent this or do you have other suggestions to manage the problem?
I'm pretty sure you mean BorderLayout, not BoxLayout, because there is no BoxLayout.CENTER and it looks like you use a BorderLayout to place the components.
I think the problem here is that you only set the preferred size of the panel that you add to BorderLayout.CENTER. This doesn't have any effect. Instead you need nested layouts.
In this example I added the JPanel called centerPanel, which is using a standard GridBagLayout (to center the added component), to BorderLayout.CENTER. Then I added the additional JPanel called panel, which has a custom preferrdSize, to centerPanel. This way panel won't get stretched.
Code:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JPanel;
public class Example {
public Example() {
JMenuBar menuBar = new JMenuBar();
menuBar.setBorder(BorderFactory.createMatteBorder(0, 0, 1, 0, Color.BLACK));
DefaultListModel<String> listModel = new DefaultListModel<String>();
JList<String> list = new JList<String>(listModel);
list.setBorder(BorderFactory.createMatteBorder(0, 0, 0, 1, Color.BLACK));
JPanel panel = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
// Uncomment the following lines if you also want to prevent the
// 'wrapping' of the panel.
/*
* #Override public Dimension getMinimumSize() { return new
* Dimension(400, 400); }
*/
};
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
panel.setBorder(BorderFactory.createLineBorder(Color.BLUE));
for (int i = 1; i <= 5; i++) {
menuBar.add(new JMenu("Menu " + i));
listModel.addElement("Element " + i);
panel.add(new JLabel("Label " + i));
}
JPanel centerPanel = new JPanel(new GridBagLayout());
centerPanel.add(panel);
JPanel contentPanel = new JPanel(new BorderLayout());
contentPanel.add(menuBar, BorderLayout.NORTH);
contentPanel.add(list, BorderLayout.WEST);
contentPanel.add(centerPanel);
JFrame frame = new JFrame();
frame.setContentPane(contentPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(800, 600);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new Example();
}
});
}
}
Add your existing JPanel to a JPanel having Flowlayout, the default, or having GridBagLayout with default constraints. Add this panel to the frame's center, BorderLayout.CENTER by default.
Panel centerPane = new Panel(new GridBagLayout())`;
centerPane.add(yourJPanel);
frame.add(centerPane, BorderLayout.CENTER);
Also consider using Box, rather than a JPanel having BoxLayout.
Also consider using the frame's setJMenuBar(), rather than add(BorderLayout.PAGE_START).
I'm using a JEditorPane inside a JPanel which I've called my contentPane in the example below. The content pane is inside a JScrollPane. I would like the editor pane to fill as little space as possible (to just contain it's text) and the rest of the space available in the content pane be left empty to the bottom, and on either side. If the text gets too large, the editor pane will grow, and eventually the scroll pane will create scroll bars to browse through all of the content. However, instead of the editor pane only taking up its preferred size (which is the size of the text it contains) it fills up the entire content pane which fills the entire view port of the scroll pane. Here's some example code to demonstrate my problem:
import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.BoxLayout;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
#SuppressWarnings("serial")
public class ScrollPaneExample extends JFrame {
public static void main(String[] args) {
new ScrollPaneExample();
}
public ScrollPaneExample() {
super("ScrollPaneExample");
setSize(400, 400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
JEditorPane editorPane = new JEditorPane("text/plain", "");
editorPane.setBackground(Color.YELLOW);
for (int i = 0; i < 5; i++)
editorPane.setText(editorPane.getText() + "Hello World\n");
JPanel contentPane = new JPanel();
contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
contentPane.setBackground(Color.BLUE);
contentPane.add(editorPane);
JScrollPane scrollPane = new JScrollPane(contentPane);
add(scrollPane, BorderLayout.CENTER);
setVisible(true);
}
}
When run, this is what the window looks like:
By the yellow background, we can see that the editor pane is taking up all the space. Here is a (Photoshopped) example of what I want the layout to look like:
The blue background represents the content pane, and the yellow represents the editor pane.
Edit: In my working program, there is more than just an editor pane in the contentPane. This is why I am using a BoxLayout instead of a FlowLayout for the contentPane; because the vertical page-flow layout is desired.
Just use a FlowLayout for the content pane. BorderLayout won't respect preferred size and will stretch the component to fit. See more about layout managers at Laying out Components Withing a Container
If you want to set an initial size for the editor pane, just like with any other component that is Scollable, you can override getPreferredScrollableViewportSize() to set the size for the scroll pane view (when the component is added)
Also you should be adding the editor to the scroll pane, not the panel. Doing the latter, the editor will not be scrollable in the scroll pane.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
#SuppressWarnings("serial")
public class ScrollPaneDemo extends JFrame {
public static void main(String[] args) {
new ScrollPaneDemo();
}
public ScrollPaneDemo() {
super("ScrollPaneExample");
setSize(400, 400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new FlowLayout());
JEditorPane editorPane = new JEditorPane("text/plain", "") {
#Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(200, 200);
}
};
editorPane.setBackground(Color.YELLOW);
for (int i = 0; i < 50; i++) {
editorPane.setText(editorPane.getText()
+ "Hello World Hello World\n");
}
JScrollPane scrollPane = new JScrollPane(editorPane);
add(scrollPane);
setVisible(true);
}
}
UPDATE
In my working program, there is more than just an editor pane in the contentPane. This is why I am using a BoxLayout instead of a FlowLayout for the contentPane; because the vertical page-flow layout is desired.
The BoxLayout is the problem. You need to set a maximum size for the editor pane. Or just get rid of the BoxLayout all together. FlowLayout or GridBagLayout will respect the preferred size
UPDATE 2
Here is an example using GridBagLayout that may more suitable for your "expanding" editor.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.Timer;
#SuppressWarnings("serial")
public class ScrollPaneExample extends JFrame {
public static void main(String[] args) {
new ScrollPaneExample();
}
public ScrollPaneExample() {
super("ScrollPaneExample");
setSize(400, 400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
//getContentPane().setBackground(Color.BLUE);
final JEditorPane editorPane = new JEditorPane("text/plain", "") {
};
editorPane.setBackground(Color.YELLOW);
for (int i = 0; i < 5; i++)
editorPane.setText(editorPane.getText() + "Hello World\n");
JPanel contentPane = new JPanel();
contentPane.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weighty = 1;
contentPane.setBackground(Color.BLUE);
contentPane.add(editorPane, gbc);
gbc.gridy++;
contentPane.add(new JButton("Button"), gbc);
gbc.gridy++;
contentPane.add(new JButton("Button"), gbc);
JPanel panel = new JPanel();
panel.add(contentPane);
JScrollPane scrollPane = new JScrollPane(panel);
add(scrollPane);
setVisible(true);
Timer timer = new Timer(1000, new ActionListener(){
public void actionPerformed(ActionEvent e) {
editorPane.setText(editorPane.getText() + "Hello World\n");
setVisible(true);
}
});
timer.start();
}
}
I designed an interface for the welcome screen with one JFrame included two JPanels (JPanel1 on right and JPanel2 on left). The buttons on the left is to switch the Panels in JPanel1. I want to press on a button to replace JPanel1 content with another JPanel but I don`t know how. Please help.
Here is a very simple example of something that should approximate your description. On the left, we have a hug button to toggle the content of the right panel. On the right, you have a panel with a given border and a label. When you press the button, the content on the right is swapped with the other panel.
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class TestCardLayout2 {
protected void initUI() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel leftPanel = new JPanel(new BorderLayout());
JLabel label = new JLabel("Left panel");
leftPanel.add(label, BorderLayout.NORTH);
JButton button = new JButton("Toggle right panel");
leftPanel.add(button);
frame.add(leftPanel, BorderLayout.WEST);
final CardLayout cardLayout = new CardLayout();
final JPanel rightPanel = new JPanel(cardLayout);
rightPanel.setPreferredSize(new Dimension(200, 500));
JPanel rightPanel1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
rightPanel1.setBorder(BorderFactory.createLineBorder(Color.RED));
JPanel rightPanel2 = new JPanel(new FlowLayout(FlowLayout.RIGHT));
rightPanel2.setBorder(BorderFactory.createLineBorder(Color.BLUE));
JLabel label1 = new JLabel("Right panel 1 with a red border");
JLabel label2 = new JLabel("Right panel 2 with a blue borer");
rightPanel1.add(label1);
rightPanel2.add(label2);
rightPanel.add(rightPanel1, "panel1");
rightPanel.add(rightPanel2, "panel2");
frame.add(rightPanel, BorderLayout.EAST);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
cardLayout.next(rightPanel);
}
});
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new TestCardLayout2().initUI();
}
});
}
}
An alternative to CardLayout would be JRootPane and its JRootPane.setContentPane() method. Here's an example:
final JPanel panel1 = ...;
final JPanel panel2 = ...;
boolean showingPanel1 = true;
final JRootPane rootPane = new JRootPane();
rootPane.setContentPane(panel1);
JButton switchButton = new JButton("Switch");
switchButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
if (showingPanel1) {
rootPane.setContentPane(panel2);
} else {
rootPane.setContentPane(panel1);
}
showingPanel = !showingPanel;
}
});
Add the rootPane and switchButton components to your window, and then clicking switchButton will switch out the panels.
Here's a tutorial. You should mostly be concerned with JRootPane.setContentPane, the other stuff in the tutorial isn't relevant.
The best answer I found is that I will create one JFrame only and gonna make one big JPanel include two JPanels (JPanelLeft include the buttons and JPanelRight include what the button do) then I will copy the main JPanel for each JButton.
When I press on any button I will do (JFrame.getContentPane.removeAll) to remove the old JPanel then (JFrame.getContentPane.Add(NewJPanel).
This works for me and keep my design as I Want. Thanks for every body.
Hello I would like to make this TextArea stick to the windows size whene I resize it by mouse, the same way as lower buttons does. This is the code it is perfectly working no bugs, please have a glance at it.
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class Rozklady extends JFrame {
public Rozklady() {
super();
}
public void createGUI(){
setPreferredSize(new Dimension(400,150));
JPanel jp = new JPanel();
// jp.setLayout(new BoxLayout(jp, BoxLayout.Y_AXIS));
jp.setLayout(new GridLayout(0,1));
JPanel gora = new JPanel();
JPanel dol = new JPanel();
pack();
JTextArea jt1 = new JTextArea("JF1");
gora.add(jt1);
jt1.setPreferredSize(new Dimension(getWidth(),getHeight()/2));
dol.setLayout(new BorderLayout());
JPanel lewo = new JPanel();
JPanel prawo = new JPanel();
JPanel srodek = new JPanel();
dol.add(lewo, BorderLayout.EAST);
dol.add(prawo,BorderLayout.WEST);
dol.add(srodek, BorderLayout.CENTER);
lewo.setLayout(new GridLayout(2,2));
prawo.setLayout(new GridLayout(2,2));
srodek.setLayout(new GridLayout(0,1));
for(int i = 0; i < 4; i++){
lewo.add(new JButton(i+""));
prawo.add(new JButton(i+""));
if(i < 3){
srodek.add(new JTextField("JF"+i));
}
}
jp.add(gora);
jp.add(dol);
add(jp);
setVisible(true);
pack();
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new Rozklady().createGUI();
}
});
}
}
Use BorderLayout for you gora panel. Put text area to the center:
gora.setLayout(new BorderLayout());
gora.add(jt1, BorderLayout.CENTER);
// declare a GridLayout in constructor, one component will 'fill the container'
JPanel gora = new JPanel(new GridLayout());
JPanel dol = new JPanel();
// this should be called after all components are added! BNI
pack();
JTextArea jt1 = new JTextArea("JF1");
// be sure to use a scroll pane for multi-line text components
gora.add(new JScrollPane(jt1));
// ..
Stretching a single component to fill the available space can be achieved various was. Two common ways are using either BorderLayout as mentioned by AlexR or GridLayout. See this answer for sample code. I prefer GridLayout because it is shorter (less typing). ;)
I have a JPanel with multiple Object(custom class extends Jpanel) objects in it. The JPanel has a grid layout with 7 rows and 1 column. I'm trying to add a JPanel with 7 object in it to another JScrollPane so I can scroll to view all of the objects, but it's doing strange things. The scroll bar doesn't show up no matter how many objects are in the JPanel. Any ideas? Thanks in advance.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JScrollPane;
import javax.swing.ScrollPaneLayout;
public class Main {
#SuppressWarnings("deprecation")
public static void main(String[] args) {
JFrame frame = new JFrame("Test");
frame.setLayout(new BorderLayout());
JLabel title = new JLabel("Game", JLabel.CENTER);
title.setPreferredSize(new Dimension(60,60));
title.setBorder(BorderFactory.createLineBorder(Color.black,5));
frame.add(title,BorderLayout.NORTH);
frame.setSize(850,480);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Grid g = new Grid();
JPanel jp = new JPanel();
jp.setLayout(new GridLayout(1,3));
jp.add(g);
JPanel test = new JPanel();
test.setLayout(new GridLayout(7,1));
test.add(p1);
test.add(p2);
test.add(p3);
test.add(p4);
test.add(p5);
test.add(p6);
test.add(p7);
JScrollPane jsp = new JScrollPane(test);
jsp.setViewportView(test);
jsp.getVerticalScrollBar().setUnitIncrement(50);
jsp.setCorn
jsp.setVerticalScrollBarPolicy(22);
jp.add(jsp,BorderLayout.EAST);
frame.add(jp);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
The jp JPanel uses JPanel's default FlowLayout and this may prevent you from resizing your JScrollPane and seeing that it actually is working properly. Why not either add the JScrollPane to the JFrame's contentPane or make jp use a BorderLayout? Also you don't need to set the JScrollPane's viewportView as you're already doing this by passing "test" into its constructor.
Your code don't compile. Please look at the following code. It can scroll vertically and horizontally.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
class MyPanel extends JPanel {
MyPanel(Color c) {
setBackground(c);
}
}
public class Test {
public static void main(String[] args) {
JPanel panel = new JPanel();
// the size of this panel is larger than the frame
panel.setPreferredSize(new Dimension(500, 2000));
panel.setLayout(new GridLayout(7, 1));
// add 7 sub panels
panel.add(new MyPanel(Color.magenta));
panel.add(new MyPanel(Color.cyan));
panel.add(new MyPanel(Color.blue));
panel.add(new MyPanel(Color.green));
panel.add(new MyPanel(Color.yellow));
panel.add(new MyPanel(Color.orange));
panel.add(new MyPanel(Color.red));
JScrollPane scroll = new JScrollPane(panel);
scroll.setViewportView(panel);
scroll.getVerticalScrollBar().setUnitIncrement(50);
JFrame frame = new JFrame("Test");
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(scroll);
frame.setVisible(true);
}
}