I would like to dynamically place buttons in a JPanel. For that, I chose to apply a GridBagLayout to this panel (the one to contain the buttons).
the problem is that my buttons appear from the center of my panel while I would like them to be placed from top to bottom.
here is my code:
void placerListeUsers(){
jPanel49.setLayout(new GridBagLayout());
//jPanel49 est le panel sur lequel je place mes boutons.
//jPanel49 est placé dans une JScrollPane
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.fill = GridBagConstraints.HORIZONTAL;
//c.anchor=GridBagConstraints.NORTH;
c.weightx = 1;
//c.weighty = 0;
for (int i = 0; i < 5; i++) {
c.gridwidth = GridBagConstraints.REMAINDER;
c.gridy = i;
jPanel49.add(new JButton("Super"), c);
}
and what he produces:
thank you for helping me fix this problem
the problem is that my buttons appear from the center of my panel while I would like them to be placed from top to bottom.
You need to specify weightx/y constraints, otherwise the components gather in the middle.
Read the Swing tutorial on How to Use GridBagLayout. The section on Specifying Constraints will give you more information.
It looks to me like you just have vertical buttons. Maybe a GridLayout or BoxLayout added to the BorderLayout.PAGE_START of the frame would be easier.
Even though you did not provide a MCVE as requested. I try to provide a solution for your layout... ;)
The problem is, as already mentioned by camickr, you need to tell GridBagLayout where to put all the extra space of your Panel after calculating the size of the buttons:
anchor has to be GridBagConstraints.NORTH.
weighty needs to be set to 1 for the last button added to your panel.
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.addWindowListener(new WindowAdapter() {
#Override
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Container content = frame.getContentPane();
GridBagLayout layout = new GridBagLayout();
JPanel panel = new JPanel(layout);
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.fill = GridBagConstraints.HORIZONTAL;
c.anchor = GridBagConstraints.NORTH;
c.weightx = 1;
int buttonCount = 5;
for (int i = 0; i < buttonCount; i++) {
c.weighty = i == buttonCount - 1 ? 1 : 0;
c.gridwidth = GridBagConstraints.REMAINDER;
c.gridy = i;
JButton button = new JButton("Super");
panel.add(button, c);
}
content.add(new JScrollPane(panel));
frame.pack();
frame.setSize(400, 400);
frame.setVisible(true);
}
I have read several articles regarding this topic as well the documentation, yet I still can't seem to solve my problem.
I have created a GUI that needs to be resizeable; however, I would like to maintain that there are 3 JTextFields for each row.
I have tried adjusting the weightx, yet no success.
Here is a snippet of my code:
JPanel panelMain = new JPanel();
getContentPane().add(panelMain);
JPanel panelForm = new JPanel(new GridBagLayout());
panelMain.add(panelForm);
//JScrollPane scrollpane = new JScrollPane(panelForm);
//panelMain.add(scrollpane);
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
// Row 1
buttonAddCourses = new JButton("Add Credit Hours");
buttonAddCourses.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
c.gridx = 0;
c.weightx = 0.2;
for(int i = 0; i < 15; i++) {
JTextField newTextField = new JTextField(20);
listTextFields.add(newTextField);
panelMain.add(newTextField,c);
c.gridy++;
}
panelMain.validate();
panelMain.repaint();
}
});
panelForm.add(buttonAddCourses, c);
c.gridx++;
Before Resize : !https://imgur.com/a/XCUtJ
After Resize :
!https://imgur.com/a/a4Qo4
JPanel panelMain = new JPanel(); // <- gets a FlowLayout by default
// ..
JPanel panelForm = new JPanel(new GridBagLayout()); // panel with GBL
// ...
panelMain.add(newTextField,c); // No, this should be panelForm.add(..);
I am trying to create a login page. I wrote code for two textboxes and one button. One textbox next to Username and other one next to Password. One "Sign In" button below. But I am not sure why the textbox's and button are not shown on my output. I only get the Username and password label's on my ouput screen.
Strange thing is whenever I stretch my output frame, (I mean either pulling the screen horizontally or vertically) the two textboxes and the button shows up.
Please check my code and let me know what's wrong. I was trying to put pictures to make easier to understand but I do not have enough reputation. Please help.
import javax.swing.*;
import java.awt.*;
public class HomeScreen{
public static void main(String args[]){
JFrame frame = new JFrame("Medical Store");
frame.setVisible(true);
frame.setSize(600,400);
JPanel panel = new JPanel(new GridBagLayout());
frame.getContentPane().add(panel, BorderLayout.NORTH);
GridBagConstraints c = new GridBagConstraints();
JLabel label1 = new JLabel("Username");
c.gridx = 0;
c.gridy = 0;
c.insets = new Insets(10,10,10,10);
panel.add(label1,c);
JLabel label2 = new JLabel("Password");
c.gridx = 0;
c.gridy = 1;
panel.add(label2,c);
JTextField textbox1 = new JTextField(10);
c.gridx = 1;
c.gridy = 1;
panel.add(textbox1,c);
JTextField textbox2 = new JTextField(10);
c.gridx = 2;
c.gridy = 1;
panel.add(textbox2,c);
JButton button1 = new JButton("Sign In");
c.gridx = 1;
c.gridy = 2;
panel.add(button1,c);
}
}
You're calling setVisible(true) before adding all components, and so your GUI is doing just that, drawing itself before components are added.
JFrame frame = new JFrame("Medical Store");
frame.setVisible(true);
// all components added here
Solution: make the setVisible(true) call at the end after adding all components.
JFrame frame = new JFrame("Medical Store");
// all components added here
frame.setVisible(true);
Now all components should be visualized.
Other quibbles:
Avoid calling setSize(...) on anything. Instead let the layout managers and component preferred sizes do that for you.
Call pack() on the JFrame just prior to setting it visible so that the above will happen.
I am trying to get a basic GUI program. It doesnt have to do much but the buttons at the bottom have to work. I am having trouble placing the components (The text, combobox, etc) in the proper spot. Using the GridBag I am able to change the location with the c.gridx and c.gridy but in a very weird way. If I put the gridy values 0-7 with x being 0 everything is on top of eachother. I try putting the combo box next to the text by changing the gridx value and everything gets messed up. The alignment is off on the components after the one I was trying to move over. How do I fix this? I tried the BorderLayout.DIRECTION with no luck. The actual change doesn't take effect at all (moving then to the bottom). How do I fix this? Thanks
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package javaredesign;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Timer;
/**
*
* #author
*/
public class Window extends JFrame {
//Default global variables
private JButton submit;
private JButton cancel;
private JButton reset;
private JPanel panel = new JPanel(new GridBagLayout());
private String searchOutput = "";
//Default constructor
public Window() {
//Title of the window
super("LIBSYS: Search");
//Creating the flow layout to which we can work on and adding panel to frame
setLayout(new FlowLayout());
add(panel, BorderLayout.SOUTH);
//Creating the grid to location of the parts
GridBagConstraints c = new GridBagConstraints();
//Initializing the buttons
submit = new JButton("Submit");
c.insets = new Insets(10, 10, 10, 5);
c.gridx = 1;
c.gridy = 20;
panel.add(submit, c);
reset = new JButton("Reset");
c.gridx = 2;
c.gridy = 20;
panel.add(reset, c);
cancel = new JButton("Cancel");
c.gridx = 3;
c.gridy = 20;
panel.add(cancel, c);
//Handler constructor to do the actionlistening
Handler handler = new Handler();
submit.addActionListener(handler);
reset.addActionListener(handler);
cancel.addActionListener(handler);
//Creating the two dropdowns with the words next to them
JLabel chooseCollection = new JLabel("Choose Collection");
String[] ccString = {"All", "Mostly", "Some", "Few"};
JComboBox ccComboBox = new JComboBox(ccString);
JLabel searchUsing = new JLabel("Search Using");
String[] suString = {"Title", "Artist", "Arthor", "Type"};
JComboBox suComboBox = new JComboBox(suString);
//Adding all the text and dropdown menus to the panel
c.gridx = 0;
c.gridy = 24;
panel.add(chooseCollection, c);
c.gridx = 0;
c.gridy = 25;
panel.add(ccComboBox, c);
c.gridx = 1;
c.gridy = 25;
panel.add(searchUsing, c);
c.gridx = 0;
c.gridy = 27;
panel.add(suComboBox, c);
c.gridx = 1;
c.gridy = 27;
//Setting up the text inputbox
JLabel keyword = new JLabel("Keyword or phrase");
JTextField textField = new JTextField(20);
//Adding lable and text box to the panel
panel.add(keyword);
panel.add(textField);
}
}
I would not try and force the buttons into the same layout as the other components. They are independant and should be free floating evenly spaced.
The button panel should be in a panel set with flowlayout. Then this panel should be added to the frame with borderlayout at SOUTH.
The rest of the components should go into a panel with gridbaglayout and added to the frame at CENTER.
The gridbaglayout panel then should have all its components set at the coordinates listed in the picture. If the component covers more than two cells (ie combo) then set the gridWidth property to 2.
I'd do it by having an outer BorderLayout. In the CENTER would be a GroupLayout for the label/control pairs. In the PAGE_END would be a FlowLayout for the buttons.
This uses a TitledBorder instead of the JLabel to show LIBSYS Search. If it really needs a label, put it in the PAGE_START of the border layout.
import java.awt.*;
import java.util.HashMap;
import java.util.Map;
import javax.swing.*;
import javax.swing.border.*;
public class LibSysSearch {
private JComponent ui = null;
LibSysSearch() {
initUI();
}
public void initUI() {
if (ui != null) {
return;
}
ui = new JPanel(new BorderLayout(4, 4));
ui.setBorder(new EmptyBorder(4, 4, 4, 4));
// Here is our control. This puts a titled border around it,
// instead of using a label in the PAGE_START
JPanel libSysSearchControl = new JPanel(new BorderLayout());
ui.add(libSysSearchControl);
JPanel actionPanel = new JPanel(
new FlowLayout(FlowLayout.CENTER, 15, 15));
libSysSearchControl.add(actionPanel, BorderLayout.PAGE_END);
String[] actionNames = {"Search", "Reset", "Cancel"};
for (String name : actionNames) {
actionPanel.add(new JButton(name));
}
// Use GroupLayout for the label/cotrnl combos.
// make the arrays for the factory method
String[] labels = {
"Choose Collection", "Search Using",
"Keyword or phrase", "Adjacent words"
};
String[] ccString = {"All", "Mostly", "Some", "Few"};
String[] suString = {"Title", "Artist", "Arthor", "Type"};
JPanel confirmAdjacent = new JPanel(new FlowLayout(FlowLayout.LEADING,5,0));
confirmAdjacent.add(new JRadioButton("Yes", true));
confirmAdjacent.add(new JRadioButton("No"));
JComponent[] controls = {
new JComboBox(ccString),
new JTextField(20),
new JComboBox(suString),
confirmAdjacent
};
libSysSearchControl.add(getTwoColumnLayout(labels, controls));
// throw in a few borders for white space
Border border = new CompoundBorder(
new EmptyBorder(10, 10, 10, 10),
new TitledBorder("LIBSYS Search"));
border = new CompoundBorder(
border,
new EmptyBorder(10, 10, 10, 10));
libSysSearchControl.setBorder(border);
}
public JComponent getUI() {
return ui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception useDefault) {
}
LibSysSearch o = new LibSysSearch();
JFrame f = new JFrame("Library System Search");
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(o.getUI());
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
/**
* Provides a JPanel with two columns (labels & fields) laid out using
* GroupLayout. The arrays must be of equal size.
*
* Typical fields would be single line textual/input components such as
* JTextField, JPasswordField, JFormattedTextField, JSpinner, JComboBox,
* JCheckBox.. & the multi-line components wrapped in a JScrollPane -
* JTextArea or (at a stretch) JList or JTable.
*
* #param labels The first column contains labels.
* #param fields The last column contains fields.
* #param addMnemonics Add mnemonic by next available letter in label text.
* #return JComponent A JPanel with two columns of the components provided.
*/
public static JComponent getTwoColumnLayout(
JLabel[] labels,
JComponent[] fields,
boolean addMnemonics) {
if (labels.length != fields.length) {
String s = labels.length + " labels supplied for "
+ fields.length + " fields!";
throw new IllegalArgumentException(s);
}
JComponent panel = new JPanel();
GroupLayout layout = new GroupLayout(panel);
panel.setLayout(layout);
// Turn on automatically adding gaps between components
layout.setAutoCreateGaps(true);
// Create a sequential group for the horizontal axis.
GroupLayout.SequentialGroup hGroup = layout.createSequentialGroup();
GroupLayout.Group yLabelGroup = layout.createParallelGroup(GroupLayout.Alignment.TRAILING);
hGroup.addGroup(yLabelGroup);
GroupLayout.Group yFieldGroup = layout.createParallelGroup();
hGroup.addGroup(yFieldGroup);
layout.setHorizontalGroup(hGroup);
// Create a sequential group for the vertical axis.
GroupLayout.SequentialGroup vGroup = layout.createSequentialGroup();
layout.setVerticalGroup(vGroup);
int p = GroupLayout.PREFERRED_SIZE;
// add the components to the groups
for (JLabel label : labels) {
yLabelGroup.addComponent(label);
}
for (Component field : fields) {
yFieldGroup.addComponent(field, p, p, p);
}
for (int ii = 0; ii < labels.length; ii++) {
vGroup.addGroup(layout.createParallelGroup().
addComponent(labels[ii]).
addComponent(fields[ii], p, p, p));
}
if (addMnemonics) {
addMnemonics(labels, fields);
}
return panel;
}
private final static void addMnemonics(
JLabel[] labels,
JComponent[] fields) {
Map<Character, Object> m = new HashMap<Character, Object>();
for (int ii = 0; ii < labels.length; ii++) {
labels[ii].setLabelFor(fields[ii]);
String lwr = labels[ii].getText().toLowerCase();
for (int jj = 0; jj < lwr.length(); jj++) {
char ch = lwr.charAt(jj);
if (m.get(ch) == null && Character.isLetterOrDigit(ch)) {
m.put(ch, ch);
labels[ii].setDisplayedMnemonic(ch);
break;
}
}
}
}
/**
* Provides a JPanel with two columns (labels & fields) laid out using
* GroupLayout. The arrays must be of equal size.
*
* #param labelStrings Strings that will be used for labels.
* #param fields The corresponding fields.
* #return JComponent A JPanel with two columns of the components provided.
*/
public static JComponent getTwoColumnLayout(
String[] labelStrings,
JComponent[] fields) {
JLabel[] labels = new JLabel[labelStrings.length];
for (int ii = 0; ii < labels.length; ii++) {
labels[ii] = new JLabel(labelStrings[ii]);
}
return getTwoColumnLayout(labels, fields);
}
/**
* Provides a JPanel with two columns (labels & fields) laid out using
* GroupLayout. The arrays must be of equal size.
*
* #param labels The first column contains labels.
* #param fields The last column contains fields.
* #return JComponent A JPanel with two columns of the components provided.
*/
public static JComponent getTwoColumnLayout(
JLabel[] labels,
JComponent[] fields) {
return getTwoColumnLayout(labels, fields, true);
}
}
The problem is that you need to understand GridBagLayout. You need to layout your components onto a proper grid:
So you should have 5 rows and 12 columns to layout the way you described in your picture. Don't mind the padding (I tried to add that to make it more illustrative). Your first three rows should each have elements of gridwidth = 6 and the first should be at gridx = 0 and the second at gridx = 6. Then your "yes" and "no" buttons should each have gridwidth = 3 at gridx = 6 and gridx = 9, respectively. Finally your last row, the buttons, should each have gridwidth = 2 and gridx = 1, gridx = 5, and gridx = 9, respectively. Instead of using padding, I would just use gbc.anchor = GridBagConstraints.CENTER (for all of the components) so that the components are centered inside of their grid.
I would suggest using gbc.fill = GridBagConstraints.HORIZONTAL for the text field and combo boxes so that they line up "nice and pretty" but don't forget to set that back to gbc.fill = GridBagConstraints.NONE for the radio buttons and regular buttons (unless you want them to stretch as well).
I very haphazardly changed your code (which appeared to be in no logical order):
// Creating the grid to location of the parts
GridBagConstraints c = new GridBagConstraints();
c.anchor = GridBagConstraints.CENTER;
// Initializing the buttons
submit = new JButton("Submit");
c.insets = new Insets(10, 10, 10, 5);
c.gridx = 1;
c.gridy = 5;
c.gridwidth = 2;
panel.add(submit, c);
reset = new JButton("Reset");
c.gridx = 5;
// c.gridy = 20;
panel.add(reset, c);
cancel = new JButton("Cancel");
c.gridx = 9;
// c.gridy = 20;
panel.add(cancel, c);
// Handler constructor to do the actionlistening
Handler handler = new Handler();
submit.addActionListener(handler);
reset.addActionListener(handler);
cancel.addActionListener(handler);
// Creating the two dropdowns with the words next to them
JLabel chooseCollection = new JLabel("Choose Collection");
String[] ccString = { "All", "Mostly", "Some", "Few" };
JComboBox ccComboBox = new JComboBox(ccString);
JLabel searchUsing = new JLabel("Search Using");
String[] suString = { "Title", "Artist", "Arthor", "Type" };
JComboBox suComboBox = new JComboBox(suString);
// Adding all the text and dropdown menus to the panel
c.gridx = 0;
c.gridy = 0;
c.gridwidth = 6;
c.anchor = GridBagConstraints.WEST;
panel.add(chooseCollection, c);
c.gridx = 6;
// c.gridy = 25;
c.fill = GridBagConstraints.HORIZONTAL;
panel.add(ccComboBox, c);
c.gridx = 0;
c.gridy = 2;
c.fill = GridBagConstraints.NONE;
panel.add(searchUsing, c);
c.gridx = 6;
// c.gridy = 27;
c.fill = GridBagConstraints.HORIZONTAL;
panel.add(suComboBox, c);
// Setting up the text inputbox
JLabel keyword = new JLabel("Keyword or phrase");
JTextField textField = new JTextField(20);
// Adding lable and text box to the panel
c.gridx = 0;
c.gridy = 1;
c.fill = GridBagConstraints.NONE;
panel.add(keyword, c);
c.gridx = 6;
panel.add(textField, c);
Which produced the following layout:
i would probably do it like this:
public class Test {
public Test() {
JFrame frame = new JFrame();
JPanel mainPanel = new JPanel(new GridLayout(0, 1));
JPanel chooseCollectionPanel = new JPanel(new BorderLayout());
JPanel keywordPanel = new JPanel(new BorderLayout());
JPanel searchCategoryPanel = new JPanel(new BorderLayout());
// ...
mainPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
chooseCollectionPanel.setBorder(BorderFactory.createEmptyBorder(5, 0,
5, 0));
keywordPanel.setBorder(BorderFactory.createEmptyBorder(5, 0, 5, 0));
searchCategoryPanel.setBorder(BorderFactory.createEmptyBorder(5, 0, 5,
0));
JLabel chooseCollectionLabel = new JLabel("Choose Collection: ");
JComboBox<String> chooseCollectionCB = new JComboBox<String>();
chooseCollectionCB.addItem("All");
chooseCollectionPanel.add(chooseCollectionLabel, BorderLayout.WEST);
chooseCollectionPanel.add(chooseCollectionCB, BorderLayout.CENTER);
JLabel chooseCollectionkeywordLabel = new JLabel("Choose Collection: ");
JTextField keywordCB = new JTextField(10);
keywordPanel.add(chooseCollectionkeywordLabel, BorderLayout.WEST);
keywordPanel.add(keywordCB, BorderLayout.CENTER);
// ...
mainPanel.add(chooseCollectionPanel);
mainPanel.add(keywordPanel);
mainPanel.add(searchCategoryPanel);
// ...
frame.add(mainPanel);
frame.setSize(400, 400);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
new Test();
}
}
I have a JPanel with the following code:
JPanel pane = new JPanel();
pane.setLayout(new GridLayout(3, 2, 10, 30));
final JTextField fileName = new JTextField();
pane.add(fileName);
JButton creater = new JButton("Create File");
pane.add(creater);
JButton deleter = new JButton("Delete File");
pane.add(deleter);
I was wondering, how do I make it so that the JTextField takes up two spaces on the GridLayout, while having the two buttons share a row by taking up one space each on the same line?
It is a hard to do with GridLyout. You have create wider cells (e.g. new GridLayout(2, 2, 10, 30), then add TextField to the fist cell. Then you have to create yet another panel with GridLayout(2, 1), put it into the cell in second line and add your button into 1 st cell of this nested grid layout.
Shortly you need GridLayout into other GridLayout.
There are better tools to implement this. First take a look on GridBagLayout. It is just to be sure that life is not always pick-nick :). Then take a look on alternative solutions like MigLayout. It is not a part of JDK but it really powerful tool that makes your life easier.
You cannot do column spans with GridLayout. I recomend you try GridBagLayout and GridBagConstraints
After trashing the suggestion of 3rd party layouts, and since I possess a malevolent hatred of GBL, I thought it was about to time to 'put my code where my mouth is' for public scrutiny (and trashing).
This SSCCE uses a nested layout.
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
class SimpleLayoutTest {
public static void main(String[] args) {
Runnable r = new Runnable() {
public void run() {
JPanel ui = new JPanel( new BorderLayout(20,20) );
// I would go for an EmptyBorder here, but the filled
// border is just to demonstrate where the border starts/ends
ui.setBorder( new LineBorder(Color.RED,15) );
// this should be a button that pops a JFileChooser, or perhaps
// a JTree of the existing file system structure with a JButton
// to prompt for the name of a new File.
final JTextField fileName = new JTextField();
ui.add(fileName, BorderLayout.NORTH);
JPanel buttonPanel = new JPanel(new GridLayout(1, 0, 10, 30));
ui.add(buttonPanel, BorderLayout.CENTER);
JButton creater = new JButton("Create File");
buttonPanel.add(creater);
JButton deleter = new JButton("Delete File");
buttonPanel.add(deleter);
JOptionPane.showMessageDialog(null, ui);
}
};
SwingUtilities.invokeLater(r);
}
}
Take a look at the tutorial on How to Use GridBagLayout.
Sample code:
JPanel pane = new JPanel();
GridBagLayout gridbag = new GridBagLayout();
pane.setLayout(gridbag);
GridBagConstraints c = new GridBagConstraints();
final JTextField fileName = new JTextField();
c.fill = GridBagConstraints.HORIZONTAL;
c.gridwidth = 2;
c.gridx = 0;
c.gridy = 0;
pane.add(fileName, c);
JButton creater = new JButton("Create File");
c.fill = GridBagConstraints.HORIZONTAL;
c.gridwidth = 1;
c.gridx = 0;
c.gridy = 1;
pane.add(creater, c);
JButton deleter = new JButton("Delete File");
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 1;
pane.add(deleter, c);