I see that GridBagLayout
positions it's children with center alignment within cells. How to align left or right?
UPDATE
Constructing code (I know I could reuse c
)
// button panel
JPanel button_panel = new JPanel();
button_panel.add(ok_button);
button_panel.add(cancel_button);
// placing controls to dialog
GridBagConstraints c;
GridBagLayout layout = new GridBagLayout();
setLayout(layout);
c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
add(inputSource_label, c);
c = new GridBagConstraints();
c.gridx = 1;
c.gridy = 0;
add(inputSource_combo, c);
c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 1;
add(output_label, c);
c = new GridBagConstraints();
c.gridx = 1;
c.gridy = 1;
add(output_combo, c);
c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 2;
c.gridwidth = 2;
add(button_panel, c);
When using GridBagLayout for a tabular display of JLabel : JTextField, I like to have a method that makes my GridBagConstraints for me based on the x, y position. For example something like so:
private GridBagConstraints createGbc(int x, int y) {
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = x;
gbc.gridy = y;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.anchor = (x == 0) ? GridBagConstraints.WEST : GridBagConstraints.EAST;
gbc.fill = (x == 0) ? GridBagConstraints.BOTH
: GridBagConstraints.HORIZONTAL;
gbc.insets = (x == 0) ? WEST_INSETS : EAST_INSETS;
gbc.weightx = (x == 0) ? 0.1 : 1.0;
gbc.weighty = 1.0;
return gbc;
}
The following code makes a GUI that looks like this:
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.util.HashMap;
import java.util.Map;
import javax.swing.*;
public class GridBagEg {
private static void createAndShowGui() {
PlayerEditorPanel playerEditorPane = new PlayerEditorPanel();
int result = JOptionPane.showConfirmDialog(null, playerEditorPane,
"Edit Player", JOptionPane.OK_CANCEL_OPTION,
JOptionPane.PLAIN_MESSAGE);
if (result == JOptionPane.OK_OPTION) {
// TODO: do something with info
for (PlayerEditorPanel.FieldTitle fieldTitle :
PlayerEditorPanel.FieldTitle.values()) {
System.out.printf("%10s: %s%n", fieldTitle.getTitle(),
playerEditorPane.getFieldText(fieldTitle));
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
@SuppressWarnings("serial")
class PlayerEditorPanel extends JPanel {
enum FieldTitle {
NAME("Name"), SPEED("Speed"), STRENGTH("Strength");
private String title;
private FieldTitle(String title) {
this.title = title;
}
public String getTitle() {
return title;
}
};
private static final Insets WEST_INSETS = new Insets(5, 0, 5, 5);
private static final Insets EAST_INSETS = new Insets(5, 5, 5, 0);
private Map<FieldTitle, JTextField> fieldMap = new HashMap<FieldTitle, JTextField>();
public PlayerEditorPanel() {
setLayout(new GridBagLayout());
setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Player Editor"),
BorderFactory.createEmptyBorder(5, 5, 5, 5)));
GridBagConstraints gbc;
for (int i = 0; i < FieldTitle.values().length; i++) {
FieldTitle fieldTitle = FieldTitle.values()[i];
gbc = createGbc(0, i);
add(new JLabel(fieldTitle.getTitle() + ":", JLabel.LEFT), gbc);
gbc = createGbc(1, i);
JTextField textField = new JTextField(10);
add(textField, gbc);
fieldMap.put(fieldTitle, textField);
}
}
private GridBagConstraints createGbc(int x, int y) {
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = x;
gbc.gridy = y;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.anchor = (x == 0) ? GridBagConstraints.WEST : GridBagConstraints.EAST;
gbc.fill = (x == 0) ? GridBagConstraints.BOTH
: GridBagConstraints.HORIZONTAL;
gbc.insets = (x == 0) ? WEST_INSETS : EAST_INSETS;
gbc.weightx = (x == 0) ? 0.1 : 1.0;
gbc.weighty = 1.0;
return gbc;
}
public String getFieldText(FieldTitle fieldTitle) {
return fieldMap.get(fieldTitle).getText();
}
}
In this example, I display the JPanel in a JOptionPane, but it could just as easily be displayed in a JFrame or JApplet or JDialog or ...