Hello so I wanted to add text area, text field and a button to my panel. I wanted area to use 3/4 of height and full width, field to use 1/4 of height and 3/4 of width and a button to use 1/4 height and 1/4 width. I post a pic to show what I want to get. Code for this looks like:
// My JPanel class
public MainPanel() {
setLayout(new GridBagLayout());
add(area, new GBC(0, 0, 4, 3).setWeight(4,4).setFill(GBC.BOTH));
add(field, new GBC(0, 3, 3, 1).setWeight(1,1).setFill(GBC.HORIZONTAL));
}
GBC is my class which inherits from GridBagConstraints class:
public class GBC extends GridBagConstraints {
public GBC(int gridx, int gridy) {
this.gridx = gridx;
this.gridy = gridy;
weightx = 100;
weighty = 100;
}
public GBC(int gridx, int gridy, int gridwidth, int gridheight) {
this(gridx, gridy);
this.gridwidth = gridwidth;
this.gridheight = gridheight;
}
public GBC setFill(int fill) {
this.fill = fill;
return this;
}
}
So the problem is that both area and field take half of height and a button is in the center, hidden under field... Look terrible anyway, how to solve if?
weightx and weighty is what specifies how extra space is distributed. In your case, they both have the same value horizontally and vertically which is 100.
Try to set weightx and weighty to 4 for JTextArea and set weightx and weighty to 1 for JTextField
You can check the doc for what does every field do in GridBagConstraints:
http://docs.oracle.com/javase/7/docs/api/java/awt/GridBagConstraints.html
That's how it should look like:
add(area, new GBC(0, 0, 4, 3).setWeight(4,4).setFill(GBC.BOTH));
add(field, new GBC(0, 3, 3, 1).setWeight(1,1).setFill(GBC.HORIZONTAL));
Also read about weightx and weighty, cause you're using them in wrong way
Related
I've implemented a JPanel using a GridBagLayout as follows:
fileSelectionDetails = new JPanel();
fileSelectionGridBagLayout = new GridBagLayout();
fileSelectionDetails.setLayout(fileSelectionGridBagLayout);
JLabel lblFile1 = new JLabel("File 1:");
JTextField txtFile1Path = new JTextField();
JButton btnBrowseFile1 = new JButton("Browse...");
addComponentToFileSelectionGrid(lblFile1, 0, 0, 1, 1, 20, 100, GridBagConstraints.NONE, GridBagConstraints.WEST);
addComponentToFileSelectionGrid(txtFile1Path, 1, 0, 3, 1, 60, 100, GridBagConstraints.HORIZONTAL, GridBagConstraints.WEST);
addComponentToFileSelectionGrid(btnBrowseFile1, 2, 0, 1, 1, 20, 100, GridBagConstraints.HORIZONTAL, GridBagConstraints.WEST);
private void addComponentToFileSelectionGrid(Component component, int gridX, int gridY,
int gridWidth, int gridHeight, int weightX,
int weightY, int fill, int anchor) {
GridBagConstraints constraint = new GridBagConstraints();
constraint.gridx = gridX;
constraint.gridy = gridY;
constraint.gridwidth = gridWidth;
constraint.gridheight = gridHeight;
constraint.weightx = weightX;
constraint.weighty = weightY;
constraint.fill = fill;
constraint.anchor = anchor;
fileSelectionGridBagLayout.setConstraints(component, constraint);
fileSelectionDetails.add(component);
}
I want to see my components laid out as follows:
However, what I'm actually seeing is:
i.e. the 'Browse...' button is missing! Why is this?
From your drawing, I’m guessing you don’t want relative widths at all. It appears you want the label and button to be their preferred sizes, and the JTextField to stretch to take up all of the width not used by the label and button.
As camickr suggested, you should give the JTextField a meaningful preferred size by initializing it with a column count, like new JTextField(20).
You can then take advantage of some useful aspects of GridBagLayout and GridBagConstraints:
The default value of gridx and gridy is RELATIVE, which means each component you add is placed to the right of the last one added. Which just happens to be exactly what you want. Therefore, you should not set gridx or gridy at all.
The default value of gridwidth and gridheight is 1. This is what you want. GridBagLayout cells are flexible, so setting one component’s gridwidth to 3 does not make it three times wider than a component whose gridwidth is 1. The width of a cell, or span of cells, depends entirely on what it contains.
When you add a component to a GridBagLayout, the GridBagConstraints object is cloned inside the GridBagLayout. This means you can safely reuse the same GridBagConstraints object over and over, changing just the fields that need to change.
With this knowledge, your code can be simplified to:
fileSelectionDetails = new JPanel(new GridBagLayout());
JLabel lblFile1 = new JLabel("File 1:");
JTextField txtFile1Path = new JTextField(20);
JButton btnBrowseFile1 = new JButton("Browse\u2026");
txtFile1Path.setMinimumSize(txtFile1Path.getPreferredSize());
GridBagConstraints constraints = new GridBagConstraints();
constraints.fill = GridBagConstraints.HORIZONTAL;
constraints.weight = 0;
fileSelectionDetails.add(lblFile1, constraints);
constraints.weight = 1;
fileSelectionDetails.add(txtFile1Path, constraints);
constraints.weight = 0;
fileSelectionDetails.add(btnBrowseFile1, constraints);
You define gridWidth=3 for txtFile1Path but add btnBrowseFile1 at gridX=2. You must set addComponentToFileSelectionGrid(btnBrowseFile1, 4 ...etc.
In this JFrame with a GridBagLayout with 4 columns, the brown line should be the limit between columns 1 and 2, and OK and Cancel buttons should be on each side of this limit:
The problems:
OK + Cancel set is not centered with other buttons.
Left and right JTextArea don't have the same width.
Column 1 seems to have a zero width when I was expecting columns 1 and 2 to be equal.
The code used:
import java.awt.Component;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;
public class GblSO extends JFrame {
// Instance variables
GridBagConstraints gbc = new GridBagConstraints();
public GblSO() {
// Set frame
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLayout(new GridBagLayout());
// Text areas
JTextArea left = new JTextArea("Left!");
JTextArea right = new JTextArea("Right!");
setConstraints(1, 1, GridBagConstraints.BOTH, null);
addToFrame(left, 0, 1, 1, 5, GridBagConstraints.CENTER);
addToFrame(right, 3, 1, 1, 5, GridBagConstraints.CENTER);
// Transfer buttons
JButton addBtn = new JButton(">");
JButton rmvBtn = new JButton("<");
setConstraints(0, 0, GridBagConstraints.NONE, new Insets(3, 5, 3, 5));
addToFrame(addBtn, 1, 1, 2, 1, GridBagConstraints.CENTER);
addToFrame(rmvBtn, 1, 3, 2, 1, GridBagConstraints.CENTER);
// OK / Cancel buttons
JButton okBtn = new JButton("OK");
JButton canBtn = new JButton("Cancel");
setConstraints(0, 0, GridBagConstraints.NONE, new Insets(15, 4, 15, 4));
addToFrame(okBtn, 0, 6, 2, 1, GridBagConstraints.EAST);
addToFrame(canBtn, 2, 6, 2, 1, GridBagConstraints.WEST);
// Show
pack();
setVisible(true);
}
private void setConstraints(double weightx, double weighty, int fill, Insets insets) {
gbc.weightx = weightx; // how much cell resizes
gbc.weighty = weighty; // "
gbc.fill = fill; // how component fills cell
gbc.insets = (insets == null ? new Insets(0, 0, 0, 0) : insets);
}
private void addToFrame(Component comp,
int gridx, int gridy, int gridwidth, int gridheight, int anchor) {
gbc.gridx = gridx;
gbc.gridy = gridy;
gbc.gridwidth = gridwidth;
gbc.gridheight = gridheight;
gbc.anchor = anchor;
add(comp, gbc);
}
public static void main(String[] args) {
new GblSO();
}
}
For a test only: If I add the > and < buttons to the JFrame respectively in column 1 and 2, and don't span multiple columns, columns 1 and 2 are forced to have the same width and the bottom buttons set is now centered.
Code changed:
addToFrame(addBtn, 1, 1, 1, 1, GridBagConstraints.CENTER);
addToFrame(rmvBtn, 2, 3, 1, 1, GridBagConstraints.CENTER);
Result:
The two JTextArea have still a different width :-(, and obviously > and < are not going to be aligned!
How can I solve this problem so that buttons are centered, and the two JTextArea have the same width? Thanks by advance for your help.
(this code is inspired by this tutorial)
That is because you don't have any components added on each column, which is somehow needed for GridBagLayout to work as one would expect.
A few remarks now:
Did you noticed in the tutorial you linked to, the OK and Cancel buttons are aligned with the JTextArea, not the overall upper components?
When working with GridBagLayout it is better to instanciate a new GridBagConstraint for each component you're adding. It prevents you from forgetting to reset an attribute somewhere, which is difficult to troubleshoot.
Then, if you want your OK and Cancel buttons to be center-aligned with your upper components, the easiest would be to create two JPanel: one with the upper components, the other one with your buttons. You can still use GridBagLayout for the upper panel and the default one (FlowLayout) for the buttons. You would put them into a BorderLayout position CENTER and SOUTH and you'd be good to go. Note that the panels would be center-aligned, not the space between the OK / Cancel buttons and the < / > buttons.
Back to the solution to your problem: you have to add "empty" components (Container, JPanel, emtpy JLabel, ...) on the first (or last) line with weightx set to 1.0 so the cells are actually filled in X direction, and weighty set to 0.0 so they are not visible in Y direction (and vice-versa if you want to use gridheight instead of gridwidth).
...
setLayout(new GridBagLayout());
setConstraints(1, 0, GridBagConstraints.BOTH, null);
addToFrame(new Container(), 0, 0, 1, 1, GridBagConstraints.CENTER);
addToFrame(new Container(), 1, 0, 1, 1, GridBagConstraints.CENTER);
addToFrame(new Container(), 2, 0, 1, 1, GridBagConstraints.CENTER);
addToFrame(new Container(), 3, 0, 1, 1, GridBagConstraints.CENTER);
// Text areas
...
That way the cells will exist and you'll get the expected result.
I'm learning how to use GridBagLayout. I created two buttons in a JFrame. I tried making it that one of them occupies one collumn (the default), and the other two collumns, thus being twice the size of the first one (I know I can acheive this using setPrefferredSize, but my intention is to learn how to use gridwidth and gridheight).
What's the problem? Thanks
import java.awt.*;
import javax.swing.*;
public class Main extends JFrame {
Main(){
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(500,500);
JPanel panel1 = new JPanel(new GridBagLayout());
JButton b1,b2;
b1 = new JButton("button 1");
b2 = new JButton("button 2");
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridwidth = 1;
panel1.add(b1);
gbc.gridx = 2;
gbc.gridwidth = 2;
panel1.add(b2);
add(panel1);
setVisible(true);
}
public static void main(String[]args){
Main m = new Main();
}
}
It doesn't matter how many columns the second button's width.
Actually both buttons will be asked for their preferred width and the width will be set to them if it's enough space for them.
If it's less space then min width is used.
If there is extra space it's distributed between controls according to weights proportions.
You can try to set iPadX=100 for the first and iPadx=200 and set proportion iPadX=1 for the first and iPadx=2 for the second.
The problem is that all the columns of a GridBagLayout don't have the same width. The widths are computed based on the preferred size of the components they contain. So, you could use 3, 4 or 100 as the gridwidth for the second button, it wouldn't change anything.
You need to use fillx and weightx to change the way the buttons resize.
Try using GridBagConstraint in this way, hope this will help you.
import java.awt.*;
import javax.swing.*;
public class Main extends JFrame {
Main(){
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(500,500);
JPanel panel1 = new JPanel(new GridBagLayout());
JButton b1,b2;
b1 = new JButton("button 1");
b2 = new JButton("button 2");
panel1.add(b1, new GridBagConstraints(0, 0, 1, 1, 0.0, 0.0, GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(0, 0, 0, 0), 0, 0));
panel1.add(b2, new GridBagConstraints(1, 0, 1, 1, 2.0, 0.0, GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(0, 0, 0, 0), 0, 0));
add(panel1);
setVisible(true);
}
public static void main(String[]args){
Main m = new Main();
}
}
EDIT
Or change in your code Like this below:
gbc.gridx = 1;
gbc.gridwidth = 1;
panel1.add(b1, gbc);
gbc.gridx = 2;
gbc.gridwidth = 2;
gbc.fill = gbc.HORIZONTAL; //set fill property to HORIZONTAL
gbc.weightx= 2.0;
panel1.add(b2, gbc); //While adding button also add it with gbc
this.rootComponent.setLayout(new GridBagLayout());
GridBagConstraints gbc=new GridBagConstraints();
//gbc.gridwidth=2;
gbc.gridx=0;
gbc.gridy=0;
gbc.gridwidth=8;
gbc.anchor=GridBagConstraints.FIRST_LINE_START;
this.rootComponent.add(new JLabel("Test label 1"),gbc);
gbc.gridx=8;
gbc.gridy=12;
gbc.gridwidth=GridBagConstraints.REMAINDER;
gbc.anchor=GridBagConstraints.FIRST_LINE_START;
this.rootComponent.add(new JLabel("Test label"),gbc);
Want to format it like this. grey part shows the jpanel part. Initially i want to layout the first 2 jpanel correctly . which is not working. how to fix it?
You are failing to specify any weightx and weighty values to the GridBagConstraints. Moreover your gridwidth values are wrong, since it only needs to be 2 for the bottom most JPanel, for the rest it needs to be 1.
Explanation of what I am doing :
Consider JPanels BLUE and RED, they are to be placed along the X-AXIS, in the ratio
70:30, with respect to each other (therefore their weightx will be 0.7 and 0.3 respectively. Since the total area along the X-AXIS is 1.0).
Now both of these BLUE and RED JPanels are to be placed along the Y-AXIS, with respect to the third GREEN JPanel in the ratio 90:10, therefore, both of these BLUE and RED will have weighty = 0.9, and the GREEN JPanel will have weighty = 0.1, but since GREEN JPanel is suppose to occupy the whole area (with respect to X-AXIS), as occupied by BLUE and RED JPanels, for that matter, its gridwidth = 2 and weightx = 1.0.
Try this code example :
import java.awt.*;
import javax.swing.*;
public class GridBagLayoutExample
{
private GridBagConstraints gbc;
public GridBagLayoutExample()
{
gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.FIRST_LINE_START;
}
private void displayGUI()
{
JFrame frame = new JFrame("GridBagLayout Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
JPanel contentPane = getPanel(Color.WHITE);
contentPane.setLayout(new GridBagLayout());
JPanel leftPanel = getPanel(Color.BLUE);
JPanel rightPanel = getPanel(Color.RED);
JPanel bottomPanel = getPanel(Color.GREEN.darker());
addComp(contentPane, leftPanel
, 0, 0, 0.7, 0.9, 1, 1, GridBagConstraints.BOTH);
addComp(contentPane, rightPanel
, 1, 0, 0.3, 0.9, 1, 1, GridBagConstraints.BOTH);
addComp(contentPane, bottomPanel
, 0, 1, 1.0, 0.1, 2, 1, GridBagConstraints.BOTH);
frame.setContentPane(contentPane);
//frame.pack();
frame.setSize(300, 300);
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private void addComp(JPanel panel, JComponent comp
, int gridX, int gridY
, double weightX, double weightY
, int gridWidth, int gridHeight, int fill)
{
gbc.gridx = gridX;
gbc.gridy = gridY;
gbc.weightx = weightX;
gbc.weighty = weightY;
gbc.gridwidth = gridWidth;
gbc.gridheight = gridHeight;
gbc.fill = fill;
panel.add(comp, gbc);
}
private JPanel getPanel(Color backColour)
{
JPanel panel = new JPanel();
panel.setOpaque(true);
panel.setBackground(backColour);
panel.setBorder(
BorderFactory.createEmptyBorder(5, 5, 5, 5));
return panel;
}
public static void main(String[] args)
{
Runnable runnable = new Runnable()
{
#Override
public void run()
{
new GridBagLayoutExample().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
}
Here is the OUTPUT of the same :
this is my first question on here, so please forgive me when i am breaking any rules, or not using the right format
I am creating a simple form in java swing which consists of 1 JLabel, 1 JTextField, and 1 Button
|---------------------------|
| |
| JLabel |
| |
|---------------------------|
| JTextField | Button |
|---------------------------|
The Button should be in the bottom-right corner, the JTextField left of it, the JLabel on the top, spanning both columns
I want the Button to be a fixed size, the JTextField a fixed height, but using the full width (except for what is in use by the Button), and the JLabel using all other space (with and height)
I am not even sure if i should use a GridBagLayout or another Layout ?
This is probably a very easy question, but got me puzzled for quite some time (too many options with the GridBarLayout i guess)
First, set the layout of your panel to GridBagLayout.
Then, create a GridBagConstraints object and set the fill to GridBagConstraints.BOTH.
For the JLabel, set the following properties on the constraints object: gridx = 0, gridy = 0, gridwidth = 2, gridheight = 2, weightx = 1, weighty = 1.
For the JTextField, set the following properties on the constraints object: gridx = 0, gridy = 1, gridwidth = 1, gridheight = 1, weightx = 1, weighty = 0.
For the JButton, set the following properties on the constraints object: gridx = 1, gridy = 1, gridwidth = 1, gridheight = 1, weightx = 0, weighty = 0.
Class BorderLayout is easy to use, less powerful than GridBagLayout.
But when thing are simple, solution have to be the same.
panel.add( label, BorderLayout.CENTER );
JPanel south = new JPanel();
south.add( textfield );
south.add( button );
button.setPreferredSize( x, y );
panel.add( south, BorderLayout.SOUTH );
OK here is a demo code that should get you going:
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class TestGridBagLayout {
protected void initUI() {
JFrame frame = new JFrame(TestGridBagLayout.class.getSimpleName());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("A button");
JTextField textField = new JTextField();
JLabel label = new JLabel("A cool long nice label that will stretch.");
label.setHorizontalAlignment(JLabel.CENTER);
label.setBorder(BorderFactory.createLineBorder(Color.GREEN));
JPanel panel = new JPanel(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.fill = GridBagConstraints.BOTH;// Fill the "cell" in both direction
gbc.weightx = 1.0;// Allocate extra-width to the label
gbc.weighty = 1.0;// Allocate extra-height to the label
gbc.gridwidth = GridBagConstraints.REMAINDER;// The label takes all the available width of the "row"
panel.add(label, gbc);
gbc.weighty = 0; // Don't stretch TF vertically
gbc.fill = GridBagConstraints.HORIZONTAL; // Fill horizontally
gbc.gridwidth = GridBagConstraints.RELATIVE;
panel.add(textField, gbc);
gbc.weightx = 0; // No extra horizontal space is given to the button
gbc.fill = GridBagConstraints.NONE; // No fill for the button
panel.add(button, gbc);
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new TestGridBagLayout().initUI();
}
});
}
}
I don't know this is a common thing to do, but below is code which is working (mainly code from Dan and Guillaume)
//show stuff
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
//show label
c.fill = GridBagConstraints.BOTH; // Fill the "cell" in both direction
c.weightx = 1.0; // Allocate extra-width to the label
c.weighty = 1.0; // Allocate extra-height to the label
c.gridwidth = GridBagConstraints.REMAINDER; // The label takes all the available width of the "row"
add(mlblShow,c);
//show cmd txt
c.weighty = 0; // Don't stretch TF vertically
c.fill = GridBagConstraints.BOTH; // Fill horizontally and vertically
c.gridwidth = GridBagConstraints.RELATIVE;
add(mtxtCmd,c);
//show send button
c.weightx = 0; // No extra horizontal space is given to the button
c.fill = GridBagConstraints.NONE; // No fill for the button
add(cmdSend,c);