Develop Reference

The component doesn't display correctly with GridBagLayout

I'm learning java swing and this is very confused to me. The quit button doesn't display. However, if I move the code part of textArea after the two parts of buttons, it will display correctly. So why?
package exercise1;
import javax.swing.*;
import java.awt.*;
public class ChatClient {
private JTextArea textArea;
private JTextField textField;
private JButton btnSend;
private JButton btnQuit;
private JFrame frame;
private JPanel panel;
private JScrollPane scrollPane;
private void launchFrame() {
panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
textArea = new JTextArea(10, 50);
scrollPane = new JScrollPane(textArea);
c.gridx = 0;
c.gridy = 0;
c.gridheight = 3;
panel.add(scrollPane, c);
btnSend = new JButton("Send");
c.gridx = 1;
c.gridy = 0;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnSend, c);
btnQuit = new JButton("Quit");
c.gridx = 1;
c.gridy = 1;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnQuit, c);
}
protected ChatClient() {
frame = new JFrame("Chat Room");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
launchFrame();
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
ChatClient client = new ChatClient();
}
}

Simple: You forgot to reset c.gridheight = 1; after adding the JScrollPane. Without doing this, the send button will overlie the quit button.
private void launchFrame() {
panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL; // ** This is also worthwhile **
textArea = new JTextArea(10, 50);
scrollPane = new JScrollPane(textArea);
c.gridx = 0;
c.gridy = 0;
c.gridheight = 3;
panel.add(scrollPane, c);
btnSend = new JButton("Send");
c.gridx = 1;
c.gridy = 0;
c.gridheight = 1; // ********* ADD THIS *********
c.anchor = GridBagConstraints.NORTH;
panel.add(btnSend, c);
btnQuit = new JButton("Quit");
c.gridx = 1;
c.gridy = 1;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnQuit, c);
}

Getting rid of extra spaces between components when the JFrame is resized

I am using the GridBagLayout to arrange some components in a frame.
When the frame is first created, the components have a decent space in between them.
But as soon as I resize the frame there are alot of unwanted space between the components
I tried adjusting the weights and insets as suggested by some users, but it does not seem to fix the problem
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JTextArea;
public class Frame1 extends JFrame {
JLabel one = new JLabel("one");
JLabel two = new JLabel("two");
JLabel three = new JLabel("three");
JTextField oneF = new JTextField(20);
JTextField twoF = new JTextField(20);
JTextField threeF = new JTextField(20);
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("menu");
GridBagConstraints c = new GridBagConstraints();
public Frame1() {
setTitle("GridBagLayout Test");
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLayout(new GridBagLayout());
menuBar.add(menu);
c.gridx = 0;
c.gridy = 0;
c.gridwidth = c.REMAINDER;
c.fill = c.HORIZONTAL;
c.gridheight = 1;
c.weightx = 1;
c.weighty = 1;
c.anchor = c.NORTH;
c.insets = new Insets(5,5,5,5);
add(menuBar, c);
c.gridx = 0;
c.gridy = 1;
c.gridwidth = 1;
c.fill = c.NONE;
c.gridheight = 1;
c.weightx = 1;
c.weighty = 1;
c.anchor = c.NORTH;
c.insets = new Insets(5,5,5,5);
add(one, c);
c.gridx = 1;
c.gridy = 1;
c.gridwidth = 1;
c.fill = c.NONE;
c.gridheight = 1;
c.weightx = 1;
c.weighty = 1;
c.anchor = c.NORTH;
c.insets = new Insets(5,5,5,5);
add(oneF, c);
c.gridx = 0;
c.gridy = 2;
c.gridwidth = 1;
c.fill = c.NONE;
c.gridheight = 1;
c.weightx = 1;
c.weighty = 1;
c.anchor = c.NORTH;
c.insets = new Insets(5,5,5,5);
add(two, c);
c.gridx = 1;
c.gridy = 2;
c.gridwidth = 1;
c.fill = c.NONE;
c.gridheight = 1;
c.weightx = 1;
c.weighty = 1;
c.anchor = c.NORTH;
c.insets = new Insets(5,5,5,5);
add(twoF, c);
c.gridx = 0;
c.gridy = 3;
c.gridwidth = 1;
c.fill = c.NONE;
c.gridheight = 1;
c.weightx = 1;
c.weighty = 1;
c.anchor = c.NORTH;
c.insets = new Insets(5,5,5,5);
add(three, c);
c.gridx = 1;
c.gridy = 3;
c.gridwidth = 1;
c.fill = c.NONE;
c.gridheight = 1;
c.weightx = 1;
c.weighty = 1;
c.anchor = c.NORTH;
c.insets = new Insets(5,5,5,5);
add(threeF, c);
//setResizable(false);
pack();
setVisible(true);
}
}
ps:- I am new to GUI programming, so please forgive me for any noob mistakes.
edit 1: This is the what I want to have after I am done. I know the currently it does not look anyway near what I have in mind... I am still working on it
Thanks

use an nested layout (combinations of a few LayoutManagers), your picture talks me about,
still you can use GridBagLayout for components placed into left side,
in my code (simplest idea as is possible) JComponents placed on left side can't be resizable because are restricted from LayoutManager`s defaults, more in Oracle tutorial
.
.
painted from SSCCE/MCVE
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MyFrame {
private static final long serialVersionUID = 1L;
private JFrame myFrame = new JFrame("Whatever");
private JPanel parentPanel = new JPanel(new BorderLayout(10, 10)) {
private static final long serialVersionUID = 1L;
#Override
public Dimension getPreferredSize() {
return new Dimension(600, 400);
}
#Override
public Color getBackground() {
return new Color(255, 000, 000);
}
};
private JPanel leftPanel = new JPanel(/*default is FlowLayout*/) {
private static final long serialVersionUID = 1L;
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 400);
}
#Override
public Color getBackground() {
return new Color(255, 255, 000);
}
};
private JPanel leftChildPanel = new JPanel() {
private static final long serialVersionUID = 1L;
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 400);
}
#Override
public Color getBackground() {
return new Color(255, 255, 225);
}
};
private JPanel rightPanel = new JPanel(new BorderLayout(10, 10)) {
private static final long serialVersionUID = 1L;
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 380);
}
#Override
public Color getBackground() {
return new Color(000, 255, 225);
}
};
public MyFrame() {
parentPanel.add(leftPanel, BorderLayout.WEST);
leftPanel.add(leftChildPanel);
parentPanel.add(rightPanel);
myFrame.add(parentPanel);
myFrame.setLocation(150, 150);
myFrame.pack();
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myFrame.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
new MyFrame();
});
}
}

The idea is to add empty row / columns that will grow to fill the available space:
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JTextField;
public class Frame1 extends JFrame {
JLabel one = new JLabel("one");
JLabel two = new JLabel("two");
JLabel three = new JLabel("three");
JTextField oneF = new JTextField(20);
JTextField twoF = new JTextField(20);
JTextField threeF = new JTextField(20);
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("menu");
public Frame1() {
setTitle("GridBagLayout Test");
setDefaultCloseOperation(EXIT_ON_CLOSE);
GridBagLayout gridBagLayout = new GridBagLayout();
gridBagLayout.rowHeights = new int[]{0, 0, 0, 0}; //this defines 4 rows
//make 2 last empty row grow
gridBagLayout.rowWeights = new double[]{0.0, 0.0, 1.0,1.0};
//do the same for columns
gridBagLayout.columnWidths = new int[]{0, 0, 0, 0};
gridBagLayout.columnWeights = new double[]{0.0, 0.0, 1.0,1.0};
getContentPane().setLayout(gridBagLayout);
menuBar.add(menu);
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
c.gridwidth = 5;
c.fill = c.HORIZONTAL;
c.anchor = c.NORTH;
c.insets = new Insets(5, 5, 5, 0);
getContentPane().add(menuBar, c);
//better have a new GridBagConstraints for each component added
GridBagConstraints c1 = new GridBagConstraints();
c1.gridx = 0;
c1.gridy = 1;
c1.gridwidth = 1;
c1.fill = c1.NONE;
c1.anchor = c1.NORTH;
c1.insets = new Insets(5, 5, 0, 5);
getContentPane().add(one, c1);
GridBagConstraints c2 = new GridBagConstraints();
c2.gridx = 1;
c2.gridy = 1;
c2.fill = c2.NONE;
c2.anchor = GridBagConstraints.NORTHWEST;
c2.insets = new Insets(5, 5, 0, 5);
getContentPane().add(oneF, c2);
pack();
setVisible(true);
}
public static void main(String[] args) {
new Frame1();
}
}
EDIT: in response to your edit: use the additional "growing" column for the "cover art"

The problem is your assignments of c.weightx and c.weighty. weightx and weighty determine how extra space is allocated to grid cells in a GridBagLayout when the container is made larger than necessary to accommodate the preferred sizes of the components.
The weightx and weighty should be zero for all cells except those cells which you want to grow larger when the window is made larger.

I have no real idea on how it is supposed to look like, but you could try to set for the labels c.anchor=GridBagConstraints.EAST and c.anchor=GridBagConstraints.WEST for the textfields.
Try also setting c.fill = GridBadConstraints.BOTH.

Is it possible to build the same GridBagLayout interface but without using extra JPanel as a container?

I am using GridBagLayout to design the interface. The interface has one JTabbedPane set at north and fill both directions as I resize, and just below the JTabbedPane there are two JButtons.
What I want to achieve is putting these two buttons at east with using only GridBagLayout capabilities (without introducing an extra JPanel), but I failed to do so.
|-[tab]--------------------------|
|---------------------------------|
|---------------------------------|
|---------------------------------|
|---------------------------------|
|-------------[button][button]|
When I set the layout constraint for both buttons to WEST (not EAST). Both go west correctly!
c.anchor = GridBagConstraints.WEST;
But when I set the layout constraint for both buttons to east
c.anchor = GridBagConstraints.EAST;
One of them go to east and the other go to west!
To solve this issue I added a JPanel which hold both buttons and added this JPanel into the interface, and set its layout constraint to c.anchor = GridBagConstraints.EAST;. It works well.
But is it possible to build the same GridBagLayout interface without using an extra JPanel as a container?
The following two classes are in SSCCE format; the first one show the problem GridBagTest, and the other show the solution GridBagTest_solved that make use of extra JPanel
Problem class:
import javax.swing.*;
import java.awt.*;
public class GridBagTest extends JPanel {
JFrame frame;
JTabbedPane tabbedPane;
JPanel panel_tab;
JButton btn_previous;
JButton btn_next;
private void create_and_layout() {
this.setLayout(new GridBagLayout());
tabbedPane = new JTabbedPane() {
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 150);
}
};
panel_tab = new JPanel();
tabbedPane.addTab("Tab 1", panel_tab);
btn_previous = new JButton("previous");
btn_next = new JButton(" next ");
GridBagConstraints c;
c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
c.weightx = 1;
c.gridwidth = 2;
c.weighty = 1;
c.fill = GridBagConstraints.BOTH;
c.anchor = GridBagConstraints.NORTH;
this.add(tabbedPane, c);
c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 1;
c.anchor = GridBagConstraints.EAST;
c.insets = new Insets(2, 0, 2, 2);
this.add(btn_previous, c);
c = new GridBagConstraints();
c.gridx = 1;
c.gridy = 1;
c.anchor = GridBagConstraints.EAST;
c.insets = new Insets(2, 0, 2, 2);
this.add(btn_next, c);
}
private void initGUI() {
create_and_layout();
frame = new JFrame("GridBagTest");
frame.getContentPane().add(this);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new GridBagTest()::initGUI);
}
}
Solution class:
import javax.swing.*;
import java.awt.*;
public class GridBagTest_solved extends JPanel {
JFrame frame;
JTabbedPane tabbedPane;
JPanel panel_tab;
JPanel panel_buttons;
JButton btn_previous;
JButton btn_next;
private void create_and_layout() {
this.setLayout(new GridBagLayout());
tabbedPane = new JTabbedPane() {
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 150);
}
};
panel_tab = new JPanel();
tabbedPane.addTab("Tab 1", panel_tab);
panel_buttons = new JPanel(new GridBagLayout());
btn_previous = new JButton("previous");
btn_next = new JButton(" next ");
GridBagConstraints c;
// Adding buttons to panel_buttons
c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
c.insets = new Insets(2, 0, 2, 2);
panel_buttons.add(btn_previous, c);
c = new GridBagConstraints();
c.gridx = 1;
c.gridy = 0;
c.insets = new Insets(2, 0, 2, 2);
panel_buttons.add(btn_next, c);
// Adding tabbedPane & panel_buttons to this (GridBagTest_solved)
c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
c.weightx = 1;
c.weighty = 1;
c.fill = GridBagConstraints.BOTH;
c.anchor = GridBagConstraints.NORTH;
this.add(tabbedPane, c);
c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 1;
c.anchor = GridBagConstraints.EAST;
this.add(panel_buttons, c);
}
private void initGUI() {
create_and_layout();
frame = new JFrame("GridBagTest_solved");
frame.getContentPane().add(this);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new GridBagTest_solved()::initGUI);
}
}

If you only have the three components - the JTabbedPane and two JButtons, you should consider using a simpler layout than GridBag. Just use a BorderLayout for the main panel, placing the JTabbedPane in CENTER, and a JPanel in SOUTH that has a FlowLayout with alignment of TRAILING, then just add the two buttons to that JPanel.

How do I align components in a JPanel to the left?

I have created a layout for a basic text editor, I would like the top bar to have the buttons alligned to the left, the top bar is a JPanel and it is using the FlowLayout manager. It is inside of a grid using the GridBag layout manager. Any suggestions?
import java.awt.*;
import javax.swing.*;
public class GridTest {
private static JButton firstButton, secondButton, thirdButton;
private static JPanel panel, sidebar, infoPanel;
private static JTextArea textArea;
public static void addComponentsToPane(Container container) {
container.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
firstButton = new JButton("Button 1");
secondButton = new JButton("Button 2");
thirdButton = new JButton("Button 3");
panel = new JPanel(new FlowLayout());
sidebar = new JPanel(new FlowLayout());
infoPanel = new JPanel(new FlowLayout());
textArea = new JTextArea("This is some generic text!");
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 0;
c.weighty = 0;
c.weightx = 1;
c.gridx = 0;
c.gridwidth = 3;
c.gridy = 0;
c.anchor = GridBagConstraints.LINE_START;
container.add(panel, c);
panel.setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
panel.setBorder(BorderFactory.createLineBorder(Color.black));
panel.add(firstButton);
panel.add(secondButton);
panel.add(thirdButton);
c.fill = GridBagConstraints.BOTH;
c.ipady = 300;
c.ipadx = 100;
c.weighty = 1;
c.weightx = 0;
c.gridx = 0;
c.gridheight = 2;
c.gridwidth = 1;
c.gridy = 1;
container.add(sidebar, c);
sidebar.setBorder(BorderFactory.createLineBorder(Color.black));
c.fill = GridBagConstraints.BOTH;
c.ipady = 40;
c.weightx = 1;
c.weighty = 1;
c.gridwidth = 2;
c.gridheight = 1;
c.gridx = 1;
c.gridy = 1;
container.add(textArea, c);
textArea.setFont(new Font("Serif", Font.ITALIC, 16));
textArea.setLineWrap(true);
textArea.setWrapStyleWord(true);
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 20;
c.weighty = 0;
c.weightx = 0;
c.anchor = GridBagConstraints.PAGE_END;
c.gridx = 1;
c.gridwidth = 2;
c.gridy = 2;
container.add(infoPanel, c);
infoPanel.setBorder(BorderFactory.createLineBorder(Color.black));
}
private static void createAndShowGUI() {
JFrame frame = new JFrame("Grid test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
addComponentsToPane(frame.getContentPane());
frame.setSize(800,600);
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}

Consider using a JToolBar instead of a JPanel, as it has it's own layout manager, which, basically, does this any way.
Images from following tutorial...
Check out How to use Tool Bars for more details

One way: Change your FlowLayout to one that prefers to place its components on the left:
panel = new JPanel(new FlowLayout(FlowLayout.LEADING));

How to put a background image on GridBagLayout

I am trying to work with layout managers for the first time, and they are just kicking me in the teeth. I am trying to make a background image and then put buttons on top, using GridBagLayout, if there is a a better layoutmanager please do tell. As for trying to learn how to use layout managers, its very difficult and any learning references would also be much appreciated.
This is what it looks like currently,
I can get the frame to show the full image, but when i use gridlayout manager, it does that
public void addComponentsToPane(Container pane){
BackgroundImage image = new BackgroundImage();
JButton button1, button2, button3, button4, button5;
pane.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
if(shouldFill){
c.fill = GridBagConstraints.NONE;
}
button1 = new JButton("Button 1");
if (shouldWeightX) {
c.weightx = 0.5;
}
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 1;
c.gridy = 0;
button1.setOpaque(false);
pane.add(button1, c);
button2 = new JButton("Button 2");
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 0.5;
c.gridx = 0;
c.gridy = 0;
button2.setOpaque(false);
pane.add(button2, c);
button3 = new JButton("Button 3");
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 0.5;
c.gridx = 2;
c.gridy = 0;
button3.setOpaque(false);
pane.add(button3, c);
button4 = new JButton("Long-Named Button 4");
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 40; //make this component tall
c.weightx = 0.0;
c.gridwidth = 3;
c.gridx = 0;
c.gridy = 1;
pane.add(button4, c);
button5 = new JButton("button 1");
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 0; //reset to default
c.weighty = 1.0; //request any extra vertical space
c.anchor = GridBagConstraints.PAGE_END; //bottom of space
c.insets = new Insets(10,0,0,0); //top padding
c.gridx = 1; //aligned with button 2
c.gridwidth = 2; //2 columns wide
c.gridy = 2; //third row
pane.add(button5, c);
c.ipadx = 800;
c.ipady = 400;
pane.add(image, c);
}
This is what i'm trying to make it look like

Here is one way to do it: using a JLabel as a container with an image (it's a bit unusual but actually works pretty well):
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.net.MalformedURLException;
import java.net.URL;
import javax.swing.Box;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class TestBackgroundImage {
private static final String BACKHGROUND_IMAGE_URL = "http://www.okyn.org/wp-content/uploads/2013/04/League_of_Legends.jpeg";
protected void initUI() throws MalformedURLException {
JFrame frame = new JFrame(TestBackgroundImage.class.getSimpleName());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final ImageIcon backgroundImage = new ImageIcon(new URL(BACKHGROUND_IMAGE_URL));
JLabel mainPanel = new JLabel(backgroundImage) {
#Override
public Dimension getPreferredSize() {
Dimension size = super.getPreferredSize();
Dimension lmPrefSize = getLayout().preferredLayoutSize(this);
size.width = Math.max(size.width, lmPrefSize.width);
size.height = Math.max(size.height, lmPrefSize.height);
return size;
}
};
mainPanel.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(10, 10, 10, 10);
gbc.weightx = 1.0;
gbc.anchor = GridBagConstraints.WEST;
gbc.gridwidth = GridBagConstraints.REMAINDER;
for (int i = 0; i < 5; i++) {
mainPanel.add(new JButton("Button " + (i + 1)), gbc);
}
// Let's put a filler bottom component that will push the rest to the top
gbc.weighty = 1.0;
mainPanel.add(Box.createGlue(), gbc);
frame.add(mainPanel);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
try {
new TestBackgroundImage().initUI();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
}
And the result:
GridBagLayout is unable to handle layering of components (so if you have overlapping gridx/gridy pairs, it won't handle it as layering, I would think that the output is pretty much undetermined.
Try to avoid using gridx/gridy as it make a code hard to maintain. Playing with relative values on gridwidth/gridheight is much easier to maintain.

Check out the Background Panel for a couple of solutions depending on your requirement:
Use a JLabel for painting the image at its actual size.
Use the BackgroundPanel to allow for scaling of the background image.