I've been having trouble with my Java Swing GUI. First of all, I created a panel with the GridBagLayout on it and added all my labels to it. However, I also created a panel to the right of the other JPanel that adds in a button and 2 sliders which are suppose to like match with the labels.
The problem is that the JLabels are smaller than the components from the right of the other panel which, makes it look like this....
ex. water option -- JSLIDER (the jslider looks a lot bigger)
I tried to make the components larger by adding ipadx to a bigger value and also I've tried to set the grid width for the labels panel bigger, but nothing seems to work. It just doesn't respond.
Here is the code:
package gui;
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.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
public class Options extends JFrame{
//water option (button changes text on or off)
//make a button listener
JSlider renderDistance;
JSlider grassDensity;
JButton waterToggleButton;
JLabel rdTitle;
JLabel gdTitle;
JLabel wtTitle;
JButton buttonClose;
static final int RD_MIN_VALUE = 0;
static final int RD_MAX_VALUE = 1000;
static final int RD_INIT_VALUE = 500;
static final int GD_MIN_VALUE = 0;
static final int GD_MAX_VALUE = 1000;
static final int GD_INIT_VALUE = 500;
public Options() {
this.setTitle("Settings");
this.setSize(getMaximumSize());
this.setLocationRelativeTo(null);
createView();
this.setVisible(true);
}
private void createView() {
//Making panels and adding them to window*
JPanel pOptions = new JPanel();
this.add(pOptions);
//These are for the labels that I added so people know which option they are using
JPanel pOptionLabels = new JPanel(new GridBagLayout());
pOptions.add(pOptionLabels);
//These are for the middle columns, the objects like button and slider
JPanel pOptionObjects = new JPanel(new GridBagLayout());
pOptions.add(pOptionObjects);
//Making panels and adding them to window*
//Initializing Objects*
GridBagConstraints gbcLabels = new GridBagConstraints();
GridBagConstraints gbcObjects = new GridBagConstraints();
renderDistance = new JSlider(RD_MIN_VALUE, RD_MAX_VALUE, RD_INIT_VALUE);
grassDensity = new JSlider(GD_MIN_VALUE, GD_MAX_VALUE, GD_INIT_VALUE);
waterToggleButton = new JButton("On");
rdTitle = new JLabel("Render Distance");
gdTitle = new JLabel("Grass Density");
wtTitle = new JLabel("Water Terrain Visibility");
//Initializing Objects*
//Giving objects some attributes using methods*
renderDistance.setMinorTickSpacing(100);
renderDistance.setMajorTickSpacing(500);
renderDistance.setPaintTicks(true);
renderDistance.setPaintLabels(true);
grassDensity.setMinorTickSpacing(100);
grassDensity.setMajorTickSpacing(500);
grassDensity.setPaintTicks(true);
grassDensity.setPaintLabels(true);
gbcLabels.gridx = 0;
gbcLabels.gridy = 0;
gbcLabels.anchor = GridBagConstraints.LINE_START;
gbcObjects.gridx = 0;
gbcObjects.gridy = 0;
waterToggleButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(waterToggleButton.getText().equals("Off")) {
waterToggleButton.setText("On");
}else {
waterToggleButton.setText("Off");
}
}
});
//Giving objects some attributes using methods*
//Add things to panel ex. p.add();
pOptionLabels.add(rdTitle, gbcLabels);
gbcLabels.gridy++;
pOptionLabels.add(gdTitle, gbcLabels);
gbcLabels.gridy++;
pOptionLabels.add(wtTitle, gbcLabels);
gbcObjects.gridx++;
pOptionObjects.add(renderDistance, gbcObjects);
gbcObjects.gridy++;
pOptionObjects.add(grassDensity, gbcObjects);
gbcObjects.gridy++;
pOptionObjects.add(waterToggleButton, gbcObjects);
}
public static void main(String[] args) {
new Options();
}
}
Change the way you are thinking. Instead of trying to layout all the labels and all the "other" components in separate containers, consider putting them all in the same container.
This way, when they are laid out, the layout calculations are made in relationship to all the components in a single context.
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.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
public class Options extends JFrame {
//water option (button changes text on or off)
//make a button listener
JSlider renderDistance;
JSlider grassDensity;
JButton waterToggleButton;
JLabel rdTitle;
JLabel gdTitle;
JLabel wtTitle;
JButton buttonClose;
static final int RD_MIN_VALUE = 0;
static final int RD_MAX_VALUE = 1000;
static final int RD_INIT_VALUE = 500;
static final int GD_MIN_VALUE = 0;
static final int GD_MAX_VALUE = 1000;
static final int GD_INIT_VALUE = 500;
public Options() {
this.setTitle("Settings");
createView();
pack();
this.setLocationRelativeTo(null);
this.setVisible(true);
}
private void createView() {
//Making panels and adding them to window*
JPanel pOptions = new JPanel();
this.add(pOptions);
//These are for the labels that I added so people know which option they are using
JPanel pOptionLabels = new JPanel(new GridBagLayout());
pOptions.add(pOptionLabels);
GridBagConstraints gbc = new GridBagConstraints();
renderDistance = new JSlider(RD_MIN_VALUE, RD_MAX_VALUE, RD_INIT_VALUE);
grassDensity = new JSlider(GD_MIN_VALUE, GD_MAX_VALUE, GD_INIT_VALUE);
waterToggleButton = new JButton("On");
rdTitle = new JLabel("Render Distance");
gdTitle = new JLabel("Grass Density");
wtTitle = new JLabel("Water Terrain Visibility");
//Initializing Objects*
//Giving objects some attributes using methods*
renderDistance.setMinorTickSpacing(100);
renderDistance.setMajorTickSpacing(500);
renderDistance.setPaintTicks(true);
renderDistance.setPaintLabels(true);
grassDensity.setMinorTickSpacing(100);
grassDensity.setMajorTickSpacing(500);
grassDensity.setPaintTicks(true);
grassDensity.setPaintLabels(true);
gbc.gridx = 0;
gbc.gridy = 0;
gbc.anchor = GridBagConstraints.LINE_START;
gbc.insets = new Insets(2, 2, 2, 2);
waterToggleButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (waterToggleButton.getText().equals("Off")) {
waterToggleButton.setText("On");
} else {
waterToggleButton.setText("Off");
}
}
});
//Giving objects some attributes using methods*
//Add things to panel ex. p.add();
pOptionLabels.add(rdTitle, gbc);
gbc.gridy++;
pOptionLabels.add(gdTitle, gbc);
gbc.gridy++;
pOptionLabels.add(wtTitle, gbc);
gbc.gridx++;
gbc.gridy = 0;
pOptionLabels.add(renderDistance, gbc);
gbc.gridy++;
pOptionLabels.add(grassDensity, gbc);
gbc.gridy++;
pOptionLabels.add(waterToggleButton, gbc);
}
public static void main(String[] args) {
new Options();
}
}
What you are experiencing is technically correct since you have two JPanels with two separate instances of the GridBagLayout manager so the rows (and columns) in one layout manager have no information about the rows in the other.
A single GridBagLayout is the way to go if you plan to use JComponents inside them and create a table like appearance. You can later add others JPanels (with different layout managers or with more GridBagLayouts!) but INSIDE your main GridBagLayout JPanel.
GridBagLayout is a really powerful layout, I would recommend sticking with is and master it since it will help you layout things nicely (and fast) in the long run.
This is a great resource to learn more about the GridBagLayout:
https://docs.oracle.com/javase/tutorial/uiswing/layout/gridbag.html
One small comment: IMO the GridBagLayout is not the best layout manager to use as the "root" layout container. I would instead recommend creating a "root" JPanel with a BorderLayout() and add your GridBagLayout JPanel to the center of the BorderLayout panel add(yourGridPanel, BorderLayout.CENTER) since the BorderLayout usually gives for free the ability for things to fill horizontally/vertically and will let you pack your window nicely at the center (with the possibility of adding more things later to the NORTH/SOUTH/EAST/WEST sides).
Good luck!
Related
I'm creating a gui with java swing who is supposed to be implemented on an LCD touch screen. The gui will take all the screen and is not supposed to be closable. So "setUndecorated(true)" is essential.
Problem, when I'm using it, all the content of the frame is not displaying, only the buttons appears when I'm moving my mouse over them. Then all the content appears when I maximise and minimise the frame.
Here is the code I'm using :
public static void main(String[] args) {
//Création de notre JFrame
fenetre = new JFrame();
fenetre.setTitle("IHM");
fenetre.setSize(800, 600);
fenetre.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
fenetre.setLocationRelativeTo(null);
support = new JPanel();
///////Adding content to the JPanel()/////////////
fenetre.setContentPane(support);
fenetre.setUndecorated(true);
fenetre.setVisible(true);
}
The only solution I've find so far is to change the size of the frame after set the frame visible like so :
fenetre.setSize(801, 601);
fenetre.setSize(800, 600);
But I'm not really correcting the problem, just getting around it.
(EDIT)
My appologies for that uncomplete code.
Here is a complete exemple that you can test yourself.
First test it with undecorated to false, then try with undecorated to true and visualise the content of the window by maximising and minimising the gui.
Finally, try it with the Quick fix in the bottom of the code.
the code :
package test;
import java.awt.Color;
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.JPanel;
public class test {
//Declarations
private static JFrame fenetre;
private static JPanel support;
private static JLabel l1, l2;
private static JComboBox<String> c1, c2;
private static JButton b1, b2;
//List to initiate the comboBoxes
private static String[] listC1 = {"Peter", "Alex", "Jhon", "Bran"};
private static String[] listC2 = {"10", "20", "32", "45"};
public static void main(String[] args) {
//Initialisation of the JFrame
fenetre = new JFrame();
fenetre.setTitle("IHM");
fenetre.setSize(800, 600);
fenetre.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
fenetre.setLocationRelativeTo(null);
//Initialisation of the JPanel
support = new JPanel();
support.setBackground(Color.red);
support.setPreferredSize(fenetre.getSize());
//Initialisation of the components
l1 = new JLabel("What's my name");
l2 = new JLabel("What's my age");
c1 = new JComboBox<String>(listC1);
c2 = new JComboBox<String>(listC2);
b1 = new JButton("validate name");
b2 = new JButton("validate age");
//Creating layout
support.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
//Adding components
gbc.fill = GridBagConstraints.BOTH;
gbc.insets = new Insets(20, 20, 0, 0);
gbc.gridx = 0;
gbc.gridy = 0;
support.add(l1, gbc);
gbc.gridy = 1;
support.add(c1, gbc);
gbc.insets = new Insets(20, 20, 20, 0);
gbc.gridy = 2;
support.add(b1, gbc);
gbc.insets = new Insets(20, 20, 0, 20);
gbc.gridx = 1;
gbc.gridy = 0;
support.add(l2, gbc);
gbc.gridy = 1;
support.add(c2, gbc);
gbc.insets = new Insets(20, 20, 20, 20);
gbc.gridy = 2;
support.add(b2, gbc);
//Adding Listeners
b1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("My name is " + c1.getSelectedItem());
}
});
b2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("My age is " + c2.getSelectedItem());
}
});
//Adding the JPanel to the content pane of the JFrame
fenetre.setContentPane(support);
//Setting undecorated true (switch between true and false for testing)
fenetre.setUndecorated(false);
fenetre.setVisible(true);
//Quick fix, uncomment to test
//fenetre.setSize(801, 601);
//fenetre.setSize(800, 600);
}
}
You don't add any buttons to your JPanel so how do you expect it to display them?
Either way, here's a simple example of displaying a button:
JFrame fenetre = new JFrame();
fenetre.setTitle("IHM");
fenetre.setExtendedState(JFrame.MAXIMIZED_BOTH);
fenetre.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
fenetre.setLocationRelativeTo(null);
JPanel support = new JPanel();
JButton button = new JButton("button");
support.add(button);
fenetre.setContentPane(support);
fenetre.setVisible(true);
Note that you should use a proper layout.
I also added setExtendedState(JFrame.MAXIMIZED_BOTH) to fill the screen, and setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE) as you didn't want the screen to be closable.
Problem, when I'm using it, all the content of the frame is not displaying, only the buttons appears when I'm moving my mouse over them.
Components should be added to the panel/frame BEFORE the frame is made visible.
If you add components to a visible frame, then the basic logic is:
panel.add(...);
panel.revalidate(); // to invoke the layout manager
panel.repaint(); // make sure panel is repainted
I have a Java Swing GUI that consists of some JScrollPanes containing JTextAreas that get filled with data so that the scrollbars appear. Once the scrollbars appear, when I move the window to my second monitor, the JScrollPane gets very small so that I can no longer see the text it contains.
Example:
Here is the window on my main monitor with the JScrollPane filled with text:
Here is the window after I filled it with text and moved it to the second monitor:
Here is a small example program that demonstrates the problem:
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
public class Main extends JFrame {
public Main() {
Test theGui = new Test();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setResizable(true);
add(theGui);
pack();
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new Main();
}
});
}
}
class Test extends JPanel {
private static final int PADDING = 3;
private JLabel label;
private JTextArea textarea;
private JScrollPane scrollpane;
private GridBagConstraints gbc;
public Test() {
super(new GridBagLayout());
label = new JLabel("Fill this text box with text so the scrollbars appear, then move the window to 2nd monitor:");
textarea = new JTextArea(10, 40);
scrollpane = new JScrollPane(textarea);
gbc = new GridBagConstraints();
gbc.gridheight = 1;
gbc.insets = new Insets(PADDING, PADDING, PADDING, PADDING);
gbc.anchor = GridBagConstraints.LINE_START;
gbc.fill = GridBagConstraints.BOTH;
gbc.gridwidth = 4;
gbc.gridx = 0;
gbc.gridy = 0;
add(label, gbc);
gbc.gridx = 0;
gbc.gridy = 1;
add(scrollpane, gbc);
}
}
Note that the JScrollPane only gets very small when moving to the other monitor when it is filled with text. If there is no text in it, it seems to stay the right size.
My question is, how can I prevent the JScrollPane from getting very small when I move the window to my second monitor?
GridBagLayout will revert to the components minimumSize property when the available space for the component is less then the components preferredSize.
You can override this by using the GridBagConstraints, weightx/weighty properties, for example.
gbc.gridx = 0;
gbc.gridy = 1;
gbc.weightx = 1;
gbc.weighty = 1;
add(scrollpane, gbc);
How do I use setRows and setColumns to change the amount of rows and columns in my window?
Here's a copy of my code and where I tried to implement the set rows and columns:
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Toolkit;
import java.awt.*;
#SuppressWarnings("unused")
public class GUI
{
public static void main(String[] args)
{
new GUI();
}
public GUI()
{
JFrame AG = new JFrame("Adventure Game");
AG.setExtendedState(JFrame.MAXIMIZED_BOTH);
AG.setResizable(true);
AG.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel p=new JPanel();
p.setLayout (new GridBagLayout());
AG.add(p);
GridBagConstraints GBC = new GridBagConstraints();
GridLayout.setRows(100);//heres the set rows<<<<<<<<<<<<<<<<<<<
GridLayout.setColumns(100);//heres the set columns<<<<<<<<<<<<<<<<<<<
AG.getContentPane().add(p, BorderLayout.NORTH);
JButton saveButton =new JButton("Save");
JButton loadButton =new JButton("Load");
JButton optionsButton = new JButton("Options");
JLabel textBox= new JLabel("Story line will go here.");
JLabel label11 = new JLabel("Test 1");
GBC.gridx = 0;
GBC.gridy = 1;
p.add(label11,GBC);
JLabel label12 = new JLabel("Test 2");
GBC.gridx = 0;
GBC.gridy = 2;
p.add(label12,GBC);
JLabel label13 = new JLabel("Test 3");
GBC.gridx = 0;
GBC.gridy = 3;
p.add(label13,GBC);
JLabel label14 = new JLabel("Test 4");
GBC.gridx = 0;
GBC.gridy = 5;
p.add(label14,GBC);
AG.setVisible(true);
}
}
GridBagConstraints work with the GridBagLayout, not the GridLayout. Your call to GridLayout doesn't do anything.
To set the rows and columns with GridBagConstraints, you need to use GBC.gridx = ...; and GBC.gridy = ...;
If you are trying to place gaps between your buttons, empty GridBag cells are not the way to do it; use the insets of your GridBagConstraints for that.
To make a component in a GridBagLayout disappear without the other components shifting around, place the button in a JPanel with a CardLayout, and make sure you add that JPanel to your GridBagLayout instead of the button:
private JButton optionalButton;
private void buildWindow() {
// ...
optionalButton = new JButton("Optional Action");
JPanel optionalButtonPanel = new JPanel(new CardLayout());
optionalButtonPanel.add(optionalButton, "BUTTON");
optionalButtonPanel.add(new JLabel(), "BLANK");
// ...
}
private void setOptionalButtonVisible(boolean visible) {
Container optionalButtonPanel = optionalButton.getParent();
CardLayout layout = (CardLayout) optionalButtonPanel.getLayout();
layout.show(optionalButtonPanel, visible ? "BUTTON" : "BLANK");
}
CardLayout always displays one and only one of its components, but it sizes its associated container to fit all the components, including the invisible ones.
I'm trying to create this basic GUI, but cannot get my panels to setup correctly.(Numbers are pixel sizes)
I've tried using this tutorial as a reference (http://www.youtube.com/watch?v=Kl3klve_rmQ) but, mine never works the same.
My code declares variables in the top of the class, then creates a constructor which add the components (panels, buttons, etc), then it calls the constructor in the main method.
import java.awt.BorderLayout;
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.JPanel;
public class FinalProject extends JPanel
{
private static final long serialVersionUID = 1L;
static JPanel nav;
static JPanel queue;
static JPanel menu;
GridBagConstraints gbc = new GridBagConstraints();
public FinalProject()
{
nav = new JPanel();
nav.setLayout(new GridBagLayout());
nav.setBackground(Color.RED);
gbc.gridy = 0;
gbc.gridx = 0;
gbc.gridheight = 1;
gbc.gridwidth = 1;
add(nav, gbc);
queue = new JPanel();
queue.setLayout(new GridBagLayout());
queue.setBackground(Color.GREEN);
gbc.gridy = 1;
gbc.gridx = 1;
gbc.gridheight = 1;
gbc.gridwidth = 1;
add(queue, gbc);
menu = new JPanel();
menu.setLayout(new GridBagLayout());
menu.setBackground(Color.BLUE);
gbc.gridy = 2;
gbc.gridx = 2;
gbc.gridheight = 1;
gbc.gridwidth = 1;
add(menu, gbc);
}
public static void main(String[] args)
{
FinalProject p = new FinalProject();
JFrame f = new JFrame();
f.add(nav);
f.add(queue);
f.add(menu);
f.setTitle("Subway");
f.setSize(800, 500);
f.setLocationRelativeTo(null);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
f.setResizable(false);
f.add(p);
}
}
How should I go about getting this layout right? Panels in Panels, Panels independent of each other, etc.?
No, don't use a GridBagLayout for this as you'll be adding more complexity than is actually needed. Myself, I try to avoid using this layout and all its potential pitfalls as much as possible, and usually you can get all you need by nesting JPanels, each using its own more simple layout. For instance here, all you need is a BorderLayout:
Place the top JPanel in the BorderLayout.NORTH position
Place the left JPanel in the BorderLayout.WEST position
Place the center JPanel in the BorderLayout.CENTER position.
That's it.
Again, please check out the Swing and the layout manager tutorials as the information is well presented there.
Edit
Note that nothing shows up on your JFrame because you're not adding your JPanel to the JFrame!
Edit 2
For example:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import javax.swing.*;
public class SimpleLayout {
private static final Color GREEN = new Color(200, 255, 200);
private static final Color BLUE = new Color(200, 200, 255);
private static void createAndShowGui() {
JFrame frame = new JFrame("SimpleLayout");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// note that a JFrame's contentPane uses BorderLayout by default
frame.getContentPane().add(new ColorPanel(Color.pink, 800, 80), BorderLayout.NORTH);
frame.getContentPane().add(new ColorPanel(GREEN, 300, 420), BorderLayout.WEST);
frame.getContentPane().add(new ColorPanel(BLUE, 500, 420), BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class ColorPanel extends JPanel {
private static final float FONT_POINTS = 24f;
private int prefW;
private int prefH;
public ColorPanel(Color color, int prefW, int prefH) {
setBackground(color);
this.prefW = prefW;
this.prefH = prefH;
// GBL can be useful for simply centering components
setLayout(new GridBagLayout());
String text = String.format("%d x %d", prefW, prefH);
JLabel label = new JLabel(text, SwingConstants.CENTER);
label.setFont(label.getFont().deriveFont(FONT_POINTS));
label.setForeground(Color.gray);
add(label);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(prefW, prefH);
}
}
This displays as:
GridLayout I've never actually used but I'm not sure if it can do this.
BorderLayout can do this and is simpler to use than GridBagLayout.
GridBagLayout can do this.
In general GridBagLayout is one of the most flexible LayoutManagers and is well worth learning so I'd recommend using it here to get used to it on a simple case before you need it anyway for something more complex.
If you are familiar with HTML then think of GridBagLayout as working like HTML tables.
Very quickly - create the three panels and set the sizes/borders/whatever you need in them.
Add one in cell 0,0 with a colspan of 2.
Add one in cell 1,0
Add one in cell 1,1
After that you are done although you will probably want to specify resize/anchor/etc behaviour.
What I am looking for is a suggestion for the best layout to use for my scenario. I basically have any number of child panels which can be in a container panel that can be dynamically resized by the user. All of the child panels will be 300 pixels in width, and can have a variable height. I would like the panels to be placed into the panel from left-to-right, top-to-bottom, just like the FlowLayout. However, anything I try with the FlowLayout will vertically center the panel with less height. I would instead like the panel to be anchored to the top of the screen.
I have created the following example using the FlowLayout to show what I mean.
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class DynamicPanel extends JPanel {
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame("Test");
frame.add(new DynamicPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
});
}
public DynamicPanel() {
setupGUI();
}
private void setupGUI() {
this.setLayout(new FlowLayout(FlowLayout.LEFT));
this.add(getPanel(1, 4));
this.add(getPanel(2, 2));
}
private JPanel getPanel(int panelNum, int numButtons) {
JPanel panel = new JPanel(new GridBagLayout()) {
#Override
public Dimension getPreferredSize() {
Dimension ret = super.getPreferredSize();
ret.width = 300;
return ret;
}
};
panel.add(new JLabel("Panel "+panelNum), getGrid(0, 0, 1.0, 0));
for(int i = 0; i < numButtons; i++) {
panel.add(new JButton("Button"), getGrid(0, i+1, 1.0, 0));
}
return panel;
}
/*
* Returns the GridBagConstraints for the given x, y grid location
*/
private GridBagConstraints getGrid(int x, int y, double xweight, double yweight) {
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.BOTH;
c.gridx = x;
c.gridy = y;
c.weightx = xweight;
c.weighty = yweight;
return c;
}
}
In this example, I would like the labels Panel1, and Panel2 to be straight across from each other, instead of Panel2 being set lower because the associated panel is centered.
I guess I could use GridBagLayout, and add a component listener to the container panel, and edit the GridBagContraints accordingly for each child panel when the container panel is resized, but I am wondering if there is a better way to do this? In case this matters, in the actual program the child panels will be custom panels, not just a list of buttons.
Thanks in advance for any help!
I was able to achieve this
Using this...
private void setupGUI() {
this.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.NORTH;
gbc.weighty = 1;
this.add(getPanel(1, 4), gbc);
this.add(getPanel(2, 2), gbc);
}
The problem is, you're going to need to get your hands a little dirty, as no layout manager will do exactly what you want (with the possible exception of MigLayout, but I've never used it)
What I would do, is create a JPanel per row, set it's layout to GridBagLayout and use the above concept to layout to layout the number of columns you need, then do this for each row...