So I have created three classes, the main method class, the Frame class and the JPanel class. Inside the JPanel class i would like to add three more JPanels, one at the top of the JFrame, one in the center and one at the bottom. My Code for the classes JPanel and JFrame are as follows:
JPanel:
public class ConcertPanel extends JPanel
{
public ConcertPanel()
{
JPanel ConcertPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
JPanel Panel1 = new JPanel();
Panel1.setSize(800,200);
Panel1.setBackground(Color.BLUE);
JPanel Panel2 = new JPanel();
Panel2.setSize(800,400);
Panel1.setBackground(Color.GREEN);
JPanel Panel3 = new JPanel();
Panel3.setSize(800,200);
Panel1.setBackground(Color.GRAY);
this.add(Panel1);
this.add(Panel2);
this.add(Panel3);
}
}
public class ConcertFrame extends JFrame
{
private ConcertPanel controlPane;
// The constructor
public ConcertFrame()
{
controlPane = new ConcertPanel() ;
this.add(controlPane);
....
When this project is ran, there are no errors showing up, but when the JFrame pops up it doesn't give me the three different colored panels within it but only a small grey box at the top. Can anyone tell me why or help?
One main problem is that the code does not take preferredSize nor layout managers into consideration.
The preferred sizes of all your color JPanels is 0,0, and setting the size does not affect this. Since they're being added to a JPanel who's default layout manager is FlowLayout, then the layout does not increase their sizes. So since most all layout managers respect preferred size and not actual size, and the FlowLayout doesn't change this, the JPanels are added, but are never seen.
Instead consider using other layouts for the main container such as GridLayout if all components have the same size, or BoxLayout, if all components are placed in a row or in a column. Consider overriding the getPreferredSize method as well but carefully and only if needed.
A "cheat" solution would be to change setSize(...) to setPreferredSize(new Dimensnion(...)), but that's frowned upon.
For example:
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.*;
#SuppressWarnings("serial")
public class ColorPanels extends JPanel {
public ColorPanels() {
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(new ColorPanel(Color.BLUE, 800, 200));
add(new ColorPanel(Color.GREEN, 800, 400));
add(new ColorPanel(Color.GRAY, 800, 200));
}
private static class ColorPanel extends JPanel {
private int w;
private int h;
public ColorPanel(Color color, int w, int h) {
this.w = w;
this.h = h;
setBackground(color);
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(w, h);
}
}
private static void createAndShowGui() {
ColorPanels mainPanel = new ColorPanels();
JFrame frame = new JFrame("ColorPanels");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
Related
I am trying to resize the center panel of my BorderLayout but the size is not changing. It keeps filling the rest of the frame that is available. I have tried setting the preferred size but has no effect. I would like how size of the frame but only need a portion of the center to be actually a panel for later use.
import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;
public class Gui extends JFrame {
Border blackline = BorderFactory.createLineBorder(Color.black);
private JPanel board;
private JPanel buttons;
private JButton setMissing, by4, by8;
public Gui(){
setUpGui();
}
public void setUpGui(){
this.setSize(1000,1000);
this.setTitle("Comp361 Assignment One");
addButtons();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
board = new JPanel();
board.setPreferredSize(new Dimension(400,400));
this.add(board, BorderLayout.CENTER);
//Sboard.setBackground(Color.Gray);
board.setBorder(blackline);
this.setVisible(true);
}
public void addButtons(){
buttons = new JPanel(new FlowLayout());
setMissing = new JButton("Set X");
by4 = new JButton("4 by 4");
by8 = new JButton("8 by 8");
buttons.add(setMissing);
buttons.add(by4);
buttons.add(by8);
this.add(buttons,BorderLayout.PAGE_START);
}
public static void main (String[] args){
new Gui();
}
}
For extra padding around the central panel, you might put it to a panel with GridBagLayout (with no constraint) to center it, then add the GBL panel to the CENTER of the BorderLayout.
I've create a JFrame named homeWindowFrame and set its size to (600, 500) and then I added a JPanel named mainContainerPanel to the JFrame. I set a new size to JPanel but it's not working. JPanel size is remaining same as that of JFrame instead of updating. How can I set size to JPanels in a JFrame.Thanks in advance. Here my code:
/**
* Main window construction
*/
JFrame homeWindowFrame = new JFrame("Home - Crime File Management System");
if (isInvalidLogin) {
homeWindowFrame.setSize(600, 500);
} else {
homeWindowFrame.setSize(600, 400);
}
homeWindowFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
homeWindowFrame.setLocation((screenSize.width / 2) - (homeWindowFrame.getWidth() / 2), (screenSize.height / 2) - (homeWindowFrame.getHeight() / 2));
/**
* Main panel construction
*/
JPanel mainContainerPanel;
if (isInvalidLogin) {
mainContainerPanel = new JPanel(new GridLayout(4, 2));
} else {
mainContainerPanel = new JPanel(new GridLayout(3, 2));
}
homeWindowFrame.add(mainContainerPanel);
Your code appears to be ignoring how Java Swing layout managers work. When you add a JPanel to a JFrame, the default lay out is BorderLayout, and this will center the panel in the frame and size it to fill the frame. If you wish to have a panel at different size, and its preferredSize needs to be set somehow, and the container that holds the JPanel will need to use a different layout manager. A GridBagLayout used in a "default" way (adding one component, no GridBagConstraints) for instance would center the JPanel if this is what you desire. If these suggestions do not help, then you should create a posterior own MCVE (please read the link).
For example, MY MCVE:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import javax.swing.*;
#SuppressWarnings("serial")
public class DiffSizedPanel extends JPanel {
private static final int PANEL_W = 400;
private static final int PANEL_H = 300;
private static final int FRAME_W = 600;
private static final int FRAME_H = 500;
private static final Color BG_COLOR = Color.PINK;
public DiffSizedPanel() {
setBackground(BG_COLOR);
// set the JPanel the preferred size desired
setPreferredSize(new Dimension(PANEL_W, PANEL_H));
setBorder(BorderFactory.createTitledBorder("This is the JPanel"));
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Different Sized Panel");
// set the JFrame the preferred size desired
frame.setPreferredSize(new Dimension(FRAME_W, FRAME_H));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// change the content pane's layout from default BorderLayout to GridBagLayout
frame.getContentPane().setLayout(new GridBagLayout());
frame.getContentPane().add(new DiffSizedPanel()); // add the JPanel
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
I'm trying to get a JTextArea with a "save" JButton centered underneath it, maybe with a small bit of padding between the components as well as the components to the frame if possible. I've tried messing around with layout managers, panels, etc. and can't seem to get the result i want. Just looking for the simplest way to do this. Thanks.
Suggestions:
The overall layout of the GUI container could be BorderLayout.
Add the JScrollPane that holds your JTextArea BorderLayout.CENTER.
Create a JPanel just to hold the JButton and don't give it a specific layout manager. It will now use JPanel's default FlowLayout and will center components in the horizontal direction.
Add your JButton to this last JPanel.
Add that same JPanel to the GUI in the BorderLayout.PAGE_END (bottom) position.
For example:
import java.awt.BorderLayout;
import javax.swing.*;
public class SimpleLayout extends JPanel {
private static final int ROWS = 20;
private static final int COLS = 60;
private JTextArea textArea = new JTextArea(ROWS, COLS);
private JButton button = new JButton("Button");
public SimpleLayout() {
JPanel buttonPanel = new JPanel();
buttonPanel.add(button);
setLayout(new BorderLayout());
add(new JScrollPane(textArea), BorderLayout.CENTER);
add(buttonPanel, BorderLayout.PAGE_END);
}
private static void createAndShowGui() {
SimpleLayout mainPanel = new SimpleLayout();
JFrame frame = new JFrame("SimpleLayout");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
createAndShowGui();
});
}
}
In the below code, I am using gridbaglayout to have all my buttons displayed in two lines on a frame size of 600 X 400. Commenting out setSize() or pack() in the below code did not help. my question is how to get frame of size 600 X 400, and the bottom of frame has a panel with alpabet buttons. Thanks for help.
import javax.swing.*;
import java.awt.GridBagConstraints;
import java.awt.GridLayout;
import java.awt.event.*;
public class HangmanGUI {
public static void main(String[] args){
new HangmanGUI();
}
//constructor for Hangman
/**
* Instantiates a new hangman gui.
*/
public HangmanGUI() {
JFrame myframe= new JFrame();
JPanel myPanel = new JPanel();
myPanel.setLayout(new GridLayout());
GridBagConstraints gbc = new GridBagConstraints();
myframe.setSize(600,400);
int x =0; int y=5;
for (char alphabet = 'A';alphabet<='Z';alphabet++){
gbc.gridx=x;
gbc.gridy=y;
myPanel.add(new JButton(alphabet+""),gbc);
x++;
if (x>15){
y =6;x=0;
}
}
myframe.add(myPanel);
myframe.pack();
myframe.setTitle("Hangman Game");
myframe.setVisible(true);
myframe.setLocationRelativeTo(null);
myframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
When packed, the frame size is computed based on the preferred size of it's content pane.
Personally, I'd care less about the window size and the functionality of the program and let the underlying framework figure it all out...but, if it's important to you...
Start with, something like, a JPanel and override it's getPreferredSize method...
public class BigPane extends JPanel {
public Dimension getPreferredSize() {
return new Dimension(600, 400);
}
}
Set this panel as the frame's content pane...
JFrame myframe= new JFrame();
myFrame.setContentPane(new BigPane());
// This is important as the panels default layout is FlowLayout...
myFrame.setLayout(new BorderLayout());
If you want you button pane to positioned in the south position, then you simply need to supply the correct layout constraint for the layout, in this case, BorderLayout...
myFrame.add(myPanel, BorderLayout.SOUTH);
This will allow you to add a "main" component to the CENTER position.
As has already being suggested, it might be better to use a GridLayout for the buttons, but this will depend on what you want to achieve.
Take a look at Laying out components within a container for more details
In your last Q&A you were advised to use GridLayout as opposed to GridBagLayout. GridBagConstraints are only used in the latter.
This is probably not how you want the GUI to look, but take it as a basic guide of what GridLayout is actually good for.
import javax.swing.*;
import java.awt.*;
import java.awt.image.*;
public class HangmanGUI {
/**
* Instantiates a new hangman gui.
*/
public HangmanGUI() {
JPanel gui = new JPanel(new BorderLayout(2,2));
BufferedImage bi = new BufferedImage(
600,200,BufferedImage.TYPE_INT_RGB);
gui.add(new JLabel(new ImageIcon(bi)));
JFrame myframe= new JFrame();
JPanel myPanel = new JPanel();
gui.add(myPanel,BorderLayout.PAGE_END);
myPanel.setLayout(new GridLayout(2,0,0,0));
int x =0; int y=5;
for (char alphabet = 'A';alphabet<='Z';alphabet++){
myPanel.add(new JButton(alphabet+""));
x++;
if (x>15){
y =6;x=0;
}
}
myframe.add(gui);
myframe.pack();
myframe.setTitle("Hangman Game");
myframe.setVisible(true);
myframe.setLocationRelativeTo(null);
myframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args){
new HangmanGUI();
}
}
JFrame myframe= new JFrame();
myframe.getContentPane().setLayout(new BorderLayout());
JPanel myPanel = new JPanel();
myPanel.setLayout(new GridLayout(2,13));
GridBagConstraints gbc = new GridBagConstraints();
myframe.setSize(600,400);
int x =0; int y=5;
for (char alphabet = 'A';alphabet<='Z';alphabet++){
gbc.gridx=x;
gbc.gridy=y;
myPanel.add(new JButton(alphabet+""),gbc);
x++;
if (x>15){
y =6;x=0;
}
}
myframe.getContentPane().add(myPanel, BorderLayout.SOUTH);
myframe.setTitle("Hangman Game");
myframe.setVisible(true);
myframe.setLocationRelativeTo(null);
myframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
I added the BorderLayout to the ContentPane and then added the Panel to the bottom of the ContentPane.
Also removed the pack.
And added the constraints in your new GridLayout to specify 2 rows of 13 columns
I'm completely new to using the GUI in java, so I'm having a bit of trouble figuring out how to align everything that I need to. I have to panels in my JFrame that I need to align (One to the left, one to the right) and a few buttons in one of the panels that I need to be centered in the panel. Here is my code.
package application;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.io.*;
import java.nio.*;
import java.util.*;
public class Main extends JPanel
{
public static void main(String[] args)
{
//set the ui to the native OS
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}catch(ClassNotFoundException | InstantiationException | IllegalAccessException
| UnsupportedLookAndFeelException e)
{
}
JFrame frame = new JFrame("Application Name");
Menu menu = new Menu();
JPanel iconPanel = new JPanel();
final JPanel grid = new JPanel(new FlowLayout());
JButton firewallButton = new JButton("Firewall");
JButton networkButton = new JButton("Network");
JButton printerButton = new JButton("Printer");
int iconPanelSizeX;
int iconPanelSizeY;
int gridSizeX;
int gridSizeY;
int gridPosition;
//frame setting
frame.setSize(800, 600);
frame.setMinimumSize(new Dimension(800, 600));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
//add grid and iconPanel JPanels to the frame
frame.add(iconPanel);
iconPanel.add(firewallButton);
iconPanel.add(networkButton);
iconPanel.add(printerButton);
frame.add(grid);
//iconPanel settings
iconPanel.setBorder(BorderFactory.createLoweredSoftBevelBorder());
iconPanel.setBackground(Color.gray);
iconPanel.setLayout(new FlowLayout());
iconPanel.setSize(new Dimension(100, 600));
iconPanel.setVisible(true);
//grid setting
grid.setBackground(Color.red);
grid.setSize(new Dimension(700, 600));
grid.setVisible(true);
//this is for resizing components when the user resizes the window
int counter = 0;
while(counter == 0)
{
firewallButton.setSize(new Dimension(iconPanel.getWidth(), 50));
networkButton.setSize(new Dimension(iconPanel.getWidth(), 50));
printerButton.setSize(new Dimension(iconPanel.getWidth(), 50));
iconPanelSizeX = frame.getWidth() / 10;
iconPanelSizeY = frame.getHeight();
gridSizeX = (frame.getWidth() / 10) * 9;
gridSizeY = frame.getHeight();
iconPanel.setSize(new Dimension(iconPanelSizeX, iconPanelSizeY));
grid.setSize(new Dimension(gridSizeX, gridSizeY));
}
}
}
As you can see, the second JPanel (grid) doesn't line up with the right side of the frame, and the buttons inside iconTray don't center either. I realize these are both probably simple layout fixes, but I have no clue where to start.
For simple splitting of JFrame you can use GridLayout with 1 row and 2 colums.
frame.setLayout(new GridLayout(1,2,3,3)); //3,3 are gaps
frame.add(grid);
frame.add(iconPanel);
For centering components in panels you can use FlowLayout which is by default set on JPanels:
Doing it manualy:
grid.setLayout(new FlowLayout()); //Centered components
grid.setLayout(new FlowLayout(FlowLayout.LEFT,3,3)); //Components aligned to left
grid.setLayout(new FlowLayout(FlowLayout.RIGHT,3,3)); //Components aligned to right
This is how it looks:
Also, few observations:
Never call setXXXSize() methods for your components;
Try to avoid calling setSize(); for JFrame, call pack(); instead;
Call setVisible(true); in the end of code;
All your huge code can be "stripped" to this:
import javax.swing.*;
import java.awt.*;
public class Main extends JPanel
{
public static void main(String[] args)
{
JFrame frame = new JFrame("Application Name");
JPanel iconPanel = new JPanel();
JPanel grid = new JPanel(new FlowLayout());
JButton firewallButton = new JButton("Firewall");
JButton networkButton = new JButton("Network");
JButton printerButton = new JButton("Printer");
frame.add(iconPanel);
iconPanel.add(firewallButton);
iconPanel.add(networkButton);
iconPanel.add(printerButton);
grid.setBackground(Color.GREEN);
frame.setLayout(new GridLayout(1,2,3,3));
frame.add(grid);
frame.add(iconPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
how to align buttons vertically?
This example uses a vertical Box in the WEST area of the frame's default BorderLayout:
import java.awt.*;
import javax.swing.*;
/** #see http://stackoverflow.com/a/14927280/230513 */
public class Main {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
display();
}
});
}
private static void display() throws HeadlessException {
JFrame frame = new JFrame("Application Name");
JButton firewallButton = new JButton("Firewall");
JButton networkButton = new JButton("Network");
JButton printerButton = new JButton("Printer");
//iconPanel settings
Box iconPanel = new Box(BoxLayout.Y_AXIS);
iconPanel.add(firewallButton);
iconPanel.add(networkButton);
iconPanel.add(printerButton);
iconPanel.setBackground(Color.gray);
iconPanel.setVisible(true);
frame.add(iconPanel, BorderLayout.WEST);
//grid setting
JPanel grid = new JPanel() {
#Override
// arbitrary placeholder size
public Dimension getPreferredSize() {
return new Dimension(320, 230);
}
};
grid.setBackground(Color.red);
frame.add(grid, BorderLayout.CENTER);
//frame setting
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
I suggest you take some time going through A Visual Guide to Layout Managers. This will help you become familiar with the layout managers which are available with the Standard API. It takes some experience and hard work to figure out which of these is the right tool to get the exact look you want. Once you become comfortable with what is available from the Standard API, you should also look around for third-party Layout Manager APIs which provide other options.
I have to panels in my JFrame that I need to align (One to the left,
one to the right) and a few buttons in one of the panels that I need
to be centered in the panel. Here is my code.
I realize these are both probably simple layout fixes, but I have no
clue where to start.
Use more complex layout than simple FlowLayout which you actually using. I suggest to you use
GridBagLayout
BoxLayout
Check references here