How to locate JTextField under other JTextField? - java

I am making authentication GUI which should contain 2 text fields, username JTextField and password JPasswordField. I want to make the password field be below the username field. my current code is as follows:
public class GuiAuthentication extends JFrame {
private static final int WIDTH = 1000;
private static final int HEIGHT = 650;
private JTextField tfUsername;
private JPasswordField tfPassword;
public GuiAuthentication() {
try {
setTitle("Metaspace Launcher");
getContentPane().setLayout(new FlowLayout());
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setSize(WIDTH, HEIGHT);
tfUsername = new JTextField("Username");
tfPassword = new JPasswordField("********");
tfUsername.setBounds(10, 10, 50, 20);
tfPassword.setBounds(10, 50, 50, 20);
getContentPane().add(tfUsername);
getContentPane().add(tfPassword);
setPreferredSize(new Dimension(WIDTH, HEIGHT));
setMinimumSize (new Dimension(WIDTH, HEIGHT));
setMaximumSize (new Dimension(WIDTH, HEIGHT));
setResizable(false);
requestFocus();
setLocationRelativeTo(null);
setVisible(true);
} catch (final Exception ex) {
ex.printStackTrace();
System.exit(ex.toString().hashCode());
}
}
#Override
public void paint(final Graphics g) {
super.paint(g);
Gui.drawBackground(this, g, WIDTH, HEIGHT);
Gui.drawRect(g, WIDTH/3, HEIGHT/3 + 20, 325, 200, 0xAA000000);
}
However, this results in the password field being located against the username field, and both of them are centered, and not located at X position 10 which I specify:
--> Screenshot (click)
Is the problem in the layout I currently use (FlowLayout)? If so, which one should I use then? If not, what else might be wrong?
Tried using GridBagLayout as well. It results in this (fields side by side, centered):

Your GridBagLayout attempt images suggest that either you're not using GridBagConstraints when adding components or that you're using the incorrectly.
If you want to center your text components in the GUI, one over the other, and say put them in their own box, then use a GridBagLayout for the container that holds them, and also pass in appropriate GridBagConstraints that will work well with your desire. This will mean giving the constraints an appropriate gridx and gridy value to match where in the grid you wish to place the component. Also you will want to anchor the component correctly, and you will usually want to set the constraints insets to give an empty space buffer around your components so that they don't crowd each other. Myself, when I do something like this, I often use a 4 x 4 grid with two rows and two columns including a column of JLabels on the left so the user knows what each text component in the right column represents. I often use a helper method to help create my constraints, something like this:
private GridBagConstraints createGbc(int x, int y) {
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = x;
gbc.gridy = y;
gbc.fill = GridBagConstraints.HORIZONTAL; // stretch components horizontally
gbc.weightx = 1.0;
gbc.weighty = 0.0; // increase if you want component location to stretch vert.
// I_GAP is a constant and is the size of the gap around
// each component
gbc.insets = new Insets(I_GAP, I_GAP, I_GAP, I_GAP);
// if the x value is odd, anchor to the left, otherwise if even to the right
gbc.anchor = x % 2 == 0 ? GridBagConstraints.WEST : GridBagConstraints.EAST;
return gbc;
}
And then I'd use it like this:
JPanel innerPanel = new JPanel(new GridBagLayout());
JLabel userNameLabel = new JLabel("User Name:");
userNameLabel.setForeground(Color.LIGHT_GRAY);
innerPanel.add(userNameLabel, createGbc(0, 0)); // add w/ GBC
innerPanel.add(tfUsername, createGbc(1, 0)); // etc...
JLabel passwordLabel = new JLabel("Password:");
passwordLabel.setForeground(Color.LIGHT_GRAY);
innerPanel.add(passwordLabel, createGbc(0, 1));
innerPanel.add(tfPassword, createGbc(1, 1));
A working example could look like so:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.border.Border;
#SuppressWarnings("serial")
public class MetaSpaceLauncherPanel extends JPanel {
// path to a public starry image
public static final String IMG_PATH = "https://upload.wikimedia.org/wikipedia/"
+ "commons/thumb/b/be/Milky_Way_at_Concordia_Camp%2C_Karakoram_Range%2"
+ "C_Pakistan.jpg/1280px-Milky_Way_at_Concordia_Camp%2C_Karakoram_Range"
+ "%2C_Pakistan.jpg";
private static final int I_GAP = 10;
private static final int COLS = 15;
private JTextField tfUsername = new JTextField(COLS);
private JPasswordField tfPassword = new JPasswordField(COLS);
private BufferedImage background = null;
public MetaSpaceLauncherPanel(BufferedImage background) {
this.background = background;
// close window if enter pressed and data within fields
ActionListener listener = e -> {
String userName = tfUsername.getText().trim();
char[] password = tfPassword.getPassword();
Window window = SwingUtilities.getWindowAncestor(MetaSpaceLauncherPanel.this);
if (userName.isEmpty() || password.length == 0) {
// both fields need to be filled!
String message = "Both user name and password fields must contain data";
String title = "Invalid Data Entry";
JOptionPane.showMessageDialog(window, message, title, JOptionPane.ERROR_MESSAGE);
} else {
// simply close the dialog
window.dispose();
}
};
tfUsername.addActionListener(listener);
tfPassword.addActionListener(listener);
JPanel innerPanel = new JPanel(new GridBagLayout());
innerPanel.setOpaque(false);
Border outerBorder = BorderFactory.createEtchedBorder();
Border innerBorder = BorderFactory.createEmptyBorder(I_GAP, I_GAP, I_GAP, I_GAP);
Border border = BorderFactory.createCompoundBorder(outerBorder, innerBorder);
innerPanel.setBorder(border);
JLabel userNameLabel = new JLabel("User Name:");
userNameLabel.setForeground(Color.LIGHT_GRAY);
innerPanel.add(userNameLabel, createGbc(0, 0));
innerPanel.add(tfUsername, createGbc(1, 0));
JLabel passwordLabel = new JLabel("Password:");
passwordLabel.setForeground(Color.LIGHT_GRAY);
innerPanel.add(passwordLabel, createGbc(0, 1));
innerPanel.add(tfPassword, createGbc(1, 1));
setLayout(new GridBagLayout());
add(innerPanel); // add without constraints to center it
}
public String getUserName() {
return tfUsername.getText();
}
public char[] getPassword() {
return tfPassword.getPassword();
}
private GridBagConstraints createGbc(int x, int y) {
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = x;
gbc.gridy = y;
gbc.fill = GridBagConstraints.HORIZONTAL; // stretch components horizontally
gbc.weightx = 1.0;
gbc.weighty = 0.0; // increase if you want component location to stretch vert.
// I_GAP is a constant and is the size of the gap around
// each component
gbc.insets = new Insets(I_GAP, I_GAP, I_GAP, I_GAP);
// if the x value is odd, anchor to the left, otherwise if even to the right
gbc.anchor = x % 2 == 0 ? GridBagConstraints.WEST : GridBagConstraints.EAST;
return gbc;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (background != null) {
g.drawImage(background, 0, 0, this);
}
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet() || background == null) {
return super.getPreferredSize();
}
int w = background.getWidth();
int h = background.getHeight();
return new Dimension(w, h);
}
private static void createAndShowGui() {
BufferedImage img = null;
try {
// just using this as an example image, one available to all
// you would probably use your own image
URL imgUrl = new URL(IMG_PATH); // online path to starry image
img = ImageIO.read(imgUrl);
} catch (IOException e) {
e.printStackTrace();
System.exit(-1); // no image available -- exit!
}
MetaSpaceLauncherPanel launcherPanel = new MetaSpaceLauncherPanel(img);
JDialog dialog = new JDialog(null, "MetaSpace Launcher", ModalityType.APPLICATION_MODAL);
dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
dialog.getContentPane().add(launcherPanel);
dialog.pack();
dialog.setLocationRelativeTo(null);
dialog.setVisible(true);
// test to see if we can get the data
String userName = launcherPanel.getUserName();
char[] password = launcherPanel.getPassword();
// don't convert password into String as I'm doing below as it is now
// not secure
String message = String.format("<html>User Name: %s<br/>Password: %s</html>", userName,
new String(password));
JOptionPane.showMessageDialog(null, message);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}

Related

how can I use JTextField and JLabel together?

I need a text field on a label but when i run this code there is no text field on the screen. How can i fix it.
JFrame jf = new JFrame() ;
JPanel panel = new JPanel() ;
JLabel label = new JLabel() ;
JTextField tField = new JTextField("asd" , 10) ;
label.add( tField ) ;
panel.add( label ) ;
jf.setSize( 500,400 ) ;
jf.add( panel ) ;
jf.setVisible(true) ;
JLabel's have no default layout manager, and so while your JTextField is being added tot he JLabel, it's not showing because the label has no idea how to show it.
There can be several ways to solve this depending on what you're trying to achieve:
Give the JLabel a layout manager, and then add the JTextField to it: but then the JTextField covers the JLabel, its text (if it has any) and its icon (if it has one), not good.
Create a JPanel to hold both, and give it an appropriate layout manager: probably a good bet.
Add them both to the same JPanel, using a layout manager that can easily place them in association: another good bet. GridBagLayout works well for this.
Don't forget to also call the JLabel's setLabelFor(...) method to associate it tightly with the JTextField, as per the JLabel Tutorial
For example:
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.KeyEvent;
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", KeyEvent.VK_N), SPEED("Speed", KeyEvent.VK_P), STRENGTH("Strength", KeyEvent.VK_T);
private String title;
private int mnemonic;
private FieldTitle(String title, int mnemonic) {
this.title = title;
this.mnemonic = mnemonic;
}
public String getTitle() {
return title;
}
public int getMnemonic() {
return mnemonic;
}
};
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];
JLabel label = new JLabel(fieldTitle.getTitle() + ":", JLabel.LEFT);
JTextField textField = new JTextField(10);
label.setDisplayedMnemonic(fieldTitle.getMnemonic());
label.setLabelFor(textField);
gbc = createGbc(0, i);
add(label, gbc);
gbc = createGbc(1, i);
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();
}
}
Which displays as
Note that the JLabels have underlines on mnemonic chars, chars that when pressed in alt-key combination will bring the focus to the JTextField that the JLabel was linked to via, setLabelFor(...), and is caused by this code:
FieldTitle fieldTitle = FieldTitle.values()[i]; // an enum that holds label texts
JLabel label = new JLabel(fieldTitle.getTitle() + ":", JLabel.LEFT); // create JLabel
JTextField textField = new JTextField(10); // create JTextField
// set the label's mnemonic -- brings focus to the linked text field
label.setDisplayedMnemonic(fieldTitle.getMnemonic());
// *** here we *link* the JLabel with the JTextField
label.setLabelFor(textField);

Laying out JLabels and JTextFields

When I run this program, both text fields appear right next to each other; if possible, how can I make it to where the password field is under the username field?
public static void main(String[] args) {
JTextField username = new JTextField(10);
JPasswordField password = new JPasswordField(10);
final JPanel login = new JPanel();
login.add(new JLabel("Username:"));
login.add(username);
login.add(Box.createHorizontalStrut(50));
login.add(new JLabel("Password:"));
login.add(password);
int result = JOptionPane.showConfirmDialog(null, login,
"Login Form", JOptionPane.OK_CANCEL_OPTION);
if (result == JOptionPane.OK_OPTION) {
System.out.println("Username: " + username.getText());
System.out.println("Password: " + password.getText());
}
}
Myself, I'd use a GridBagLayout since with this layout, you can specify what position in a grid you'd like to place your components, how they fill the grid cell, how they expand when the GUI expands, etc. How to use it is explained well in the GridBagLayout tutorial and in other tutorials and examples on this site.
For example:
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.*;
public class SimpleLogin {
public static void main(String[] args) {
SimpleLoginPanel simpleLoginPanel = new SimpleLoginPanel();
int result = JOptionPane.showConfirmDialog(null, simpleLoginPanel,
"Login Form", JOptionPane.OK_CANCEL_OPTION);
if (result == JOptionPane.OK_OPTION) {
System.out.println("Username: " + simpleLoginPanel.getUserName());
// the code below is dangerous as it translates a char[] to a String
// making the password potentially discoverable by outside programs.
System.out.println("Password: " + new String(simpleLoginPanel.getPassword()));
}
}
}
// create a JPanel to hold our components
#SuppressWarnings("serial")
class SimpleLoginPanel extends JPanel {
// insets provide blank space around the gridbag layout cells
private static final Insets INSETS = new Insets(5, 5, 5, 5);
private JTextField username = new JTextField(10);
private JPasswordField password = new JPasswordField(10);
public SimpleLoginPanel() {
setLayout(new GridBagLayout());
add(new JLabel("User Name:"), createGbc(0, 0));
add(username, createGbc(1, 0));
add(new JLabel("Password:"), createGbc(0, 1));
add(password, createGbc(1, 1));
}
// so that outside classes can extract the data in the password field
public char[] getPassword() {
return password.getPassword();
}
// so that outside classes can extract the username's text
public String getUserName() {
return username.getText();
}
// the main method of this example, one that creates the GridBagConstraints
// depending on the x, y position of the component.
// this one is written for a two column grid.
private GridBagConstraints createGbc(int x, int y) {
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = x;
gbc.gridy = y;
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.insets = INSETS;
if (x == 0) {
// if the left column, then anchor it to the left
// and fill completely since it's a JLabel
gbc.fill = GridBagConstraints.BOTH;
gbc.anchor = GridBagConstraints.LINE_START;
} else {
// if the right column, anchor to the right and
// only fill horizontally since its a JTextField.
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.anchor = GridBagConstraints.LINE_END;
}
return gbc;
}
}
You can try to use BoxLayout:
login.setLayout(new BoxLayout(login, BoxLayout.PAGE_AXIS));
however it also set a Labels in a row with text fields.

Resize components on frame resize Java

I'm having some trouble trying to resize the components in my GUI when I resize the GUI. Right now, when I resize the GUI, the size of the components don't change, they keep to the static size I set them to. When I resize the GUI passed the minimum size needed to display them, they are no longer displayed. I want them to resize and maintain an aspect ratio when the GUI is resized.
Here's the code I have for the GUI:
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.awt.image.ImageObserver;
import java.io.*;
import java.net.*;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.text.*;
import javax.swing.text.html.*;
public class DraftGUI implements MouseListener {
private JPanel jpPack;
private JPanel jpCards;
private JPanel jpInfo;
private JPanel jpChat;
private TextField tf;
private StyledDocument doc;
private JTextPane tp;
private JScrollPane sp;
public void mousePressed(MouseEvent e) {
}
public void mouseReleased(MouseEvent e) {
}
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
public void mouseClicked(MouseEvent e) {
e.getComponent().setVisible(false);
}
private Client client;
public GUI(Client client) throws IOException {
JFrame frame = new JFrame("Draft");
//set the size to fullscreen to start
frame.setSize(Toolkit.getDefaultToolkit().getScreenSize().width, Toolkit.getDefaultToolkit().getScreenSize().height);
//set the content pane, we'll add everything to it and then add it to the frame
JPanel contentPane = new JPanel();
contentPane.setSize(Toolkit.getDefaultToolkit().getScreenSize().width, Toolkit.getDefaultToolkit().getScreenSize().height);
contentPane.setLayout(new GridBagLayout());
//creates some panels with some default values for now
JPanel jpCards = new JPanel(new BorderLayout());
jpCards.setOpaque(true); //ensures it paints every pixel
jpCards.setBackground(Color.BLUE);
JPanel jpInfo = new JPanel();
jpInfo.setOpaque(true);
jpInfo.setBackground(Color.GREEN);
JPanel jpPack = new JPanel(new GridBagLayout());
jpPack.setOpaque(true);
jpPack.setBackground(Color.RED);
//grab some info to make the JTextPane and make it scroll
this.client = client;
tf = new TextField();
doc = new DefaultStyledDocument();
tp = new JTextPane(doc);
tp.setEditable(false);
tf.addActionListener(this.client);
sp = new JScrollPane(tp);
//adding the quantities to the chat panel
JPanel jpChat = new JPanel();
jpChat.setLayout(new BorderLayout());
jpChat.add("North", tf);
jpChat.add("Center", sp);
//a new GridBagConstraints used to set the properties/location of the panels
GridBagConstraints c = new GridBagConstraints();
//adding some panels to the content pane
//set it to start from the top left of the quadrant if it's too small
c.anchor = GridBagConstraints.FIRST_LINE_START;
c.fill = GridBagConstraints.BOTH; //set it to fill both vertically and horizontally
c.gridx = 0; //set it to quadrant x=0 and
c.gridy = 0; //set it to quadrant y=0
c.weightx = 0.7;
c.weighty = 0.3;
contentPane.add(jpCards, c);
c.gridx = 1;
c.gridy = 0;
c.weightx = 0.3;
c.weighty = 0.3;
contentPane.add(jpInfo, c);
c.gridx = 0;
c.gridy = 1;
c.weightx = 0.7;
c.weighty = 0.7;
contentPane.add(jpPack, c);
c.gridx = 1;
c.gridy = 1;
c.weightx = 0.3;
c.weighty = 0.7;
contentPane.add(jpChat, c);
//set some necessary values
frame.setContentPane(contentPane);
frame.setLocationByPlatform(true);
frame.setVisible(true);
//This code works for adding an Image
//need to learn how to specify a path not dependent on the specific users's machine
//this is not a high priority for now though
GridBagConstraints d = new GridBagConstraints();
d.gridx = 0;
d.gridy = 0;
ImageLabel imageLabel1 = new ImageLabel("path-to-file");
imageLabel1.setPreferredSize(new Dimension(223, 310));
jpPack.add(imageLabel1, d);
ImageLabel imageLabel2 = new ImageLabel("path-to-file");
imageLabel2.setPreferredSize(new Dimension(223, 310));
ImageLabel imageLabel3 = new ImageLabel("path-to-file");
imageLabel3.setPreferredSize(new Dimension(223, 310));
d.gridx = 1;
jpPack.add(imageLabel2, d);
d.gridy = 1;
jpPack.add(imageLabel3, d);
imageLabel1.addMouseListener(this);
imageLabel2.addMouseListener(this);
imageLabel3.addMouseListener(this);
//223, 310 are the aspect values for a card image, width, height
//these need to be maintained as the GUI size changes
}
}
class ImageLabel extends JLabel {
Image image;
ImageObserver imageObserver;
// constructor with filename
ImageLabel(String filename) {
ImageIcon icon = new ImageIcon(filename);
image = icon.getImage();
imageObserver = icon.getImageObserver();
}
// constructor with icon
ImageLabel(ImageIcon icon) {
image = icon.getImage();
imageObserver = icon.getImageObserver();
}
// overload setIcon method
void setIcon(ImageIcon icon) {
image = icon.getImage();
imageObserver = icon.getImageObserver();
}
// overload paint()
public void paint( Graphics g ) {
super.paint( g );
g.drawImage(image, 0 , 0 , getWidth() , getHeight() , imageObserver);
}
}
For some reason, there's no default resizing property for the frame's components, so when the frame resizes, the components don't do anything. I'm not sure what I'm doing wrong or missed, but clearly I left something out.
Also, if anyone knows, the ImageLabels are taking up extra space around them. The padding is set to 0 by default, so I'm not sure why it's creating like a border around them.
Thanks.
EDIT for Guillaume:
I know a main is necessary if I want to run it as a standalone, it's currently part of another application and gets called separately from within it. It was probably not the best decision to post it without a main for completeness, but whatever, it can't be that big of a problem.
Your code took out the portion where the picture was actually displayed. "path-to-file" was supposed to be replaced by an actual image file path, so you would display the image. It's hard to actually see the issue at hand when it's simply text in there.
When you have the image displayed correctly, and you try to resize the entire GUI, you will notice that the image doesn't shrink. It keeps to its preferred size and has issues when it becomes smaller than it. In my code, it stops displaying the picture completely when it can't display at least the preferred size. In your code, it cuts off part of the picture when it shrinks.
What I want is for it to actually resize the JLabel containing the picture, so that as the GUI resizes, so will the image. It's necessary that the image shrinks accordingly for my program. The user will eventually have functionality based on clicking the images, so displaying only some images or portions of them simply won't do.
Please try your code/my code again and reproduce the issue I'm having, testing with pictures, so that we can find a correct solution. Thanks.
JFrame.setVisible(true) should be the last line you call.
GridBagLayout can adapt the size of your components according to the frame size, as long as you use weightx/weighty and fill
UPDATE:
Forget about setting preferred size, this is just going down the path to GUI-problems
If you use LayoutManager's (and it is a very good idea), forget about calling setSize()/setBounds()/setLocation(), the LayoutManager's will override them anyway
You need to take care of the resizing of the image in order to maintain the original image ratio
If you use weightx/weighty, you should also use anchor and/or fill
Use frame.pack() to size properly your frame
Use setExtendedState() to maximize a frame
Btw, an SSCCE means that you make a runnable example for others, this includes changing local path to images to online URL's (see the example below).
With the following snippet, everything seems to work ok:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.TextField;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.net.MalformedURLException;
import java.net.URL;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;
import javax.swing.SwingUtilities;
import javax.swing.text.DefaultStyledDocument;
import javax.swing.text.StyledDocument;
public class DraftGUI implements MouseListener {
private static final String IMAGE_URL = "http://images.paramountbusinessjets.com/space/spaceshuttle.jpg";
private JPanel jpPack;
private JPanel jpCards;
private JPanel jpInfo;
private JPanel jpChat;
private TextField tf;
private StyledDocument doc;
private JTextPane tp;
private JScrollPane sp;
#Override
public void mousePressed(MouseEvent e) {
}
#Override
public void mouseReleased(MouseEvent e) {
}
#Override
public void mouseEntered(MouseEvent e) {
}
#Override
public void mouseExited(MouseEvent e) {
}
#Override
public void mouseClicked(MouseEvent e) {
}
public DraftGUI() throws MalformedURLException {
final JFrame frame = new JFrame("Draft");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// set the content pane, we'll add everything to it and then add it to the frame
JPanel contentPane = new JPanel();
contentPane.setLayout(new GridBagLayout());
// creates some panels with some default values for now
JPanel jpCards = new JPanel(new BorderLayout());
jpCards.setBackground(Color.BLUE);
JPanel jpInfo = new JPanel();
jpInfo.setBackground(Color.GREEN);
JPanel jpPack = new JPanel(new GridBagLayout());
jpPack.setBackground(Color.RED);
// grab some info to make the JTextPane and make it scroll
tf = new TextField();
doc = new DefaultStyledDocument();
tp = new JTextPane(doc);
tp.setEditable(false);
sp = new JScrollPane(tp);
// adding the quantities to the chat panel
JPanel jpChat = new JPanel();
jpChat.setLayout(new BorderLayout());
jpChat.add("North", tf);
jpChat.add("Center", sp);
// a new GridBagConstraints used to set the properties/location of the panels
GridBagConstraints c = new GridBagConstraints();
// adding some panels to the content pane
// set it to start from the top left of the quadrant if it's too small
c.anchor = GridBagConstraints.FIRST_LINE_START;
c.fill = GridBagConstraints.BOTH; // set it to fill both vertically and horizontally
c.gridx = 0; // set it to quadrant x=0 and
c.gridy = 0; // set it to quadrant y=0
c.weightx = 0.7;
c.weighty = 0.3;
contentPane.add(jpCards, c);
c.gridx = 1;
c.gridy = 0;
c.weightx = 0.3;
c.weighty = 0.3;
contentPane.add(jpInfo, c);
c.gridx = 0;
c.gridy = 1;
c.weightx = 0.7;
c.weighty = 0.7;
contentPane.add(jpPack, c);
c.gridx = 1;
c.gridy = 1;
c.weightx = 0.3;
c.weighty = 0.7;
contentPane.add(jpChat, c);
// set some necessary values
frame.setContentPane(contentPane);
frame.setLocationByPlatform(true);
// This code works for adding an Image
// need to learn how to specify a path not dependent on the specific users's machine
// this is not a high priority for now though
GridBagConstraints d = new GridBagConstraints();
d.weightx = 1.0;
d.weighty = 1.0;
d.fill = GridBagConstraints.BOTH;
d.gridx = 0;
d.gridy = 0;
ImageLabel imageLabel1 = new ImageLabel(new ImageIcon(new URL(IMAGE_URL)));
jpPack.add(imageLabel1, d);
ImageLabel imageLabel2 = new ImageLabel(new ImageIcon(new URL(IMAGE_URL)));
d.gridx++;
jpPack.add(imageLabel2, d);
ImageLabel imageLabel3 = new ImageLabel(new ImageIcon(new URL(IMAGE_URL)));
d.gridy++;
jpPack.add(imageLabel3, d);
imageLabel1.addMouseListener(this);
imageLabel2.addMouseListener(this);
imageLabel3.addMouseListener(this);
frame.pack();
// 223, 310 are the aspect values for a card image, width, height
// these need to be maintained as the GUI size changes
frame.setExtendedState(frame.getExtendedState() | JFrame.MAXIMIZED_BOTH);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
try {
new DraftGUI();
} catch (MalformedURLException e) {
e.printStackTrace();
}
}
});
}
public static class ImageLabel extends JPanel {
private static int counter = 1;
private ImageIcon icon;
private int id = counter++;
public ImageLabel(ImageIcon icon) {
super();
setOpaque(false);
this.icon = icon;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(icon.getIconWidth(), icon.getIconHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
double zoom = Math.min((double) getWidth() / icon.getIconWidth(), (double) getHeight() / icon.getIconHeight());
int width = (int) (zoom * icon.getIconWidth());
int height = (int) (zoom * icon.getIconHeight());
g.drawImage(icon.getImage(), (getWidth() - width) / 2, (getHeight() - height) / 2, width, height, this);
g.setFont(g.getFont().deriveFont(36.0f));
g.drawString(String.valueOf(id), getWidth() / 2, getHeight() / 2);
}
}
}
I suggest this way to resize the contents of a window
JPanel jPanel = new JPanel(new BorderLayout()); // Create a panel that contains the elements you want to resize, in this example I use BorderLayout as the layout manager
jPanel.add(somePanel, BorderLayout.NORTH);
// this will resize the con
this.addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
somePanel.setSize(e.getComponent().getSize());
jPanel.paintComponents(getGraphics());
}
});

Sizing issue with scrollable JTextField

I have a form with lots of text fields and some of those text fields may contain very long strings. To make it work I made those text fields scrollable using this code:
JScrollPane scroll = new JScrollPane(textField);
scroll.setPreferredSize(new Dimension((int)textField.getPreferredSize().getWidth(), (int)textField.getPreferredSize().getHeight() * 2));
Then I put scroll into my form using GridBagLayout.
Second line in my example is required for scroller to show up. But it has downside. When I resize window to fit whole text in text field, then scroll disapears leaving me with just two times higher then others text field, which looks ridiculous.
How can I make this all work and show me normal size of text field after scroller is hidden?
EDIT:
You may use following as a demo code to reproduce the issue:
import javax.swing.*;
import java.awt.*;
public class ScrollTextDemo extends JFrame{
public ScrollTextDemo(){
super();
this.setPreferredSize(new Dimension(500, 300));
JPanel panel = new JPanel();
panel.setLayout(new GridBagLayout());
JTextField textField = new JTextField("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
textField.setCursor(new Cursor(0));
textField.setEditable(false);
JScrollPane scroll = new JScrollPane(textField);
scroll.setPreferredSize(new Dimension(70, 40) );
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridy = 1;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.weightx = 0.5;
gbc.insets = new Insets(5, 5, 0, 5);
panel.add(scroll,gbc);
//let's add one more text field without scroll bar to compare
JTextField textField2 = new JTextField("abc");
gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridy = 2;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.weightx = 0.5;
gbc.insets = new Insets(5, 5, 0, 5);
panel.add(textField2,gbc);
this.add(panel);
}
public static void main(String args[]){
ScrollTextDemo demo = new ScrollTextDemo();
demo.pack();
demo.setVisible(true);
}
}
For this , in the absence of a good SSCCE, I think you hadn't provided any constraint that goes for fill, which is used for
Used when the component's display area is larger than the component's requested size to determine whether and how to resize the component. Valid values (defined as GridBagConstraints constants) include NONE (the default), HORIZONTAL (make the component wide enough to fill its display area horizontally, but do not change its height), VERTICAL (make the component tall enough to fill its display area vertically, but do not change its width), and BOTH (make the component fill its display area entirely).
So you must add something like this to your GridBagConstraints
constraintsGridBag.fill = GridBagConstraints.HORIZONTAL;
This will only allow it to expand HORIZONTALLY not both ways.
** EDIT : As for the added code **
Never specify setPreferredSize(...) for any component in Swing. Let the Layout Manager you are using, take care for that. Remove all setPreferredSize(...) thingies, will let it remain in normal size upon resizing.
*EDIT 2 : *
Code to tell you what I am saying :
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.*;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
public class GridBagTest extends JFrame
{
private JPanel topPanel;
private JPanel bottomPanel;
public GridBagTest()
{
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
//gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.fill = GridBagConstraints.BOTH;
gbc.weightx = 1.0;
gbc.weighty = 0.8;
// Setting TOP PANEL.
topPanel = new JPanel();
topPanel.setLayout(new GridBagLayout());
GridBagConstraints constraintsTopPanel = new GridBagConstraints();
constraintsTopPanel.gridwidth = 2; // Specifies that this component will take two columns.
constraintsTopPanel.gridheight = 1; // specifies that the component will take one row.
/*
* fill with HORIZONTAL, means the component upon resize, will
* only expand along the X-Axis.
*/
constraintsTopPanel.fill = GridBagConstraints.NONE;
constraintsTopPanel.insets = new Insets(5, 5, 5, 5);
constraintsTopPanel.ipadx = 2;
constraintsTopPanel.ipady = 2;
constraintsTopPanel.weightx = 0.3;
constraintsTopPanel.weighty = 0.2;
constraintsTopPanel.gridx = 0;
constraintsTopPanel.gridy = 0;
JTextField tfield1 = new JTextField("kajslkajfkl dsjlafj lksdj akljsd lfkajflkdj lkaj flkdjalk jflkaj lkfdsj salkj flkaj flkja dslkfjal ksjdflka jlfjd aflsdj", 10);
topPanel.add(tfield1, constraintsTopPanel);
constraintsTopPanel.gridx = 2;
constraintsTopPanel.gridy = 0;
final JTextField tfield2 = new JTextField("kajslkajfkl dsjlafj lksdj akljsd lfkajflkdj lkaj flkdjalk jflkaj lkfdsj salkj flkaj flkja dslkfjal ksjdflka jlfjd aflsdj", 10);
topPanel.add(tfield2, constraintsTopPanel);
constraintsTopPanel.gridx = 4;
constraintsTopPanel.gridy = 0;
JTextField tfield3 = new JTextField("kajslkajfkl dsjlafj lksdj akljsd lfkajflkdj lkaj flkdjalk jflkaj lkfdsj salkj flkaj flkja dslkfjal ksjdflka jlfjd aflsdj", 10);
topPanel.add(tfield3, constraintsTopPanel);
topPanel.setBackground(Color.WHITE);
add(topPanel, gbc);
constraintsTopPanel.gridx = 0;
constraintsTopPanel.gridy = 2;
constraintsTopPanel.gridwidth = 6; // Specifies that this component will take two columns.
constraintsTopPanel.gridheight = 1; // specifies that the component will take one row.
JButton button = new JButton("REMOVE");
button.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
topPanel.remove(tfield2);
topPanel.revalidate();
topPanel.repaint();
}
});
topPanel.add(button, constraintsTopPanel);
//Setting BOTTOM PANEL.
bottomPanel = new JPanel();
bottomPanel.setLayout(new BorderLayout());
bottomPanel.setBackground(Color.DARK_GRAY);
JLabel label3 = new JLabel("I am a new JLABEL for the bottom JPanel", JLabel.CENTER);
label3.setForeground(Color.WHITE);
bottomPanel.add(label3, BorderLayout.CENTER);
gbc.weighty = 0.2;
add(bottomPanel, gbc);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
pack();
setVisible(true);
}
public static void main(String... args)
{
javax.swing.SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new GridBagTest();
}
});
}
}
Well the best I've got is looking ugly in code, but does exactly what I need to the textField. Below is changed sample code from initial question. I'd be thankfull for any ideas how to make it better:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
public class ScrollTextDemo extends JFrame{
public ScrollTextDemo(){
super();
this.setPreferredSize(new Dimension(500, 300));
JPanel panel = new JPanel();
panel.setLayout(new GridBagLayout());
JTextField textField = new JTextField("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
textField.setCursor(new Cursor(0));
textField.setEditable(false);
JScrollPane scroll = new JScrollPane(textField, JScrollPane.VERTICAL_SCROLLBAR_NEVER,JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridy = 1;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.weightx = 0.5;
//gbc.ipady = 20;//gives some room for scroll to appear and don't hide text area under the scroll.
gbc.insets = new Insets(5, 5, 0, 5);
panel.add(scroll,gbc);
//let's add one more text field without scroll bar to compare
JTextField textField2 = new JTextField("bbbbbbbb");
gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridy = 2;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.weightx = 0.5;
gbc.insets = new Insets(5, 5, 0, 5);
panel.add(textField2,gbc);
scroll.addComponentListener( new ScrollTextComponentListener(scroll, textField2));
this.add(panel);
}
public static void main(String args[]){
ScrollTextDemo demo = new ScrollTextDemo();
demo.pack();
demo.setVisible(true);
}
}
class ScrollTextComponentListener implements ComponentListener {
private boolean scrollVisible;
private JScrollPane scroll;
private JComponent compareComponent;
public ScrollTextComponentListener(JScrollPane scroll, JComponent compareComponent) {
this.scroll = scroll;
this.compareComponent = compareComponent;
}
private boolean isScrollVisible() {
return scroll.getHorizontalScrollBar().getModel().getExtent() != scroll.getHorizontalScrollBar().getModel().getMaximum();
}
private void setScrollSize(){
boolean scrollVisible = isScrollVisible();
if (scrollVisible){
scroll.setPreferredSize(new Dimension(compareComponent.getWidth(),compareComponent.getHeight()*2));
//also had to set both min and max sizes, because only preffered size didn't always work
scroll.setMinimumSize(new Dimension(compareComponent.getWidth(),compareComponent.getHeight()*2));
scroll.setMaximumSize(new Dimension(compareComponent.getWidth(),compareComponent.getHeight()*2));
}
else {
scroll.setPreferredSize(new Dimension(compareComponent.getWidth(),compareComponent.getHeight()));
scroll.setMinimumSize(new Dimension(compareComponent.getWidth(),compareComponent.getHeight()));
scroll.setMaximumSize(new Dimension(compareComponent.getWidth(),compareComponent.getHeight()));
}
this.scrollVisible = scrollVisible;
}
#Override
public void componentResized(ComponentEvent e) {
if (isScrollVisible() != scrollVisible) setScrollSize();
}
#Override
public void componentMoved(ComponentEvent e) {
}
#Override
public void componentShown(ComponentEvent e) {
setScrollSize();
}
#Override
public void componentHidden(ComponentEvent e) {
}
}

What is the preferred layout manager for a container with collapsable JPanels

My code has a JPanel that contains three collapsible JPanels. The outer JPanel uses the BoxLayout to stack the three JPanels vertically. However, when I collapse a JPanel, the top JPanel will always expands to fill the region (even if I setMaximumSize() or such), whereas I want the lower JPanels to expand upward. It is generally glitchy. I was looking at the GridBagLayout, would that be more suitable for this sort of endeavor?
Thanks.
This is a VB image of what I dream about in my wildest dreams (images with title "Vertical Panels"):
http://www.codeproject.com/KB/cpp/CollapsiblePanelVB.aspx
I don't know what a collapsable panel is. Does it collapse all the way to 0, or does is have a minimum height?
If you manage the maximum size to always equal the preferred size then you should be able to use a BoxLayout. Just make sure you also use:
panel.add( Box.createVerticalGlue() );
at the bottom of your panel to allow the extra space to be used by the glue.
It would take me forever to cut out a compilable snippet from the 500 lines of garbage sprawled out before me.
And that is the reason for creating a SSCCE and forgetting about your garbage code. All you need is a panel with 3 collapsable panels. Then you add a button to collapse the panel and see what happens. Its better to start with demo code then write 500 lines of code and find out it doesn't work.
I strongly suggest MigLayout. It's very powerful and very easy to use. It's also widely used.
or old classic based on GridBagLayout
import java.awt.*;
import java.awt.event.*;
import java.awt.font.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class ExpansiblePanel {
public static void main(String[] args) {
CollapsablePanel cp = new CollapsablePanel("test", buildPanel());
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(new JScrollPane(cp));
f.setPreferredSize(new Dimension(360, 200));
f.setLocation(150, 150);
f.pack();
f.setVisible(true);
}
public static JPanel buildPanel() {
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(2, 1, 2, 1);
gbc.weightx = 1.0;
gbc.weighty = 1.0;
JPanel p1 = new JPanel(new GridBagLayout());
gbc.gridwidth = GridBagConstraints.RELATIVE;
p1.add(new JButton("button 1"), gbc);
gbc.gridwidth = GridBagConstraints.REMAINDER;
p1.add(new JButton("button 2"), gbc);
gbc.gridwidth = GridBagConstraints.RELATIVE;
p1.add(new JButton("button 3"), gbc);
gbc.gridwidth = GridBagConstraints.REMAINDER;
p1.add(new JButton("button 4"), gbc);
p1.setBackground(Color.blue);
return p1;
}
private ExpansiblePanel() {
}
}
class CollapsablePanel extends JPanel {
private static final long serialVersionUID = 1L;
private boolean selected;
private JPanel contentPanel_;
private HeaderPanel headerPanel_;
private class HeaderPanel extends JPanel implements MouseListener {
private static final long serialVersionUID = 1L;
private String text_;
private Font font;
private BufferedImage open, closed;
final int OFFSET = 30, PAD = 5;
HeaderPanel(String text) {
addMouseListener(this);
text_ = text;
font = new Font("sans-serif", Font.PLAIN + Font.BOLD, 12);
// setRequestFocusEnabled(true);
setPreferredSize(new Dimension(200, 25));
setBackground(Color.black);
setForeground(Color.red);
int w = getWidth();
int h = getHeight();
/*try {
open = ImageIO.read(new File("images/arrow_down_mini.png"));
closed = ImageIO.read(new File("images/arrow_right_mini.png"));
} catch (IOException e) {
e.printStackTrace();
}*/
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
int h = getHeight();
/*if (selected)
g2.drawImage(open, PAD, 0, h, h, this);
else
g2.drawImage(closed, PAD, 0, h, h, this);
*/ // Uncomment once you have your own images
g2.setFont(font);
FontRenderContext frc = g2.getFontRenderContext();
LineMetrics lm = font.getLineMetrics(text_, frc);
float height = lm.getAscent() + lm.getDescent();
float x = OFFSET;
float y = (h + height) / 2 - lm.getDescent();
g2.drawString(text_, x, y);
}
#Override
public void mouseClicked(MouseEvent e) {
toggleSelection();
}
#Override
public void mouseEntered(MouseEvent e) {
}
#Override
public void mouseExited(MouseEvent e) {
}
#Override
public void mousePressed(MouseEvent e) {
}
#Override
public void mouseReleased(MouseEvent e) {
}
}
CollapsablePanel(String text, JPanel panel) {
super(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(1, 3, 0, 3);
gbc.weightx = 1.0;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.gridwidth = GridBagConstraints.REMAINDER;
selected = false;
headerPanel_ = new HeaderPanel(text);
setBackground(Color.orange);
contentPanel_ = panel;
add(headerPanel_, gbc);
add(contentPanel_, gbc);
contentPanel_.setVisible(false);
JLabel padding = new JLabel();
gbc.weighty = 1.0;
add(padding, gbc);
}
public void toggleSelection() {
selected = !selected;
if (contentPanel_.isShowing()) {
contentPanel_.setVisible(false);
} else {
contentPanel_.setVisible(true);
}
revalidate();
headerPanel_.repaint();
}
}

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