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Change JTextField height on Swing

I'm trying to fix the height of the "amountField" text field, but I can't.
I would like the height of amountField to have the same height as the JComboBox that it's above, so it looks better.
Right now, the JTextField looks very tall compared with the rest of design.
I've tried everything that I've read in this forum, but nothing seems to work.
I don't know if it's relevant, but this whole JPanel (WithdrawalScreen) is inside another JPanel with BorderLayout. This panel is the center part of it
Thanks
PictureHere
public class WithdrawalScreen extends JPanel {
Public JPanel init() {
this.setLayout(new GridLayout(0,1));
account = new JLabel("account");
accountSelect = new JComboBox(labels);
amount = new JLabel("amount");
amountField = new JTextField("");
submit = new JButton("SUBMIT");
this.add(account);
this.add(accountSelect);
this.add(amount);
this.add(amountField);
this.add(submit);
return this;
}
}

Try creating the Grid Layout with 5 rows and 1 column. I think the height is messed up because you are not setting the constructor arguments properly.
new GridLayout(5,1);

Grid layout will stretch the component and give the same size to all of its components. In order to keep the "default" size of each component, you can use BoxLayout with BoxLayout.Y_AXIS parameter in its constructor. Another way would be to use a dummy-nested JPanel with another layout. Let's say FlowLayout.
JTextField textField = new JTextField(10);
JPanel nestedPanel = new JPanel(new FlowLayout());
nestedPanel.add(textField);
gridLayoutPanel.add(nestedPanel);
JTextField will not be stretched. nestedPanel will be. Do some experiments yourself and you will find the way that fits your needs.
A link that will help you: A visoual guide to Layout Managers.

Creating a board game layout using JLayeredPane

I have an assignment which requires me to create the layout that you see in the image as part of the development of a game. I've never worked with Java for desktop applications before so i'm a complete noob when it comes to using the Swing & AWT libraries. The image suggests that we use a JLayeredPane as our root container and then add the rest on top of it. My issue is that i've tried starting with the background image and the gridLayout but i can't seem to make anything other than the background show up. The grid doesn't show up at all (no border line, no background of the cells) and any other component i've added to it has failed. Can somebody point me in the right direction here? I've read the docs & saw some example of various layouts,containers and components but i can't seem to make all of them work together.
Here's my code so far:
public class BoardView extends JFrame{
// Constructor
public BoardView() {
JFrame window = new JFrame("Sorry Game"); // create a new Jwindow instance
ImageIcon appIcon = new ImageIcon(getClass().getClassLoader().getResource("res/icon.png")); // create the icon for the app
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // when the 'X' button is clicked, the app stops
window.setSize(new Dimension(1000, 700)); // setting the size of the window
window.setResizable(false); // Window won't be resizable
window.setIconImage(appIcon.getImage()); // set the icon for the app
window.setLayout(new BorderLayout());
JLayeredPane layeredPane = new JLayeredPane();
JLabel background = new JLabel();
background.setSize(1000,700);
background.setIcon(new ImageIcon(getClass().getClassLoader().getResource("res/background.png"))); for the JLabel
layeredPane.add(background,0);
JPanel gridPanel = new JPanel(new GridLayout(16,16));
gridPanel.setSize(650,700);
layeredPane.add(gridPanel);
for(int i = 0; i < 256; i++) {
JLabel tile = new JLabel();
tile.setBackground(Color.red);
tile.setBorder(new LineBorder(Color.black));
gridPanel.add(tile);
}
JLabel logo = new JLabel();
logo.setIcon(new ImageIcon(getClass().getClassLoader().getResource("res/sorryImage.png")));
layeredPane.add(logo);
window.add(layeredPane);
window.setLocationRelativeTo(null); // centers the window to the screen
window.setVisible(true); // make the window visible
}
}
My thought process was that i could set the JFrame's layout to a BorderLayout so that i can brake the final layout down into two parts, the West one and the East one. The West one would contain the Grid and the various JLabels and Buttons and the East one would contain the rest of the components. I've tried using the BorderLayout.WEST & EAST parameters when adding components to the JFrame but none has worked or changed a single thing. I've also tried using an index for the depth when adding components to the JLayeredPane as per the docs but again nothing changes.
P.S. Please note that i'm not looking for someone to create the layout for me. I want someone to help me understand what i'm doing wrong and what the best way of creating such layouts is.

In order to initialize the cells of the grid that i want to have images in, don't i need to add them manually in those positions?
If you use a GridLayout every cell must have a component and the components must be added in sequential order. That is as components are added they will wrap automatically to the next row as required.
So even if you don't want an image in a cell you would need to add a dummy component, lets say a JLabel with no text/icon.
An easier approach might be to use a GridBagLayout. The GridBagLayout can be configured to "reserve" space for cells that don't have components. So you can add a component to a specific cell.
import java.awt.*;
import java.util.*;
import javax.swing.*;
import javax.swing.border.*;
public class GridBagLayoutSparse extends JPanel
{
public GridBagLayoutSparse()
{
setBorder( new LineBorder(Color.RED) );
GridBagLayout gbl = new GridBagLayout();
setLayout( gbl );
/*
// Set up a grid with 5 rows and columns.
// The minimimum width of a column is 50 pixels
// and the minimum height of a row is 20 pixels.
int[] columns = new int[5];
Arrays.fill(columns, 50);
gbl.columnWidths = columns;
int[] rows = new int[5];
Arrays.fill(rows, 20);
gbl.rowHeights = rows;
*/
// Add components to the grid at top/left and bottom/right
GridBagConstraints gbc = new GridBagConstraints();
gbc.fill = GridBagConstraints.BOTH;
gbc.gridx = 0;
gbc.gridy = 0;
addLabel("Cell 0:0", gbc);
gbc.gridx = 3;
gbc.gridy = 4;
addLabel("Cell 3:4", gbc);
}
private void addLabel(String text, GridBagConstraints gbc)
{
JLabel label = new JLabel(text);
label.setBorder( new LineBorder(Color.BLUE) );
add(label, gbc);
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("GridBagLayoutSparse");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout( new GridBagLayout() );
frame.add(new GridBagLayoutSparse());
frame.setSize(300, 300);
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args) throws Exception
{
java.awt.EventQueue.invokeLater( () -> createAndShowGUI() );
}
}
Run the code as is and the components will be grouped together in the center.
Uncomment the block comment and run again. The components will be positioned in the appropriate cell.

Java swing GUI absolute positioning

I know that absolute positioning is not recommended, but I need to show my labels randomly scattered as well as randomly changing their positions.
I have researched how to use setBounds but it doesn't seem to work. The following code shows the labels in a Flow Layout, and when I use setLayout(null) it shows a blank frame.
public class GUI extends JFrame{
device mobiles[];
device station;
JPanel pane= new JPanel();
public GUI()
{
setTitle("communication is Key");
setSize(1000, 1000);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pane.setBackground(Color.WHITE);
int x=0; int y=0;
mobiles= new device[10];
for (int i = 0; i < 10; i++) {
x=randInt();
y=randInt();
mobiles[i]= new device(1,x,y);
pane.add(mobiles[i]);
}
x=randInt();
y=randInt();
station = new device(0,x,y);
pane.add(station);
this.add(pane);
}
and this is class "devices" that extends JLabel
public class device extends JLabel{
ImageIcon mob = new ImageIcon("mob.png");
ImageIcon tow = new ImageIcon("tower.png");
public device(int num, int x, int y)
{ if(num==1)
this.setIcon(mob);
else this.setIcon(tow);
this.setBounds(x, y, 3, 7);
}
}
any help in finding out what the problem is, would be be appreciated.

The following code shows the labels in a Flow Layout, and when I use setLayout(null) it shows a blank frame.
The layout manager sets the size and location of the component.
If you don't use the layout manager, then you are responsible for set the size and location of each component.
Typically I would set the size to equal to the components preferred size.
Also, did you display the x/y value that are randomly generated? Maybe the values are larger than the size of the panel.
and when I use setLayout(null) it shows a blank frame.
What layout is set to null? The panel of the frame. Your code doesn't use the above method. Post the code that you use to cause the problem. We don't want to guess what you may or may not be doing.

thanks to #CasparNoree ... the answer suggested was to initialize the Japnel from the start:
JPanel pane = new JPanel(null);

When you set the layout to null you can set the bounds manually with coordinates.
JFrame jf = new JFrame();
JPanel p = new JPanel();
JButton jb = new JButton();
// this is where you make it so setting the bounds actually does something
p.setLayout(null);
jb.setBounds(100,100,100,100);
p.add(jb);
jf.add(p);
jf.setVisible(true);

Java: How to nest JPanel in a GridLayout?

I want to know how to nest JPanels using a GridLayout. This is how it should look like.
I approached this problem by 2 ways so far,
using JPanels and
using JLabels,
and none of them worked (only the first panel created is shown).
Here is the code for the JPanel approach:
int x=20, y=20;
JPanel [] panels = new JPanel[3];
JLabel animal = new JLabel(new ImageIcon(getClass().getResource("Pictures/animal.gif")));
JLabel map = new JLabel(new ImageIcon(getClass().getResource("Pictures/map.gif")));
JLabel mountain = new JLabel(new ImageIcon(getClass().getResource("Pictures/mountain.gif")));
for(int i=0;i<panels.length;i++)
{
if(i>0)
{
x+=x;
y+=y;
}
panels[i] = new JPanel(new GridLayout(2,2));
panels[i].setPreferredSize(new Dimension(x,y));
if(i==0)
panels[i].add(new JPanel());
else
panels[i].add(panels[i-1]);
panels[i].add(mountain);
panels[i].add(map);
panels[i].add(animal);
}
add(panels[2]);

One option is to create a class that will represent a panel divided into the grid with the images. The only issue would be the top left quadrant which would usually contain the nested panel, at some point you want this to contain just a blank panel. So maybe something like this (barring various optimizations):
class GridPanel extends JPanel{
JLabel mountain, map, animal;
public GridPanel(JPanel panel){
super();
setLayout(new GridLayout(2, 2));
animal = new JLabel(new ImageIcon(getClass().getResource("pictures/animal.gif")));
map = new JLabel(new ImageIcon(getClass().getResource("pictures/map.gif")));
mountain = new JLabel(new ImageIcon(getClass().getResource("pictures/mountain.gif")));
add(panel);
add(mountain);
add(map);
add(animal);
}
}
Notice that it accepts the panel that is to be displayed in the top left corner of the grid. This coud then be called with the panel specified. So at the point where you want to create the main panel:
JPanel grid = new GridPanel(new JPanel()); //initial
for(int i = 1; i <= 5; i++){
grid = new GridPanel(grid);
}
add(grid);
The initial grid is created with a blank JPanel. And every subsequent grid will contain the previous one as the top left panel. You have to resize your images and such and maybe even avoid loading the images multiple times etc. But that is another question. This example shows 5 nested panels.
Just to be clear, you should use ImageIO to load the images once and reuse the images. For example You can create a BufferedImage like this in your main class:
BufferedImage mointainImg = ImageIO.read(new File("pictures/mountain.gif"));
And when you want to create the JLabel you can do this:
mountain = new JLabel(new ImageIcon(mountainImg));
And the advantage is that you can manipulate the image a bit if you want.

One issue that you have is that the images are not scaled. To scale images, use Image.getScaledInstance(). Proper scaling would at least fix the problem of the visible images being cut off. It also might cause the other images to be shown as they might just be hiding behind the visible images because they are too big.

How to increase the slow scroll speed on a JScrollPane?

I am adding a JPanel in a JScrollPane in my project.
All is working fine, but there is one problem about mouse scroll using the mouse-Wheel in JPanel. It's speed is very slow on scrolling. How to make it faster?
My code is :
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
objCheckBoxList = new CheckBoxList();
BaseTreeExplorer node = (BaseTreeExplorer)projectMain.objCommon.tree.getLastSelectedPathComponent();
if (node.getObject() != null) {
cmbList.setSelectedItem(node.getParent().toString());
} else {
if (node.toString().equalsIgnoreCase("List of attributes")) {
cmbList.setSelectedIndex(0);
} else {
cmbList.setSelectedItem(node.toString());
}
}
panel.add(objCheckBoxList);
JScrollPane myScrollPanel = new JScrollPane(panel);
myScrollPanel.setPreferredSize(new Dimension(200, 200));
myScrollPanel.setBorder(BorderFactory.createTitledBorder("Attribute List"));

You can set your scrolling speed with this line of code myJScrollPane.getVerticalScrollBar().setUnitIncrement(16);
Here is details.

This bug seems to occur because swing interprets the scroll speed in pixels instead of lines of text. If you are looking for a more accessible alternative to the accepted solution, you can use the following function to calculate and set the actual desired scroll speed in pixels:
public static void fixScrolling(JScrollPane scrollpane) {
JLabel systemLabel = new JLabel();
FontMetrics metrics = systemLabel.getFontMetrics(systemLabel.getFont());
int lineHeight = metrics.getHeight();
int charWidth = metrics.getMaxAdvance();
JScrollBar systemVBar = new JScrollBar(JScrollBar.VERTICAL);
JScrollBar systemHBar = new JScrollBar(JScrollBar.HORIZONTAL);
int verticalIncrement = systemVBar.getUnitIncrement();
int horizontalIncrement = systemHBar.getUnitIncrement();
scrollpane.getVerticalScrollBar().setUnitIncrement(lineHeight * verticalIncrement);
scrollpane.getHorizontalScrollBar().setUnitIncrement(charWidth * horizontalIncrement);
}
Note that swing does calculate the scroll speed correctly when it contains a single component like a JTable or JTextArea. This fix is specifically for when your scroll pane contains a JPanel.