Develop Reference

How to set size of custom button?

I've created a GUI program with custom icons for buttons. I'm unable, however, to set the size of these buttons in Java, so they remain their original size, 230x227. I'm trying to get them to be around 20x20 so I used the following code:
classAlcBtn.setPreferredSize(new Dimension(20,20));
classAlcBtn.setIcon(new ImageIcon(getClass().getResource("Alchemist.png")));
classAlcBtn.setBorder(null);
classAlcBtn.setBorderPainted(false);
classAlcBtn.setContentAreaFilled(false);
classAlcBtn.setPressedIcon(
new ImageIcon(getClass().getResource("alchemistClicked.png")));
classAlcBtn.setCursor(new Cursor(Cursor.HAND_CURSOR));
Is there a way to force these icons to size down, or do I have to size down the actual icon file? Thanks for any help.

Assuming you can size down the buttons, without icons. So use the following method to size down the image, without changing the size of original file:
ImageIcon icon = new ImageIcon("whatever.jpg");
Image img = icon.getImage() ;
Image newImg = img.getScaledInstance( NEW_WIDTH, NEW_HEIGHT, java.awt.Image.SCALE_SMOOTH ) ;
icon = new ImageIcon( newImg );
...
classAlcBtn.setIcon(icon);
And if Button resizing itself is not working, then you can try using setMaximumSize() instead of setPreferredSize() method as following:
classAlcBtn.setMaximumSize(new Dimension(100,100));
See this for more info. about sizes. Hope this Helps:)

Libgdx Label multiline text height

i have done a small test on LibGdx, on Multi-line Label, it seems that i cant get the wrapped line's height. Following is the code. Theoretically, height for aLebel should be > bLabel. But the result appear the same.
code:
aLabel.setText("this is a super long long long text that need wrapping."); // line wrapped into 3 lines
aLabel.setWrap(true);
aLabel.setWidth(470);
doLog("aLabel.getHeight(): " + aLabel.getHeight());
bLabel.setText("this is short."); // unwrapped line
bLabel.setWrap(true);
bLabel.setWidth(470);
doLog("bLabel.getHeight(): " + bLabel.getHeight());
result:
aLabel.getHeight(): 45.0
bLabel.getHeight(): 45.0
Do anyone have any idea how to get the actual multi-line height in LibGdx? Thanks in advance.

I had this issue for years and accidentally solved it by setting the width and packing the label twice. Note that multiline labels were never intended to figure out their own width, so you have to set them externally, preferably from it's parent.
public Label createLabel() {
// Create label and set wrap
Label label = new Label("Some long string here...", skin);
label.setWrap(true);
// Pack label
label.pack(); // This might not be necessary, unless you're changing other attributes such as font scale.
// Manual sizing
label.setWidth(textWidth); // Set the width directly
label.pack(); // Label calculates it's height here, but resets width to 0 (bug?)
label.setWidth(textWidth); // Set width again
return label;
}
LibGDX version used: 1.6.4

Pack sizes the widget to its pref size, nothing more. Pref width of a label with wrapping is 0.
Label label = new Label(...);
label.setWrap(true);
label.setWidth(123);
label.setHeight(label.getPrefHeight());

I had the same issue and it seems there doesn't exist a method in Label class to solve this. Also, I agree with you, the getHeight() method should return the real height of the Actor, so I don't know if that's a bug or there is a reasoning behind that behaviour.
Anyways, how I solved the issue is by using BitmapFont's getWrappedBounds method. It's not short, but for your example it would be the following:
doLog("aLabel.getHeight(): " + aLabel.getStyle().font.getWrappedBounds(aLabel.getText(), aLabel.getWidth()).height);

This could be done by adding a restriction to the cell that contains the Label in the Table:
Label label = new Label("Example", new Label.LabelStyle(font, Color.WHITE));
label.setWrap(true);
Table table = new Table();
table.add(label).width(WITH);
For more information about how to use Table go to: https://github.com/libgdx/libgdx/wiki/Table

How can I scale font size to automatically accommodate a static JTextField size?

I'm making a Matrix calculator in Java using a two-dimensional array of JTextFields on a JPanel to input a given Matrix. Since the panel that this matrix is placed on has a fixed size, I want to scale down the text size to accommodate how long the number is as it's being typed in.
For example:
If it's one digit long, font size = 18. If it's two digits long, font size = 14. Etc.
I want this to dynamically occur as the user is entering the text, and I want repainting to occur everytime the user interacts with the JTextField, not only after the user presses "enter". This is because the field is transparent and currently looks sloppy (numbers overlapping) until the user presses enter.
What's the most straightforward and reliable way to do this? Here's my current code if it helps anyone answer my question:
public class MatrixPanel extends JPanel implements ActionListener
{
float[][] matrice = new float[3][3];
JTextField[][] parameter = new JTextField[3][3];
Font font = new Font("SansSerif", Font.BOLD, 40);
public MatrixPanel(String title)
{
setLayout(null);
setOpaque(false);
for (int width = 0; width < 3; width++){
for (int height = 0; height < 3; height++){
matrice[width][height] = 0;
parameter[width][height] = new JTextField();
parameter[width][height].setHorizontalAlignment(JTextField.CENTER);
parameter[width][height].setFont(font);
parameter[width][height].setText("0");
parameter[width][height].setLocation((50*width), (50*height));
parameter[width][height].setSize(50,50);
parameter[width][height].setOpaque(false);
parameter[width][height].setBorder(null);
parameter[width][height].addActionListener(this);
add(parameter[width][height]);
}
setSize(150,150);
}
}

I want to scale down the text size to accommodate how long the number
is as it's being typed in.
Take a look to How to Write a DocumentListener to achieve your goal.
Some useful tips:
About setSize(150,150) and setLocation((50*width), (50*height)): please have a look to this topic Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing? (yes we should). Components size and location should be handled by layout managers.
You may want to try GridLayout to place the text fields in a grid and forget about the fixed size/location. See How to Use GridLayout and Laying Out Components Within a Container tutorials for a better understanding on this subject.
If you want to input floats (or doubles) in your matrix then maybe formatted text fields or spinners are a better choice than plain text fields. Take a look to How to Use Formatted Text Fields and How to Use Spinners tutorials.

Scale string to fit into label (Java, AWT)

I have to write app, which can scale font's size of label and buttons depending on size of entire frame. My idea is to increase size of font until whole text fits into label or button.
How can I check is all string fit to button/label?

Something like the following
JComponent c = ... // it can be label, button or any other component
FontMetrics fm = c.getFontMetrics(c.getFont()); // or another font
int strw = fm.stringWidth("My text");
I took this example from Getting string size in java (without having a Graphics object available)

Make JCheckbox bigger..?

i want to make my JCheckboxes in a JTable bigger (for Touchscreen), but it doesn't change the size.
I tried it with
setPrefferedSize
setSize
What should I do?..

I assume you mean you want a bigger check box. If so then you need to create images to represent the unselected and selected icons of the check box. Then you can create a renderer and editor using these icons. Finally you would need to increase the height of each row in the table. The code might look something like:
Icon normal = new ImageIcon(...);
Icon selected = new ImageIcon(...);
JTable table = new JTable(...);
table.setRowHeight(...);
TableCellRenderer renderer = table.getDefaultRenderer(Boolean.class);
JCheckBox checkBoxRenderer = (JCheckBox)renderer;
checkBoxRenderer.setIcon( normal );
checkBoxRenderer.setSelectedIcon( selected );
DefaultCellEditor editor = (DefaultCellEditor)table.getDefaultEditor(Boolean.class);
JCheckBox checkBoxEditor = (JCheckBox)editor.getComponent();
checkBoxEditor.setIcon( normal );
checkBoxEditor.setSelectedIcon( selected );

IMPORTANT NOTE: This was only tested with the default 'Metal' look and feel. I do not guarantee that this will work for any other look and feel. Also I am not entirely sure how it works because it is admittedly a bit of a hack.
I was able to solve this in a slightly different way.
I wanted to use the existing images and just apply a scale to it. I am already scaling the font of my application using the UI defaults and so I have a rather large font. I wondered if I could leverage that and scale the check boxes accordingly.
After scouring the internet and trying a bunch of things I came up with this method:
public static void scaleCheckBoxIcon(JCheckBox checkbox){
boolean previousState = checkbox.isSelected();
checkbox.setSelected(false);
FontMetrics boxFontMetrics = checkbox.getFontMetrics(checkbox.getFont());
Icon boxIcon = UIManager.getIcon("CheckBox.icon");
BufferedImage boxImage = new BufferedImage(
boxIcon.getIconWidth(), boxIcon.getIconHeight(), BufferedImage.TYPE_INT_ARGB
);
Graphics graphics = boxImage.createGraphics();
try{
boxIcon.paintIcon(checkbox, graphics, 0, 0);
}finally{
graphics.dispose();
}
ImageIcon newBoxImage = new ImageIcon(boxImage);
Image finalBoxImage = newBoxImage.getImage().getScaledInstance(
boxFontMetrics.getHeight(), boxFontMetrics.getHeight(), Image.SCALE_SMOOTH
);
checkbox.setIcon(new ImageIcon(finalBoxImage));
checkbox.setSelected(true);
Icon checkedBoxIcon = UIManager.getIcon("CheckBox.icon");
BufferedImage checkedBoxImage = new BufferedImage(
checkedBoxIcon.getIconWidth(), checkedBoxIcon.getIconHeight(), BufferedImage.TYPE_INT_ARGB
);
Graphics checkedGraphics = checkedBoxImage.createGraphics();
try{
checkedBoxIcon.paintIcon(checkbox, checkedGraphics, 0, 0);
}finally{
checkedGraphics.dispose();
}
ImageIcon newCheckedBoxImage = new ImageIcon(checkedBoxImage);
Image finalCheckedBoxImage = newCheckedBoxImage.getImage().getScaledInstance(
boxFontMetrics.getHeight(), boxFontMetrics.getHeight(), Image.SCALE_SMOOTH
);
checkbox.setSelectedIcon(new ImageIcon(finalCheckedBoxImage));
checkbox.setSelected(false);
checkbox.setSelected(previousState);
}
What it does is get the size of the font from the checkbox's font metrics. Then using that it derives a new icon based on the icon found in the 'Look and Feel'.
One odd thing that I am not able to explain is how the icon for the checkbox in its 'un-selected' or default state, changes to the 'selected' icon, when I am accessing the same property to get each one.
I start by saving the state of the control so I can restore it at the end. This is done because in order for the icons to be set properly, the state needs to be unchecked when you first request the icon from the UIManager and then it will need to be checked when you request the icon the second time to get the 'selected' icon.
I am not entirely sure how the UIManager works or why the checkbox icon changes when we call the same property just by setting the 'selected' value of a single checkbox, but that is what is required in order to get both the necessary icons.
If you did not want to base the size on the font you could easily just pass in the height and width as parameters and use them instead of the font's height when setting the buffered image size.
I might mention that this same methodology works with radiobuttons