Develop Reference

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

Change Swing font size from command line

I am using a Swing application which on my computer shows text with a ridiculously small font size.
Is there a way to change the font size, or maybe some kind of DPI setting, from the command line or with some kind of configuration file (for example, something like a swing.properties file)?
I don't have access to the source code.
EDIT:
Small font sizes should not be a problem any more since Java 9. Swing has started to scale its GUI components depending on the screen resolution.

There is no command line switch to change the font size for Swing. What you would have to do is to invoke the following method:
public static void adjustFontSize(int adjustment) {
UIDefaults defaults = UIManager.getDefaults();
List<Object> newDefaults = new ArrayList<Object>();
Map<Object, Font> newFonts = new HashMap<Object, Font>();
Enumeration<Object> en = defaults.keys();
while (en.hasMoreElements()) {
Object key = en.nextElement();
Object value = defaults.get(key);
if (value instanceof Font) {
Font oldFont = (Font)value;
Font newFont = newFonts.get(oldFont);
if (newFont == null) {
newFont = new Font(oldFont.getName(), oldFont.getStyle(), oldFont.getSize() + adjustment);
newFonts.put(oldFont, newFont);
}
newDefaults.add(key);
newDefaults.add(newFont);
}
}
defaults.putDefaults(newDefaults.toArray());
}
where adjustment is the number of points that should be added to each font size.
If you don't have access to the source code, you can always write your own wrapper main class where you call
UIManager.addPropertyChangeListener(new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent event) {
if (event.getPropertyName().equals("lookAndFeel")) {
adjustFontSize(5);
}
}
});
before invoking the main method of the actual application.
However, if the font size is very small, it has likely been set explicitly, so changing the defaults might not help.

I don't think there are such options since all the component Font sizes are defined in Look and Feel (L&F) default values. Some of L&Fs allow quick font changes, some of them doesn't. In most cases you should be able change the font size by changing the UI defaults:
UIManager.put ( "Button.font", new SwingLazyValue ( "javax.swing.plaf.FontUIResource", null, new Object[]{ fontName, fontStyle, fontSize } ) );
UIManager.put ( "Label.font", new SwingLazyValue ( "javax.swing.plaf.FontUIResource", null, new Object[]{ fontName, fontStyle, fontSize } ) );
UIManager.put ( "TextField.font", new SwingLazyValue ( "javax.swing.plaf.FontUIResource", null, new Object[]{ fontName, fontStyle, fontSize } ) );
e.t.c for each component.
And i am not sure if those values could be passed to application without changing its code or atleast having some font-size change support inside the application.

I have not tested it, but you might try launching the app. using Java Web Start. It allows properties like swing.useSystemFontSettings & swing.metalTheme to be specified even for sand-boxed apps. Doing either might 'override' small fonts set in the code.
See the JNLP file syntax for more details.

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

Beautiful (Anti-alias) Chinese Character Display

(source: google.com)
Recently, I realize the Chinese Character displayed are rather ugly in my application.
I thought I should make them to "anti-alias". But, how can I do that in Java?
FYI, I didn't explicitly choose the font I want to use in my GUI application. I solely let the system decide their own during startup. I however, do explicitly set the locale, before show up the GUI.
Locale.setDefault(locale);
The system will always choose
javax.swing.plaf.FontUIResource[family=Tahoma,name=Tahoma,style=plain,size=11]
no matter I am in English or Chinese locale.

Anti-aliasing considered harmful: http://www.joelonsoftware.com/articles/fog0000000041.html
The point is, that beauty of characters is not necessarily the user interface goal. It is not everything. What you should look for, is readability of text. When your Chinese characters look not smooth, it may be exactly what helps human eye's control loop to know that it is in focus and stop blaming the eye muscules for blurriness. Really, don't fall in this pitfal.

Here's a method to read a truetype font from the classpath and register it with the graphics environment:
private static Font readFont(String name) {
InputStream in = Fonts.class.getResourceAsStream(name + ".ttf");
if (in == null) {
throw new IllegalArgumentException(name);
}
try {
Font retval = Font.createFont(Font.TRUETYPE_FONT, in);
GraphicsEnvironment.getLocalGraphicsEnvironment().registerFont(retval);
return retval;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
You can then use this font object to derive characters of different sizes, or you could try applying this font using Swing CSS. In this case, the value you would put in the "font-family" attribute is the value returned by Font.getName().
For example:
static {
Font font = readFont("VeraMono");
if (font != null) {
font = font.deriveFont(14f);
} else {
throw new IllegalStateException();
}
MONOSPACED_TEXT_FONT = font;
MONOSPACED_TEXT_FONT_STYLE = "font-family: " + font.getName() + "; font-size: 14pt; font-weight: normal;";
}

SWT Link flickers with gradient background

I'm developing a an eclipse plugin that uses an SWT interface. I need to display text, and within that text there needs to be links. The only two widgets that I've found that will allow me to include clickable links in text are Link and Browser. Browser, however, is overkill for my needs, and I couldn't properly customize the look of it. This only leaves the Link widget.
The problem is I need the Link widget to inherit a gradient from the Composite in which it is in. It does this correctly, only when it is resized or scrolled the Link component flickers. The Link is the only component in which I have seen this effect.
In an attempt to fix this I've tried manipulating other components into having clickable links, but I haven't found a good solution yet.
Is there anyway to fix the flickering effect on the Link, or is there a different component which would support links?
Thanks,
Brian

After spending the day working on this, I came up with a workaround. I created a Composite for the text area. For each word that isn't part of a url,got its own label. For links, each letter got its own label. Then the labels for the url characters got a listener to launch a browser. Using this method provided the Link functionality, handled resizing properly, and has no flicker.

Have you tried passing SWT.NO_BACKGROUND to your Link widget? It might get a little strange... and you may have to do a little more work to get the gui drawing properly, but that would be my first guess.
Other than that, here's my Quick n' dirty implementation of a link inside of a StyledText. You will need to fill in for changing the cursor (if that's something you want), as well as coming up with a good "text to link" mapping scheme.
The only thing is I'm not sure if StyledText will inherit your background... give it a shot.
public class StyledTextExample {
public static void main(String [] args) {
// create the widget's shell
Shell shell = new Shell();
shell.setLayout(new FillLayout());
shell.setSize(200, 100);
Display display = shell.getDisplay();
// create the styled text widget
final StyledText widget = new StyledText(shell, SWT.NONE);
String text = "This is the StyledText widget.";
widget.setText(text);
widget.setEditable(false);
final StyleRange hyperlinkStyle = new StyleRange();
String linkWord = "StyledText";
hyperlinkStyle.start = text.indexOf(linkWord);
hyperlinkStyle.length = linkWord.length();
hyperlinkStyle.fontStyle = SWT.BOLD;
hyperlinkStyle.foreground = display.getSystemColor(SWT.COLOR_BLUE);
widget.setStyleRange(hyperlinkStyle);
widget.addMouseListener(new MouseAdapter() {
public void mouseUp(MouseEvent arg0) {
Point clickPoint = new Point(arg0.x, arg0.y);
try {
int offset = widget.getOffsetAtLocation(clickPoint);
if (widget.getStyleRangeAtOffset(offset) != null) {
System.out.println("link");
}
} catch (IllegalArgumentException e) {
//ignore, clicked out of text range.
}
}});
shell.open();
while (!shell.isDisposed())
if (!display.readAndDispatch()) display.sleep();
}
}