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

How to set the line spacing in a JtextPane?

First of all, i set the JTextPane like this:
HTMLEditorKit editorKit = new HTMLEditorKit();
HTMLDocument document = (HTMLDocument) editorKit.createDefaultDocument();
JTextPane textPane = new JTextPane();
textPane.setContentType("text/html");
textPane.setDocument(document);
and i want to set the line spacing in the JtextPane , this is my idea,but it can't work:
SimpleAttributeSet aSet = new SimpleAttributeSet();
StyleConstants.setLineSpacing(aSet, 50);
textPane.setParagraphAttributes(aSet, false);
i was wrong?

When you call textPane.setParagraphAttributes(aSet, false);
it tries to apply line spacing to selection but nothing is selected
Call it another way
document.setParagraphAttributes(0, document.getLength(), attr, replace);

To style JTextPane you could use Stylesheets: Look for HtmlEditorKit#setStyleSheet
StyleSheet sh = editorKit.getStyleSheet();
sh.addRule("body {line-height: 50px}");

I was struggling with this problem and then in the API of the method public void setParagraphAttributes(AttributeSet attr, boolean replace), I found this:
If there is a selection, the attributes are applied to the paragraphs that intersect the selection. If there is no selection, the attributes are applied to the paragraph at the current caret position.
So the approach of OP will work, but you must apply textPane.selectAll() before setting the line spacing. You only have to do it once, and all the text appended to this JTextPane will have the same line space, even though you may have no text in the pane when you set the line spacing. I do it when it's instantiated.
Thus the code working for me is:
/**
* Select all the text of a <code>JTextPane</code> first and then set the line spacing.
* #param the <code>JTextPane</code> to apply the change
* #param factor the factor of line spacing. For example, <code>1.0f</code>.
* #param replace whether the new <code>AttributeSet</code> should replace the old set. If set to <code>false</code>, will merge with the old one.
*/
private void changeLineSpacing(JTextPane pane, float factor, boolean replace) {
pane.selectAll();
MutableAttributeSet set = new SimpleAttributeSet(pane.getParagraphAttributes());
StyleConstants.setLineSpacing(set, factor);
txtAtributosImpresora.setParagraphAttributes(set, replace);
}
Note: it will replace the current line spacing with factor*(line height of text), not factor * original line spacing. Strange enough.
If the JTextPane is in a JScrollPane and the length of text is too long, it will scroll to the very bottom. Usually we want to see the top part. To reset the position of the scroll, at last you can add:
pane.setCaretPosition(0); //scroll to the top at last.
P.S.: To set the paragraph margin, we have:
textPane.setMargin(new Insets(10, 5, 10, 5)); //top, left, bottom, right

Java - Change font in a JTextPane containing HTML

I have a JTextPane and I have some text within that JTextPane. However, because I have been using HTML within the Pane, the text seems to have been automatically changed to Times New Roman.
I'm trying to set the font type within the JTextPane to the default font of the GUI (the font of the JTextPane when it's not HTML). However I can't just set the font to one font because it differs from operating system, therefore I want to find a way to get the default font and then change the text I have to the default font.
To demonstrate how the text is swapped to Times New Roman when converted, the following code is the format I have used. How could I change it to achieve my goal?
import javax.swing.JFrame;
import javax.swing.JTextPane;
public class GUIExample {
public static void main(String[] args) {
JFrame frame = new JFrame("My App");
frame.setSize(300,300);
JTextPane pane = new JTextPane();
pane.setContentType("text/html");
pane.setText("<html><b>This is some text!</b></html>");
frame.add(pane);
frame.setVisible(true);
}
}
Thanks!

The following will do the trick:
pane.putClientProperty(JEditorPane.HONOR_DISPLAY_PROPERTIES, true);
(Note that JTextPane extends JEditorPane.)
Update (Aug 2016):
For the setting to survive Look & Feel and system changes (e.g. Fonts changed in the Windows Control Panel) the line can be placed here:
#Override
public void updateUI() {
super.updateUI();
putClientProperty(JEditorPane.HONOR_DISPLAY_PROPERTIES, true);
}
(This is also called during construction.)

Simplest way is probably something like this:
string fontfamily = pane.getFont().getFamily();
That will give you the default font. Then just apply it using CSS:
pane.setText("<html><body style=\"font-family: " + fontfamily + "\"<b>This is some text!</b></html>");

The JComponent html renderer uses its own font, and not that of the JComponent. In order to get the component to render the same, you need to set the font attributes in the html string. Among other things, you will need to set the font family, size, bold/italics, etc.
As an example, you could do the following:
JTextPane pane = new JTextPane();
Font font = pane.getFont();
pane.setContentType("text/html");
pane.setText("<html><font face=\"" + font.getFamily() + "\" size=\"" + font.getSize() + "\"></font>This is some text!</html>");
It would be fairly trivial to create a function that does this for you. Pass it a JComponent and a string, and it would create the html text for you, including all the font tags.

Text widget with self-adjusting height based on interactively entered text?

Using SWT and Java, I have a Text widget defined which is set for multi-line and wrap properties. I added a listener which will monitor any changes to the text inside this text widget, and I want the height of the widget to automatically change if the user adds a new line of text, or if the text wraps around to the next line. So, I want all of the text visible in the text widget if the user adds new text, or deletes text. Here's a sample of what I'm trying to do:
mTextValue = new Text(compositeEditor, SWT.BORDER | SWT.WRAP | SWT.MULTI);
mTextValue.setBackground(SWTResourceManager.getColor(SWT.COLOR_WHITE));
mTextValue.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 1, 1));
mTextValue.addListener(SWT.Modify,new Listener()
{
protected int lines=1;
public void handleEvent(Event e)
{
Text text = (Text) e.widget;
int newlines = text.getLineCount();
if (newlines!=lines)
{
lines=newlines;
height = lines*16;
width = 240;
text.setSize(width,height);
text.getShell().pack(true);
}
}
});
Now, this seems to work ok if I add a single line of text and press the return key to add the next line. The text widget grows in height when I add lines of text, and shrinks in height when I remove lines. Just as I want. But, when I have text that wraps around and I try to add a new line, the text widget is resized in width also. I want to keep the width fixed, and only self adjust the height.
Can anyone offer a suggestion to how I can have the text widget self adjust its height to fit all of the entered text, but keep the width of the text widget always fixed at a prescribed value?
Thanks.

It may be because pack() re-computes the preferred size. I don't see any direct way to set the prefered width to constant. But you may try overriding computeSize method so that you pass fixed width as hint to super class.
i.e
public Point computeSize(int wHint,
int hHint,
boolean changed)
{
return super.computeSize(240, hHint, changed);
}

Java: Linebreaks in JLabels?

I'm trying to make a Swing JLabel with multiple lines of text. It's added just fine, but the line breaks don't come through. How do I do this? Alternatively, can I just specify a maximum width for a JLabel and know that the text would wrap, like in a div?
private void addLegend() {
JPanel comparisonPanel = getComparisonPanel();
//this all displays on one line
JLabel legend = new JLabel("MMM FFF MMM FFFO O OOM M MMMM.\nMMM FFF MMM FFFO O OOM M MMMM.\nMMM FFF MMM FFFO O OOM M MMMM.\n");
comparisonPanel.add(legend);
}

Use HTML in setText, e.g.
myLabel.setText("<html><body>with<br>linebreak</body></html>");

You can get automatic line break if you set the paragraph width in html.
label.setText("<html><p style=\"width:100px\">"+paragraph+"</p></html>");

By default, Swing does not wrap text. If you specify a size on the JLabel it will only paint the part of the text that fits and then add "..." to the end.
As suggested you can use HTML to enable line wrapping. However, I've actually created a custom Swing UI delegate not long ago to achieve this and even more: MultiLineLabelUI.
It will wrap your text to fit the available space and also respect hard line breaks. If you choose to try it out, it is as simple as:
JLabel label = new JLabel("Text that'll wrap if necessary");
label.setUI(MultiLineLabelUI.labelUI);
Or alternatively use the custom MultiLineLabel class that in addition to wrapping text supports vertical and horizontal text alignment.
UPDATE
I lost the domain with the original code samples. It can now be viewed on github instead: https://github.com/sasjo/multiline

You can put HTML inside of a JLabel and use the linebreak tag to achieve this.

What about using the wrapping feature in a JTextArea?
String text = "some really long string that might need to"+
"be wrapped if the window is not wide enough";
JTextArea multi = new JTextArea(text);
multi.setWrapStyleWord(true);
multi.setLineWrap(true);
multi.setEditable(false);
JLabel single = new JLabel(text);
JPanel textpanel = new JPanel(new GridLayout(2,1));
textpanel.add(multi);
textpanel.add(single);
JFrame frame = new JFrame();
frame.add(textpanel);
frame.pack();
frame.setVisible(true);

Simple,use HTML. Java Swing components though does not provide a 'fantastic' support for the HTML, you can use it for such simple purposes.
label.setText("<html>This is first line.<br/>This is second line.</html>");

I did not manage to specify a maximum width for a label but you can specify a concrete width.
By measuring the current width of a JLabel we can only apply the new fixed width if the JLabels's width is higher that our maxWidth:
JLabel label = new JLabel("<html>" + myVeryLongMessage + "<html>");
int maxWidth = 400;
Dimension size = label.getPreferredSize();
if (size.width > maxWidth) {
// Estimate the number of lines
int lineCount = (int) Math.ceil(((double) size.width) / maxWidth);
lineCount += 1; // Add one extra line as reserve
size.width = maxWidth; // Apply the maximum width
// Increase the height so that all lines will be visible
size.height *= lineCount;
label.setPreferredSize(size);
}

You can use a JTextArea and disable the TextArea, this way, you will only display what you want, and the user won't be able to type in
JTextArea area = new JTextArea("Here \n\n you \n\n put \n\n your \n\n text");
area.setBounds(10, 11, 500, 143);
area.setEditable(false);
yourPannel.add(area);