scrolling JLabel in Java

Question

i have a little issue with jlabel. When the label displays doubles which are to large for the screen, I would like to have a scrollbar to see them anyway. I have just added a scrollbar to the whole panel, but it does not check, when a overlong double is displayed.

here is my code

 public class OverviewPanel extends JPanel {
    private static final long serialVersionUID = 1L;
    private JLabel textNoNodes = new JLabel();
    private JLabel textNoEdges = new JLabel();
    private JLabel textInitial = new JLabel();
    private JLabel textTargets = new JLabel();
    private JLabel textFilename = new JLabel();
    private JLabel textProbabilityModelCheck = new JLabel();
    private JLabel textProbabilityCounterExample = new JLabel();
    private JLabel textNoSteps = new JLabel();

    public OverviewPanel() {
        super(new SpringLayout());
        addRow("Number states", textNoNodes);
        addRow("Number edges", textNoEdges);
        addRow("Initial", textInitial);
        addRow("Targets", textTargets);
        addRow("Filename", textFilename);
        addRow("Prob. model check", textProbabilityModelCheck);
        addRow("Prob. counter example", textProbabilityCounterExample);
        addRow("Number steps", textNoSteps);
        SpringUtilities.makeCompactGrid(this, 8, 2, // rows, cols
                6, 6, // initX, initY
                6, 6); // xPad, yPad
        setDefault();
    }

    private void addRow(String text, JComponent component) {
        JLabel l = new JLabel(text);
        add(l);
        l.setLabelFor(component);       
        add(component);
    }
   ...
   }

are you re_create OverviewPanel on Runtime or OverviewPanel is created once times and you want to resize JComponets depends of its contents, converting lenght of text to the pixels — mKorbel, Jan 10 '12 at 13:22
It is initially created with default values and reloads when an action did happen, but not like a listener. the reload function is explicitly called. — user1140737, Jan 10 '12 at 13:45

trashgod · Answer 1 · 2012-01-10T15:58:55.863

3

Use pack(), which "Causes this Window to be sized to fit the preferred size and layouts of its subcomponents." An sscce may be helpful, too.

Addendum: An instance of DecimalFormat may be help control extreme size variability.

edited Jan 10 '12 at 15:58

answered Jan 10 '12 at 13:22

trashgod

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I do not see how pack() is applicable to the outPutPanel. In fact it works with frames, but this is a JPanel. – user1140737 Jan 10 '12 at 13:42
1

Yes, you should invoke `pack()` on the panel's enclosing `Window`. Dynamically, you can use `revalidate()`, typically followed by `repaint()`. – trashgod Jan 10 '12 at 13:47
Moreover, pack() will de-maximize a window... better use revalidate()+repaint() – gotch4 Jan 10 '12 at 17:38

score 2 · Answer 2 · answered Jan 10 '12 at 15:26

2

IMHO, I would use a modified JTextArea (i.e. disabled, wrapped, and opaque). No scrolling, resizing, or font metric calculations required!

answered Jan 10 '12 at 15:26

mre

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+1 Along the same lines, a one-column `JTable` gives a nice result with type `Double`. – trashgod Jan 10 '12 at 15:54

score 1 · Answer 3 · answered Jan 10 '12 at 13:20

1

I'm not sure, because I don't know springlayout, anyway I think you have to set the size of the label to the size of the text. To get it you can use:

FontMetrics fm = someComponent.getFontMetrics(someFont);
  int width = fm.stringWidth(someString);

maybe adding some extra space. Then with the label at the actual width the container should scroll...

Of course I'm talking of minimumSize or it is ineffective...

answered Jan 10 '12 at 13:20

gotch4

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This seems needlessly laborious; the `JLabel` itself can calculate its own preferred size on validation. – trashgod Jan 10 '12 at 13:25

scrolling JLabel in Java

3 Answers3