Java JLabel Size getPreferredSize(JLabel label)

Description

get Preferred Size

License

Open Source License

Declaration

public static Dimension getPreferredSize(JLabel label) 

Method Source Code

//package com.java2s;
/* /*ww w  . j ava 2 s. co  m*/
 * The MIT License
 *
 * Copyright 2014 Kamnev Georgiy (nt.gocha@gmail.com).
 */

import java.awt.Component;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.geom.Rectangle2D;
import java.lang.ref.WeakReference;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import javax.swing.border.Border;

public class Main {
    private static WeakReference<Component> host = null;

    public static Dimension getPreferredSize(JLabel label) {
        if (label == null) {
            throw new IllegalArgumentException("label==null");
        }

        Dimension preferredSize = null;

        Dimension dm = getTextDimension(label);
        dm = extendByIcon(label, dm);
        dm = extendByBorder(label, dm);
        preferredSize = dm;

        return preferredSize;
    }

    public static Dimension getTextDimension(JLabel label) {
        if (label == null) {
            throw new IllegalArgumentException("label==null");
        }

        int width = 0;
        int height = 0;

        String text = label.getText();
        if (text != null) {
            Component c = getHost();
            Graphics2D gs = null;

            if (c == null) {
                gs = (Graphics2D) label.getGraphics();
            } else {
                gs = (Graphics2D) c.getGraphics();
            }

            FontMetrics fm = label.getFontMetrics(label.getFont());

            if (gs == null) {
                height = fm.getHeight();
                width = fm.stringWidth(text);
            } else {
                Rectangle2D rect = fm.getStringBounds(text, gs);
                double w = rect.getWidth();
                double h = rect.getHeight();
                width = (int) w;
                height = (int) h;
                gs.dispose();
            }
        }

        return new Dimension(width, height);
    }

    public static Dimension extendByIcon(JLabel label, Dimension dm) {
        if (label == null) {
            throw new IllegalArgumentException("label==null");
        }
        if (dm == null) {
            throw new IllegalArgumentException("dm==null");
        }

        javax.swing.Icon icon = label.getIcon();
        if (icon == null)
            return dm;

        int vertTextPos = label.getVerticalTextPosition();
        int horzTextPos = label.getHorizontalTextPosition();

        int iconTextGap = label.getIconTextGap();
        int icoWidth = icon.getIconWidth();
        int icoHeight = icon.getIconHeight();

        if (vertTextPos == SwingConstants.CENTER) {
            if (horzTextPos == SwingConstants.CENTER) {
                int nw = -1;
                int nh = -1;
                if (dm.getWidth() < icoWidth)
                    nw = icoWidth;
                if (dm.getHeight() < icoHeight)
                    nh = icoHeight;
                if (nw < 0 && nh < 0)
                    return dm;
                return new Dimension(nw < 0 ? dm.width : nw,
                        nh < 0 ? dm.height : nh);
            } else {
                int nh = -1;
                if (dm.getHeight() < icoHeight)
                    nh = icoHeight;
                return new Dimension(icoWidth + iconTextGap + dm.width,
                        nh < 0 ? dm.height : nh);
            }
        } else {
            int nw = -1;
            if (dm.getWidth() < icoWidth)
                nw = icoWidth;
            return new Dimension(nw < 0 ? dm.width : nw, dm.height
                    + iconTextGap + icoHeight);
        }
    }

    public static Dimension extendByBorder(JLabel label, Dimension dm) {
        if (label == null) {
            throw new IllegalArgumentException("label==null");
        }
        if (dm == null) {
            throw new IllegalArgumentException("dm==null");
        }

        Border border = label.getBorder();
        if (border != null) {
            Insets insets = border.getBorderInsets(label);
            return new Dimension(dm.width + insets.left + insets.right,
                    dm.height + insets.top + insets.bottom);
        }
        return dm;
    }

    public static Component getHost() {
        if (host == null)
            return null;
        return host.get();
    }
}

Related

1. adjustLabelSizes(List labels)
2. getLabelPreferredSize(JLabel label)
3. getPreferredLabelSize(JLabel c, int widthHint)
4. makeSameSize(int alignment, JLabel... labels)
5. resizeLabel(JLabel label, Dimension newDim)