// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.gui;
import java.awt.Dimension;
import java.awt.Rectangle;
import javax.swing.JLabel;
import javax.swing.plaf.basic.BasicHTML;
import javax.swing.text.View;
/**
* Creates a normal label that will wrap its contents if there less width than
* required to print it in one line. Additionally the maximum width of the text
* can be set using setMaxWidth.
*
* Note that this won't work if JMultilineLabel is put into a JScrollBox or
* similar as the bounds will never change. Instead scrollbars will be displayed.
*/
public class JMultilineLabel extends JLabel {
private int maxWidth = Integer.MAX_VALUE;
private Dimension superPreferred = null;
private Rectangle oldbounds = null;
private Dimension oldPreferred = null;
/**
* Constructs a normal label but adds HTML tags if not already done so.
* Supports both newline characters (\n) as well as the HTML
* <br> to insert new lines.
*
* Use setMaxWidth to limit the width of the label.
* @param text
*/
public JMultilineLabel(String text)
{
super();
text = text.trim().replaceAll("\n", "
");
if(!text.startsWith("")) {
text = "" + text + "";
}
super.setText(text);
}
/**
* Set the maximum width. Use this method instead of setMaximumSize because
* this saves a little bit of overhead and is actually taken into account.
*
* @param width
*/
public void setMaxWidth(int width) {
this.maxWidth = width;
}
/**
* Tries to determine a suitable height for the given contents and return
* that dimension.
*/
@Override
public Dimension getPreferredSize()
{
// Without this check it will result in an infinite loop calling
// getPreferredSize. Remember the old bounds and only recalculate if
// the size actually changed.
if(this.getBounds().equals(oldbounds) && oldPreferred != null)
return oldPreferred;
oldbounds = this.getBounds();
this.superPreferred = super.getPreferredSize();
// Make it not larger than required
int width = Math.min(superPreferred.width, maxWidth);
// Calculate suitable width and height
final View v = (View) super.getClientProperty(BasicHTML.propertyKey);
if(v == null)
return superPreferred;
v.setSize(width, 0);
int w = (int) Math.ceil(v.getPreferredSpan(View.X_AXIS));
int h = (int) Math.ceil(v.getPreferredSpan(View.Y_AXIS));
oldPreferred = new Dimension(w, h);
return oldPreferred;
}
}