| 1 | // License: GPL. For details, see LICENSE file. |
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| 2 | |
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| 3 | package org.openstreetmap.josm.gui; |
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| 4 | |
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| 5 | import java.awt.Dimension; |
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| 6 | import java.awt.Rectangle; |
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| 7 | |
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| 8 | import javax.swing.JLabel; |
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| 9 | import javax.swing.plaf.basic.BasicHTML; |
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| 10 | import javax.swing.text.View; |
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| 11 | |
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| 12 | /** |
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| 13 | * Creates a normal label that will wrap its contents if there less width than |
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| 14 | * required to print it in one line. Additionally the maximum width of the text |
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| 15 | * can be set using <code>setMaxWidth</code>. |
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| 16 | * |
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| 17 | * Note that this won't work if JMultilineLabel is put into a JScrollBox or |
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| 18 | * similar as the bounds will never change. Instead scrollbars will be displayed. |
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| 19 | */ |
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| 20 | public class JMultilineLabel extends JLabel { |
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| 21 | private int maxWidth = Integer.MAX_VALUE; |
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| 22 | private Dimension superPreferred = null; |
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| 23 | private Rectangle oldbounds = null; |
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| 24 | private Dimension oldPreferred = null; |
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| 25 | |
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| 26 | /** |
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| 27 | * Constructs a normal label but adds HTML tags if not already done so. |
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| 28 | * Supports both newline characters (<code>\n</code>) as well as the HTML |
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| 29 | * <code><br></code> to insert new lines. |
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| 30 | * |
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| 31 | * Use setMaxWidth to limit the width of the label. |
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| 32 | * @param text |
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| 33 | */ |
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| 34 | public JMultilineLabel(String text) |
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| 35 | { |
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| 36 | super(); |
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| 37 | text = text.trim().replaceAll("\n", "<br>"); |
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| 38 | if(!text.startsWith("<html>")) { |
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| 39 | text = "<html>" + text + "</html>"; |
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| 40 | } |
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| 41 | super.setText(text); |
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| 42 | } |
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| 43 | |
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| 44 | /** |
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| 45 | * Set the maximum width. Use this method instead of setMaximumSize because |
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| 46 | * this saves a little bit of overhead and is actually taken into account. |
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| 47 | * |
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| 48 | * @param width |
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| 49 | */ |
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| 50 | public void setMaxWidth(int width) { |
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| 51 | this.maxWidth = width; |
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| 52 | } |
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| 53 | |
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| 54 | /** |
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| 55 | * Tries to determine a suitable height for the given contents and return |
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| 56 | * that dimension. |
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| 57 | */ |
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| 58 | @Override |
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| 59 | public Dimension getPreferredSize() |
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| 60 | { |
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| 61 | // Without this check it will result in an infinite loop calling |
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| 62 | // getPreferredSize. Remember the old bounds and only recalculate if |
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| 63 | // the size actually changed. |
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| 64 | if(this.getBounds().equals(oldbounds) && oldPreferred != null) |
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| 65 | return oldPreferred; |
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| 66 | oldbounds = this.getBounds(); |
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| 67 | |
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| 68 | this.superPreferred = super.getPreferredSize(); |
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| 69 | // Make it not larger than required |
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| 70 | int width = Math.min(superPreferred.width, maxWidth); |
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| 71 | |
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| 72 | // Calculate suitable width and height |
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| 73 | final View v = (View) super.getClientProperty(BasicHTML.propertyKey); |
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| 74 | |
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| 75 | if(v == null) |
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| 76 | return superPreferred; |
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| 77 | |
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| 78 | v.setSize(width, 0); |
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| 79 | int w = (int) Math.ceil(v.getPreferredSpan(View.X_AXIS)); |
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| 80 | int h = (int) Math.ceil(v.getPreferredSpan(View.Y_AXIS)); |
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| 81 | |
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| 82 | oldPreferred = new Dimension(w, h); |
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| 83 | return oldPreferred; |
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| 84 | } |
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| 85 | } |
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