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Java/media/FirstMatchBreaker.java

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+/*   
+FTextBreaker.java
+ *    
+ *    Copyright (c) 2001, Ted Nelson and Tuomas Lukka
+ *
+ *    You may use and distribute under the terms of either the GNU Lesser
+ *    General Public License, either version 2 of the license or,
+ *    at your choice, any later version. Alternatively, you may use and
+ *    distribute under the terms of the XPL.
+ *
+ *    See the LICENSE.lgpl and LICENSE.xpl files for the specific terms of 
+ *    the licenses.
+ *
+ *    This software is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the README
+ *    file for more details.
+ *
+ */
+/*
+ * Written by Benjamin Fallenstein
+ */
+
+package org.gzigzag;
+import java.awt.*;
+import java.util.*;
+
+/** A class doing linebreaking of FTexts with the stupid first match algorithm.
+ * @see FText
+ */
+
+public class FirstMatchBreaker {
+public static final String rcsid = "$Id$";
+    public static boolean dbg = false;
+    private static final void p(String s) { if(dbg) System.out.println(s); }
+    private static final void pa(String s) { System.out.println(s); }
+
+    static class Word {
+	FText.Part p; int start, end;
+	/** Is a line break enforced after this word? */
+	boolean forced;
+	FText.Part get() { return p.subpart(start, end); }
+	int width() { return p.fm.stringWidth(p.s.substring(start, end)); }
+	Word(FText.Part p, int s, int e, boolean f) { 
+	    this.p=p; start=s; end=e; forced=f;
+	}
+    }
+
+    /** Internal convenience: concatenate all adjacent words in a vector. */
+    private static void concat(Vector v) {
+	int i=0;
+	while(i+1 < v.size()) {
+	    Word w1 = (Word)v.elementAt(i), w2 = (Word)v.elementAt(i+1);
+	    if(w1.p == w2.p && w1.end == w2.start) {
+		w1.end = w2.end;
+		v.removeElement(w2);
+	    } else
+		i++;
+	}
+    }
+
+    /** Internal convenience: search a number of tokens in a string
+     * Returns the next occurence of any of the tokens after the given 
+     * position.
+     */
+    static int indOf(String s, int pos, char[] toks) {
+	for(int i=pos+1; i<s.length(); i++) {
+	    char c = s.charAt(i);
+	    for(int j=0; j<toks.length; j++)
+		if(toks[j] == c) return i;
+	}
+	return -1;
+    }
+
+    /** Prepare an FText for the linebreaker (find possible breaks).
+     * Returns a Vector of Word objects.
+     */
+    public static Vector prepare(FText txt) {
+	final char[] delims = new char[] { ' ', '\n' };
+	
+	if(txt.parts.length == 0)
+	    throw new ZZError("FText has length 0");
+	Vector v = new Vector();
+	p("prepare: Old FText (len "+txt.parts.length+"): "+txt.get());
+	
+	for(int i=0; i<txt.parts.length; i++) {
+	    FText.Part p = txt.parts[i];
+	    String s = p.s;
+	    int here, last = -1;
+	    while((here = indOf(s, last, delims)) >= 0) {
+		char c = s.charAt(here);
+		v.addElement(new Word(p, last+1, here+1, c == '\n'));
+		last = here;
+	    }
+	    v.addElement(new Word(p, last+1, s.length(), false));
+	}
+
+	return v;
+    }
+
+    /** Internal convenience: Vector to array. */
+    private static FText.Part[] v2a(Vector v) {
+	concat(v);
+	FText.Part[] res = new FText.Part[v.size()];
+	for(int i=0; i<res.length; i++)
+	    res[i] = ((Word)v.elementAt(i)).get();
+	return res;
+    }
+
+    public static FText.Part[][] stupidBreak(FText ftxt, int width) {
+	Vector prep = prepare(ftxt); int psize = prep.size();
+	Vector lineset = new Vector(), line = new Vector();
+	int x = 0, linestart = 0;
+	p("FTextBreaker.stupidBreak...");
+	for(int i=0; i<psize; i++) {
+	    Word w = (Word)prep.elementAt(i);
+	    x += w.width();
+	    if(!w.forced && x <= width) {
+		line.addElement(w);
+		continue;
+	    }
+	    if(i > linestart && x > width) {
+		lineset.addElement(v2a(line));
+		line.removeAllElements();
+		x = w.width(); linestart = i;
+	    }
+	    line.addElement(w);
+	    if(x > width || w.forced) {
+		/* w alone doesn't fit on our line, or forced break after w */
+		lineset.addElement(v2a(line));
+		line.removeAllElements();
+		x = 0; linestart = i+1;
+	    }
+	}
+	if(line.size() > 0) lineset.addElement(v2a(line));
+	FText.Part[][] res = new FText.Part[lineset.size()][];
+	for(int j=0; j<res.length; j++) {
+	    res[j] = (FText.Part[])lineset.elementAt(j);
+	    if(dbg) pa("	"+(j+1)+". "+new FText(res[j]).get());
+	}
+	return res;
+    }
+}