/*
* Copyright (c) 1997, 1999, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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/*
* (C) Copyright Taligent, Inc. 1996 - 1997, All Rights Reserved
* (C) Copyright IBM Corp. 1996 - 1998, All Rights Reserved
*
* The original version of this source code and documentation is
* copyrighted and owned by Taligent, Inc., a wholly-owned subsidiary
* of IBM. These materials are provided under terms of a License
* Agreement between Taligent and Sun. This technology is protected
* by multiple US and International patents.
*
* This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
package java.awt.font;
/*
* one info for each side of each glyph
* separate infos for grow and shrink case
* !!! this doesn't really need to be a separate class. If we keep it
* separate, probably the newJustify code from TextLayout belongs here as well.
*/
class TextJustifier {
private GlyphJustificationInfo[] info;
private int start;
private int limit;
static boolean DEBUG = false;
/** {@collect.stats}
* Initialize the justifier with an array of infos corresponding to each
* glyph. Start and limit indicate the range of the array to examine.
*/
TextJustifier(GlyphJustificationInfo[] info, int start, int limit) {
this.info = info;
this.start = start;
this.limit = limit;
if (DEBUG) {
System.out.println("start: " + start + ", limit: " + limit);
for (int i = start; i < limit; i++) {
GlyphJustificationInfo gji = info[i];
System.out.println("w: " + gji.weight + ", gp: " +
gji.growPriority + ", gll: " +
gji.growLeftLimit + ", grl: " +
gji.growRightLimit);
}
}
}
public static final int MAX_PRIORITY = 3;
/** {@collect.stats}
* Return an array of deltas twice as long as the original info array,
* indicating the amount by which each side of each glyph should grow
* or shrink.
*
* Delta should be positive to expand the line, and negative to compress it.
*/
public float[] justify(float delta) {
float[] deltas = new float[info.length * 2];
boolean grow = delta > 0;
if (DEBUG)
System.out.println("delta: " + delta);
// make separate passes through glyphs in order of decreasing priority
// until justifyDelta is zero or we run out of priorities.
int fallbackPriority = -1;
for (int p = 0; delta != 0; p++) {
/*
* special case 'fallback' iteration, set flag and recheck
* highest priority
*/
boolean lastPass = p > MAX_PRIORITY;
if (lastPass)
p = fallbackPriority;
// pass through glyphs, first collecting weights and limits
float weight = 0;
float gslimit = 0;
float absorbweight = 0;
for (int i = start; i < limit; i++) {
GlyphJustificationInfo gi = info[i];
if ((grow ? gi.growPriority : gi.shrinkPriority) == p) {
if (fallbackPriority == -1) {
fallbackPriority = p;
}
if (i != start) { // ignore left of first character
weight += gi.weight;
if (grow) {
gslimit += gi.growLeftLimit;
if (gi.growAbsorb) {
absorbweight += gi.weight;
}
} else {
gslimit += gi.shrinkLeftLimit;
if (gi.shrinkAbsorb) {
absorbweight += gi.weight;
}
}
}
if (i + 1 != limit) { // ignore right of last character
weight += gi.weight;
if (grow) {
gslimit += gi.growRightLimit;
if (gi.growAbsorb) {
absorbweight += gi.weight;
}
} else {
gslimit += gi.shrinkRightLimit;
if (gi.shrinkAbsorb) {
absorbweight += gi.weight;
}
}
}
}
}
// did we hit the limit?
if (!grow) {
gslimit = -gslimit; // negative for negative deltas
}
boolean hitLimit = (weight == 0) || (!lastPass && ((delta < 0) == (delta < gslimit)));
boolean absorbing = hitLimit && absorbweight > 0;
// predivide delta by weight
float weightedDelta = delta / weight; // not used if weight == 0
float weightedAbsorb = 0;
if (hitLimit && absorbweight > 0) {
weightedAbsorb = (delta - gslimit) / absorbweight;
}
if (DEBUG) {
System.out.println("pass: " + p +
", d: " + delta +
", l: " + gslimit +
", w: " + weight +
", aw: " + absorbweight +
", wd: " + weightedDelta +
", wa: " + weightedAbsorb +
", hit: " + (hitLimit ? "y" : "n"));
}
// now allocate this based on ratio of weight to total weight
int n = start * 2;
for (int i = start; i < limit; i++) {
GlyphJustificationInfo gi = info[i];
if ((grow ? gi.growPriority : gi.shrinkPriority) == p) {
if (i != start) { // ignore left
float d;
if (hitLimit) {
// factor in sign
d = grow ? gi.growLeftLimit : -gi.shrinkLeftLimit;
if (absorbing) {
// sign factored in already
d += gi.weight * weightedAbsorb;
}
} else {
// sign factored in already
d = gi.weight * weightedDelta;
}
deltas[n] += d;
}
n++;
if (i + 1 != limit) { // ignore right
float d;
if (hitLimit) {
d = grow ? gi.growRightLimit : -gi.shrinkRightLimit;
if (absorbing) {
d += gi.weight * weightedAbsorb;
}
} else {
d = gi.weight * weightedDelta;
}
deltas[n] += d;
}
n++;
} else {
n += 2;
}
}
if (!lastPass && hitLimit && !absorbing) {
delta -= gslimit;
} else {
delta = 0; // stop iteration
}
}
if (DEBUG) {
float total = 0;
for (int i = 0; i < deltas.length; i++) {
total += deltas[i];
System.out.print(deltas[i] + ", ");
if (i % 20 == 9) {
System.out.println();
}
}
System.out.println("\ntotal: " + total);
System.out.println();
}
return deltas;
}
}