FOP-3280: Optimise memory when font has no kerning

Author: simonsteiner1984

fop-core/src/main/java/org/apache/fop/layoutmgr/inline/TextLayoutManager.java

@@ -98,7 +98,7 @@ private PendingChange(final GlyphMapping mapping, final int index) {
      * be used to influence the start position of the first letter. The entry i+1 defines the
      * cursor advancement after the character i. A null entry means no special advancement.
      */
-    private final MinOptMax[] letterSpaceAdjustArray; //size = textArray.length + 1
+    private MinOptMax[] letterSpaceAdjustArray; //size = textArray.length + 1
 
     /** Font used for the space between words. */
     private Font spaceFont;
@@ -142,7 +142,6 @@ private PendingChange(final GlyphMapping mapping, final int index) {
      */
     public TextLayoutManager(FOText node, FOUserAgent userAgent) {
         foText = node;
-        letterSpaceAdjustArray = new MinOptMax[node.length() + 1];
         mappings = new ArrayList<GlyphMapping>();
         this.userAgent = userAgent;
     }
@@ -267,7 +266,7 @@ private void addMappingAreas(GlyphMapping mapping, int wordSpaceCount, int lette
         }
 
         for (int i = mapping.startIndex; i < mapping.endIndex; i++) {
-            MinOptMax letterSpaceAdjustment = letterSpaceAdjustArray[i + 1];
+            MinOptMax letterSpaceAdjustment = getLetterSpaceAdjustment(i + 1);
             if (letterSpaceAdjustment != null && letterSpaceAdjustment.isElastic()) {
                 letterSpaceCount++;
             }
@@ -659,8 +658,7 @@ private void addLetterAdjust(GlyphMapping wordMapping) {
                 int j = letterSpaceAdjustIndex + i;
                 if (j > 0) {
                     int k = wordMapping.startIndex + i;
-                    MinOptMax adj = (k < letterSpaceAdjustArray.length)
-                        ? letterSpaceAdjustArray [ k ] : null;
+                    MinOptMax adj = getLetterSpaceAdjustment(k);
                     letterSpaceAdjust [ j ] = (adj == null) ? 0 : adj.getOpt();
                 }
                 if (letterSpaceCount > 0) {
@@ -975,6 +973,9 @@ private GlyphMapping processWord(final int alignment, final KnuthSequence sequen
         char breakOpportunityChar = breakOpportunity ? ch : 0;
         char precedingChar = prevMapping != null && !prevMapping.isSpace
                 && prevMapping.endIndex > 0 ? foText.charAt(prevMapping.endIndex - 1) : 0;
+        if (letterSpaceAdjustArray == null && font.hasKerning()) {
+            letterSpaceAdjustArray = new MinOptMax[foText.length() + 1];
+        }
         GlyphMapping mapping = GlyphMapping.doGlyphMapping(foText, thisStart, lastIndex, font,
                 letterSpaceIPD, letterSpaceAdjustArray, precedingChar, breakOpportunityChar,
                 endsWithHyphen, level, false, false, retainControls);
@@ -1076,7 +1077,7 @@ public void hyphenate(Position pos, HyphContext hyphContext) {
                 newIPD = newIPD.plus(font.getCharWidth(cp));
                 //if (i > startIndex) {
                 if (i < stopIndex) {
-                    MinOptMax letterSpaceAdjust = letterSpaceAdjustArray[i + 1];
+                    MinOptMax letterSpaceAdjust = getLetterSpaceAdjustment(i + 1);
                     if (i == stopIndex - 1 && hyphenFollows) {
                         //the letter adjust here needs to be handled further down during
                         //element generation because it depends on hyph/no-hyph condition
@@ -1388,7 +1389,7 @@ private void addElementsForAWordFragment(List baseList, int alignment, GlyphMapp
             MinOptMax widthIfNoBreakOccurs = null;
             if (mapping.endIndex < foText.length()) {
                 //Add in kerning in no-break condition
-                widthIfNoBreakOccurs = letterSpaceAdjustArray[mapping.endIndex];
+                widthIfNoBreakOccurs = getLetterSpaceAdjustment(mapping.endIndex);
             }
             //if (mapping.breakIndex)
 
@@ -1523,4 +1524,10 @@ public String toString() {
             + "}";
     }
 
+    protected MinOptMax getLetterSpaceAdjustment(int i) {
+        if (letterSpaceAdjustArray == null || i >= letterSpaceAdjustArray.length) {
+            return null;
+        }
+        return letterSpaceAdjustArray[i];
+    }
 }

fop-core/src/test/java/org/apache/fop/layoutmgr/inline/TextLayoutManagerTestCase.java

@@ -0,0 +1,29 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* $Id$ */
+package org.apache.fop.layoutmgr.inline;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TextLayoutManagerTestCase {
+    @Test
+    public void testLetterSpaceAdjustArray() {
+        Assert.assertNull(new TextLayoutManager(null, null).getLetterSpaceAdjustment(1));
+    }
+}