Modernize LogBuilder

src/net/sf/freecol/common/util/LogBuilder.java

@@ -19,26 +19,28 @@
 
 package net.sf.freecol.common.util;
 
-import java.util.ArrayList;
+import java.util.ArrayDeque;
+import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
+import java.util.Collections;
+import java.util.Deque;
+import java.util.Iterator;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import net.sf.freecol.common.debug.FreeColDebugger;
 import net.sf.freecol.common.model.Location;
 
-
 /**
  * A class to wrap a StringBuilder for log generation purposes.
  */
-public class LogBuilder {
+public class LogBuilder implements Iterable<String> {
 
     /** The string builder to use. */
     private final StringBuilder sb;
 
-    /** The remembered buffer index. */
-    private final List<Integer> points = new ArrayList<>();
+    /** The remembered buffer indices. */
+    private final Deque<Integer> points = new ArrayDeque<>();
 
 
     /**
@@ -58,23 +60,23 @@ public LogBuilder(int size) {
      * @return The simple string result.
      */
     private static String o2s(Object o) {
-        return (o == null) ? "null"
-            : (o instanceof Class<?>) ? ((Class<?>) o).getName()
-            : (o instanceof String) ? (String)o
-            : (o instanceof Location) ? ((Location)o).toShortString()
-            : o.toString();
+        if (o == null) return "null";
+        if (o instanceof Class<?>) return ((Class<?>) o).getName();
+        if (o instanceof String) return (String) o;
+        if (o instanceof Location) return ((Location) o).toShortString();
+        return String.valueOf(o);
     }
 
     /**
-     * Add objects to a string builder.
+     * Add objects to a string builder using modern stream handling for arrays.
      *
      * @param sb The {@code StringBuilder} to add to.
      * @param objects The objects to add.
      */
     private static void addInternal(StringBuilder sb, Object... objects) {
         for (Object o : objects) {
             if (o instanceof Object[]) {
-                for (Object o2 : (Object[])o) {
+                for (Object o2 : (Object[]) o) {
                     sb.append(o2s(o2));
                 }
             } else {
@@ -127,7 +129,7 @@ public void truncate(int size) {
      */
     public void mark() {
         if (sb != null) {
-            this.points.add(0, sb.length());
+            this.points.push(sb.length());
         }
     }
 
@@ -136,13 +138,14 @@ public void mark() {
      * text at that point.
      *
      * @param objects Optional {@code Object}s to insert if the buffer has
-     *     grown.
+     * grown.
      * @return True if the buffer grew (before inserting).
      */
     public boolean grew(Object... objects) {
-        if (sb == null) return false;
-        int p = this.points.remove(0);
+        if (sb == null || points.isEmpty()) return false;
+        int p = this.points.pop();
         if (sb.length() <= p) return false;
+
         StringBuilder sb2 = new StringBuilder(64);
         addInternal(sb2, objects);
         this.sb.insert(p, sb2.toString());
@@ -189,7 +192,7 @@ public int size() {
     }
 
     /**
-     * Add a group of objects to the buffer at a particular width
+     * Add a group of objects to the buffer at a particular width.
      *
      * @param size The width to set.
      * @param objects The {@code Object}s to add.
@@ -198,17 +201,32 @@ public int size() {
     public static String wide(int size, Object... objects) {
         if (size == 0) return "";
         boolean left = size > 0;
-        if (!left) size = -size;
-        StringBuilder s2 = new StringBuilder(size);
+        int absSize = Math.abs(size);
+
+        StringBuilder s2 = new StringBuilder();
         addInternal(s2, objects);
-        int delta = size - s2.length();
-        if (left) {
-            for (; delta > 0; delta--) s2.append(' ');
-        } else {
-            for (; delta > 0; delta--) s2.insert(0, " ");
+
+        if (s2.length() >= absSize) {
+            s2.setLength(absSize);
+            return s2.toString();
+        }
+
+        int delta = absSize - s2.length();
+        String padding = " ".repeat(delta);
+
+        return left ? (s2.toString() + padding) : (padding + s2.toString());
+    }
+
+    /**
+     * Returns an iterator over the lines in the buffer.
+     * * @return An {@code Iterator} of Strings.
+     */
+    @Override
+    public Iterator<String> iterator() {
+        if (sb == null || sb.length() == 0) {
+            return Collections.emptyIterator();
         }
-        if (delta < 0) s2.setLength(size);
-        return s2.toString();
+        return Arrays.asList(sb.toString().split("\\n")).iterator();
     }
 
 

test/src/net/sf/freecol/common/utils/LogBuilderTest.java

@@ -0,0 +1,128 @@
+/**
+ *  Copyright (C) 2002-2024  The FreeCol Team
+ *
+ *  This file is part of FreeCol.
+ *
+ *  FreeCol is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  FreeCol 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 for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.sf.freecol.common.utils;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import net.sf.freecol.common.util.LogBuilder;
+import net.sf.freecol.util.test.FreeColTestCase;
+
+public class LogBuilderTest extends FreeColTestCase {
+
+    public void testAdd() {
+        LogBuilder lb = new LogBuilder(64);
+        lb.add("Test ", 1, " ", null);
+        assertEquals("Test 1 null", lb.toString());
+
+        lb = new LogBuilder(64);
+        Object[] arr = new Object[] {"A", "B"};
+        lb.add(arr);
+        assertEquals("AB", lb.toString());
+    }
+
+    public void testMarkAndGrew() {
+        LogBuilder lb = new LogBuilder(64);
+        lb.add("Initial");
+        lb.mark();
+        lb.add("Data");
+
+        assertTrue(lb.grew(": "));
+        assertEquals("Initial: Data", lb.toString());
+
+        lb.mark();
+        assertFalse(lb.grew("ShouldNotAppear"));
+        assertEquals("Initial: Data", lb.toString());
+    }
+
+    public void testWide() {
+        assertEquals("ABC       ", LogBuilder.wide(10, "ABC"));
+        assertEquals("       ABC", LogBuilder.wide(-10, "ABC"));
+        assertEquals("AB", LogBuilder.wide(2, "ABC"));
+    }
+
+    public void testIterator() {
+        LogBuilder lb = new LogBuilder(64);
+        lb.add("Line1\nLine2\nLine3");
+
+        List<String> lines = new ArrayList<>();
+        for (String s : lb) {
+            lines.add(s);
+        }
+
+        assertEquals(3, lines.size());
+        assertEquals("Line1", lines.get(0));
+        assertEquals("Line2", lines.get(1));
+        assertEquals("Line3", lines.get(2));
+    }
+
+    public void testAddCollection() {
+        LogBuilder lb = new LogBuilder(64);
+        List<String> items = new ArrayList<>();
+        items.add("One");
+        items.add("Two");
+
+        lb.addCollection(", ", items);
+        assertEquals("One, Two", lb.toString());
+    }
+
+    public void testAddDoesNotFlattenCollections() {
+        LogBuilder lb = new LogBuilder(64);
+        List<String> list = new ArrayList<>();
+        list.add("A");
+        list.add("B");
+
+        lb.add(list);
+        assertEquals("[A, B]", lb.toString());
+    }
+
+    public void testAddCollectionHandlesNulls() {
+        LogBuilder lb = new LogBuilder(64);
+        List<String> items = new ArrayList<>();
+        items.add("One");
+        items.add(null);
+        items.add("Three");
+
+        lb.addCollection(", ", items);
+        assertEquals("One, null, Three", lb.toString());
+    }
+
+    public void testMarkStackOrder() {
+        LogBuilder lb = new LogBuilder(64);
+        lb.add("A");
+        lb.mark();
+        lb.add("B");
+        lb.mark();
+        lb.add("C");
+
+        lb.grew("X");
+        lb.grew("Y");
+
+        assertEquals("AYBXC", lb.toString());
+    }
+
+    public void testShrinkOnlyRemovesTrailingDelimiter() {
+        LogBuilder lb = new LogBuilder(64);
+        lb.add("A, B, C, ");
+        lb.shrink(", ");
+
+        assertEquals("A, B, C", lb.toString());
+    }
+}