Introduce string literal syntax and load some icon colors trough deferred property resolution at patch time.

core/src/main/resources/com/github/weisj/darklaf/properties/icons/files.properties

@@ -24,5 +24,5 @@
 #
 # suppress inspection "UnusedProperty" for whole file
 #
-Icons.image.sky.color           = %palette.teal
-Icons.image.grass.color         = %palette.green
+Icons.image.sky.color           = '%palette.teal'
+Icons.image.grass.color         = '%palette.green'

core/src/main/resources/com/github/weisj/darklaf/properties/icons/frame.properties

@@ -24,19 +24,19 @@
 #
 # suppress inspection "UnusedProperty" for whole file
 #
-Icons.windowClose.color            = %windowButton
-Icons.windowCloseHover.color       = %windowCloseHovered
-Icons.windowCloseInactive.color    = %windowButtonDisabled
+Icons.windowClose.color            = '%windowButton'
+Icons.windowCloseHover.color       = '%windowCloseHovered'
+Icons.windowCloseInactive.color    = '%windowButtonDisabled'
 
-Icons.windowHelp.color             = %windowButton
-Icons.windowHelpInactive.color     = %windowButtonDisabled
+Icons.windowHelp.color             = '%windowButton'
+Icons.windowHelpInactive.color     = '%windowButtonDisabled'
 
-Icons.windowMaximize.color         = %windowButton
-Icons.windowMaximizeInactive.color = %windowButtonDisabled
+Icons.windowMaximize.color         = '%windowButton'
+Icons.windowMaximizeInactive.color = '%windowButtonDisabled'
 
-Icons.windowMinimize.color         = %windowButton
-Icons.windowMinimizeInactive.color = %windowButtonDisabled
+Icons.windowMinimize.color         = '%windowButton'
+Icons.windowMinimizeInactive.color = '%windowButtonDisabled'
 
-Icons.windowRestore.color          = %windowButton
-Icons.windowRestoreInactive.color  = %windowButtonDisabled
+Icons.windowRestore.color          = '%windowButton'
+Icons.windowRestoreInactive.color  = '%windowButtonDisabled'
 

property-loader/src/main/java/com/github/weisj/darklaf/parser/ParserUtil.java

@@ -53,6 +53,14 @@ final class ParserUtil implements Delimiters {
         return parser != null ? parser.parse(p, c) : p;
     }
 
+    static boolean startsWith(final ParseResult parseResult, final String prefix) {
+        return parseResult.value.startsWith(prefix);
+    }
+
+    static boolean startsWith(final ParseResult parseResult, final char prefix) {
+        return parseResult.value.length() > 0 && parseResult.value.charAt(0) == prefix;
+    }
+
     static boolean stripPrefixFromKey(final ParseResult parseResult, final String prefix) {
         if (parseResult.key.startsWith(prefix)) {
             parseResult.key = parseResult.key.substring(prefix.length());
@@ -62,7 +70,7 @@ final class ParserUtil implements Delimiters {
     }
 
     static boolean stripPrefixFromValue(final ParseResult parseResult, final String prefix) {
-        if (parseResult.value.startsWith(prefix)) {
+        if (startsWith(parseResult, prefix)) {
             parseResult.value = parseResult.value.substring(prefix.length());
             return true;
         }

property-loader/src/main/java/com/github/weisj/darklaf/parser/PrimitiveParser.java

@@ -30,6 +30,7 @@ import com.github.weisj.darklaf.util.PropertyValue;
 public class PrimitiveParser implements PropertyParser {
 
     public static final String COLOR_PREFIX = "#";
+    public static final char STRING_DELIMITER = '\'';
 
     @Override
     public ParseResult doParse(final ParseResult parseResult, final ParserContext context) {
@@ -45,6 +46,13 @@ public class PrimitiveParser implements PropertyParser {
             }
         }
         if (parseResult.finished) return parseResult;
+        if (ParserUtil.startsWith(parseResult, STRING_DELIMITER)) {
+            ParserUtil.setNonNull(parseResult,
+                    ParserUtil.parseBetween(STRING_DELIMITER, STRING_DELIMITER,
+                            PropertyParser.of(String::valueOf), String.class,
+                            parseResult, context).orElse(null));
+        }
+        if (parseResult.finished) return parseResult;
         ParserUtil.setNonNull(parseResult, getInteger(parseResult.value));
         if (parseResult.finished) return parseResult;
         ParserUtil.setNonNull(parseResult, getBoolean(parseResult.value));