Refactored property replacements.

core/src/main/java/com/github/weisj/darklaf/task/FontDefaultsInitTask.java

@@ -75,12 +75,7 @@ public class FontDefaultsInitTask implements DefaultsInitTask {
     }
 
     private void patchMacOSFonts(final UIDefaults defaults) {
-        for (Map.Entry<Object, Object> entry : defaults.entrySet()) {
+        PropertyLoader.replacePropertiesOfType(Font.class, defaults, this::macOSFontFromFont);
-            if (entry.getValue() instanceof Font) {
-                Font font = (Font) entry.getValue();
-                entry.setValue(macOSFontFromFont(font));
-            }
-        }
     }
 
     private Font macOSFontFromFont(final Font font) {
@@ -95,11 +90,7 @@ public class FontDefaultsInitTask implements DefaultsInitTask {
     private void applyFontRule(final Theme currentTheme, final UIDefaults defaults) {
         FontSizeRule rule = currentTheme.getFontSizeRule();
         if (rule == null || rule.getType() == FontSizeRule.AdjustmentType.NO_ADJUSTMENT) return;
-        for (Map.Entry<Object, Object> entry : defaults.entrySet()) {
+        PropertyLoader.replacePropertiesOfType(Font.class, defaults, f -> fontWithRule(f, rule, defaults));
-            if (entry != null && entry.getValue() instanceof Font) {
-                entry.setValue(fontWithRule((Font) entry.getValue(), rule, defaults));
-            }
-        }
     }
 
     private Font fontWithRule(final Font font, final FontSizeRule rule, final UIDefaults defaults) {

core/src/main/java/com/github/weisj/darklaf/task/ThemeDefaultsInitTask.java

@@ -92,16 +92,14 @@ public class ThemeDefaultsInitTask implements DefaultsInitTask {
                 globalSettings.put(((String) key).substring(GLOBAL_PREFIX.length()), uiProps.get(key));
             }
         }
-
+        PropertyLoader.replaceProperties(
-        for (final Object key : defaults.keySet()) {
+            defaults,
-            if (key instanceof String && ((String) key).contains(".")) {
+            e -> e.getKey() instanceof String && ((String) e.getKey()).contains("."),
-                final String s = (String) key;
+            e -> {
+                final String s = (String) e.getKey();
                 final String globalKey = s.substring(s.lastIndexOf('.') + 1);
-                if (globalSettings.containsKey(globalKey)) {
+                return globalSettings.get(globalKey);
-                    defaults.put(key, globalSettings.get(globalKey));
+            });
-                }
-            }
-        }
     }
 
     private void initUIProperties(final Theme currentTheme, final UIDefaults defaults, final Properties uiProps) {

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

@@ -44,6 +44,8 @@ import java.io.InputStream;
 import java.text.AttributedCharacterIterator;
 import java.util.List;
 import java.util.*;
+import java.util.function.Function;
+import java.util.function.Predicate;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -130,6 +132,35 @@ public final class PropertyLoader {
         }
     }
 
+    public static void replaceProperties(final Map<Object, Object> properties,
+                                         final Predicate<Map.Entry<Object, Object>> predicate,
+                                         final Function<Map.Entry<Object, Object>, Object> mapper) {
+        replacePropertiesOfType(Object.class, properties, predicate, mapper);
+    }
+
+    public static <T> void replacePropertiesOfType(final Class<T> type,
+                                                   final Map<Object, Object> properties,
+                                                   final Function<T, T> mapper) {
+        replacePropertiesOfType(type, properties, e -> true, e -> mapper.apply(e.getValue()));
+    }
+
+    @SuppressWarnings("unchecked")
+    public static <T> void replacePropertiesOfType(final Class<T> type,
+                                                   final Map<Object, Object> properties,
+                                                   final Predicate<Map.Entry<Object, T>> predicate,
+                                                   final Function<Map.Entry<Object, T>, T> mapper) {
+        for (Map.Entry<Object, Object> entry : properties.entrySet()) {
+            if (type == Object.class || type.isAssignableFrom(entry.getValue().getClass())) {
+                if (predicate.test((Map.Entry<Object, T>) entry)) {
+                    T newValue = mapper.apply((Map.Entry<Object, T>) entry);
+                    if (newValue != null) {
+                        entry.setValue(newValue);
+                    }
+                }
+            }
+        }
+    }
+
     private static String parseKey(final String key) {
         if (addReferenceInfo) return key;
         return key.startsWith(String.valueOf(REFERENCE_PREFIX)) ? key.substring(1) : key;