OptionPane: fixed button order on Mac

flatlaf-core/src/main/java/com/formdev/flatlaf/UIDefaultsLoader.java

@@ -40,6 +40,7 @@ import com.formdev.flatlaf.util.ColorFunctions;
 import com.formdev.flatlaf.util.DerivedColor;
 import com.formdev.flatlaf.util.ScaledNumber;
 import com.formdev.flatlaf.util.StringUtils;
+import com.formdev.flatlaf.util.SystemInfo;
 
 /**
  * Load UI defaults from properties files associated to Flat LaF classes and add to UI defaults.
@@ -96,6 +97,27 @@ class UIDefaultsLoader
 				}
 			}
 
+			// collect all platform specific keys (but do not modify properties)
+			ArrayList<String> platformSpecificKeys = new ArrayList<>();
+			for( Object key : properties.keySet() ) {
+				if( ((String)key).startsWith( "[" ) )
+					platformSpecificKeys.add( (String) key );
+			}
+
+			// remove platform specific properties and re-add only properties
+			// for current platform, but with platform prefix removed
+			if( !platformSpecificKeys.isEmpty() ) {
+				String platformPrefix =
+					SystemInfo.IS_WINDOWS ? "[win]" :
+					SystemInfo.IS_MAC ? "[mac]" :
+					SystemInfo.IS_LINUX ? "[linux]" : "[unknown]";
+				for( String key : platformSpecificKeys ) {
+					Object value = properties.remove( key );
+					if( key.startsWith( platformPrefix ) )
+						properties.put( key.substring( platformPrefix.length() ), value );
+				}
+			}
+
 			Function<String, String> resolver = value -> {
 				return resolveValue( properties, value );
 			};

flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLaf.properties

@@ -206,6 +206,7 @@ OptionPane.buttonMinimumWidth={scaledNumber}72
 OptionPane.sameSizeButtons=true
 OptionPane.setButtonMargin=false
 OptionPane.buttonOrientation=4
+[mac]OptionPane.isYesLast=true
 
 OptionPane.errorIcon=com.formdev.flatlaf.icons.FlatOptionPaneErrorIcon
 OptionPane.informationIcon=com.formdev.flatlaf.icons.FlatOptionPaneInformationIcon