chore: Move last remaining shadow variable to declarative shadow variables

Author: Christopher-Chianelli

java/food-packaging/src/main/java/org/acme/foodpackaging/domain/Job.java

@@ -38,15 +38,7 @@ public class Job {
     @InverseRelationShadowVariable(sourceVariableName = "jobs")
     private Line line;
 
-    // TODO: Replace me when declarative shadow variables support
-    //       non-declarative shadow on non-declarative shadow sources
-    @ShadowVariable(
-            variableListenerClass = LineOperatorUpdatingVariableListener.class,
-            sourceEntityClass = Line.class,
-            sourceVariableName = "operator")
-    @ShadowVariable(
-            variableListenerClass = JobOperatorUpdatingVariableListener.class,
-            sourceVariableName = "line")
+    @ShadowVariable(supplierName = "lineOperatorSupplier")
     private Operator lineOperator;
     @JsonIgnore
     @PreviousElementShadowVariable(sourceVariableName = "jobs")
@@ -194,6 +186,14 @@ public void setEndDateTime(LocalDateTime endDateTime) {
     // ************************************************************************
     // Complex methods
     // ************************************************************************
+    @SuppressWarnings("unused")
+    @ShadowSources({"line", "line.operator"})
+    private Operator lineOperatorSupplier() {
+        if (line == null) {
+            return null;
+        }
+        return line.getOperator();
+    }
 
     @SuppressWarnings("unused")
     @ShadowSources({"line", "previousJob.endDateTime"})

java/food-packaging/src/main/java/org/acme/foodpackaging/domain/JobOperatorUpdatingVariableListener.java

@@ -50,7 +50,7 @@ public MaintenanceSchedule(HardSoftLongScore score, SolverStatus solverStatus) {
     public List<LocalDate> createStartDateList() {
         return workCalendar.getFromDate().datesUntil(workCalendar.getToDate())
                 // Skip weekends. Does not work for holidays.
-                // Keep in sync with EndDateUpdatingVariableListener.updateEndDate().
+                // Keep in sync with Job.calculateEndDate().
                 // To skip holidays too, cache all working days in WorkCalendar.
                 .filter(date -> date.getDayOfWeek() != DayOfWeek.SATURDAY
                         && date.getDayOfWeek() != DayOfWeek.SUNDAY)