src/de/steamwar/linkage/LinkageProcessor.java

@@ -36,6 +36,7 @@ import javax.lang.model.element.VariableElement;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.TypeMirror;
 import javax.tools.Diagnostic;
+import javax.tools.StandardLocation;
 import java.io.*;
 import java.lang.annotation.Annotation;
 import java.nio.file.Files;
@@ -56,6 +57,8 @@ public class LinkageProcessor extends AbstractProcessor {
     private String name;
     private String className;
 
+    private Set<String> disabledFeatures = new HashSet<>();
+
     private Messager messager;
     private boolean processed = false;
 
@@ -75,6 +78,7 @@ public class LinkageProcessor extends AbstractProcessor {
 
         className = "LinkageUtils";
         mainClass();
+        disabledFeatures();
     }
 
     @SneakyThrows
@@ -102,6 +106,18 @@ public class LinkageProcessor extends AbstractProcessor {
         }
     }
 
+    @SneakyThrows
+    private void disabledFeatures() {
+        File file = new File(System.getProperty("user.dir"), "disabled-features.txt");
+        if (!file.exists()) return;
+        @Cleanup BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
+        reader.lines()
+                .map(String::trim)
+                .filter(line -> !line.isEmpty())
+                .filter(line -> !line.startsWith("#"))
+                .forEach(disabledFeatures::add);
+    }
+
     @SneakyThrows
     @Override
     public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
@@ -111,9 +127,27 @@ public class LinkageProcessor extends AbstractProcessor {
         Writer writer = processingEnv.getFiler().createSourceFile("de.steamwar." + name + ".linkage.LinkageUtils").openWriter();
         BuildPlan buildPlan = new BuildPlan("de.steamwar." + name + ".linkage", className);
 
+        Set<TypeElement> disabledElements = new HashSet<>();
+
         Set<TypeElement> elements = roundEnv.getElementsAnnotatedWith(Linked.class).stream()
                 .filter(element -> element.getKind() == ElementKind.CLASS)
                 .map(TypeElement.class::cast)
+                .peek(element -> {
+                    String featureName = element.getAnnotation(Linked.class).feature();
+                    if (featureName.isEmpty()) {
+                        String tempName = element.getQualifiedName().toString();
+                        if (tempName.contains(".features.")) {
+                            tempName = tempName.substring(tempName.indexOf(".features.") + 10);
+                            featureName = tempName.substring(0, tempName.indexOf('.'));
+                        } else {
+                            tempName = tempName.substring(0, tempName.lastIndexOf('.'));
+                            featureName = tempName.substring(tempName.lastIndexOf('.') + 1);
+                        }
+                    }
+                    if (disabledFeatures.contains(featureName) || disabledFeatures.contains("*")) {
+                        disabledElements.add(element);
+                    }
+                })
                 .peek(typeElement -> System.out.println("Found element: " + typeElement.getQualifiedName().toString()))
                 .collect(Collectors.toSet());
 
@@ -147,8 +181,14 @@ public class LinkageProcessor extends AbstractProcessor {
                     messager.printMessage(Diagnostic.Kind.ERROR, "Field " + variableElement.getSimpleName() + " must be non final", variableElement);
                     continue;
                 }
-                neededFields.put(typeElement.getQualifiedName().toString(), typeElement);
                 TypeElement fieldType = (TypeElement) ((DeclaredType) variableElement.asType()).asElement();
+                if (disabledElements.contains(fieldType)) {
+                    continue;
+                }
+                if (disabledElements.contains(typeElement)) {
+                    continue;
+                }
+                neededFields.put(typeElement.getQualifiedName().toString(), typeElement);
                 neededFields.put(fieldType.getQualifiedName().toString(), fieldType);
 
                 fieldInjections.add(() -> {
@@ -159,6 +199,7 @@ public class LinkageProcessor extends AbstractProcessor {
             }
         }
         neededFields.forEach((s, typeElement) -> {
+            if (disabledElements.contains(typeElement)) return;
             buildPlan.addImport(typeElement.getQualifiedName().toString());
             String t = typeElement.getSimpleName().toString();
             t = t.substring(0, 1).toLowerCase() + t.substring(1);
@@ -188,8 +229,13 @@ public class LinkageProcessor extends AbstractProcessor {
                     return methodBuilder;
                 });
 
-                if (!entry.getKey().isEmpty()) method.addLine("if (" + String.join(" && ", entry.getKey()) + ") {");
+                boolean generated = false;
                 for (Map.Entry<TypeElement, List<LinkageType>> toGenerate : group.getValue().entrySet()) {
+                    if (disabledElements.contains(toGenerate.getKey())) continue;
+                    if (!generated && !entry.getKey().isEmpty()) {
+                        method.addLine("if (" + String.join(" && ", entry.getKey()) + ") {");
+                        generated = true;
+                    }
                     TypeElement typeElement = toGenerate.getKey();
                     String instance = getElement(typeElement, neededFields);
                     if (toGenerate.getValue().size() > 1 && instance.startsWith("new ")) {
@@ -202,7 +248,7 @@ public class LinkageProcessor extends AbstractProcessor {
                         linkageType.generateCode(buildPlan, method, finalInstance, typeElement);
                     });
                 }
-                if (!entry.getKey().isEmpty()) method.addLine("}");
+                if (generated && !entry.getKey().isEmpty()) method.addLine("}");
             }
         }
 

src/de/steamwar/linkage/Linked.java

@@ -24,4 +24,5 @@ import java.lang.annotation.*;
 @Retention(RetentionPolicy.SOURCE)
 @Target({ElementType.TYPE})
 public @interface Linked {
+    String feature() default "";
 }