diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTMethodOrConstructorDeclaration.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTMethodOrConstructorDeclaration.java
index 1a8277e94b..31bfd87751 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTMethodOrConstructorDeclaration.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTMethodOrConstructorDeclaration.java
@@ -4,11 +4,9 @@
 
 package net.sourceforge.pmd.lang.java.ast;
 
-import net.sourceforge.pmd.lang.ast.Node;
-
 /**
  * @author Clément Fournier
  */
-public interface ASTMethodOrConstructorDeclaration extends QualifiableNode, Node, AccessNode {
+public interface ASTMethodOrConstructorDeclaration extends QualifiableNode, AccessNode, JavaNode {
 
 }
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/AbstractMetric.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/AbstractMetric.java
index ba74498d54..115e0bbb7d 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/AbstractMetric.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/AbstractMetric.java
@@ -8,21 +8,19 @@ import java.util.ArrayList;
 import java.util.List;
 
 import net.sourceforge.pmd.lang.java.ast.ASTMethodOrConstructorDeclaration;
+import net.sourceforge.pmd.lang.java.ast.AccessNode;
 import net.sourceforge.pmd.lang.java.ast.QualifiedName;
 import net.sourceforge.pmd.lang.java.oom.api.Metric;
 
 
 /**
  * Base class for metrics. Metric objects encapsulate the computational logic required to compute a metric from a
- * PackageStats and node.
+ * PackageStats and node. They're stateless.
  *
  * @author Clément Fournier
  */
 public abstract class AbstractMetric implements Metric {
 
-    // TODO:cf useful?
-    protected boolean isAbstractHandler = false;
-
     /**
      * Gives access to the toplevel package stats to metrics without having to pass them as a parameter to metrics.
      *
@@ -42,14 +40,15 @@ public abstract class AbstractMetric implements Metric {
     }
 
     /**
-     * Checks if the metric can be computed on that node.
+     * Default implementation of the supports method, which filters out abstract nodes. Metrics that support abstract
+     * nodes should override this method.
      *
-     * @param node The node to check for
+     * @param node The node to check.
      *
-     * @return True if the metric can be computed, false otherwise.
+     * @return True if the metric can be computed on this node.
      */
-    // TODO:cf better wrap that around the metrics implementation
-    protected boolean isSupported(ASTMethodOrConstructorDeclaration node) {
-        return isAbstractHandler || !node.isAbstract();
+    @Override
+    public boolean supports(AccessNode node) {
+        return !node.isAbstract();
     }
 }
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/Metrics.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/Metrics.java
index 9e111e84fb..ca9553e9c4 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/Metrics.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/Metrics.java
@@ -32,8 +32,7 @@ public final class Metrics {
      *
      * @return The top level package stats.
      */
-    /* default */
-    static PackageStats getTopLevelPackageStats() {
+    /* default */ static PackageStats getTopLevelPackageStats() {
         return TOP_LEVEL_PACKAGE;
     }
 
@@ -89,6 +88,10 @@ public final class Metrics {
      */
     public static double get(ClassMetricKey key, ASTClassOrInterfaceDeclaration node, MetricVersion version,
                              ResultOption option) {
+        if (!key.getCalculator().supports(node)) {
+            return Double.NaN;
+        }
+
         MetricVersion safeOption = (version == null) ? Version.STANDARD : version;
 
         return TOP_LEVEL_PACKAGE.compute(key, node, false, safeOption, option);
@@ -117,6 +120,10 @@ public final class Metrics {
      * @return The value of the metric, or {@code Double.NaN} if the value couln't be computed.
      */
     public static double get(OperationMetricKey key, ASTMethodOrConstructorDeclaration node, MetricVersion version) {
+        if (!key.getCalculator().supports(node)) {
+            return Double.NaN;
+        }
+
         MetricVersion safeOption = (version == null) ? Version.STANDARD : version;
 
         return TOP_LEVEL_PACKAGE.compute(key, node, false, safeOption);
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/api/Metric.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/api/Metric.java
index 68f5023e63..d85fdd28be 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/api/Metric.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/api/Metric.java
@@ -4,6 +4,8 @@
 
 package net.sourceforge.pmd.lang.java.oom.api;
 
+import net.sourceforge.pmd.lang.java.ast.AccessNode;
+
 /**
  * Umbrella marker interface for metrics.
  *
@@ -11,6 +13,16 @@ package net.sourceforge.pmd.lang.java.oom.api;
  */
 public interface Metric {
 
+
+    /**
+     * Checks if the metric can be computed on the node.
+     *
+     * @param node The node to check.
+     *
+     * @return True if the metric can be computed.
+     */
+    boolean supports(AccessNode node);
+
     /** Default metric version. */
     enum Version implements MetricVersion {
         /** Standard option, used as a default. */
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/api/OperationMetric.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/api/OperationMetric.java
index 7086eaf334..cb1dca8b06 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/api/OperationMetric.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/api/OperationMetric.java
@@ -23,5 +23,4 @@ public interface OperationMetric extends Metric {
      */
     double computeFor(ASTMethodOrConstructorDeclaration node, MetricVersion version);
 
-
 }
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/AtfdMetric.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/AtfdMetric.java
index e461526ed2..0b8395c43e 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/AtfdMetric.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/AtfdMetric.java
@@ -8,6 +8,7 @@ import java.util.List;
 
 import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration;
 import net.sourceforge.pmd.lang.java.ast.ASTMethodOrConstructorDeclaration;
+import net.sourceforge.pmd.lang.java.ast.AccessNode;
 import net.sourceforge.pmd.lang.java.ast.QualifiedName;
 import net.sourceforge.pmd.lang.java.oom.AbstractMetric;
 import net.sourceforge.pmd.lang.java.oom.api.ClassMetric;
@@ -25,11 +26,14 @@ import net.sourceforge.pmd.lang.java.oom.signature.Signature.Visibility;
  */
 public class AtfdMetric extends AbstractMetric implements ClassMetric, OperationMetric {
 
+    @Override
+    public boolean supports(AccessNode node) {
+        return node instanceof ASTClassOrInterfaceDeclaration
+            || node instanceof ASTMethodOrConstructorDeclaration && !node.isAbstract();
+    }
+
     @Override // TODO:cf
     public double computeFor(ASTMethodOrConstructorDeclaration node, MetricVersion version) {
-        if (!isSupported(node)) {
-            return Double.NaN;
-        }
 
         OperationSigMask targetOps = new OperationSigMask();
         targetOps.restrictVisibilitiesTo(Visibility.PUBLIC);
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/CycloMetric.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/CycloMetric.java
index d37269bcb2..c864163e66 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/CycloMetric.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/CycloMetric.java
@@ -63,11 +63,13 @@ public class CycloMetric extends AbstractClassAndOperationMetric {
         return (double) cyclo.getValue();
     }
 
+
     @Override
     public OperationMetricKey getOperationMetricKey() {
         return OperationMetricKey.CYCLO;
     }
 
+
     /** Variants of CYCLO. */
     public enum Version implements MetricVersion {
         /** Do not count the paths in boolean expressions as decision points. */
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/LocMetric.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/LocMetric.java
index c4cb5bff89..53b78525b5 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/LocMetric.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/LocMetric.java
@@ -6,6 +6,7 @@ package net.sourceforge.pmd.lang.java.oom.metrics;
 
 import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration;
 import net.sourceforge.pmd.lang.java.ast.ASTMethodOrConstructorDeclaration;
+import net.sourceforge.pmd.lang.java.ast.AccessNode;
 import net.sourceforge.pmd.lang.java.oom.api.MetricVersion;
 import net.sourceforge.pmd.lang.java.oom.api.OperationMetricKey;
 
@@ -20,6 +21,12 @@ import net.sourceforge.pmd.lang.java.oom.api.OperationMetricKey;
  */
 public class LocMetric extends AbstractClassAndOperationMetric {
 
+
+    @Override
+    public boolean supports(AccessNode node) {
+        return true;
+    }
+
     @Override
     protected double computeDefaultResultOption(ASTClassOrInterfaceDeclaration node, MetricVersion version) {
         return node.getEndLine() - node.getBeginLine();
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/NcssMetric.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/NcssMetric.java
index d188a971ce..f1631c2fae 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/NcssMetric.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/metrics/NcssMetric.java
@@ -31,6 +31,7 @@ import net.sourceforge.pmd.lang.java.ast.ASTSwitchStatement;
 import net.sourceforge.pmd.lang.java.ast.ASTSynchronizedStatement;
 import net.sourceforge.pmd.lang.java.ast.ASTThrowStatement;
 import net.sourceforge.pmd.lang.java.ast.ASTWhileStatement;
+import net.sourceforge.pmd.lang.java.ast.AccessNode;
 import net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter;
 import net.sourceforge.pmd.lang.java.oom.api.MetricVersion;
 import net.sourceforge.pmd.lang.java.oom.api.OperationMetricKey;
@@ -46,6 +47,10 @@ import net.sourceforge.pmd.lang.java.oom.api.OperationMetricKey;
  */
 public class NcssMetric extends AbstractClassAndOperationMetric {
 
+    @Override
+    public boolean supports(AccessNode node) {
+        return true;
+    }
 
     @Override
     protected double computeDefaultResultOption(ASTClassOrInterfaceDeclaration node, MetricVersion version) {