X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=blobdiff_plain;f=bundles%2Forg.simantics.utils%2Fsrc%2Forg%2Fsimantics%2Futils%2FReflectionUtils.java;fp=bundles%2Forg.simantics.utils%2Fsrc%2Forg%2Fsimantics%2Futils%2FReflectionUtils.java;h=5368b2e345a1fd579d3e2cadc3933b81b4a39bee;hp=0000000000000000000000000000000000000000;hb=969bd23cab98a79ca9101af33334000879fb60c5;hpb=866dba5cd5a3929bbeae85991796acb212338a08

diff --git a/bundles/org.simantics.utils/src/org/simantics/utils/ReflectionUtils.java b/bundles/org.simantics.utils/src/org/simantics/utils/ReflectionUtils.java
new file mode 100644
index 000000000..5368b2e34
--- /dev/null
+++ b/bundles/org.simantics.utils/src/org/simantics/utils/ReflectionUtils.java
@@ -0,0 +1,82 @@
+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+package org.simantics.utils;
+
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+
+public class ReflectionUtils {
+
+    /**
+     * For a class <code>C extends PC&lt;P&gt;</code>, where <code>PC</code> is
+     * a class, not an interface, retrieves class <code>P</code>.
+     * 
+     * @param clazz
+     * @return
+     */
+    public static Class<?> getSingleParameterType(Class<?> clazz) {
+
+        Type t = clazz.getGenericSuperclass();
+        if(t instanceof Class<?>) {
+            throw new UnsupportedOperationException("Missing parameter type for input class '" + clazz.getCanonicalName() + "'");
+        } else if (t instanceof ParameterizedType) {
+            ParameterizedType type = (ParameterizedType)t;
+            Type argType = type.getActualTypeArguments()[0];
+            if (argType instanceof Class<?>) {
+                return (Class<?>) argType;
+            } else if (argType instanceof ParameterizedType) {
+                // This happens if the input class X<T>
+                // parameter T is also parameterized.
+                ParameterizedType pargType = (ParameterizedType) argType;
+                return (Class<?>) pargType.getRawType();
+            } else {
+                throw new UnsupportedOperationException("Unsupported parameter type in class '" + clazz.getCanonicalName() + "': " + argType);
+            }
+        } else {
+            throw new UnsupportedOperationException("Unknown case in class '" + clazz.getCanonicalName() + "'");
+        }
+
+    }
+
+    /**
+     * Works like {@link #getSingleParameterType(Class)} assuming the retrieved
+     * parameter class extends <code>T</code>.
+     * 
+     * @param clazz
+     * @return
+     */
+    @SuppressWarnings("unchecked")
+    public static <T> Class<T> getSingleParameterTypeExtending(Class<?> clazz) {
+
+        Type t = clazz.getGenericSuperclass();
+        if(t instanceof Class<?>) {
+            throw new UnsupportedOperationException("Missing parameter type for input class '" + clazz.getCanonicalName() + "'");
+        } else if (t instanceof ParameterizedType) {
+            ParameterizedType type = (ParameterizedType)t;
+            Type argType = type.getActualTypeArguments()[0];
+            if (argType instanceof Class<?>) {
+                return (Class<T>) argType;
+            } else if (argType instanceof ParameterizedType) {
+                // This happens if the input class X<T>
+                // parameter T is also parameterized.
+                ParameterizedType pargType = (ParameterizedType) argType;
+                return (Class<T>) pargType.getRawType();
+            } else {
+                throw new UnsupportedOperationException("Unsupported parameter type in class '" + clazz.getCanonicalName() + "': " + argType);
+            }
+        } else {
+            throw new UnsupportedOperationException("Unknown case in class '" + clazz.getCanonicalName() + "'");
+        }
+
+    }
+
+}