Implement that you can navigate to all declarations of external library symbols

Author: halirutan

src/de/halirutan/mathematica/codeinsight/navigation/MathematicaGotoDeclarationProvider.java

@@ -1,3 +1,25 @@
+/*
+ * Copyright (c) 2018 Patrick Scheibe
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
 package de.halirutan.mathematica.codeinsight.navigation;
 
 import com.intellij.codeInsight.navigation.actions.GotoDeclarationHandler;
@@ -38,8 +60,8 @@ public PsiElement[] getGotoDeclarationTargets(@Nullable PsiElement sourceElement
         final ResolveResult[] resolve = symbol.multiResolve(false);
         if (resolve.length > 0) {
           final PsiElement elm = resolve[0].getElement();
-          if (elm != null) {
-            return new PsiElement[]{elm};
+          if (elm instanceof Symbol) {
+            return findDeclarations((Symbol) elm);
           }
         }
       }
@@ -62,7 +84,7 @@ private PsiElement[] findDeclarations(@NotNull Symbol symbol) {
       c.getAssignments().get(symbol.getSymbolName()).forEach(
           assignmentProperty -> result.add(assignmentProperty.myLhsOfAssignment));
     }
-    return result.toArray(new PsiElement[result.size()]);
+    return result.toArray(PsiElement.EMPTY_ARRAY);
   }
 
 }