feature #630: use of ellipsis/varargs in COM methods

CHANGES.md

@@ -48,6 +48,7 @@ Features
 * [#621](https://github.com/java-native-access/jna/pull/621): Added TYPEFLAGS-constants for `wTypeFlags` in `com.sun.jna.platform.win32.OaIdl.TYPEATTR` - [@SevenOf9Sleeper](https://github.com/SevenOf9Sleeper).
 * [#625](https://github.com/java-native-access/jna/pull/625): Make conversion to/from java to/from VARIANT in `com.sun.jna.platform.win32.COM.util.Convert` more flexible and dependable - [@matthiasblaesing](https://github.com/matthiasblaesing).
 * [#639](https://github.com/java-native-access/jna/pull/639): Add getloadavg() to OS X and Unix - [@dbwiddis](https://github.com/dbwiddis).
+* [#642](https://github.com/java-native-access/jna/pull/642): COM calls with variable number of arguments (varargs) are now supported - [@SevenOf9Sleeper](https://github.com/SevenOf9Sleeper).
 
 Bug Fixes
 ---------

contrib/platform/src/com/sun/jna/platform/win32/COM/util/ProxyObject.java

@@ -13,6 +13,7 @@
 package com.sun.jna.platform.win32.COM.util;
 
 import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Proxy;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeoutException;
@@ -51,7 +52,6 @@
 import com.sun.jna.platform.win32.COM.util.annotation.ComProperty;
 import com.sun.jna.ptr.IntByReference;
 import com.sun.jna.ptr.PointerByReference;
-import java.lang.reflect.InvocationTargetException;
 
 /**
  * This object acts as the invocation handler for interfaces annotated with
@@ -232,12 +232,13 @@ public Object invoke(final Object proxy, final java.lang.reflect.Method method,
 
 		ComMethod meth = method.getAnnotation(ComMethod.class);
 		if (null != meth) {
+                        Object[] fullLengthArgs = unfoldWhenVarargs(method, args);
                         int dispId = meth.dispId();
                         if(dispId != -1) {
-                            return this.invokeMethod(returnType, new DISPID(dispId), args);
+                            return this.invokeMethod(returnType, new DISPID(dispId), fullLengthArgs);
                         } else {
                             String methName = this.getMethodName(method, meth);
-                            return this.invokeMethod(returnType, methName, args);
+                            return this.invokeMethod(returnType, methName, fullLengthArgs);
                         }
 		}
 
@@ -401,6 +402,21 @@ public <T> T invokeMethod(Class<T> returnType, DISPID dispID, Object... args) {
                 return (T) Convert.toJavaObject(result, returnType, factory, false, true);
 	}
 
+	private Object[] unfoldWhenVarargs(java.lang.reflect.Method method, Object[] argParams) {
+        if (null == argParams) {
+            return null;
+        }
+        if (argParams.length == 0 || !method.isVarArgs() || !(argParams[argParams.length - 1] instanceof Object[])) {
+            return argParams;
+        }
+        // when last parameter is Object[] -> unfold the ellipsis:
+        Object[] varargs = (Object[]) argParams[argParams.length - 1];
+        Object[] args = new Object[argParams.length - 1 + varargs.length];
+        System.arraycopy(argParams, 0, args, 0, argParams.length - 1);
+        System.arraycopy(varargs, 0, args, argParams.length - 1, varargs.length);
+        return args;
+    }
+
 	@Override
 	public <T> T queryInterface(Class<T> comInterface) throws COMException {
                 assert COMUtils.comIsInitialized() : "COM not initialized";

contrib/platform/test/com/sun/jna/platform/win32/COM/util/ProxyObject_Test.java

@@ -15,6 +15,8 @@
 import com.sun.jna.Pointer;
 import static org.junit.Assert.*;
 
+import java.io.File;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -41,8 +43,53 @@ interface Application extends IUnknown {
 
 		@ComMethod
 		void Quit(boolean SaveChanges, Object OriginalFormat, Boolean RouteDocument);
+
+		@ComMethod
+		public void Quit(Object... someArgs);
+
+		@ComMethod(dispId = 0x00000183)
+		public float PointsToPixels(float points, Object... someArgs);
+
+		@ComProperty(dispId = 0x00000006)
+		public Documents getDocuments();
 	}	
-
+
+	@ComInterface(iid = "{0002096C-0000-0000-C000-000000000046}")
+	public interface Documents extends IDispatch {
+		@ComMethod
+		public _Document Add(Object template, Object newTemplate, Object documentType, Object visible);
+
+		@ComMethod
+		public _Document Add(Object... someArgs);
+	}
+
+	@ComInterface(iid = "{0002096B-0000-0000-C000-000000000046}")
+	public interface _Document extends IDispatch {
+		@ComMethod
+		public void SaveAs(Object fileName, Object fileFormat, Object lockComments, Object password,
+		        Object addToRecentFiles, Object writePassword, Object readOnlyRecommended, Object embedTrueTypeFonts,
+		        Object saveNativePictureFormat, Object saveFormsData, Object saveAsAOCELetter, Object encoding,
+		        Object insertLineBreaks, Object allowSubstitutions, Object lineEnding, Object addBiDiMarks);
+
+		@ComMethod
+		public void SaveAs(Object... someArgs);
+	}
+
+	public enum WdSaveFormat implements IComEnum {
+		wdFormatDocument(0), wdFormatText(2), wdFormatRTF(6), wdFormatHTML(8), wdFormatPDF(17);
+
+		private long _value;
+
+		private WdSaveFormat(long value) {
+			_value = value;
+		}
+
+		@Override
+		public long getValue() {
+			return _value;
+		}
+	}
+
 	@ComObject(progId="Word.Application")
 	interface MsWordApp extends Application {
 	}
@@ -116,4 +163,27 @@ public void accessWhilstDisposing() {
 
 	}
 
+	@Test
+	public void testVarargsCallWithoutVarargParameter() {
+		MsWordApp comObj = this.factory.createObject(MsWordApp.class);
+
+		// call must work without exception:
+		float f = comObj.PointsToPixels(25.3f);
+		comObj.Quit();
+	}
+
+	@Test
+	public void testVarargsCallWithParameter() {
+		MsWordApp comObj = this.factory.createObject(MsWordApp.class);
+
+		Documents documents = comObj.getDocuments();
+		_Document myDocument = documents.Add();
+
+		String path = new File(".").getAbsolutePath();
+		myDocument.SaveAs(path + "\\abcdefg", WdSaveFormat.wdFormatPDF);
+		comObj.Quit();
+
+		boolean wasDeleted = new File("abcdefg.pdf").delete();
+		assertTrue(wasDeleted);
+	}
 }