move TransferableWrapper to platforrm-impl to re-use ProjectViewDropTarget functionality (moved to FileCopyPasteUtil)

platform/lang-impl/src/com/intellij/ide/favoritesTreeView/FavoritesPanel.java

@@ -17,7 +17,7 @@ package com.intellij.ide.favoritesTreeView;
 
 import com.intellij.ide.dnd.*;
 import com.intellij.ide.dnd.aware.DnDAwareTree;
-import com.intellij.ide.projectView.impl.TransferableWrapper;
+import com.intellij.ide.dnd.TransferableWrapper;
 import com.intellij.ide.util.treeView.AbstractTreeBuilder;
 import com.intellij.ide.util.treeView.AbstractTreeNode;
 import com.intellij.openapi.project.Project;

platform/lang-impl/src/com/intellij/ide/hierarchy/HierarchyBrowserBaseEx.java

@@ -27,7 +27,7 @@ import com.intellij.ide.dnd.DnDManager;
 import com.intellij.ide.dnd.DnDSource;
 import com.intellij.ide.dnd.aware.DnDAwareTree;
 import com.intellij.ide.projectView.impl.ProjectViewTree;
-import com.intellij.ide.projectView.impl.TransferableWrapper;
+import com.intellij.ide.dnd.TransferableWrapper;
 import com.intellij.ide.util.scopeChooser.EditScopesDialog;
 import com.intellij.ide.util.treeView.NodeDescriptor;
 import com.intellij.openapi.actionSystem.*;

platform/lang-impl/src/com/intellij/ide/navigationToolbar/NavBarPanel.java

@@ -28,7 +28,7 @@ import com.intellij.ide.navigationToolbar.ui.NavBarUIManager;
 import com.intellij.ide.projectView.ProjectView;
 import com.intellij.ide.projectView.impl.AbstractProjectViewPane;
 import com.intellij.ide.projectView.impl.ProjectRootsUtil;
-import com.intellij.ide.projectView.impl.TransferableWrapper;
+import com.intellij.ide.dnd.TransferableWrapper;
 import com.intellij.ide.ui.UISettings;
 import com.intellij.ide.ui.customization.CustomActionsSchema;
 import com.intellij.ide.util.DeleteHandler;

platform/lang-impl/src/com/intellij/ide/projectView/impl/ProjectViewDropTarget.java

@@ -19,6 +19,7 @@ import com.intellij.ide.DataManager;
 import com.intellij.ide.dnd.DnDEvent;
 import com.intellij.ide.dnd.DnDNativeTarget;
 import com.intellij.ide.dnd.FileCopyPasteUtil;
+import com.intellij.ide.dnd.TransferableWrapper;
 import com.intellij.ide.projectView.impl.nodes.DropTargetNode;
 import com.intellij.openapi.actionSystem.DataContext;
 import com.intellij.openapi.actionSystem.LangDataKeys;
@@ -103,8 +104,8 @@ class ProjectViewDropTarget implements DnDNativeTarget {
     else {
       // it seems like it's not possible to obtain dragged items _before_ accepting _drop_ on Macs, so just skip this check
       if (!SystemInfo.isMac) {
-        final PsiFileSystemItem[] psiFiles = getPsiFiles(getFileListFromAttachedObject(attached));
-        if (psiFiles == null) return false;
+        final PsiFileSystemItem[] psiFiles = getPsiFiles(FileCopyPasteUtil.getFileListFromAttachedObject(attached));
+        if (psiFiles == null || psiFiles.length == 0) return false;
         if (!MoveHandler.isValidTarget(getPsiElement(targetNode), psiFiles)) return false;
       }
     }
@@ -115,17 +116,6 @@ class ProjectViewDropTarget implements DnDNativeTarget {
     return false;
   }
 
-  @Nullable
-  private static List<File> getFileListFromAttachedObject(Object attached) {
-    if (attached instanceof TransferableWrapper) {
-      return ((TransferableWrapper)attached).asFileList();
-    }
-    else if (attached instanceof EventInfo) {
-      return FileCopyPasteUtil.getFileList(((EventInfo)attached).getTransferable());
-    }
-    return null;
-  }
-
   @Override
   public void drop(DnDEvent event) {
     final Object attached = event.getAttachedObject();
@@ -135,8 +125,8 @@ class ProjectViewDropTarget implements DnDNativeTarget {
     final int dropAction = event.getAction().getActionId();
     if (sourceNodes == null) {
       if (FileCopyPasteUtil.isFileListFlavorSupported(event)) {
-        final List<File> fileList = getFileListFromAttachedObject(attached);
-        if (fileList != null) {
+        List<File> fileList = FileCopyPasteUtil.getFileListFromAttachedObject(attached);
+        if (!fileList.isEmpty()) {
           getDropHandler(dropAction).doDropFiles(fileList, targetNode);
         }
       }

platform/platform-impl/src/com/intellij/ide/dnd/FileCopyPasteUtil.java

@@ -18,6 +18,8 @@ package com.intellij.ide.dnd;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.util.text.StringUtil;
+import com.intellij.openapi.vfs.VfsUtil;
+import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -27,6 +29,8 @@ import java.awt.datatransfer.FlavorMap;
 import java.awt.datatransfer.SystemFlavorMap;
 import java.awt.datatransfer.Transferable;
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -115,4 +119,34 @@ public class FileCopyPasteUtil {
     return null;
   }
 
+  @NotNull
+  public static List<File> getFileListFromAttachedObject(Object attached) {
+    List<File> result;
+    if (attached instanceof TransferableWrapper) {
+      result = ((TransferableWrapper)attached).asFileList();
+    }
+    else if (attached instanceof DnDNativeTarget.EventInfo) {
+      result = getFileList(((DnDNativeTarget.EventInfo)attached).getTransferable());
+    }
+    else {
+      result = null;
+    }
+    return result == null? Collections.<File>emptyList() : result;
+  }
+
+  @NotNull
+  public static List<VirtualFile> getVirtualFileListFromAttachedObject(Object attached) {
+    List<VirtualFile> result;
+    List<File> fileList = getFileListFromAttachedObject(attached);
+    if (fileList.isEmpty()) {
+      result = Collections.emptyList();
+    }
+    else {
+      result = new ArrayList<VirtualFile>(fileList.size());
+      for (File file : fileList) {
+        ContainerUtil.addIfNotNull(result, VfsUtil.findFileByIoFile(file, true));
+      }
+    }
+    return result;
+  }
 }

platform/platform-impl/src/com/intellij/ide/dnd/TransferableWrapper.java

@@ -13,9 +13,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.intellij.ide.projectView.impl;
+package com.intellij.ide.dnd;
 
-import com.intellij.ide.dnd.FileFlavorProvider;
 import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.Nullable;