Have DataTransferItemList.add() methods return the added item

Source/core/platform/chromium/ClipboardChromium.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2008, 2009 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 46 matching lines @@
 // A wrapper class that invalidates a DataTransferItemList when the associated Clipboard object goes out of scope.
 class DataTransferItemListPolicyWrapper : public DataTransferItemList {
 public:
     static PassRefPtr<DataTransferItemListPolicyWrapper> create(PassRefPtr<ClipboardChromium>, PassRefPtr<ChromiumDataObject>);
     virtual ~DataTransferItemListPolicyWrapper();
 
     virtual size_t length() const;
     virtual PassRefPtr<DataTransferItem> item(unsigned long index) OVERRIDE;
     virtual void deleteItem(unsigned long index, ExceptionState&) OVERRIDE;
     virtual void clear() OVERRIDE;
-    virtual void add(const String& data, const String& type, ExceptionState&) OVERRIDE;
-    virtual void add(PassRefPtr<File>) OVERRIDE;
+    virtual PassRefPtr<DataTransferItem> add(const String& data, const String& type, ExceptionState&) OVERRIDE;
+    virtual PassRefPtr<DataTransferItem> add(PassRefPtr<File>) OVERRIDE;
 
 private:
     DataTransferItemListPolicyWrapper(PassRefPtr<ClipboardChromium>, PassRefPtr<ChromiumDataObject>);
 
     RefPtr<ClipboardChromium> m_clipboard;
     RefPtr<ChromiumDataObject> m_dataObject;
 };
 
 
 PassRefPtr<DataTransferItemListPolicyWrapper> DataTransferItemListPolicyWrapper::create(
@@ skipping 33 matching lines @@
     m_dataObject->deleteItem(index);
 }
 
 void DataTransferItemListPolicyWrapper::clear()
 {
     if (!m_clipboard->canWriteData())
         return;
     m_dataObject->clearAll();
 }
 
-void DataTransferItemListPolicyWrapper::add(const String& data, const String& type, ExceptionState& es)
+PassRefPtr<DataTransferItem> DataTransferItemListPolicyWrapper::add(const String& data, const String& type, ExceptionState& es)
 {
     if (!m_clipboard->canWriteData())
-        return;
-    m_dataObject->add(data, type, es);
+        return 0;
+    RefPtr<ChromiumDataObjectItem> item = m_dataObject->add(data, type, es);
+    if (!item)
+        return 0;
+    return DataTransferItemPolicyWrapper::create(m_clipboard, item);
 }
 
-void DataTransferItemListPolicyWrapper::add(PassRefPtr<File> file)
+PassRefPtr<DataTransferItem> DataTransferItemListPolicyWrapper::add(PassRefPtr<File> file)
 {
     if (!m_clipboard->canWriteData())
-        return;
-    m_dataObject->add(file, m_clipboard->frame()->document()->scriptExecutionContext());
+        return 0;
+    RefPtr<ChromiumDataObjectItem> item = m_dataObject->add(file, m_clipboard->frame()->document()->scriptExecutionContext());
+    if (!item)
+        return 0;
+    return DataTransferItemPolicyWrapper::create(m_clipboard, item);
 }
 
 DataTransferItemListPolicyWrapper::DataTransferItemListPolicyWrapper(
     PassRefPtr<ClipboardChromium> clipboard, PassRefPtr<ChromiumDataObject> dataObject)
     : m_clipboard(clipboard)
     , m_dataObject(dataObject)
 {
 }
 
 } // namespace
@@ skipping 322 matching lines @@
 
 PassRefPtr<DataTransferItemList> ClipboardChromium::items()
 {
     // FIXME: According to the spec, we are supposed to return the same collection of items each
     // time. We now return a wrapper that always wraps the *same* set of items, so JS shouldn't be
     // able to tell, but we probably still want to fix this.
     return DataTransferItemListPolicyWrapper::create(this, m_dataObject);
 }
 
 } // namespace WebCore