Source/core/clipboard/DataTransfer.h

/*
 * Copyright (C) 2001 Peter Kelly (pmk@post.com)
 * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
 * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
 * Copyright (C) 2003, 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef DataTransfer_h
#define DataTransfer_h

#include "bindings/core/v8/ScriptWrappable.h"
#include "core/CoreExport.h"
#include "core/clipboard/DataTransferAccessPolicy.h"
#include "core/fetch/ImageResource.h"
#include "core/fetch/ResourcePtr.h"
#include "core/page/DragActions.h"
#include "platform/geometry/IntPoint.h"
#include "platform/heap/Handle.h"
#include "wtf/Forward.h"
#include "wtf/RefCounted.h"
#include "wtf/RefPtr.h"
#include "wtf/Vector.h"

namespace blink {

class DataObject;
class DataTransferItemList;
class DragImage;
class Element;
class ExceptionState;
class FileList;
class LocalFrame;
class Node;
class Range;

// Used for drag and drop and copy/paste.
// Drag and Drop: http://www.whatwg.org/specs/web-apps/current-work/multipage/dnd.html
// Clipboard API (copy/paste): http://dev.w3.org/2006/webapi/clipops/clipops.html
class CORE_EXPORT DataTransfer : public GarbageCollectedFinalized<DataTransfer>, public ScriptWrappable {
    DEFINE_WRAPPERTYPEINFO();
public:
    // Whether this transfer is serving a drag-drop or copy-paste request.
    enum DataTransferType {
        CopyAndPaste,
        DragAndDrop,
    };

    static DataTransfer* create(DataTransferType, DataTransferAccessPolicy, DataObject*);
    ~DataTransfer();

    bool isForCopyAndPaste() const { return m_transferType == CopyAndPaste; }
    bool isForDragAndDrop() const { return m_transferType == DragAndDrop; }

    String dropEffect() const { return dropEffectIsUninitialized() ? "none" : m_dropEffect; }
    void setDropEffect(const String&);
    bool dropEffectIsUninitialized() const { return m_dropEffect == "uninitialized"; }
    String effectAllowed() const { return m_effectAllowed; }
    void setEffectAllowed(const String&);

    void clearData(const String& type = String());
    String getData(const String& type) const;
    void setData(const String& type, const String& data);

    // extensions beyond IE's API
    Vector<String> types() const;
    FileList* files() const;

    IntPoint dragLocation() const { return m_dragLoc; }
    void setDragImage(Element*, int x, int y, ExceptionState&);
    void clearDragImage();
    void setDragImageResource(ImageResource*, const IntPoint&);
    void setDragImageElement(Node*, const IntPoint&);

    PassOwnPtr<DragImage> createDragImage(IntPoint& dragLocation, LocalFrame*) const;
    void declareAndWriteDragImage(Element*, const KURL&, const String& title);
    void writeURL(const KURL&, const String&);
    void writeRange(Range*, LocalFrame*);
    void writePlainText(const String&);

    void setAccessPolicy(DataTransferAccessPolicy);
    bool canReadTypes() const;
    bool canReadData() const;
    bool canWriteData() const;
    // Note that the spec doesn't actually allow drag image modification outside the dragstart
    // event. This capability is maintained for backwards compatiblity for ports that have
    // supported this in the past. On many ports, attempting to set a drag image outside the
    // dragstart operation is a no-op anyway.
    bool canSetDragImage() const;

    DragOperation sourceOperation() const;
    DragOperation destinationOperation() const;
    void setSourceOperation(DragOperation);
    void setDestinationOperation(DragOperation);

    bool hasDropZoneType(const String&);

    DataTransferItemList* items();

    DataObject* dataObject() const;

    DECLARE_TRACE();

private:
    DataTransfer(DataTransferType, DataTransferAccessPolicy, DataObject*);

    void setDragImage(ImageResource*, Node*, const IntPoint&);

    bool hasFileOfType(const String&) const;
    bool hasStringOfType(const String&) const;

    // Instead of using this member directly, prefer to use the can*() methods above.
    DataTransferAccessPolicy m_policy;
    String m_dropEffect;
    String m_effectAllowed;
    DataTransferType m_transferType;
    Member<DataObject> m_dataObject;

    IntPoint m_dragLoc;
    ResourcePtr<ImageResource> m_dragImage;
    RefPtrWillBeMember<Node> m_dragImageElement;
};

DragOperation convertDropZoneOperationToDragOperation(const String& dragOperation);
String convertDragOperationToDropZoneOperation(DragOperation);

} // namespace blink

#endif // DataTransfer_h