/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsReadableUtils.h"

// Local Includes

#include "nsContentAreaDragDrop.h"

// Helper Classes

#include "nsString.h"

// Interfaces needed to be included

#include "nsCopySupport.h"

#include "nsISelectionController.h"

#include "nsPIDOMWindow.h"

#include "nsIFormControl.h"

#include "nsITransferable.h"

#include "nsComponentManagerUtils.h"

#include "nsXPCOM.h"

#include "nsISupportsPrimitives.h"

#include "nsServiceManagerUtils.h"

#include "nsNetUtil.h"

#include "nsIFile.h"

#include "nsFrameLoader.h"

#include "nsIWebNavigation.h"

#include "nsIDocShell.h"

#include "nsIContent.h"

#include "nsIContentInlines.h"

#include "nsIImageLoadingContent.h"

#include "nsITextControlElement.h"

#include "nsUnicharUtils.h"

#include "nsIURL.h"

#include "nsIURIMutator.h"

#include "nsIDocument.h"

#include "nsIScriptSecurityManager.h"

#include "nsIPrincipal.h"

#include "nsIDocShellTreeItem.h"

#include "nsIWebBrowserPersist.h"

#include "nsEscape.h"

#include "nsContentUtils.h"

#include "nsIMIMEService.h"

#include "imgIContainer.h"

#include "imgIRequest.h"

#include "mozilla/dom/DataTransfer.h"

#include "nsIMIMEInfo.h"

#include "nsRange.h"

#include "TabParent.h"

#include "mozilla/dom/Element.h"

#include "mozilla/dom/HTMLAreaElement.h"

#include "mozilla/dom/HTMLAnchorElement.h"

#include "mozilla/dom/Selection.h"

#include "nsVariant.h"

using namespace mozilla::dom;

using mozilla::IgnoreErrors;

class MOZ_STACK_CLASS DragDataProducer

{

public:

  DragDataProducer(nsPIDOMWindowOuter* aWindow,

                   nsIContent* aTarget,

                   nsIContent* aSelectionTargetNode,

                   bool aIsAltKeyPressed);

  nsresult Produce(DataTransfer* aDataTransfer,

                   bool* aCanDrag,

                   Selection** aSelection,

                   nsIContent** aDragNode,

                   nsACString& aPrincipalURISpec);

private:

  void AddString(DataTransfer* aDataTransfer,

                 const nsAString& aFlavor,

                 const nsAString& aData,

                 nsIPrincipal* aPrincipal,

                 bool aHidden=false);

  nsresult AddStringsToDataTransfer(nsIContent* aDragNode,

                                    DataTransfer* aDataTransfer);

  nsresult GetImageData(imgIContainer* aImage, imgIRequest* aRequest);

  static nsresult GetDraggableSelectionData(Selection* inSelection,

                                            nsIContent* inRealTargetNode,

                                            nsIContent **outImageOrLinkNode,

                                            bool* outDragSelectedText);

  static already_AddRefed<nsIContent> FindParentLinkNode(nsIContent* inNode);

  static MOZ_MUST_USE nsresult

  GetAnchorURL(nsIContent* inNode, nsAString& outURL);

  static void GetNodeString(nsIContent* inNode, nsAString & outNodeString);

  static void CreateLinkText(const nsAString& inURL, const nsAString & inText,

                              nsAString& outLinkText);

  nsCOMPtr<nsPIDOMWindowOuter> mWindow;

  nsCOMPtr<nsIContent> mTarget;

  nsCOMPtr<nsIContent> mSelectionTargetNode;

  bool mIsAltKeyPressed;

  nsString mUrlString;

  nsString mImageSourceString;

  nsString mImageDestFileName;

#if defined (XP_MACOSX)

  nsString mImageRequestMime;

#endif

  nsString mTitleString;

  // will be filled automatically if you fill urlstring

  nsString mHtmlString;

  nsString mContextString;

  nsString mInfoString;

  bool mIsAnchor;

  nsCOMPtr<imgIContainer> mImage;

};

nsresult

nsContentAreaDragDrop::GetDragData(nsPIDOMWindowOuter* aWindow,

                                   nsIContent* aTarget,

                                   nsIContent* aSelectionTargetNode,

                                   bool aIsAltKeyPressed,

                                   DataTransfer* aDataTransfer,

                                   bool* aCanDrag,

                                   Selection** aSelection,

                                   nsIContent** aDragNode,

                                   nsACString& aPrincipalURISpec)

{

  NS_ENSURE_TRUE(aSelectionTargetNode, NS_ERROR_INVALID_ARG);

  *aCanDrag = true;

  DragDataProducer

    provider(aWindow, aTarget, aSelectionTargetNode, aIsAltKeyPressed);

  return provider.Produce(aDataTransfer, aCanDrag, aSelection, aDragNode,

                          aPrincipalURISpec);

}

NS_IMPL_ISUPPORTS(nsContentAreaDragDropDataProvider, nsIFlavorDataProvider)

// SaveURIToFile

// used on platforms where it's possible to drag items (e.g. images)

// into the file system

nsresult

nsContentAreaDragDropDataProvider::SaveURIToFile(nsIURI* inSourceURI,

                                                 nsIPrincipal* inTriggeringPrincipal,

                                                 nsIFile* inDestFile,

                                                 bool isPrivate)

{

  nsCOMPtr<nsIURL> sourceURL = do_QueryInterface(inSourceURI);

  if (!sourceURL) {

    return NS_ERROR_NO_INTERFACE;

  }

  nsresult rv = inDestFile->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0600);

  NS_ENSURE_SUCCESS(rv, rv);

  // we rely on the fact that the WPB is refcounted by the channel etc,

  // so we don't keep a ref to it. It will die when finished.

  nsCOMPtr<nsIWebBrowserPersist> persist =

    do_CreateInstance("@mozilla.org/embedding/browser/nsWebBrowserPersist;1",

                      &rv);

  NS_ENSURE_SUCCESS(rv, rv);

  persist->SetPersistFlags(nsIWebBrowserPersist::PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION);

  // referrer policy can be anything since the referrer is nullptr

  return persist->SavePrivacyAwareURI(inSourceURI,

                                      inTriggeringPrincipal, 0, nullptr,

                                      mozilla::net::RP_Unset,

                                      nullptr, nullptr,

                                      inDestFile, isPrivate);

}

/*

 * Check if the provided filename extension is valid for the MIME type and

 * return the MIME type's primary extension.

 *

 * @param aExtension           [in]  the extension to check

 * @param aMimeType            [in]  the MIME type to check the extension with

 * @param aIsValidExtension    [out] true if |aExtension| is valid for

 *                                   |aMimeType|

 * @param aPrimaryExtension    [out] the primary extension for the MIME type

 *                                   to potentially be used as a replacement

 *                                   for |aExtension|

 */

nsresult

CheckAndGetExtensionForMime(const nsCString& aExtension,

                            const nsCString& aMimeType,

                            bool* aIsValidExtension,

                            nsACString* aPrimaryExtension)

{

  nsresult rv;

  nsCOMPtr<nsIMIMEService> mimeService = do_GetService("@mozilla.org/mime;1");

  if (NS_WARN_IF(!mimeService)) {

    return NS_ERROR_FAILURE;

  }

  nsCOMPtr<nsIMIMEInfo> mimeInfo;

  rv = mimeService->GetFromTypeAndExtension(aMimeType, EmptyCString(),

                                            getter_AddRefs(mimeInfo));

  NS_ENSURE_SUCCESS(rv, rv);

  rv = mimeInfo->GetPrimaryExtension(*aPrimaryExtension);

  NS_ENSURE_SUCCESS(rv, rv);

  if (aExtension.IsEmpty()) {

    *aIsValidExtension = false;

    return NS_OK;

  }

  rv = mimeInfo->ExtensionExists(aExtension, aIsValidExtension);

  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;

}

// This is our nsIFlavorDataProvider callback. There are several

// assumptions here that make this work:

//

// 1. Someone put a kFilePromiseURLMime flavor into the transferable

//    with the source URI of the file to save (as a string). We did

//    that in AddStringsToDataTransfer.

//

// 2. Someone put a kFilePromiseDirectoryMime flavor into the

//    transferable with an nsIFile for the directory we are to

//    save in. That has to be done by platform-specific code (in

//    widget), which gets the destination directory from

//    OS-specific drag information.

//

NS_IMETHODIMP

nsContentAreaDragDropDataProvider::GetFlavorData(nsITransferable *aTransferable,

                                                 const char *aFlavor,

                                                 nsISupports **aData,

                                                 uint32_t *aDataLen)

{

  NS_ENSURE_ARG_POINTER(aData && aDataLen);

  *aData = nullptr;

  *aDataLen = 0;

  nsresult rv = NS_ERROR_NOT_IMPLEMENTED;

  if (strcmp(aFlavor, kFilePromiseMime) == 0) {

    // get the URI from the kFilePromiseURLMime flavor

    NS_ENSURE_ARG(aTransferable);

    nsCOMPtr<nsISupports> tmp;

    uint32_t dataSize = 0;

    aTransferable->GetTransferData(kFilePromiseURLMime,

                                   getter_AddRefs(tmp), &dataSize);

    nsCOMPtr<nsISupportsString> supportsString =

      do_QueryInterface(tmp);

    if (!supportsString)

      return NS_ERROR_FAILURE;

    nsAutoString sourceURLString;

    supportsString->GetData(sourceURLString);

    if (sourceURLString.IsEmpty())

      return NS_ERROR_FAILURE;

    nsCOMPtr<nsIURI> sourceURI;

    rv = NS_NewURI(getter_AddRefs(sourceURI), sourceURLString);

    NS_ENSURE_SUCCESS(rv, rv);

    aTransferable->GetTransferData(kFilePromiseDestFilename,

                                   getter_AddRefs(tmp), &dataSize);

    supportsString = do_QueryInterface(tmp);

    if (!supportsString)

      return NS_ERROR_FAILURE;

    nsAutoString targetFilename;

    supportsString->GetData(targetFilename);

    if (targetFilename.IsEmpty())

      return NS_ERROR_FAILURE;

#if defined(XP_MACOSX)

    // Use the image request's MIME type to ensure the filename's

    // extension is compatible with the OS's handler for this type.

    // If it isn't, or is missing, replace the extension with the

    // primary extension. On Mac, do this in the parent process

    // because sandboxing blocks access to MIME-handler info from

    // content processes.

    if (XRE_IsParentProcess()) {

      aTransferable->GetTransferData(kImageRequestMime,

                                     getter_AddRefs(tmp), &dataSize);

      supportsString = do_QueryInterface(tmp);

      if (!supportsString)

        return NS_ERROR_FAILURE;

      nsAutoString imageRequestMime;

      supportsString->GetData(imageRequestMime);

      // If we have a MIME type, check the extension is compatible

      if (!imageRequestMime.IsEmpty()) {

        // Build a URL to get the filename extension

        nsCOMPtr<nsIURL> imageURL = do_QueryInterface(sourceURI, &rv);

        NS_ENSURE_SUCCESS(rv, rv);

        nsAutoCString extension;

        rv = imageURL->GetFileExtension(extension);

        NS_ENSURE_SUCCESS(rv, rv);

        NS_ConvertUTF16toUTF8 mimeCString(imageRequestMime);

        bool isValidExtension;

        nsAutoCString primaryExtension;

        rv = CheckAndGetExtensionForMime(extension,

                                         mimeCString,

                                         &isValidExtension,

                                         &primaryExtension);

        NS_ENSURE_SUCCESS(rv, rv);

        if (!isValidExtension) {

          // The filename extension is missing or incompatible

          // with the MIME type, replace it with the primary

          // extension.

          nsAutoCString newFileName;

          rv = imageURL->GetFileBaseName(newFileName);

          NS_ENSURE_SUCCESS(rv, rv);

          newFileName.Append(".");

          newFileName.Append(primaryExtension);

          targetFilename = NS_ConvertUTF8toUTF16(newFileName);

        }

      }

    }

    // make the filename safe for the filesystem

    targetFilename.ReplaceChar(FILE_PATH_SEPARATOR FILE_ILLEGAL_CHARACTERS,

                               '-');

#endif /* defined(XP_MACOSX) */

    // get the target directory from the kFilePromiseDirectoryMime

    // flavor

    nsCOMPtr<nsISupports> dirPrimitive;

    dataSize = 0;

    aTransferable->GetTransferData(kFilePromiseDirectoryMime,

                                   getter_AddRefs(dirPrimitive), &dataSize);

    nsCOMPtr<nsIFile> destDirectory = do_QueryInterface(dirPrimitive);

    if (!destDirectory)

      return NS_ERROR_FAILURE;

    nsCOMPtr<nsIFile> file;

    rv = destDirectory->Clone(getter_AddRefs(file));

    NS_ENSURE_SUCCESS(rv, rv);

    file->Append(targetFilename);

    bool isPrivate;

    aTransferable->GetIsPrivateData(&isPrivate);

    nsCOMPtr<nsIPrincipal> principal;

    aTransferable->GetRequestingPrincipal(getter_AddRefs(principal));

    rv = SaveURIToFile(sourceURI, principal, file, isPrivate);

    // send back an nsIFile

    if (NS_SUCCEEDED(rv)) {

      CallQueryInterface(file, aData);

      *aDataLen = sizeof(nsIFile*);

    }

  }

  return rv;

}

DragDataProducer::DragDataProducer(nsPIDOMWindowOuter* aWindow,

                                   nsIContent* aTarget,

                                   nsIContent* aSelectionTargetNode,

                                   bool aIsAltKeyPressed)

  : mWindow(aWindow),

    mTarget(aTarget),

    mSelectionTargetNode(aSelectionTargetNode),

    mIsAltKeyPressed(aIsAltKeyPressed),

    mIsAnchor(false)

{

}

//

// FindParentLinkNode

//

// Finds the parent with the given link tag starting at |inNode|. If

// it gets up to the root without finding it, we stop looking and

// return null.

//

already_AddRefed<nsIContent>

DragDataProducer::FindParentLinkNode(nsIContent* inNode)

{

  nsIContent* content = inNode;

  if (!content) {

    // That must have been the document node; nothing else to do here;

    return nullptr;

  }

  for (; content; content = content->GetParent()) {

    if (nsContentUtils::IsDraggableLink(content)) {

      nsCOMPtr<nsIContent> ret = content;

      return ret.forget();

    }

  }

  return nullptr;

}

//

// GetAnchorURL

//

nsresult

DragDataProducer::GetAnchorURL(nsIContent* inNode, nsAString& outURL)

{

  nsCOMPtr<nsIURI> linkURI;

  if (!inNode || !inNode->IsLink(getter_AddRefs(linkURI))) {

    // Not a link

    outURL.Truncate();

    return NS_OK;

  }

  nsAutoCString spec;

  nsresult rv = linkURI->GetSpec(spec);

  NS_ENSURE_SUCCESS(rv, rv);

  CopyUTF8toUTF16(spec, outURL);

  return NS_OK;

}

//

// CreateLinkText

//

// Creates the html for an anchor in the form

//  <a href="inURL">inText</a>

//

void

DragDataProducer::CreateLinkText(const nsAString& inURL,

                                 const nsAString & inText,

                                 nsAString& outLinkText)

{

  // use a temp var in case |inText| is the same string as

  // |outLinkText| to avoid overwriting it while building up the

  // string in pieces.

  nsAutoString linkText(NS_LITERAL_STRING("<a href=\"") +

                        inURL +

                        NS_LITERAL_STRING("\">") +

                        inText +

                        NS_LITERAL_STRING("</a>") );

  outLinkText = linkText;

}

//

// GetNodeString

//

// Gets the text associated with a node

//

void

DragDataProducer::GetNodeString(nsIContent* inNode,

                                nsAString & outNodeString)

{

  nsCOMPtr<nsINode> node = inNode;

  outNodeString.Truncate();

  // use a range to get the text-equivalent of the node

  nsCOMPtr<nsIDocument> doc = node->OwnerDoc();

  RefPtr<nsRange> range = doc->CreateRange(IgnoreErrors());

  if (range) {

    range->SelectNode(*node, IgnoreErrors());

    range->ToString(outNodeString, IgnoreErrors());

  }

}

nsresult

DragDataProducer::GetImageData(imgIContainer* aImage, imgIRequest* aRequest)

{

  nsCOMPtr<nsIURI> imgUri;

  aRequest->GetURI(getter_AddRefs(imgUri));

  nsCOMPtr<nsIURL> imgUrl(do_QueryInterface(imgUri));

  if (imgUrl) {

    nsAutoCString spec;

    nsresult rv = imgUrl->GetSpec(spec);

    NS_ENSURE_SUCCESS(rv, rv);

    // pass out the image source string

    CopyUTF8toUTF16(spec, mImageSourceString);

    nsCString mimeType;

    aRequest->GetMimeType(getter_Copies(mimeType));

#if defined(XP_MACOSX)

    // Save the MIME type so we can make sure the extension

    // is compatible (and replace it if it isn't) when the

    // image is dropped. On Mac, we need to get the OS MIME

    // handler information in the parent due to sandboxing.

    CopyUTF8toUTF16(mimeType, mImageRequestMime);

#else

    nsCOMPtr<nsIMIMEService> mimeService = do_GetService("@mozilla.org/mime;1");

    if (NS_WARN_IF(!mimeService)) {

      return NS_ERROR_FAILURE;

    }

    nsCOMPtr<nsIMIMEInfo> mimeInfo;

    mimeService->GetFromTypeAndExtension(mimeType, EmptyCString(),

           getter_AddRefs(mimeInfo));

    if (mimeInfo) {

      nsAutoCString extension;

      imgUrl->GetFileExtension(extension);

      bool validExtension;

      if (extension.IsEmpty() ||

          NS_FAILED(mimeInfo->ExtensionExists(extension,

                                              &validExtension)) ||

          !validExtension) {

        // Fix the file extension in the URL

        nsAutoCString primaryExtension;

        mimeInfo->GetPrimaryExtension(primaryExtension);

        rv = NS_MutateURI(imgUrl)

               .Apply(NS_MutatorMethod(&nsIURLMutator::SetFileExtension,

                                       primaryExtension, nullptr))

               .Finalize(imgUrl);

        NS_ENSURE_SUCCESS(rv, rv);

      }

    }

#endif /* defined(XP_MACOSX) */

    nsAutoCString fileName;

    imgUrl->GetFileName(fileName);

    NS_UnescapeURL(fileName);

#if !defined(XP_MACOSX)

    // make the filename safe for the filesystem

    fileName.ReplaceChar(FILE_PATH_SEPARATOR FILE_ILLEGAL_CHARACTERS, '-');

#endif

    CopyUTF8toUTF16(fileName, mImageDestFileName);

    // and the image object

    mImage = aImage;

  }

  return NS_OK;

}

nsresult

DragDataProducer::Produce(DataTransfer* aDataTransfer,

                          bool* aCanDrag,

                          Selection** aSelection,

                          nsIContent** aDragNode,

                          nsACString& aPrincipalURISpec)

{

  MOZ_ASSERT(aCanDrag && aSelection && aDataTransfer && aDragNode,

             "null pointer passed to Produce");

  NS_ASSERTION(mWindow, "window not set");

  NS_ASSERTION(mSelectionTargetNode, "selection target node should have been set");

  *aDragNode = nullptr;

  nsresult rv;

  nsIContent* dragNode = nullptr;

  *aSelection = nullptr;

  // Find the selection to see what we could be dragging and if what we're

  // dragging is in what is selected. If this is an editable textbox, use

  // the textbox's selection, otherwise use the window's selection.

  RefPtr<Selection> selection;

  nsIContent* editingElement = mSelectionTargetNode->IsEditable() ?

                               mSelectionTargetNode->GetEditingHost() : nullptr;

  nsCOMPtr<nsITextControlElement> textControl =

    nsITextControlElement::GetTextControlElementFromEditingHost(editingElement);

  if (textControl) {

    nsISelectionController* selcon = textControl->GetSelectionController();

    if (selcon) {

      selection = selcon->GetSelection(nsISelectionController::SELECTION_NORMAL);

    }

    if (!selection)

      return NS_OK;

  }

  else {

    selection = mWindow->GetSelection();

    if (!selection)

      return NS_OK;

    // Check if the node is inside a form control. Don't set aCanDrag to false

    //however, as we still want to allow the drag.

    nsCOMPtr<nsIContent> findFormNode = mSelectionTargetNode;

    nsIContent* findFormParent = findFormNode->GetParent();

    while (findFormParent) {

      nsCOMPtr<nsIFormControl> form(do_QueryInterface(findFormParent));

      if (form && !form->AllowDraggableChildren()) {

        return NS_OK;

      }

      findFormParent = findFormParent->GetParent();

    }

  }

  // if set, serialize the content under this node

  nsCOMPtr<nsIContent> nodeToSerialize;

  nsCOMPtr<nsIDocShellTreeItem> dsti = mWindow->GetDocShell();

  const bool isChromeShell =

    dsti && dsti->ItemType() == nsIDocShellTreeItem::typeChrome;

  // In chrome shells, only allow dragging inside editable areas.

  if (isChromeShell && !editingElement) {

    nsCOMPtr<nsIFrameLoaderOwner> flo = do_QueryInterface(mTarget);

    if (flo) {

      RefPtr<nsFrameLoader> fl = flo->GetFrameLoader();

      if (fl) {

        TabParent* tp = static_cast<TabParent*>(fl->GetRemoteBrowser());

        if (tp) {

          // We have a TabParent, so it may have data for dnd in case the child

          // process started a dnd session.

          tp->AddInitialDnDDataTo(aDataTransfer, aPrincipalURISpec);

        }

      }

    }

    return NS_OK;

  }

  if (isChromeShell && textControl) {

    // Only use the selection if the target node is in the selection.

    if (!selection->ContainsNode(*mSelectionTargetNode, false, IgnoreErrors()))

      return NS_OK;

    selection.swap(*aSelection);

  }

  else {

    // In content shells, a number of checks are made below to determine

    // whether an image or a link is being dragged. If so, add additional

    // data to the data transfer. This is also done for chrome shells, but

    // only when in a non-textbox editor.

    bool haveSelectedContent = false;

    // possible parent link node

    nsCOMPtr<nsIContent> parentLink;

    nsCOMPtr<nsIContent> draggedNode;

    {

      // only drag form elements by using the alt key,

      // otherwise buttons and select widgets are hard to use

      // Note that while <object> elements implement nsIFormControl, we should

      // really allow dragging them if they happen to be images.

      nsCOMPtr<nsIFormControl> form(do_QueryInterface(mTarget));

      if (form && !mIsAltKeyPressed && form->ControlType() != NS_FORM_OBJECT) {

        *aCanDrag = false;

        return NS_OK;

      }

      draggedNode = mTarget;

    }

    nsCOMPtr<nsIImageLoadingContent>  image;

    nsCOMPtr<nsIContent> selectedImageOrLinkNode;

    GetDraggableSelectionData(selection, mSelectionTargetNode,

                              getter_AddRefs(selectedImageOrLinkNode),

                              &haveSelectedContent);

    // either plain text or anchor text is selected

    if (haveSelectedContent) {

      selection.swap(*aSelection);

    } else if (selectedImageOrLinkNode) {

      // an image is selected

      image = do_QueryInterface(selectedImageOrLinkNode);

    } else {

      // nothing is selected -

      //

      // look for draggable elements under the mouse

      //

      // if the alt key is down, don't start a drag if we're in an

      // anchor because we want to do selection.

      parentLink = FindParentLinkNode(draggedNode);

      if (parentLink && mIsAltKeyPressed) {

        *aCanDrag = false;

        return NS_OK;

      }

      image = do_QueryInterface(draggedNode);

    }

    {

      // set for linked images, and links

      nsCOMPtr<nsIContent> linkNode;

      RefPtr<HTMLAreaElement> areaElem = HTMLAreaElement::FromNodeOrNull(draggedNode);

      if (areaElem) {

        // use the alt text (or, if missing, the href) as the title

        areaElem->GetAttribute(NS_LITERAL_STRING("alt"), mTitleString);

        if (mTitleString.IsEmpty()) {

          // this can be a relative link

          areaElem->GetAttribute(NS_LITERAL_STRING("href"), mTitleString);

        }

        // we'll generate HTML like <a href="absurl">alt text</a>

        mIsAnchor = true;

        // gives an absolute link

        nsresult rv = GetAnchorURL(draggedNode, mUrlString);

        NS_ENSURE_SUCCESS(rv, rv);

        mHtmlString.AssignLiteral("<a href=\"");

        mHtmlString.Append(mUrlString);

        mHtmlString.AppendLiteral("\">");

        mHtmlString.Append(mTitleString);

        mHtmlString.AppendLiteral("</a>");

        dragNode = draggedNode;

      } else if (image) {

        mIsAnchor = true;

        // grab the href as the url, use alt text as the title of the

        // area if it's there.  the drag data is the image tag and src

        // attribute.

        nsCOMPtr<nsIURI> imageURI;

        image->GetCurrentURI(getter_AddRefs(imageURI));

        if (imageURI) {

          nsAutoCString spec;

          rv = imageURI->GetSpec(spec);

          NS_ENSURE_SUCCESS(rv, rv);

          CopyUTF8toUTF16(spec, mUrlString);

        }

        nsCOMPtr<Element> imageElement(do_QueryInterface(image));

        // XXXbz Shouldn't we use the "title" attr for title?  Using

        // "alt" seems very wrong....

        // XXXbz Also, what if this is an nsIImageLoadingContent

        // that's not an <html:img>?

        if (imageElement) {

          imageElement->GetAttribute(NS_LITERAL_STRING("alt"), mTitleString);

        }

        if (mTitleString.IsEmpty()) {

          mTitleString = mUrlString;

        }

        nsCOMPtr<imgIRequest> imgRequest;

        // grab the image data, and its request.

        nsCOMPtr<imgIContainer> img =

          nsContentUtils::GetImageFromContent(image,

                                              getter_AddRefs(imgRequest));

        if (imgRequest) {

          rv = GetImageData(img, imgRequest);

          NS_ENSURE_SUCCESS(rv, rv);

        }

        if (parentLink) {

          // If we are dragging around an image in an anchor, then we

          // are dragging the entire anchor

          linkNode = parentLink;

          nodeToSerialize = linkNode;

        } else {

          nodeToSerialize = draggedNode;

        }

        dragNode = nodeToSerialize;

      } else if (draggedNode && draggedNode->IsHTMLElement(nsGkAtoms::a)) {

        // set linkNode. The code below will handle this

        linkNode = draggedNode;    // XXX test this

        GetNodeString(draggedNode, mTitleString);

      } else if (parentLink) {

        // parentLink will always be null if there's selected content

        linkNode = parentLink;

        nodeToSerialize = linkNode;

      } else if (!haveSelectedContent) {

        // nothing draggable

        return NS_OK;

      }

      if (linkNode) {

        mIsAnchor = true;

        rv = GetAnchorURL(linkNode, mUrlString);

        NS_ENSURE_SUCCESS(rv, rv);

        dragNode = linkNode;

      }

    }

  }

  if (nodeToSerialize || *aSelection) {

    mHtmlString.Truncate();

    mContextString.Truncate();

    mInfoString.Truncate();

    mTitleString.Truncate();

    nsCOMPtr<nsIDocument> doc = mWindow->GetDoc();

    NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);

    // if we have selected text, use it in preference to the node

    nsCOMPtr<nsITransferable> transferable;

    if (*aSelection) {

      rv = nsCopySupport::GetTransferableForSelection(*aSelection, doc,

                                                      getter_AddRefs(transferable));

    }

    else {

      rv = nsCopySupport::GetTransferableForNode(nodeToSerialize, doc,

                                                 getter_AddRefs(transferable));

    }

    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<nsISupports> supports;

    nsCOMPtr<nsISupportsString> data;

    uint32_t dataSize;

    rv = transferable->GetTransferData(kHTMLMime, getter_AddRefs(supports),

                                       &dataSize);

    data = do_QueryInterface(supports);

    if (NS_SUCCEEDED(rv)) {

      data->GetData(mHtmlString);

    }

    rv = transferable->GetTransferData(kHTMLContext, getter_AddRefs(supports),

                                       &dataSize);

    data = do_QueryInterface(supports);

    if (NS_SUCCEEDED(rv)) {

      data->GetData(mContextString);

    }

    rv = transferable->GetTransferData(kHTMLInfo, getter_AddRefs(supports),

                                       &dataSize);

    data = do_QueryInterface(supports);

    if (NS_SUCCEEDED(rv)) {

      data->GetData(mInfoString);

    }

    rv = transferable->GetTransferData(kUnicodeMime, getter_AddRefs(supports),

                                       &dataSize);

    data = do_QueryInterface(supports);

    NS_ENSURE_SUCCESS(rv, rv); // require plain text at a minimum

    data->GetData(mTitleString);

  }

  // default text value is the URL

  if (mTitleString.IsEmpty()) {

    mTitleString = mUrlString;

  }

  // if we haven't constructed a html version, make one now

  if (mHtmlString.IsEmpty() && !mUrlString.IsEmpty())

    CreateLinkText(mUrlString, mTitleString, mHtmlString);

  // if there is no drag node, which will be the case for a selection, just

  // use the selection target node.

  rv = AddStringsToDataTransfer(

         dragNode ? dragNode : mSelectionTargetNode.get(), aDataTransfer);

  NS_ENSURE_SUCCESS(rv, rv);

  NS_IF_ADDREF(*aDragNode = dragNode);

  return NS_OK;

}

void

DragDataProducer::AddString(DataTransfer* aDataTransfer,

                            const nsAString& aFlavor,

                            const nsAString& aData,

                            nsIPrincipal* aPrincipal,

                            bool aHidden)

{

  RefPtr<nsVariantCC> variant = new nsVariantCC();

  variant->SetAsAString(aData);

  aDataTransfer->SetDataWithPrincipal(aFlavor, variant, 0, aPrincipal, aHidden);

}

nsresult

DragDataProducer::AddStringsToDataTransfer(nsIContent* aDragNode,

                                           DataTransfer* aDataTransfer)

{

  NS_ASSERTION(aDragNode, "adding strings for null node");

  // set all of the data to have the principal of the node where the data came from

  nsIPrincipal* principal = aDragNode->NodePrincipal();

  // add a special flavor if we're an anchor to indicate that we have

  // a URL in the drag data

  if (!mUrlString.IsEmpty() && mIsAnchor) {

    nsAutoString dragData(mUrlString);

    dragData.Append('\n');

    // Remove leading and trailing newlines in the title and replace them with

    // space in remaining positions - they confuse PlacesUtils::unwrapNodes

    // that expects url\ntitle formatted data for x-moz-url.

    nsAutoString title(mTitleString);

    title.Trim("\r\n");

    title.ReplaceChar("\r\n", ' ');

    dragData += title;

    AddString(aDataTransfer, NS_LITERAL_STRING(kURLMime), dragData, principal);

    AddString(aDataTransfer, NS_LITERAL_STRING(kURLDataMime), mUrlString, principal);

    AddString(aDataTransfer, NS_LITERAL_STRING(kURLDescriptionMime), mTitleString, principal);

    AddString(aDataTransfer, NS_LITERAL_STRING("text/uri-list"), mUrlString, principal);

  }

  // add a special flavor for the html context data

  if (!mContextString.IsEmpty())

    AddString(aDataTransfer, NS_LITERAL_STRING(kHTMLContext), mContextString, principal);

  // add a special flavor if we have html info data

  if (!mInfoString.IsEmpty())

    AddString(aDataTransfer, NS_LITERAL_STRING(kHTMLInfo), mInfoString, principal);

  // add the full html

  if (!mHtmlString.IsEmpty())

    AddString(aDataTransfer, NS_LITERAL_STRING(kHTMLMime), mHtmlString, principal);

  // add the plain text. we use the url for text/plain data if an anchor is

  // being dragged, rather than the title text of the link or the alt text for

  // an anchor image.

  AddString(aDataTransfer, NS_LITERAL_STRING(kTextMime),

            mIsAnchor ? mUrlString : mTitleString, principal);

  // add image data, if present. For now, all we're going to do with

  // this is turn it into a native data flavor, so indicate that with

  // a new flavor so as not to confuse anyone who is really registered

  // for image/gif or image/jpg.

  if (mImage) {

    RefPtr<nsVariantCC> variant = new nsVariantCC();

    variant->SetAsISupports(mImage);

    aDataTransfer->SetDataWithPrincipal(NS_LITERAL_STRING(kNativeImageMime),

                                        variant, 0, principal);