The Tor Browser: content/base/src/nsContentAreaDragDrop.cpp@deefc01c0e14 (annotated)

content/base/src/nsContentAreaDragDrop.cpp@deefc01c0e14 (annotated)

content/base/src/nsContentAreaDragDrop.cpp

Thu, 15 Jan 2015 21:03:48 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 21:03:48 +0100
branch: TOR_BUG_9701
changeset 11: deefc01c0e14
permissions: -rw-r--r--

Integrate friendly tips from Tor colleagues to make (or not) 4.5 alpha 3;
This includes removal of overloaded (but unused) methods, and addition of
a overlooked call to DataStruct::SetData(nsISupports, uint32_t, bool.)

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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 "nsIDOMUIEvent.h"
 #include "nsISelection.h"
 #include "nsISelectionController.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeList.h"
 #include "nsIDOMEvent.h"
 #include "nsIDOMDragEvent.h"
 #include "nsPIDOMWindow.h"
 #include "nsIDOMRange.h"
 #include "nsIFormControl.h"
 #include "nsIDOMHTMLAreaElement.h"
 #include "nsIDOMHTMLAnchorElement.h"
 #include "nsITransferable.h"
 #include "nsComponentManagerUtils.h"
 #include "nsXPCOM.h"
 #include "nsISupportsPrimitives.h"
 #include "nsServiceManagerUtils.h"
 #include "nsNetUtil.h"
 #include "nsIFile.h"
 #include "nsIWebNavigation.h"
 #include "nsIDocShell.h"
 #include "nsIContent.h"
 #include "nsIImageLoadingContent.h"
 #include "nsITextControlElement.h"
 #include "nsUnicharUtils.h"
 #include "nsIURL.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 "mozilla/dom/Element.h"
 #include "mozilla/dom/HTMLAreaElement.h"
 using namespace mozilla::dom;
 class MOZ_STACK_CLASS DragDataProducer
 {
 public:
   DragDataProducer(nsPIDOMWindow* aWindow,
                    nsIContent* aTarget,
                    nsIContent* aSelectionTargetNode,
                    bool aIsAltKeyPressed);
   nsresult Produce(DataTransfer* aDataTransfer,
                    bool* aCanDrag,
                    nsISelection** aSelection,
                    nsIContent** aDragNode);
 private:
   void AddString(DataTransfer* aDataTransfer,
                  const nsAString& aFlavor,
                  const nsAString& aData,
                  nsIPrincipal* aPrincipal);
   nsresult AddStringsToDataTransfer(nsIContent* aDragNode,
                                     DataTransfer* aDataTransfer);
   static nsresult GetDraggableSelectionData(nsISelection* inSelection,
                                             nsIContent* inRealTargetNode,
                                             nsIContent **outImageOrLinkNode,
                                             bool* outDragSelectedText);
   static already_AddRefed<nsIContent> FindParentLinkNode(nsIContent* inNode);
   static void GetAnchorURL(nsIContent* inNode, nsAString& outURL);
   static void GetNodeString(nsIContent* inNode, nsAString & outNodeString);
   static void CreateLinkText(const nsAString& inURL, const nsAString & inText,
                               nsAString& outLinkText);
   static void GetSelectedLink(nsISelection* inSelection,
                               nsIContent **outLinkNode);
   nsCOMPtr<nsPIDOMWindow> mWindow;
   nsCOMPtr<nsIContent> mTarget;
   nsCOMPtr<nsIContent> mSelectionTargetNode;
   bool mIsAltKeyPressed;
   nsString mUrlString;
   nsString mImageSourceString;
   nsString mImageDestFileName;
   nsString mTitleString;
   // will be filled automatically if you fill urlstring
   nsString mHtmlString;
   nsString mContextString;
   nsString mInfoString;
   bool mIsAnchor;
   nsCOMPtr<imgIContainer> mImage;
 };
 nsresult
 nsContentAreaDragDrop::GetDragData(nsPIDOMWindow* aWindow,
                                    nsIContent* aTarget,
                                    nsIContent* aSelectionTargetNode,
                                    bool aIsAltKeyPressed,
                                    DataTransfer* aDataTransfer,
                                    bool* aCanDrag,
                                    nsISelection** aSelection,
                                    nsIContent** aDragNode)
 {
   NS_ENSURE_TRUE(aSelectionTargetNode, NS_ERROR_INVALID_ARG);
   *aCanDrag = true;
   DragDataProducer
     provider(aWindow, aTarget, aSelectionTargetNode, aIsAltKeyPressed);
   return provider.Produce(aDataTransfer, aCanDrag, aSelection, aDragNode);
 }
 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(nsAString& inSourceURIString,
                                                  nsIFile* inDestFile,
                                                  bool isPrivate)
 {
   nsCOMPtr<nsIURI> sourceURI;
   nsresult rv = NS_NewURI(getter_AddRefs(sourceURI), inSourceURIString);
   if (NS_FAILED(rv)) {
     return NS_ERROR_FAILURE;
   }
   nsCOMPtr<nsIURL> sourceURL = do_QueryInterface(sourceURI);
   if (!sourceURL) {
     return NS_ERROR_NO_INTERFACE;
   }
   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);
   return persist->SavePrivacyAwareURI(sourceURI, nullptr, nullptr, nullptr, nullptr,
                                       inDestFile, isPrivate);
 }
 // 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;
     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;
     // 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);
     rv = SaveURIToFile(sourceURLString, file, isPrivate);
     // send back an nsIFile
     if (NS_SUCCEEDED(rv)) {
       CallQueryInterface(file, aData);
       *aDataLen = sizeof(nsIFile*);
     }
   }
   return rv;
 }
 DragDataProducer::DragDataProducer(nsPIDOMWindow* 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
 //
 void
 DragDataProducer::GetAnchorURL(nsIContent* inNode, nsAString& outURL)
 {
   nsCOMPtr<nsIURI> linkURI;
   if (!inNode || !inNode->IsLink(getter_AddRefs(linkURI))) {
     // Not a link
     outURL.Truncate();
     return;
   }
   nsAutoCString spec;
   linkURI->GetSpec(spec);
   CopyUTF8toUTF16(spec, outURL);
 }
 //
 // 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();
   mozilla::ErrorResult rv;
   nsRefPtr<nsRange> range = doc->CreateRange(rv);
   if (range) {
     range->SelectNode(*node, rv);
     range->ToString(outNodeString);
   }
 }
 nsresult
 DragDataProducer::Produce(DataTransfer* aDataTransfer,
                           bool* aCanDrag,
                           nsISelection** aSelection,
                           nsIContent** aDragNode)
 {
   NS_PRECONDITION(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.
   nsCOMPtr<nsISelection> selection;
   nsIContent* editingElement = mSelectionTargetNode->IsEditable() ?
                                mSelectionTargetNode->GetEditingHost() : nullptr;
   nsCOMPtr<nsITextControlElement> textControl =
     nsITextControlElement::GetTextControlElementFromEditingHost(editingElement);
   if (textControl) {
     nsISelectionController* selcon = textControl->GetSelectionController();
     if (selcon) {
       selcon->GetSelection(nsISelectionController::SELECTION_NORMAL, getter_AddRefs(selection));
     }
     if (!selection)
       return NS_OK;
   }
   else {
     mWindow->GetSelection(getter_AddRefs(selection));
     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<nsIWebNavigation> webnav = do_GetInterface(mWindow);
   nsCOMPtr<nsIDocShellTreeItem> dsti = do_QueryInterface(webnav);
   const bool isChromeShell =
     dsti && dsti->ItemType() == nsIDocShellTreeItem::typeChrome;
   // In chrome shells, only allow dragging inside editable areas.
   if (isChromeShell && !editingElement)
     return NS_OK;
   if (isChromeShell && textControl) {
     // Only use the selection if the target node is in the selection.
     bool selectionContainsTarget = false;
     nsCOMPtr<nsIDOMNode> targetNode = do_QueryInterface(mSelectionTargetNode);
     selection->ContainsNode(targetNode, false, &selectionContainsTarget);
     if (!selectionContainsTarget)
       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->GetType() != NS_FORM_OBJECT) {
         *aCanDrag = false;
         return NS_OK;
       }
       draggedNode = mTarget;
     }
     nsCOMPtr<nsIDOMHTMLAreaElement>   area;   // client-side image map
     nsCOMPtr<nsIImageLoadingContent>  image;
     nsCOMPtr<nsIDOMHTMLAnchorElement> link;
     nsCOMPtr<nsIContent> selectedImageOrLinkNode;
     GetDraggableSelectionData(selection, mSelectionTargetNode,
                               getter_AddRefs(selectedImageOrLinkNode),
                               &haveSelectedContent);
     // either plain text or anchor text is selected
     if (haveSelectedContent) {
       link = do_QueryInterface(selectedImageOrLinkNode);
       if (link && mIsAltKeyPressed) {
         // if alt is pressed, select the link text instead of drag the link
         *aCanDrag = false;
         return NS_OK;
       }
       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;
       }
       area  = do_QueryInterface(draggedNode);
       image = do_QueryInterface(draggedNode);
       link  = do_QueryInterface(draggedNode);
     }
     {
       // set for linked images, and links
       nsCOMPtr<nsIContent> linkNode;
       if (area) {
         // use the alt text (or, if missing, the href) as the title
         HTMLAreaElement* areaElem = static_cast<HTMLAreaElement*>(area.get());
         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
         GetAnchorURL(draggedNode, mUrlString);
         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;
           imageURI->GetSpec(spec);
           CopyUTF8toUTF16(spec, mUrlString);
         }
         nsCOMPtr<nsIDOMElement> imageElement(do_QueryInterface(image));
         // XXXbz Shouldn't we use the "title" attr for title?  Using
         // "alt" seems very wrong....
         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));
         nsCOMPtr<nsIMIMEService> mimeService =
           do_GetService("@mozilla.org/mime;1");
         // Fix the file extension in the URL if necessary
         if (imgRequest && mimeService) {
           nsCOMPtr<nsIURI> imgUri;
           imgRequest->GetURI(getter_AddRefs(imgUri));
           nsCOMPtr<nsIURL> imgUrl(do_QueryInterface(imgUri));
           if (imgUrl) {
             nsAutoCString extension;
             imgUrl->GetFileExtension(extension);
             nsXPIDLCString mimeType;
             imgRequest->GetMimeType(getter_Copies(mimeType));
             nsCOMPtr<nsIMIMEInfo> mimeInfo;
             mimeService->GetFromTypeAndExtension(mimeType, EmptyCString(),
                                                  getter_AddRefs(mimeInfo));
             if (mimeInfo) {
               nsAutoCString spec;
               imgUrl->GetSpec(spec);
               // pass out the image source string
               CopyUTF8toUTF16(spec, mImageSourceString);
               bool validExtension;
               if (extension.IsEmpty() ||
                   NS_FAILED(mimeInfo->ExtensionExists(extension,
                                                       &validExtension)) ||
                   !validExtension) {
                 // Fix the file extension in the URL
                 nsresult rv = imgUrl->Clone(getter_AddRefs(imgUri));
                 NS_ENSURE_SUCCESS(rv, rv);
                 imgUrl = do_QueryInterface(imgUri);
                 nsAutoCString primaryExtension;
                 mimeInfo->GetPrimaryExtension(primaryExtension);
                 imgUrl->SetFileExtension(primaryExtension);
               }
               nsAutoCString fileName;
               imgUrl->GetFileName(fileName);
               NS_UnescapeURL(fileName);
               // make the filename safe for the filesystem
               fileName.ReplaceChar(FILE_PATH_SEPARATOR FILE_ILLEGAL_CHARACTERS,
                                    '-');
               CopyUTF8toUTF16(fileName, mImageDestFileName);
               // and the image object
               mImage = img;
             }
           }
         }
         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 = do_QueryInterface(draggedNode);
         }
         dragNode = nodeToSerialize;
       } else if (link) {
         // set linkNode. The code below will handle this
         linkNode = do_QueryInterface(link);    // 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;
         GetAnchorURL(linkNode, mUrlString);
         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)
 {
   nsCOMPtr<nsIWritableVariant> variant = do_CreateInstance(NS_VARIANT_CONTRACTID);
   if (variant) {
     variant->SetAsAString(aData);
     aDataTransfer->SetDataWithPrincipal(aFlavor, variant, 0, aPrincipal);
   }
 }
 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.AppendLiteral("\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) {
     nsCOMPtr<nsIWritableVariant> variant = do_CreateInstance(NS_VARIANT_CONTRACTID);
     if (variant) {
       variant->SetAsISupports(mImage);
       aDataTransfer->SetDataWithPrincipal(NS_LITERAL_STRING(kNativeImageMime),
                                           variant, 0, principal);
     }
     // assume the image comes from a file, and add a file promise. We
     // register ourselves as a nsIFlavorDataProvider, and will use the
     // GetFlavorData callback to save the image to disk.
     nsCOMPtr<nsIFlavorDataProvider> dataProvider =
       new nsContentAreaDragDropDataProvider();
     if (dataProvider) {
       nsCOMPtr<nsIWritableVariant> variant = do_CreateInstance(NS_VARIANT_CONTRACTID);
       if (variant) {
         variant->SetAsISupports(dataProvider);
         aDataTransfer->SetDataWithPrincipal(NS_LITERAL_STRING(kFilePromiseMime),
                                             variant, 0, principal);
       }
     }
     AddString(aDataTransfer, NS_LITERAL_STRING(kFilePromiseURLMime),
               mImageSourceString, principal);
     AddString(aDataTransfer, NS_LITERAL_STRING(kFilePromiseDestFilename),
               mImageDestFileName, principal);
     // if not an anchor, add the image url
     if (!mIsAnchor) {
       AddString(aDataTransfer, NS_LITERAL_STRING(kURLDataMime), mUrlString, principal);
       AddString(aDataTransfer, NS_LITERAL_STRING("text/uri-list"), mUrlString, principal);
     }
   }
   return NS_OK;
 }
 // note that this can return NS_OK, but a null out param (by design)
 // static
 nsresult
 DragDataProducer::GetDraggableSelectionData(nsISelection* inSelection,
                                             nsIContent* inRealTargetNode,
                                             nsIContent **outImageOrLinkNode,
                                             bool* outDragSelectedText)
 {
   NS_ENSURE_ARG(inSelection);
   NS_ENSURE_ARG(inRealTargetNode);
   NS_ENSURE_ARG_POINTER(outImageOrLinkNode);
   *outImageOrLinkNode = nullptr;
   *outDragSelectedText = false;
   bool selectionContainsTarget = false;
   bool isCollapsed = false;
   inSelection->GetIsCollapsed(&isCollapsed);
   if (!isCollapsed) {
     nsCOMPtr<nsIDOMNode> realTargetNode = do_QueryInterface(inRealTargetNode);
     inSelection->ContainsNode(realTargetNode, false,
                               &selectionContainsTarget);
     if (selectionContainsTarget) {
       // track down the anchor node, if any, for the url
       nsCOMPtr<nsIDOMNode> selectionStart;
       inSelection->GetAnchorNode(getter_AddRefs(selectionStart));
       nsCOMPtr<nsIDOMNode> selectionEnd;
       inSelection->GetFocusNode(getter_AddRefs(selectionEnd));
       // look for a selection around a single node, like an image.
       // in this case, drag the image, rather than a serialization of the HTML
       // XXX generalize this to other draggable element types?
       if (selectionStart == selectionEnd) {
         bool hasChildren;
         selectionStart->HasChildNodes(&hasChildren);
         if (hasChildren) {
           // see if just one node is selected
           int32_t anchorOffset, focusOffset;
           inSelection->GetAnchorOffset(&anchorOffset);
           inSelection->GetFocusOffset(&focusOffset);
           if (abs(anchorOffset - focusOffset) == 1) {
             nsCOMPtr<nsIContent> selStartContent =
               do_QueryInterface(selectionStart);
             if (selStartContent) {
               int32_t childOffset =
                 (anchorOffset < focusOffset) ? anchorOffset : focusOffset;
               nsIContent *childContent =
                 selStartContent->GetChildAt(childOffset);
               // if we find an image, we'll fall into the node-dragging code,
               // rather the the selection-dragging code
               if (nsContentUtils::IsDraggableImage(childContent)) {
                 NS_ADDREF(*outImageOrLinkNode = childContent);
                 return NS_OK;
               }
             }
           }
         }
       }
       // see if the selection is a link;  if so, its node will be returned
       GetSelectedLink(inSelection, outImageOrLinkNode);
       // indicate that a link or text is selected
       *outDragSelectedText = true;
     }
   }
   return NS_OK;
 }
 // static
 void
 DragDataProducer::GetSelectedLink(nsISelection* inSelection,
                                   nsIContent **outLinkNode)
 {
   *outLinkNode = nullptr;
   nsCOMPtr<nsIDOMNode> selectionStartNode;
   inSelection->GetAnchorNode(getter_AddRefs(selectionStartNode));
   nsCOMPtr<nsIDOMNode> selectionEndNode;
   inSelection->GetFocusNode(getter_AddRefs(selectionEndNode));
   // simple case:  only one node is selected
   // see if it or its parent is an anchor, then exit
   if (selectionStartNode == selectionEndNode) {
     nsCOMPtr<nsIContent> selectionStart = do_QueryInterface(selectionStartNode);
     nsCOMPtr<nsIContent> link = FindParentLinkNode(selectionStart);
     if (link) {
       link.swap(*outLinkNode);
     }
     return;
   }
   // more complicated case:  multiple nodes are selected
   // Unless you use the Alt key while selecting anchor text, it is
   // nearly impossible to avoid overlapping into adjacent nodes.
   // Deal with this by trimming off the leading and/or trailing
   // nodes of the selection if the strings they produce are empty.
   // first, use a range determine if the selection was marked LTR or RTL;
   // if the latter, swap endpoints so we trim in the right direction
   int32_t startOffset, endOffset;
   {
     nsCOMPtr<nsIDOMRange> range;
     inSelection->GetRangeAt(0, getter_AddRefs(range));
     if (!range) {
       return;
     }
     nsCOMPtr<nsIDOMNode> tempNode;
     range->GetStartContainer( getter_AddRefs(tempNode));
     if (tempNode != selectionStartNode) {
       selectionEndNode = selectionStartNode;
       selectionStartNode = tempNode;
       inSelection->GetAnchorOffset(&endOffset);
       inSelection->GetFocusOffset(&startOffset);
     } else {
       inSelection->GetAnchorOffset(&startOffset);
       inSelection->GetFocusOffset(&endOffset);
     }
   }
   // trim leading node if the string is empty or
   // the selection starts at the end of the text
   nsAutoString nodeStr;
   selectionStartNode->GetNodeValue(nodeStr);
   if (nodeStr.IsEmpty() ||
       startOffset+1 >= static_cast<int32_t>(nodeStr.Length())) {
     nsCOMPtr<nsIDOMNode> curr = selectionStartNode;
     nsIDOMNode* next;
     while (curr) {
       curr->GetNextSibling(&next);
       if (next) {
         selectionStartNode = dont_AddRef(next);
         break;
       }
       curr->GetParentNode(&next);
       curr = dont_AddRef(next);
     }
   }
   // trim trailing node if the selection ends before its text begins
   if (endOffset == 0) {
     nsCOMPtr<nsIDOMNode> curr = selectionEndNode;
     nsIDOMNode* next;
     while (curr) {
       curr->GetPreviousSibling(&next);
       if (next){
         selectionEndNode = dont_AddRef(next);
         break;
       }
       curr->GetParentNode(&next);
       curr = dont_AddRef(next);
     }
   }
   // see if the leading & trailing nodes are part of the
   // same anchor - if so, return the anchor node
   nsCOMPtr<nsIContent> selectionStart = do_QueryInterface(selectionStartNode);
   nsCOMPtr<nsIContent> link = FindParentLinkNode(selectionStart);
   if (link) {
     nsCOMPtr<nsIContent> selectionEnd = do_QueryInterface(selectionEndNode);
     nsCOMPtr<nsIContent> link2 = FindParentLinkNode(selectionEnd);
     if (link == link2) {
       NS_IF_ADDREF(*outLinkNode = link);
     }
   }
   return;
 }

The Tor Browser / annotate

content/base/src/nsContentAreaDragDrop.cpp@deefc01c0e14 (annotated)

content/base/src/nsContentAreaDragDrop.cpp