546425 - allow access to source of drag from dataTransfer

Status: RESOLVED FIXED

(Core :: DOM: Copy & Paste and Drag & Drop, defect)

Description

[Neil Deakin]

Attachment: add this

There are a number of cases where knowing the source of the drag (of available) would be useful. Currently, this is only available from the drag session. This patch adds a dataTransfer.mozSourceNode.

Comment 1

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

Comment on attachment 427123 [details] [diff] [review]
add this

>+nsDOMDataTransfer::GetMozSourceNode(nsIDOMNode** aSourceNode)
>+{
>+  *aSourceNode = nsnull;
>+
>+  nsCOMPtr<nsIDragSession> dragSession = nsContentUtils::GetDragSession();
>+  if (!dragSession)
>+    return NS_OK;
>+
>+  nsCOMPtr<nsIDOMNode> sourceNode;
>+  dragSession->GetSourceNode(getter_AddRefs(sourceNode));
>+  if (sourceNode && !nsContentUtils::CanCallerAccess(sourceNode))
>+    return NS_ERROR_DOM_SECURITY_ERR;

It's probably better to simply return null rather than throwing an exception. That might cause fewer page scripts to break due to use dragging from an unexpected place.

r=me with that changed.

Comment 2

[Neil Deakin]

Attachment: return null

Comment 3

[Neil Deakin]

http://hg.mozilla.org/mozilla-central/rev/32cdaca76378

Comment 4

[Eric Shepherd [:sheppy]]

Documented here:

https://developer.mozilla.org/En/DragDrop/DataTransfer#mozSourceNode