Bug 24735 – Poor setDragImage support on Windows

• Component: New Bugs
• Status: RESOLVED FIXED

[Sebastian Markbåge]

At the start of a drag operation you can use event.dataTransfer.setDragImage(...) to change the graphic to display by the cursor during the operation.

On Mac this is supported for both images and elements.

On Windows Safari has support for only images as the first parameter of setDragImage. It is not supported on <a> and <img> tags that has their own implementations that can't be overridden.

Google Chrome has the function but no graphics shows up around the cursor for any drag operation.

All versions should behave like the Mac version.

[Jessie Berlin]

<rdar://problem/5015942>

[Jessie Berlin]

*** Bug 24734 has been marked as a duplicate of this bug. ***

[Jessie Berlin]

Created attachment 31785 [details]
Adds the ability to set an element as the drag image on Windows

Does not fix the case of dragging a link where the default link image
is still used, even when the -webkit-user-drag is set to "element". This
is the same behavior as is found on OS X.

[Adam Roben (:aroben)]

Comment on attachment 31785 [details]
Adds the ability to set an element as the drag image on Windows

>  DragImageRef ClipboardWin::createDragImage(IntPoint& loc) const
>  {
>      HBITMAP result = 0;
> -    //FIXME: Need to be able to draw element <rdar://problem/5015942>
>      if (m_dragImage) {
>          result = createDragImageFromImage(m_dragImage->image());        
>          loc = m_dragLoc;
> +    } else if (m_dragImageElement) {
> +        Node* node = dragImageElement();
> +        result = node->document()->frame()->nodeImage(node);
> +        loc = m_dragLoc;
>      }

It's strange to use m_dragImageElement on the first line, then dragImageElement() on the second. I don't really have a preference, but using m_dragImageElement consistently would match the code above more closely.

r=me

[Jessie Berlin]

(In reply to comment #4)
> (From update of attachment 31785 [details] [review])
> >  DragImageRef ClipboardWin::createDragImage(IntPoint& loc) const
> >  {
> >      HBITMAP result = 0;
> > -    //FIXME: Need to be able to draw element <rdar://problem/5015942>
> >      if (m_dragImage) {
> >          result = createDragImageFromImage(m_dragImage->image());        
> >          loc = m_dragLoc;
> > +    } else if (m_dragImageElement) {
> > +        Node* node = dragImageElement();
changed to be: Node* node = m_dragImageElement.get();
> > +        result = node->document()->frame()->nodeImage(node);
> > +        loc = m_dragLoc;
> >      }
> 
> It's strange to use m_dragImageElement on the first line, then
> dragImageElement() on the second. I don't really have a preference, but using
> m_dragImageElement consistently would match the code above more closely.
> 
> r=me
> 

[Eric Seidel (no email)]

Does jberlin have commit-bit or does aroben plan to land this with modifications?

[Adam Roben (:aroben)]

(In reply to comment #6)
> Does jberlin have commit-bit

Yes. <http://trac.webkit.org/search?q=jberlin&noquickjump=1&changeset=on>

[Jessie Berlin]

(In reply to comment #6)
> Does jberlin have commit-bit or does aroben plan to land this with
> modifications?
> 

I did commit, but I didn't mark it as fixed because the bug mentions the desire to see the link tag be able to be given a custom setDragImage and that is currently not supported on either mac or windows.

Sorry I didn't respond earlier. For some reason I kept getting an "internal error" message when I navigated to this page.

[Jessie Berlin]

Comment on attachment 31785 [details]
Adds the ability to set an element as the drag image on Windows

committed with revision 45087

[Jessie Berlin]

Created a new bug for not being able to set the drag image of a link:

https://bugs.webkit.org/show_bug.cgi?id=27670

Marking this bug as fixed, since the last committed patch addressed all other concerns.