Re: Do setDragImage or addElement work?

---On 2011.Sep.08 2:43 PM, Neil Deakin wrote:
> On 11-09-08 1:18 PM, alta88[nntp] wrote:
>>
>> i've tried to set a drag image according to the doc
>> https://developer.mozilla.org/En/DragDrop/Drag_Operations#dragfeedback
>>
>> as well as usage in mozilla-central codebase (all of 2), for which
>> neither the favicon drag image when dragging 1) the urlbar identity box,
>> nor 2) a tab, actually work.
>>
>> i haven't found any working example in html5, using Fx 9a, either. can
>> anyone verify if this is indeed supported, as the docs seems to
>> indicate, and if there is an example anywhere?
>
> setDragImage is implemented. The documentation example you gave should
> work ok.
>
>

i have this code, from the doc, to set an image under the cursor when 
dnd on a Tb thread pane message.  i've tried with a visible xul <image> 
element as well. nothing shows an image.

do you have an example?  xul or html, i haven't found either anywhere. 
dnd on the Fx urlbar favicon doesn't show a dragged image for me, should it?

-----------
   var _ThreadPaneOnDragStart = ThreadPaneOnDragStart;
   ThreadPaneOnDragStart = function TM_ThreadPaneOnDragStart(aEvent) {

     if (v.editingMode) {
       // In edit mode, support drag and drop rethreading of messages.  	

       ...

       var image = 
document.createElementNS("http://www.w3.org/1999/xhtml","html:canvas");
       image.width = image.height = 50;
       var ctx = image.getContext("2d");
       ctx.lineWidth = 4;
       ctx.moveTo(0, 0);
       ctx.lineTo(50, 50);
       ctx.moveTo(0, 50);
       ctx.lineTo(50, 0);
       ctx.stroke();

       var dt = aEvent.dataTransfer;
       dt.setData('text/plain', 'Data to Drag');
   //    aEvent.dataTransfer.effectAllowed = "move";
   //    aEvent.dataTransfer.dropEffect = "move";
       dt.setDragImage(image, 0, 0);
_u.log.debug("ThreadPaneOnDragStart: image - "+ image.id);
       return;
     }

     _ThreadPaneOnDragStart(aEvent);
   }