Drag n Drop a Wav into Oscillator

[baconpaul]

@esaruoho had asked if you can drag and drop a sample into an oscillator window.

COscillatorDisplay.cpp has this code

bool COscillatorDisplay::onDrop(IDataPackage* drag, const CPoint& where)
{
   /*long size,type;
   char *filename = (char*)drag->first(size,type);
   //while(filename)
   if(filename)
   {
           if(type == CDragContainer::kFile)
           {
                   strncpy(oscdata->wt.queue_filename, filename, 255);
           }
//		filename = (char*)drag->next(size,type);
   }*/
   return true;
}

which looks like there was a start at an attempt at that. Don't think this is a release critical issue but a bit of work to pick up I stumbled across so wanted to drop it in an issue.

[baconpaul]

So I got the VSTGUI 4 drag n drop API in place and on my mac at least, I now get a filename printed to stderr when you drop any file onto the oscillator.

baconpaul branch drag-n-drop-199