Add file dragging support to NS port

* lisp/dired.el (dired-mouse-drag-files): Document that
`dired-mouse-drag-files' now works on NS.

* lisp/term/ns-win.el (x-begin-drag): Handle FILE_NAME.
* src/nsselect.m (ns_decode_data_to_pasteboard): Handle file URL
type.
(ns_lisp_to_pasteboard, Fns_begin_drag): Handle new type `file'.

1 files changed, 24 insertions, 1 deletions

diff --git a/src/nsselect.m b/src/nsselect.m
index a481e80d770..0bd840d92b7 100644
--- a/src/nsselect.m
+++ b/src/nsselect.m
@@ -561,17 +561,34 @@ static void
 ns_decode_data_to_pasteboard (Lisp_Object type, Lisp_Object data,
                               NSPasteboard *pasteboard)
 {
+  NSArray *types, *new;
+
+  types = [pasteboard types];
+
   CHECK_SYMBOL (type);
 
   if (EQ (type, Qstring))
     {
       CHECK_STRING (data);
 
-      [pasteboard declareTypes: [NSArray arrayWithObject: NSPasteboardTypeString]
+      new = [types arrayByAddingObject: NSPasteboardTypeString];
+
+      [pasteboard declareTypes: new
                          owner: nil];
       [pasteboard setString: [NSString stringWithLispString: data]
                     forType: NSPasteboardTypeString];
     }
+  else if (EQ (type, Qfile))
+    {
+      CHECK_STRING (data);
+
+      new = [types arrayByAddingObject: NSPasteboardTypeFileURL];
+
+      [pasteboard declareTypes: new
+                         owner: nil];
+      [pasteboard setString: [NSString stringWithLispString: data]
+                    forType: NSPasteboardTypeFileURL];
+    }
   else
     signal_error ("Unknown pasteboard type", type);
 }
@@ -582,6 +599,9 @@ ns_lisp_to_pasteboard (Lisp_Object object,
 {
   Lisp_Object tem, type, data;
 
+  [pasteboard declareTypes: [NSArray array]
+                     owner: nil];
+
   CHECK_LIST (object);
   for (tem = object; CONSP (tem); tem = XCDR (tem))
     {
@@ -642,6 +662,9 @@ the meaning of DATA:
   - `string' means DATA should be a string describing text that will
     be dragged to another program.
 
+  - `file' means DATA should be a file URL that will be dragged to
+    another program.
+
 ACTION is the action that will be taken by the drop target towards the
 data inside PBOARD.