Implement some drag and drop functions on NS

* lisp/term/ns-win.el (ns-selection-exists-p):
(gui-backend-set-selection):
(x-begin-drag): New functions and selection types.
* src/nsfns.m (Fns_get_resource):
(Fns_set_resource):
(Fx_server_max_request_size): Fix coding style.
* src/nsselect.m (ns_decode_data_to_pasteboard):
(ns_lisp_to_pasteboard):
(ns_dnd_action_to_operation):
(ns_dnd_action_from_operation):
(Fns_begin_drag): New functions.
(syms_of_nsselect): New subrs.
* src/nsterm.h (EmacsWindow): New fields and messages.
(NSPasteboardNameGeneral): New define.
* src/nsterm.m ([EmacsView mouseDown:]): Store last mouse event.
([EmacsWindow initWithEmacsFrame:fullscreen:screen:]): Clear that event.
([EmacsWindow dealloc]): Free last mouse event.

1 files changed, 60 insertions, 0 deletions

diff --git a/src/nsterm.m b/src/nsterm.m
index d7e62a70c49..79e30d6ff91 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -7059,6 +7059,7 @@ ns_create_font_panel_buttons (id target, SEL select, SEL cancel_action)
 {
   struct ns_display_info *dpyinfo = FRAME_DISPLAY_INFO (emacsframe);
   NSPoint p = [self convertPoint: [theEvent locationInWindow] fromView: nil];
+  EmacsWindow *window;
 
   NSTRACE ("[EmacsView mouseDown:]");
 
@@ -7070,6 +7071,9 @@ ns_create_font_panel_buttons (id target, SEL select, SEL cancel_action)
      button clicks.  */
   emacsframe->mouse_moved = 0;
 
+  window = (EmacsWindow *) [self window];
+  [window setLastDragEvent: theEvent];
+
   if ([theEvent type] == NSEventTypeScrollWheel)
     {
 #if defined (NS_IMPL_COCOA) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1070
@@ -8859,6 +8863,8 @@ ns_create_font_panel_buttons (id target, SEL select, SEL cancel_action)
 		 | NSWindowStyleMaskMiniaturizable
 		 | NSWindowStyleMaskClosable);
 
+  last_drag_event = nil;
+
   width = FRAME_TEXT_COLS_TO_PIXEL_WIDTH (f, f->text_cols);
   height = FRAME_TEXT_LINES_TO_PIXEL_HEIGHT (f, f->text_lines);
 
@@ -8974,6 +8980,11 @@ ns_create_font_panel_buttons (id target, SEL select, SEL cancel_action)
 
   /* We need to release the toolbar ourselves.  */
   [[self toolbar] release];
+
+  /* Also the last button press event .  */
+  if (last_drag_event)
+    [last_drag_event release];
+
   [super dealloc];
 }
 
@@ -9498,6 +9509,55 @@ nswindow_orderedIndex_sort (id w1, id w2, void *c)
   return YES;
 }
 
+- (void) setLastDragEvent: (NSEvent *) event
+{
+  if (last_drag_event)
+    [last_drag_event release];
+  last_drag_event = [event copy];
+}
+
+- (NSDragOperation) draggingSourceOperationMaskForLocal: (BOOL) is_local
+{
+  return drag_op;
+}
+
+- (void) draggedImage: (NSImage *) image
+	      endedAt: (NSPoint) screen_point
+	    operation: (NSDragOperation) operation
+{
+  selected_op = operation;
+}
+
+- (NSDragOperation) beginDrag: (NSDragOperation) op
+		forPasteboard: (NSPasteboard *) pasteboard
+{
+  NSImage *image;
+
+  drag_op = op;
+  selected_op = NSDragOperationNone;
+  image = [[NSImage alloc] initWithSize: NSMakeSize (1.0, 1.0)];
+
+  /* Now draw transparency onto the image.  */
+  [image lockFocus];
+  [[NSColor colorWithUnsignedLong: 0] set];
+  NSRectFillUsingOperation (NSMakeRect (0, 0, 1, 1),
+			    NSCompositingOperationCopy);
+  [image unlockFocus];
+
+  if (last_drag_event)
+    [self dragImage: image
+		 at: NSMakePoint (0, 0)
+	     offset: NSMakeSize (0, 0)
+	      event: last_drag_event
+	 pasteboard: pasteboard
+	     source: self
+	  slideBack: NO];
+
+  [image release];
+
+  return selected_op;
+}
+
 @end /* EmacsWindow */