* Drag messages can now also be started with a NULL bitmap pointer and an invalid

drag rectangle - this fixes bug #596, as Cortex obviously relies on this.
* Added a comment on how dragging without a bitmap should be done (app_server should
  directly support this without needing to drag real bitmaps).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@18964 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/interface/View.cpp

@@ -1265,7 +1265,7 @@ BView::EndRectTracking()
 void
 BView::DragMessage(BMessage *message, BRect dragRect, BHandler *replyTo)
 {
-	if (!message || !dragRect.IsValid())
+	if (!message)
 		return;
 
 	do_owner_check_no_pick();
@@ -1278,6 +1278,14 @@ BView::DragMessage(BMessage *message, BRect dragRect, BHandler *replyTo)
 		GetMouse(&offset, &buttons, false);
 	offset -= dragRect.LeftTop();
 
+	if (!dragRect.IsValid()) {
+		DragMessage(message, NULL, B_OP_BLEND, offset, replyTo);
+		return;
+	}
+
+	// TODO: that's not really what should happen - the app_server should take the chance
+	//	*NOT* to need to drag a whole bitmap around but just a frame.
+
 	// create a drag bitmap for the rect
 	BBitmap *bitmap = new BBitmap(dragRect, B_RGBA32);
 	uint32 *bits = (uint32*)bitmap->Bits();
@@ -1320,8 +1328,13 @@ void
 BView::DragMessage(BMessage *message, BBitmap *image,
 	drawing_mode dragMode, BPoint offset, BHandler *replyTo)
 {
-	// ToDo: is this correct? Isn't \a image allowed to be NULL?
+	if (message == NULL)
-	if (message == NULL || image == NULL)
+		return;
+
+	// TODO: workaround for drags without a bitmap - should not be necessary if
+	//	we move the rectangle dragging into the app_server
+	image = new (nothrow) BBitmap(BRect(0, 0, 0, 0), B_RGBA32);
+	if (image == NULL)
 		return;
 
 	if (replyTo == NULL)