[nautilus/wip/hadess/re-add-netscape-url] files-view: Re-add _NETSCAPE_URL drop support

[Bastien Nocera <hadess src gnome org>]

commit e0b64ca3e7c6aff5801c97302060e61240c43942
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Nov 20 11:15:32 2018 +0100

    files-view: Re-add _NETSCAPE_URL drop support
    
    In dropping the support for creating website links from Firefox drops,
    commit 0e0f5b9 also removed the ability to handle _NETSCAPE_URLs at all.
    Re-add the necessary bits for drag'n'drop downloads to work as they did
    in GNOME 3.28.
    
    Closes: #687

 src/nautilus-canvas-view.c    | 14 +++++++++
 src/nautilus-files-view-dnd.c | 68 +++++++++++++++++++++++++++++++++++++++++++
 src/nautilus-files-view-dnd.h |  4 +++
 3 files changed, 86 insertions(+)
---
diff --git a/src/nautilus-canvas-view.c b/src/nautilus-canvas-view.c
index 7552e2b34..4ee8d6ea3 100644
--- a/src/nautilus-canvas-view.c
+++ b/src/nautilus-canvas-view.c
@@ -1434,6 +1434,18 @@ canvas_view_handle_uri_list (NautilusCanvasContainer *container,
                                               item_uris, target_uri, action);
 }
 
+/* Handles an URL received from Mozilla */
+static void
+canvas_view_handle_netscape_url (NautilusCanvasContainer *container,
+                                 const char              *encoded_url,
+                                 const char              *target_uri,
+                                 GdkDragAction            action,
+                                 NautilusCanvasView      *view)
+{
+    nautilus_files_view_handle_netscape_url_drop (NAUTILUS_FILES_VIEW (view),
+                                                  encoded_url, target_uri, action);
+}
+
 static void
 canvas_view_handle_text (NautilusCanvasContainer *container,
                          const char              *text,
@@ -1614,6 +1626,8 @@ nautilus_canvas_view_init (NautilusCanvasView *canvas_view)
 
     g_signal_connect_object (canvas_container, "handle-uri-list",
                              G_CALLBACK (canvas_view_handle_uri_list), canvas_view, 0);
+    g_signal_connect_object (canvas_container, "handle-netscape-url",
+                             G_CALLBACK (canvas_view_handle_netscape_url), canvas_view, 0);
     g_signal_connect_object (canvas_container, "handle-text",
                              G_CALLBACK (canvas_view_handle_text), canvas_view, 0);
     g_signal_connect_object (canvas_container, "handle-raw",
diff --git a/src/nautilus-files-view-dnd.c b/src/nautilus-files-view-dnd.c
index 9a3a76b35..d5b4c21c8 100644
--- a/src/nautilus-files-view-dnd.c
+++ b/src/nautilus-files-view-dnd.c
@@ -43,6 +43,74 @@
 #define GET_ANCESTOR(obj) \
     GTK_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (obj), GTK_TYPE_WINDOW))
 
+void
+nautilus_files_view_handle_netscape_url_drop (NautilusFilesView *view,
+                                              const char        *encoded_url,
+                                              const char        *target_uri,
+                                              GdkDragAction      action)
+{
+    char *url;
+    char **bits;
+    GList *uri_list = NULL;
+    GFile *f;
+
+    f = g_file_new_for_uri (target_uri);
+
+    if (!g_file_is_native (f))
+    {
+        show_dialog (_("Drag and drop is not supported."),
+                     _("Drag and drop is only supported on local file systems."),
+                     GET_ANCESTOR (view),
+                     GTK_MESSAGE_WARNING);
+        g_object_unref (f);
+        return;
+    }
+
+    g_object_unref (f);
+
+    /* _NETSCAPE_URL_ works like this: $URL\n$TITLE */
+    bits = g_strsplit (encoded_url, "\n", 0);
+    switch (g_strv_length (bits))
+    {
+        case 0:
+        {
+            g_strfreev (bits);
+            return;
+        }
+
+        default:
+        {
+            url = bits[0];
+        }
+    }
+
+    f = g_file_new_for_uri (url);
+
+    /* We don't support GDK_ACTION_ASK or GDK_ACTION_PRIVATE
+     * and we don't support combinations either. */
+    if ((action != GDK_ACTION_DEFAULT) &&
+        (action != GDK_ACTION_COPY) &&
+        (action != GDK_ACTION_MOVE))
+    {
+        show_dialog (_("Drag and drop is not supported."),
+                     _("An invalid drag type was used."),
+                     GET_ANCESTOR (view),
+                     GTK_MESSAGE_WARNING);
+        return;
+    }
+
+    uri_list = g_list_append (uri_list, url);
+
+    nautilus_files_view_move_copy_items (view, uri_list,
+                                         target_uri,
+                                         action);
+
+    g_list_free (uri_list);
+
+    g_object_unref (f);
+    g_strfreev (bits);
+}
+
 void
 nautilus_files_view_handle_uri_list_drop (NautilusFilesView *view,
                                           const char        *item_uris,
diff --git a/src/nautilus-files-view-dnd.h b/src/nautilus-files-view-dnd.h
index 9cde15485..73b9263a7 100644
--- a/src/nautilus-files-view-dnd.h
+++ b/src/nautilus-files-view-dnd.h
@@ -44,6 +44,10 @@ void nautilus_files_view_handle_raw_drop          (NautilusFilesView *view,
                                                    GdkDragAction      action);
 void nautilus_files_view_handle_hover             (NautilusFilesView *view,
                                                    const char        *target_uri);
+void nautilus_files_view_handle_netscape_url_drop (NautilusFilesView *view,
+                                                   const char        *encoded_url,
+                                                   const char        *target_uri,
+                                                   GdkDragAction      action);
 
 void nautilus_files_view_drop_proxy_received_uris (NautilusFilesView *view,
                                                    const GList       *uris,