scroll module during d&d even if not valid move

src/develop/imageop.c

@@ -2975,13 +2975,15 @@ GtkWidget *dt_iop_gui_header_button(dt_iop_module_t *module,
 static gboolean _on_drag_motion(GtkWidget *widget, GdkDragContext *dc, gint x, gint y, guint time, dt_iop_module_t *dest)
 {
   gdk_drag_status(dc, 0, time);
+  dtgtk_expander_set_drag_hover(DTGTK_EXPANDER(widget), FALSE, TRUE, time);
 
-  GtkWidget *src_widget = gtk_widget_get_ancestor(gtk_drag_get_source_widget(dc),
-                                                  DTGTK_TYPE_EXPANDER);
+  GtkWidget *src_header = gtk_drag_get_source_widget(dc);
+  if(!src_header) return TRUE;
+  GtkWidget *src_expander = gtk_widget_get_ancestor(src_header, DTGTK_TYPE_EXPANDER);
 
   dt_iop_module_t *src = NULL;
   for(GList *iop = darktable.develop->iop; iop; iop = iop->next)
-    if(((dt_iop_module_t *)iop->data)->expander == src_widget)
+    if(((dt_iop_module_t *)iop->data)->expander == src_expander)
       src = iop->data;
   if(!src || dest == src) return TRUE;
 
@@ -3001,11 +3003,13 @@ static gboolean _on_drag_motion(GtkWidget *widget, GdkDragContext *dc, gint x, g
 
   if(x != DND_DROP)
   {
-    gboolean allow = src->iop_order < dest->iop_order
-                   ? dt_ioppr_check_can_move_after_iop(darktable.develop->iop, src, dest)
-                   : dt_ioppr_check_can_move_before_iop(darktable.develop->iop, src, dest);
-    dtgtk_expander_set_drag_hover(DTGTK_EXPANDER(widget), allow, !above);
-    if(allow) gdk_drag_status(dc, GDK_ACTION_COPY, time);
+    if(src->iop_order < dest->iop_order
+       ? dt_ioppr_check_can_move_after_iop(darktable.develop->iop, src, dest)
+       : dt_ioppr_check_can_move_before_iop(darktable.develop->iop, src, dest))
+    {
+      dtgtk_expander_set_drag_hover(DTGTK_EXPANDER(widget), TRUE, !above, time);
+      gdk_drag_status(dc, GDK_ACTION_COPY, time);
+    }
   }
   else
   {

src/dtgtk/expander.c

@@ -183,23 +183,25 @@ static void _expander_resize(GtkWidget *widget, GdkRectangle *allocation, gpoint
                                + dt_conf_get_int("darkroom/ui/transition_duration") * 1000), NULL);
 }
 
-void dtgtk_expander_set_drag_hover(GtkDarktableExpander *expander, gboolean hover, gboolean below)
+void dtgtk_expander_set_drag_hover(GtkDarktableExpander *expander, gboolean allow, gboolean below, guint time)
 {
   GtkWidget *widget = expander ? GTK_WIDGET(expander) : _drop_widget;
   // don't remove drop zone when switching between last expander and empty space to avoid jitter
-  static guint hovertime;
-  guint time = gtk_get_current_event_time();
-  if(!widget || (!hover && widget == _drop_widget && time == hovertime)) return;
+  static guint last_time;
+  if(!widget || (!allow && !below && widget == _drop_widget && time == last_time)) return;
 
   dt_gui_remove_class(widget, "module_drop_after");
   dt_gui_remove_class(widget, "module_drop_before");
 
-  if(hover)
+  if(allow || below)
   {
     _drop_widget = widget;
-    hovertime = time;
+    _last_expanded = NULL;
+    last_time = time;
 
-    if(below)
+    if(!allow)
+      gtk_widget_queue_resize(widget);
+    else if(below)
       dt_gui_add_class(widget, "module_drop_before");
     else
       dt_gui_add_class(widget, "module_drop_after");
@@ -211,7 +213,7 @@ static void _expander_drag_leave(GtkDarktableExpander *widget,
                            guint time,
                            gpointer user_data)
 {
-  dtgtk_expander_set_drag_hover(widget, FALSE, FALSE);
+  dtgtk_expander_set_drag_hover(widget, FALSE, FALSE, time);
 }
 
 // FIXME: default highlight for the dnd is barely visible
@@ -226,6 +228,7 @@ static void _expander_drag_begin(GtkWidget *widget, GdkDragContext *context, gpo
 
   // hack to render not transparent
   dt_gui_add_class(widget, "module_drag_icon");
+  gtk_widget_size_allocate(widget, &allocation);
   gtk_widget_draw(widget, cr);
   dt_gui_remove_class(widget, "module_drag_icon");
 
@@ -244,6 +247,7 @@ static void _expander_drag_begin(GtkWidget *widget, GdkDragContext *context, gpo
 
 static void _expander_drag_end(GtkWidget *widget, GdkDragContext *context, gpointer user_data)
 {
+  dtgtk_expander_set_drag_hover(NULL, FALSE, FALSE, 0);
   _drop_widget = NULL;
   gtk_widget_set_opacity(widget, 1.0);
 }

src/dtgtk/expander.h

@@ -45,7 +45,7 @@ GtkWidget *dtgtk_expander_get_body_event_box(GtkDarktableExpander *expander);
 
 void dtgtk_expander_set_expanded(GtkDarktableExpander *expander, gboolean expanded);
 gboolean dtgtk_expander_get_expanded(GtkDarktableExpander *expander);
-void dtgtk_expander_set_drag_hover(GtkDarktableExpander *expander, gboolean hover, gboolean below);
+void dtgtk_expander_set_drag_hover(GtkDarktableExpander *expander, gboolean allow, gboolean below, guint time);
 
 GtkWidget *dtgtk_expander_new(GtkWidget *header, GtkWidget *body);
 

src/gui/gtk.c

@@ -2248,7 +2248,7 @@ static gboolean _on_drag_motion_drop(GtkWidget *empty, GdkDragContext *dc, gint
 
 static void _on_drag_leave(GtkWidget *widget, GdkDragContext *dc, guint time, gpointer user_data)
 {
-  dtgtk_expander_set_drag_hover(NULL, FALSE, FALSE);
+  dtgtk_expander_set_drag_hover(NULL, FALSE, FALSE, time);
 }
 
 static gboolean _remove_modules_visibility(gpointer key,

src/libs/lib.c

@@ -1098,17 +1098,18 @@ static gboolean _on_drag_motion(GtkWidget *widget,
   }
   else
   {
-    dtgtk_expander_set_drag_hover(DTGTK_EXPANDER(widget), FALSE, FALSE);
+    dtgtk_expander_set_drag_hover(DTGTK_EXPANDER(widget), FALSE, TRUE, time);
     gdk_drag_status(dc, 0, time);
 
-    GtkWidget *src_widget = gtk_widget_get_ancestor(gtk_drag_get_source_widget(dc),
-                                                    DTGTK_TYPE_EXPANDER);
+    GtkWidget *src_header = gtk_drag_get_source_widget(dc);
+    if(!src_header) return TRUE;
+    GtkWidget *src_expander = gtk_widget_get_ancestor(src_header, DTGTK_TYPE_EXPANDER);
 
     for(GList *lib = darktable.lib->plugins; lib; lib = lib->next)
-      if(((dt_lib_module_t *)lib->data)->expander == src_widget)
+      if(((dt_lib_module_t *)lib->data)->expander == src_expander)
         src = lib->data;
 
-    if(!src_widget || !src || dest == src ) return TRUE;
+    if(!src_expander || !src || dest == src ) return TRUE;
 
     src_panel = GTK_CONTAINER(gtk_widget_get_parent(src->expander));
     dest_panel = GTK_CONTAINER(gtk_widget_get_parent(dest->expander));
@@ -1132,7 +1133,7 @@ static gboolean _on_drag_motion(GtkWidget *widget,
 
     if(x != DND_DROP)
     {
-      dtgtk_expander_set_drag_hover(DTGTK_EXPANDER(widget), TRUE, below);
+      dtgtk_expander_set_drag_hover(DTGTK_EXPANDER(widget), TRUE, below, time);
       gdk_drag_status(dc, GDK_ACTION_COPY, time);
 
       return TRUE;