app: split GimpApplicator's opacity and mode API into two functions

Added gimp_applicator_set_opacity() and remove the opacity argument
from set_mode().

app/core/gimpdrawable-combine.c

@@ -141,7 +141,8 @@ gimp_drawable_real_apply_buffer (GimpDrawable         *drawable,
                                     base_x - buffer_region->x,
                                     base_y - buffer_region->y);
 
-  gimp_applicator_set_mode (applicator, opacity, mode);
+  gimp_applicator_set_opacity (applicator, opacity);
+  gimp_applicator_set_mode (applicator, mode);
   gimp_applicator_set_affect (applicator,
                               gimp_drawable_get_active_mask (drawable));
 

app/core/gimpdrawable.c

@@ -1042,8 +1042,9 @@ gimp_drawable_sync_fs_filter (GimpDrawable *drawable,
                                            -off_x, -off_y);
         }
 
+      gimp_applicator_set_opacity (private->fs_applicator,
+                                   gimp_layer_get_opacity (fs));
       gimp_applicator_set_mode (private->fs_applicator,
-                                gimp_layer_get_opacity (fs),
                                 gimp_layer_get_mode (fs));
       gimp_applicator_set_affect (private->fs_applicator,
                                   gimp_drawable_get_active_mask (drawable));

app/core/gimpdrawablefilter.c

@@ -530,8 +530,9 @@ gimp_drawable_filter_sync_preview (GimpDrawableFilter *filter,
 static void
 gimp_drawable_filter_sync_mode (GimpDrawableFilter *filter)
 {
+  gimp_applicator_set_opacity (filter->applicator,
+                               filter->opacity);
   gimp_applicator_set_mode (filter->applicator,
-                            filter->opacity,
                             filter->paint_mode);
 }
 

app/core/gimpimage-merge.c

@@ -639,9 +639,8 @@ gimp_image_merge_layers (GimpImage     *image,
                                         - (x1 - off_x),
                                         - (y1 - off_y));
 
-      gimp_applicator_set_mode (applicator,
-                                gimp_layer_get_opacity (layer),
-                                mode);
+      gimp_applicator_set_opacity (applicator, gimp_layer_get_opacity (layer));
+      gimp_applicator_set_mode (applicator, mode);
 
       gimp_applicator_blit (applicator,
                             GEGL_RECTANGLE (0, 0,

app/gegl/gimpapplicator.c

@@ -107,7 +107,7 @@ gimp_applicator_get_property (GObject    *object,
 GimpApplicator *
 gimp_applicator_new (GeglNode *parent,
                      gboolean  linear,
-                     gboolean  use_preview_cache,
+                     gboolean  use_split_preview,
                      gboolean  use_result_cache)
 {
   GimpApplicator *applicator;
@@ -160,7 +160,7 @@ gimp_applicator_new (GeglNode *parent,
                        applicator->dup_apply_buffer_node,
                        NULL);
 
-  if (use_preview_cache)
+  if (use_split_preview)
     {
       applicator->preview_cache_node =
         gegl_node_new_child (applicator->node,
@@ -434,9 +434,8 @@ gimp_applicator_set_apply_offset (GimpApplicator *applicator,
 }
 
 void
-gimp_applicator_set_mode (GimpApplicator       *applicator,
-                          gdouble               opacity,
-                          GimpLayerModeEffects  paint_mode)
+gimp_applicator_set_opacity (GimpApplicator *applicator,
+                             gdouble         opacity)
 {
   g_return_if_fail (GIMP_IS_APPLICATOR (applicator));
 
@@ -447,6 +446,13 @@ gimp_applicator_set_mode (GimpApplicator       *applicator,
       gimp_gegl_mode_node_set_opacity (applicator->mode_node,
                                        opacity);
     }
+}
+
+void
+gimp_applicator_set_mode (GimpApplicator       *applicator,
+                          GimpLayerModeEffects  paint_mode)
+{
+  g_return_if_fail (GIMP_IS_APPLICATOR (applicator));
 
   if (applicator->paint_mode != paint_mode)
     {

app/gegl/gimpapplicator.h

@@ -89,7 +89,7 @@ GType        gimp_applicator_get_type         (void) G_GNUC_CONST;
 
 GimpApplicator * gimp_applicator_new          (GeglNode             *parent,
                                                gboolean              linear,
-                                               gboolean              use_preview_cache,
+                                               gboolean              use_split_preview,
                                                gboolean              use_result_cache);
 
 void         gimp_applicator_set_src_buffer   (GimpApplicator       *applicator,
@@ -109,8 +109,9 @@ void         gimp_applicator_set_apply_offset (GimpApplicator       *applicator,
                                                gint                  apply_offset_x,
                                                gint                  apply_offset_y);
 
+void         gimp_applicator_set_opacity      (GimpApplicator       *applicator,
+                                               gdouble               opacity);
 void         gimp_applicator_set_mode         (GimpApplicator       *applicator,
-                                               gdouble               opacity,
                                                GimpLayerModeEffects  paint_mode);
 void         gimp_applicator_set_affect       (GimpApplicator       *applicator,
                                                GimpComponentMask     affect);

app/paint/gimppaintcore.c

@@ -898,8 +898,8 @@ gimp_paint_core_paste (GimpPaintCore            *core,
                                         core->paint_buffer_x,
                                         core->paint_buffer_y);
 
-      gimp_applicator_set_mode (core->applicator,
-                                image_opacity, paint_mode);
+      gimp_applicator_set_opacity (core->applicator, image_opacity);
+      gimp_applicator_set_mode (core->applicator, paint_mode);
 
       /*  apply the paint area to the image  */
       gimp_applicator_blit (core->applicator,