UI: Grease Pencil Modifier Drag and Drop, Layout Changes

This patch implements the list panel system D7490 for grease pencil
modifiers. It also moves their drawing to a callback in
GpencilModifierTypeInfo in line with the extensible architecture
refactoring goal T75724.

This also adds the "set_error" function for grease pencil modifiers,
which hadn't been copied from mesh modifiers yet.

The implementation is basically exactly the same as for the modifier
patch (9b099c86123fc82).

Thanks to Matias Mendiola (mendio) for providing mockups for many
of the layout changes.

Differential Revision: https://developer.blender.org/D7978

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_gpencil_modifier.h b/source/blender/blenkernel/BKE_gpencil_modifier.h
index 966d3a98234..ac5f4607838 100644
--- a/source/blender/blenkernel/BKE_gpencil_modifier.h
+++ b/source/blender/blenkernel/BKE_gpencil_modifier.h
@@ -20,12 +20,14 @@
  * \ingroup bke
  */
 
+#include "BLI_compiler_attrs.h"
 #include "DNA_gpencil_modifier_types.h" /* needed for all enum typdefs */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+struct ARegionType;
 struct Depsgraph;
 struct GpencilModifierData;
 struct ID;
@@ -255,11 +257,17 @@ typedef struct GpencilModifierTypeInfo {
                          struct Object *ob,
                          GreasePencilTexWalkFunc walk,
                          void *userData);
+
+  /* Register the panel types for the modifier's UI. */
+  void (*panelRegister)(struct ARegionType *region_type);
 } GpencilModifierTypeInfo;
 
+#define GPENCIL_MODIFIER_TYPE_PANEL_PREFIX "MOD_PT_gpencil_"
+
 /* Initialize modifier's global data (type info and some common global storages). */
 void BKE_gpencil_modifier_init(void);
 
+void BKE_gpencil_modifierType_panel_id(GpencilModifierType type, char *r_idname);
 const GpencilModifierTypeInfo *BKE_gpencil_modifier_get_info(GpencilModifierType type);
 struct GpencilModifierData *BKE_gpencil_modifier_new(int type);
 void BKE_gpencil_modifier_free_ex(struct GpencilModifierData *md, const int flag);
@@ -276,6 +284,8 @@ void BKE_gpencil_modifier_copydata(struct GpencilModifierData *md,
 void BKE_gpencil_modifier_copydata_ex(struct GpencilModifierData *md,
                                       struct GpencilModifierData *target,
                                       const int flag);
+void BKE_gpencil_modifier_set_error(struct GpencilModifierData *md, const char *format, ...)
+    ATTR_PRINTF_FORMAT(2, 3);
 void BKE_gpencil_modifiers_foreach_ID_link(struct Object *ob,
                                            GreasePencilIDWalkFunc walk,
                                            void *userData);