UI: FModifier layout updates, drag and drop

This patch implements the list panel system D7490 for FCurve modifiers.

The UI layouts are updated to make use of subpanels and to be consistent
with the rest of the interface, and easier to understand.

See the differential revision for screenshots.

This commit also significantly cleans up the FModifier UI code, and
improves, mainly by replacing the old button creation code is with
the newer interface API using RNA. In turn there is a bit of complexity
added because each FModifier has a separate panel.

Although reordering of FModifiers was not implemented before, we get
drag and drop basically for free here, so it is also included.
As noted in some older to do tasks, FModifiers aren't evaluated
in perfect order, which may be a point of improvement for the future.

Differential Revision: https://developer.blender.org/D7997

1 files changed, 26 insertions, 11 deletions

diff --git a/source/blender/editors/space_graph/graph_buttons.c b/source/blender/editors/space_graph/graph_buttons.c
index 51be5afafe5..d88bf8750c2 100644
--- a/source/blender/editors/space_graph/graph_buttons.c
+++ b/source/blender/editors/space_graph/graph_buttons.c
@@ -105,6 +105,16 @@ static bool graph_panel_context(const bContext *C, bAnimListElem **ale, FCurve *
   return true;
 }
 
+FCurve *ANIM_graph_context_fcurve(const bContext *C)
+{
+  FCurve *fcu;
+  if (!graph_panel_context(C, NULL, &fcu)) {
+    return NULL;
+  }
+
+  return fcu;
+}
+
 static bool graph_panel_poll(const bContext *C, PanelType *UNUSED(pt))
 {
   return graph_panel_context(C, NULL, NULL);
@@ -1312,6 +1322,16 @@ static void graph_panel_drivers_popover(const bContext *C, Panel *panel)
 /* All the drawing code is in editors/animation/fmodifier_ui.c */
 
 #define B_FMODIFIER_REDRAW 20
+/** The start of FModifier panels registered for the graph editor. */
+#define GRAPH_FMODIFIER_PANEL_PREFIX "GRAPH"
+
+static void graph_fmodifier_panel_id(void *fcm_link, char *r_name)
+{
+  FModifier *fcm = (FModifier *)fcm_link;
+  eFModifier_Types type = fcm->type;
+  const FModifierTypeInfo *fmi = get_fmodifier_typeinfo(type);
+  BLI_snprintf(r_name, BKE_ST_MAXNAME, "%s_PT_%s", GRAPH_FMODIFIER_PANEL_PREFIX, fmi->name);
+}
 
 static void do_graph_region_modifier_buttons(bContext *C, void *UNUSED(arg), int event)
 {
@@ -1327,10 +1347,8 @@ static void graph_panel_modifiers(const bContext *C, Panel *panel)
 {
   bAnimListElem *ale;
   FCurve *fcu;
-  FModifier *fcm;
-  uiLayout *col, *row;
+  uiLayout *row;
   uiBlock *block;
-  bool active;
 
   if (!graph_panel_context(C, &ale, &fcu)) {
     return;
@@ -1355,14 +1373,7 @@ static void graph_panel_modifiers(const bContext *C, Panel *panel)
     uiItemO(row, "", ICON_PASTEDOWN, "GRAPH_OT_fmodifier_paste");
   }
 
-  active = !(fcu->flag & FCURVE_MOD_OFF);
-  /* draw each modifier */
-  for (fcm = fcu->modifiers.first; fcm; fcm = fcm->next) {
-    col = uiLayoutColumn(panel->layout, true);
-    uiLayoutSetActive(col, active);
-
-    ANIM_uiTemplate_fmodifier_draw(col, ale->fcurve_owner_id, &fcu->modifiers, fcm);
-  }
+  ANIM_fmodifier_panels(C, ale->fcurve_owner_id, &fcu->modifiers, graph_fmodifier_panel_id);
 
   MEM_freeN(ale);
 }
@@ -1426,10 +1437,14 @@ void graph_buttons_register(ARegionType *art)
   strcpy(pt->label, N_("Modifiers"));
   strcpy(pt->category, "Modifiers");
   strcpy(pt->translation_context, BLT_I18NCONTEXT_DEFAULT_BPYRNA);
+  pt->flag = PANEL_TYPE_NO_HEADER;
   pt->draw = graph_panel_modifiers;
   pt->poll = graph_panel_poll;
   BLI_addtail(&art->paneltypes, pt);
 
+  ANIM_modifier_panels_register_graph_and_NLA(art, GRAPH_FMODIFIER_PANEL_PREFIX, graph_panel_poll);
+  ANIM_modifier_panels_register_graph_only(art, GRAPH_FMODIFIER_PANEL_PREFIX, graph_panel_poll);
+
   pt = MEM_callocN(sizeof(PanelType), "spacetype graph panel view");
   strcpy(pt->idname, "GRAPH_PT_view");
   strcpy(pt->label, N_("Show Cursor"));