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, 23 insertions, 5 deletions

diff --git a/source/blender/editors/include/ED_anim_api.h b/source/blender/editors/include/ED_anim_api.h
index 9cf67816df2..2415c85e299 100644
--- a/source/blender/editors/include/ED_anim_api.h
+++ b/source/blender/editors/include/ED_anim_api.h
@@ -33,7 +33,11 @@ struct ID;
 struct ListBase;
 
 struct ARegion;
+struct ARegionType;
 struct Main;
+struct NlaStrip;
+struct FModifier;
+struct PanelType;
 struct ReportList;
 struct ScrArea;
 struct SpaceLink;
@@ -675,11 +679,25 @@ void ANIM_draw_framerange(struct Scene *scene, struct View2D *v2d);
 
 /* ------------- UI Panel Drawing -------------- */
 
-/* draw a given F-Modifier for some layout/UI-Block */
-void ANIM_uiTemplate_fmodifier_draw(struct uiLayout *layout,
-                                    struct ID *fcurve_owner_id,
-                                    ListBase *modifiers,
-                                    struct FModifier *fcm);
+struct NlaStrip *ANIM_nla_context_strip(const struct bContext *C);
+struct FCurve *ANIM_graph_context_fcurve(const struct bContext *C);
+
+/* Needed for abstraction between the graph editor and the NLA editor. */
+typedef bool (*PanelTypePollFn)(const struct bContext *C, struct PanelType *pt);
+/* Avoid including "UI_interface.h" here. */
+typedef void (*uiListPanelIDFromDataFunc)(void *data_link, char *r_idname);
+
+void ANIM_fmodifier_panels(const struct bContext *C,
+                           struct ID *owner_id,
+                           struct ListBase *fmodifiers,
+                           uiListPanelIDFromDataFunc panel_id_fn);
+
+void ANIM_modifier_panels_register_graph_and_NLA(struct ARegionType *region_type,
+                                                 const char *modifier_panel_prefix,
+                                                 PanelTypePollFn poll_function);
+void ANIM_modifier_panels_register_graph_only(struct ARegionType *region_type,
+                                              const char *modifier_panel_prefix,
+                                              PanelTypePollFn poll_function);
 
 /* ------------- Copy/Paste Buffer -------------- */