Nla Strip Controls: Added dedicated "Expander" channel to Action/Graph Editors

The "Nla Strip Controls" channel is used to house the per-strip
FCurves for controlling the strip_time and influence properties.
It sits above the active action's first group, at the same level
in the hierarchy as other groups.

TODO: It looks like a dedicated FCurve channel is needed for these
control FCurves, so that we won't accidentally apply NLA mapping
or have these FCurves disabled by the path lookups failing.

3 files changed, 172 insertions, 2 deletions

diff --git a/source/blender/editors/animation/anim_channels_defines.c b/source/blender/editors/animation/anim_channels_defines.c
index 37c40052275..11d68ed6f75 100644
--- a/source/blender/editors/animation/anim_channels_defines.c
+++ b/source/blender/editors/animation/anim_channels_defines.c
@@ -908,6 +908,106 @@ static bAnimChannelType ACF_GROUP =
 	acf_group_setting_ptr           /* pointer for setting */
 };
 
+/* NLA Control FCurves Expander ----------------------- */
+
+/* get backdrop color for nla controls widget */
+static void acf_nla_controls_color(bAnimContext *UNUSED(ac), bAnimListElem *UNUSED(ale), float r_color[3])
+{
+	// TODO: give this its own theme setting?
+	UI_GetThemeColorShade3fv(TH_GROUP, 55, r_color);
+}
+
+/* backdrop for nla controls expander widget */
+static void acf_nla_controls_backdrop(bAnimContext *ac, bAnimListElem *ale, float yminc, float ymaxc)
+{
+	bAnimChannelType *acf = ANIM_channel_get_typeinfo(ale);
+	View2D *v2d = &ac->ar->v2d;
+	short expanded = ANIM_channel_setting_get(ac, ale, ACHANNEL_SETTING_EXPAND) != 0;
+	short offset = (acf->get_offset) ? acf->get_offset(ac, ale) : 0;
+	float color[3];
+	
+	/* set backdrop drawing color */
+	acf->get_backdrop_color(ac, ale, color);
+	glColor3fv(color);
+	
+	/* rounded corners on LHS only - top only when expanded, but bottom too when collapsed */
+	UI_draw_roundbox_corner_set(expanded ? UI_CNR_TOP_LEFT : (UI_CNR_TOP_LEFT | UI_CNR_BOTTOM_LEFT));
+	UI_draw_roundbox_gl_mode(GL_POLYGON, offset,  yminc, v2d->cur.xmax + EXTRA_SCROLL_PAD, ymaxc, 5);
+}
+
+/* name for nla controls expander entries */
+static void acf_nla_controls_name(bAnimListElem *ale, char *name)
+{
+	BLI_strncpy(name, IFACE_("NLA Strip Controls"), ANIM_CHAN_NAME_SIZE);
+}
+
+/* check if some setting exists for this channel */
+static bool acf_nla_controls_setting_valid(bAnimContext *ac, bAnimListElem *UNUSED(ale), eAnimChannel_Settings setting)
+{
+	/* for now, all settings are supported, though some are only conditionally */
+	switch (setting) {
+		/* supported */
+		case ACHANNEL_SETTING_EXPAND:
+			return true;
+		
+		// TOOD: selected?
+		
+		default: /* unsupported */
+			return false;
+	}
+}
+
+/* get the appropriate flag(s) for the setting when it is valid  */
+static int acf_nla_controls_setting_flag(bAnimContext *ac, eAnimChannel_Settings setting, bool *neg)
+{
+	/* clear extra return data first */
+	*neg = false;
+	
+	switch (setting) {
+		case ACHANNEL_SETTING_EXPAND: /* expanded */
+			*neg = true;
+			return ADT_NLA_SKEYS_COLLAPSED;
+		
+		default:
+			/* this shouldn't happen */
+			return 0;
+	}
+}
+
+/* get pointer to the setting */
+static void *acf_nla_controls_setting_ptr(bAnimListElem *ale, eAnimChannel_Settings UNUSED(setting), short *type)
+{
+	AnimData *adt = (AnimData *)ale->data;
+	
+	/* all flags are just in adt->flag for now... */
+	return GET_ACF_FLAG_PTR(adt->flag, type);
+}
+
+static int acf_nla_controls_icon(bAnimListElem *UNUSED(ale))
+{
+	return ICON_NLA;
+}
+
+/* NLA Control FCurves Expander type define */
+static bAnimChannelType ACF_NLACONTROLS = 
+{
+	"NLA Controls Expander",        /* type name */
+	ACHANNEL_ROLE_EXPANDER,         /* role */
+	
+	acf_nla_controls_color,         /* backdrop color */
+	acf_nla_controls_backdrop,      /* backdrop */
+	acf_generic_indention_0,        /* indent level */
+	acf_generic_group_offset,       /* offset */
+
+	acf_nla_controls_name,          /* name */
+	NULL,                           /* name prop */
+	acf_nla_controls_icon,          /* icon */
+
+	acf_nla_controls_setting_valid, /* has setting */
+	acf_nla_controls_setting_flag,  /* flag for setting */
+	acf_nla_controls_setting_ptr    /* pointer for setting */
+};
+
 /* F-Curve ------------------------------------------- */
 
 /* name for fcurve entries */
@@ -3222,6 +3322,8 @@ static void ANIM_init_channel_typeinfo_data(void)
 		animchannelTypeInfo[type++] = &ACF_GROUP;        /* Group */
 		animchannelTypeInfo[type++] = &ACF_FCURVE;       /* F-Curve */
 		
+		animchannelTypeInfo[type++] = &ACF_NLACONTROLS;  /* NLA Control FCurve Expander */
+		
 		animchannelTypeInfo[type++] = &ACF_FILLACTD;     /* Object Action Expander */
 		animchannelTypeInfo[type++] = &ACF_FILLDRIVERS;  /* Drivers Expander */
 		
diff --git a/source/blender/editors/animation/anim_filter.c b/source/blender/editors/animation/anim_filter.c
index d6daa64a9f2..b5d1de9c7d6 100644
--- a/source/blender/editors/animation/anim_filter.c
+++ b/source/blender/editors/animation/anim_filter.c
@@ -423,6 +423,7 @@ bool ANIM_animdata_get_context(const bContext *C, bAnimContext *ac)
  *  - adtOk: line or block of code to execute for AnimData-blocks case (usually ANIMDATA_ADD_ANIMDATA)
  *  - nlaOk: line or block of code to execute for NLA tracks+strips case
  *  - driversOk: line or block of code to execute for Drivers case
+ *  - nlaKeysOk: line or block of code for NLA Strip Keyframes case
  *  - keysOk: line or block of code for Keyframes case
  *
  * The checks for the various cases are as follows:
@@ -433,9 +434,10 @@ bool ANIM_animdata_get_context(const bContext *C, bAnimContext *ac)
  *		converted to a new NLA strip, and the filtering options allow this
  *	2C) allow non-animated datablocks to be included so that datablocks can be added
  *	3) drivers: include drivers from animdata block (for Drivers mode in Graph Editor)
- *	4) normal keyframes: only when there is an active action
+ *  4A) nla strip keyframes: these are the per-strip controls for time and influence
+ *	4B) normal keyframes: only when there is an active action
  */
-#define ANIMDATA_FILTER_CASES(id, adtOk, nlaOk, driversOk, keysOk) \
+#define ANIMDATA_FILTER_CASES(id, adtOk, nlaOk, driversOk, nlaKeysOk, keysOk) \
 	{ \
 		if ((id)->adt) { \
 			if (!(filter_mode & ANIMFILTER_CURVE_VISIBLE) || !((id)->adt->flag & ADT_CURVES_NOT_VISIBLE)) { \
@@ -456,6 +458,9 @@ bool ANIM_animdata_get_context(const bContext *C, bAnimContext *ac)
 					} \
 				} \
 				else { \
+					if (ANIMDATA_HAS_NLA(id)) { \
+						nlaKeysOk \
+					} \
 					if (ANIMDATA_HAS_KEYS(id)) { \
 						keysOk \
 					} \
@@ -786,6 +791,16 @@ static bAnimListElem *make_new_animlistelem(void *data, short datatype, ID *owne
 				ale->adt = BKE_animdata_from_id(data);
 				break;
 			}
+			case ANIMTYPE_NLACONTROLS:
+			{
+				AnimData *adt = (AnimData *)data;
+				
+				ale->flag = adt->flag;
+				
+				ale->key_data = NULL;
+				ale->datatype = ALE_NONE;
+				break;
+			}
 			case ANIMTYPE_GROUP:
 			{
 				bActionGroup *agrp = (bActionGroup *)data;
@@ -1305,6 +1320,52 @@ static size_t animfilter_nla(bAnimContext *UNUSED(ac), ListBase *anim_data, bDop
 	return items;
 }
 
+/* Include the control FCurves per NLA Strip in the channel list
+ * NOTE: This is includes the expander too...
+ */
+static size_t animfilter_nla_controls(ListBase *anim_data, bDopeSheet *ads, AnimData *adt, int filter_mode, ID *owner_id)
+{
+	ListBase tmp_data = {NULL, NULL};
+	size_t tmp_items = 0;
+	size_t items = 0;
+	
+	/* add control curves from each NLA strip... */
+	BEGIN_ANIMFILTER_SUBCHANNELS(((adt->flag & ADT_NLA_SKEYS_COLLAPSED) == 0))
+	{
+		NlaTrack *nlt;
+		NlaStrip *strip;
+		
+		/* for now, we only go one level deep - so controls on grouped FCurves are not handled */
+		for (nlt = adt->nla_tracks.first; nlt; nlt = nlt->next) {
+			for (strip = nlt->strips.first; strip; strip = strip->next) {
+				tmp_items += animfilter_fcurves(&tmp_data, ads, strip->fcurves.first, NULL, filter_mode, owner_id);
+			}
+		}
+	}
+	END_ANIMFILTER_SUBCHANNELS;
+	
+	/* did we find anything? */
+	if (tmp_items) {
+		/* TODO: apply extra tags to indicate the NLA mapping does not apply here! */
+		
+		/* add the expander as a channel first */
+		if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
+			/* currently these channels cannot be selected, so they should be skipped */
+			if ((filter_mode & (ANIMFILTER_SEL | ANIMFILTER_UNSEL)) == 0) {
+				ANIMCHANNEL_NEW_CHANNEL(adt, ANIMTYPE_NLACONTROLS, owner_id);
+			}
+		}
+		
+		/* now add the list of collected channels */
+		BLI_movelisttolist(anim_data, &tmp_data);
+		BLI_assert(BLI_listbase_is_empty(&tmp_data));
+		items += tmp_items;
+	}
+	
+	/* return the numebr of items added ot the list */
+	return items;
+}
+
 /* determine what animation data from AnimData block should get displayed */
 static size_t animfilter_block_data(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, ID *id, int filter_mode)
 {
@@ -1332,6 +1393,9 @@ static size_t animfilter_block_data(bAnimContext *ac, ListBase *anim_data, bDope
 			{ /* Drivers */
 				items += animfilter_fcurves(anim_data, ads, adt->drivers.first, NULL, filter_mode, id);
 			},
+			{ /* NLA Control Keyframes */
+				items += animfilter_nla_controls(anim_data, ads, adt, filter_mode, id);
+			},
 			{ /* Keyframes */
 				items += animfilter_action(ac, anim_data, ads, adt->action, filter_mode, id);
 			}
@@ -2214,6 +2278,7 @@ static size_t animdata_filter_ds_obanim(bAnimContext *ac, ListBase *anim_data, b
 			cdata = adt;
 			expanded = EXPANDED_DRVD(adt);
 		},
+		{ /* NLA Strip Controls - no dedicated channel for now (XXX) */ },
 		{ /* Keyframes */
 			type = ANIMTYPE_FILLACTD;
 			cdata = adt->action;
@@ -2385,6 +2450,7 @@ static size_t animdata_filter_ds_scene(bAnimContext *ac, ListBase *anim_data, bD
 			cdata = adt;
 			expanded = EXPANDED_DRVD(adt);
 		},
+		{ /* NLA Strip Controls - no dedicated channel for now (XXX) */ },
 		{ /* Keyframes */
 			type = ANIMTYPE_FILLACTD;
 			cdata = adt->action;
diff --git a/source/blender/editors/include/ED_anim_api.h b/source/blender/editors/include/ED_anim_api.h
index 50581429700..829ea74f00f 100644
--- a/source/blender/editors/include/ED_anim_api.h
+++ b/source/blender/editors/include/ED_anim_api.h
@@ -141,6 +141,8 @@ typedef enum eAnim_ChannelType {
 	ANIMTYPE_GROUP,
 	ANIMTYPE_FCURVE,
 	
+	ANIMTYPE_NLACONTROLS,
+	
 	ANIMTYPE_FILLACTD,
 	ANIMTYPE_FILLDRIVERS,