17 files changed, 71 insertions, 26 deletions

diff --git a/source/blender/makesrna/intern/rna_ID.c b/source/blender/makesrna/intern/rna_ID.c
index 7e6bdf970f6..280ad4aa9b1 100644
--- a/source/blender/makesrna/intern/rna_ID.c
+++ b/source/blender/makesrna/intern/rna_ID.c
@@ -122,7 +122,7 @@ void rna_ID_name_set(PointerRNA *ptr, const char *value)
 	BLI_libblock_ensure_unique_name(G.main, id->name);
 }
 
-static int rna_ID_name_editable(PointerRNA *ptr)
+static int rna_ID_name_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	ID *id = (ID *)ptr->data;
 	
diff --git a/source/blender/makesrna/intern/rna_access.c b/source/blender/makesrna/intern/rna_access.c
index 6879a0534e9..6f054e586ec 100644
--- a/source/blender/makesrna/intern/rna_access.c
+++ b/source/blender/makesrna/intern/rna_access.c
@@ -1619,20 +1619,56 @@ bool RNA_property_editable(PointerRNA *ptr, PropertyRNA *prop)
 {
 	ID *id = ptr->id.data;
 	int flag;
+	const char *dummy_info;
 
 	prop = rna_ensure_property(prop);
-	flag = prop->editable ? prop->editable(ptr) : prop->flag;
+	flag = prop->editable ? prop->editable(ptr, &dummy_info) : prop->flag;
+
 	return ((flag & PROP_EDITABLE) &&
 	        (flag & PROP_REGISTER) == 0 &&
 	        (!id || !ID_IS_LINKED_DATABLOCK(id) || (prop->flag & PROP_LIB_EXCEPTION)));
 }
 
+/**
+ * Version of #RNA_property_editable that tries to return additional info in \a r_info that can be exposed in UI.
+ */
+bool RNA_property_editable_info(PointerRNA *ptr, PropertyRNA *prop, const char **r_info)
+{
+	ID *id = ptr->id.data;
+	int flag;
+
+	prop = rna_ensure_property(prop);
+	*r_info = "";
+
+	/* get flag */
+	if (prop->editable) {
+		flag = prop->editable(ptr, r_info);
+	}
+	else {
+		flag = prop->flag;
+		if ((flag & PROP_EDITABLE) == 0 || (flag & PROP_REGISTER)) {
+			*r_info = "This property is for internal use only and can't be edited.";
+		}
+	}
+
+	/* property from linked data-block */
+	if (id && ID_IS_LINKED_DATABLOCK(id) && (prop->flag & PROP_LIB_EXCEPTION) == 0) {
+		if (!(*r_info)[0]) {
+			*r_info = "Can't edit this property from a linked data-block.";
+		}
+		return false;
+	}
+
+	return ((flag & PROP_EDITABLE) && (flag & PROP_REGISTER) == 0);
+}
+
 bool RNA_property_editable_flag(PointerRNA *ptr, PropertyRNA *prop)
 {
 	int flag;
+	const char *dummy_info;
 
 	prop = rna_ensure_property(prop);
-	flag = prop->editable ? prop->editable(ptr) : prop->flag;
+	flag = prop->editable ? prop->editable(ptr, &dummy_info) : prop->flag;
 	return (flag & PROP_EDITABLE) != 0;
 }
 
@@ -1647,9 +1683,11 @@ bool RNA_property_editable_index(PointerRNA *ptr, PropertyRNA *prop, int index)
 	prop = rna_ensure_property(prop);
 
 	flag = prop->flag;
-	
-	if (prop->editable)
-		flag &= prop->editable(ptr);
+
+	if (prop->editable) {
+		const char *dummy_info;
+		flag &= prop->editable(ptr, &dummy_info);
+	}
 
 	if (prop->itemeditable)
 		flag &= prop->itemeditable(ptr, index);
diff --git a/source/blender/makesrna/intern/rna_animation.c b/source/blender/makesrna/intern/rna_animation.c
index e37affcf5a3..cdbf7582fa7 100644
--- a/source/blender/makesrna/intern/rna_animation.c
+++ b/source/blender/makesrna/intern/rna_animation.c
@@ -89,7 +89,7 @@ static void rna_AnimData_update(Main *UNUSED(bmain), Scene *UNUSED(scene), Point
 	DAG_id_tag_update(id, OB_RECALC_OB | OB_RECALC_DATA);
 }
 
-static int rna_AnimData_action_editable(PointerRNA *ptr)
+static int rna_AnimData_action_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	AnimData *adt = (AnimData *)ptr->data;
 	
@@ -305,7 +305,7 @@ static StructRNA *rna_ksPath_id_typef(PointerRNA *ptr)
 	return ID_code_to_RNA_type(ksp->idtype);
 }
 
-static int rna_ksPath_id_editable(PointerRNA *ptr)
+static int rna_ksPath_id_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	KS_Path *ksp = (KS_Path *)ptr->data;
 	return (ksp->idtype) ? PROP_EDITABLE : 0;
@@ -393,7 +393,7 @@ static void rna_KeyingSet_name_set(PointerRNA *ptr, const char *value)
 }
 
 
-static int rna_KeyingSet_active_ksPath_editable(PointerRNA *ptr)
+static int rna_KeyingSet_active_ksPath_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	KeyingSet *ks = (KeyingSet *)ptr->data;
 	
diff --git a/source/blender/makesrna/intern/rna_curve.c b/source/blender/makesrna/intern/rna_curve.c
index f4fb30e0793..22e45964742 100644
--- a/source/blender/makesrna/intern/rna_curve.c
+++ b/source/blender/makesrna/intern/rna_curve.c
@@ -221,7 +221,7 @@ static void rna_Curve_texspace_set(Main *UNUSED(bmain), Scene *UNUSED(scene), Po
 		BKE_curve_texspace_calc(cu);
 }
 
-static int rna_Curve_texspace_editable(PointerRNA *ptr)
+static int rna_Curve_texspace_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	Curve *cu = (Curve *)ptr->data;
 	return (cu->texflag & CU_AUTOSPACE) ? 0 : PROP_EDITABLE;
diff --git a/source/blender/makesrna/intern/rna_fcurve.c b/source/blender/makesrna/intern/rna_fcurve.c
index c521e93d33e..1d3b65bb7ba 100644
--- a/source/blender/makesrna/intern/rna_fcurve.c
+++ b/source/blender/makesrna/intern/rna_fcurve.c
@@ -199,13 +199,13 @@ static StructRNA *rna_DriverTarget_id_typef(PointerRNA *ptr)
 	return ID_code_to_RNA_type(dtar->idtype);
 }
 
-static int rna_DriverTarget_id_editable(PointerRNA *ptr)
+static int rna_DriverTarget_id_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	DriverTarget *dtar = (DriverTarget *)ptr->data;
 	return (dtar->idtype) ? PROP_EDITABLE : 0;
 }
 
-static int rna_DriverTarget_id_type_editable(PointerRNA *ptr)
+static int rna_DriverTarget_id_type_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	DriverTarget *dtar = (DriverTarget *)ptr->data;
 	
diff --git a/source/blender/makesrna/intern/rna_gpencil.c b/source/blender/makesrna/intern/rna_gpencil.c
index 7eaf8b65902..9b881c13347 100644
--- a/source/blender/makesrna/intern/rna_gpencil.c
+++ b/source/blender/makesrna/intern/rna_gpencil.c
@@ -120,7 +120,7 @@ static char *rna_GPencilLayer_path(PointerRNA *ptr)
 	return BLI_sprintfN("layers[\"%s\"]", name_esc);
 }
 
-static int rna_GPencilLayer_active_frame_editable(PointerRNA *ptr)
+static int rna_GPencilLayer_active_frame_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	bGPDlayer *gpl = (bGPDlayer *)ptr->data;
 
diff --git a/source/blender/makesrna/intern/rna_internal_types.h b/source/blender/makesrna/intern/rna_internal_types.h
index ba0705b5caa..04b85b8997e 100644
--- a/source/blender/makesrna/intern/rna_internal_types.h
+++ b/source/blender/makesrna/intern/rna_internal_types.h
@@ -62,7 +62,7 @@ struct Scene;
 typedef void (*UpdateFunc)(struct Main *main, struct Scene *scene, struct PointerRNA *ptr);
 typedef void (*ContextPropUpdateFunc)(struct bContext *C, struct PointerRNA *ptr, struct PropertyRNA *prop);
 typedef void (*ContextUpdateFunc)(struct bContext *C, struct PointerRNA *ptr);
-typedef int (*EditableFunc)(struct PointerRNA *ptr);
+typedef int (*EditableFunc)(struct PointerRNA *ptr, const char **r_info);
 typedef int (*ItemEditableFunc)(struct PointerRNA *ptr, int index);
 typedef struct IDProperty *(*IDPropertiesFunc)(struct PointerRNA *ptr, bool create);
 typedef struct StructRNA *(*StructRefineFunc)(struct PointerRNA *ptr);
@@ -188,7 +188,9 @@ struct PropertyRNA {
 	UpdateFunc update;
 	int noteflag;
 
-	/* callback for testing if editable */
+	/* Callback for testing if editable. Its r_info parameter can be used to
+	 * return info on editable state that might be shown to user. E.g. tooltips
+	 * of disabled buttons can show reason why button is disabled using this. */
 	EditableFunc editable;
 	/* callback for testing if array-item editable (if applicable) */
 	ItemEditableFunc itemeditable;
diff --git a/source/blender/makesrna/intern/rna_lattice.c b/source/blender/makesrna/intern/rna_lattice.c
index 6bc9cc38a7d..9424ddf7d0e 100644
--- a/source/blender/makesrna/intern/rna_lattice.c
+++ b/source/blender/makesrna/intern/rna_lattice.c
@@ -171,7 +171,7 @@ static void rna_Lattice_use_outside_set(PointerRNA *ptr, int value)
 	}
 }
 
-static int rna_Lattice_size_editable(PointerRNA *ptr)
+static int rna_Lattice_size_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	Lattice *lt = (Lattice *)ptr->data;
 
diff --git a/source/blender/makesrna/intern/rna_material.c b/source/blender/makesrna/intern/rna_material.c
index 2a8cc073e22..752f406264a 100644
--- a/source/blender/makesrna/intern/rna_material.c
+++ b/source/blender/makesrna/intern/rna_material.c
@@ -233,7 +233,7 @@ static void rna_Material_active_texture_set(PointerRNA *ptr, PointerRNA value)
 	set_current_material_texture(ma, value.data);
 }
 
-static int rna_Material_active_texture_editable(PointerRNA *ptr)
+static int rna_Material_active_texture_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	Material *ma = (Material *)ptr->id.data;
 
diff --git a/source/blender/makesrna/intern/rna_mesh.c b/source/blender/makesrna/intern/rna_mesh.c
index 1d734864833..df034ed85d8 100644
--- a/source/blender/makesrna/intern/rna_mesh.c
+++ b/source/blender/makesrna/intern/rna_mesh.c
@@ -662,7 +662,7 @@ static void rna_MeshLoopColor_color_set(PointerRNA *ptr, const float *values)
 	(&mcol->r)[2] = (char)(CLAMPIS(values[2] * 255.0f, 0, 255));
 }
 
-static int rna_Mesh_texspace_editable(PointerRNA *ptr)
+static int rna_Mesh_texspace_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	Mesh *me = (Mesh *)ptr->data;
 	return (me->texflag & ME_AUTOSPACE) ? 0 : PROP_EDITABLE;
diff --git a/source/blender/makesrna/intern/rna_meta.c b/source/blender/makesrna/intern/rna_meta.c
index d3b66e4c3b4..9d13bc90e72 100644
--- a/source/blender/makesrna/intern/rna_meta.c
+++ b/source/blender/makesrna/intern/rna_meta.c
@@ -53,7 +53,7 @@
 #include "WM_types.h"
 #include "WM_api.h"
 
-static int rna_Meta_texspace_editable(PointerRNA *ptr)
+static int rna_Meta_texspace_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	MetaBall *mb = (MetaBall *)ptr->data;
 	return (mb->texflag & MB_AUTOSPACE) ? 0 : PROP_EDITABLE;
diff --git a/source/blender/makesrna/intern/rna_nla.c b/source/blender/makesrna/intern/rna_nla.c
index eb87eafe16c..55bc40f573c 100644
--- a/source/blender/makesrna/intern/rna_nla.c
+++ b/source/blender/makesrna/intern/rna_nla.c
@@ -282,7 +282,7 @@ static void rna_NlaStrip_use_auto_blend_set(PointerRNA *ptr, int value)
 	}
 }
 
-static int rna_NlaStrip_action_editable(PointerRNA *ptr)
+static int rna_NlaStrip_action_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	NlaStrip *strip = (NlaStrip *)ptr->data;
 	
diff --git a/source/blender/makesrna/intern/rna_object.c b/source/blender/makesrna/intern/rna_object.c
index 2cbf23973c2..0e735350e05 100644
--- a/source/blender/makesrna/intern/rna_object.c
+++ b/source/blender/makesrna/intern/rna_object.c
@@ -712,7 +712,7 @@ static void rna_Object_active_material_set(PointerRNA *ptr, PointerRNA value)
 	assign_material(ob, value.data, ob->actcol, BKE_MAT_ASSIGN_EXISTING);
 }
 
-static int rna_Object_active_material_editable(PointerRNA *ptr)
+static int rna_Object_active_material_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	Object *ob = (Object *)ptr->id.data;
 	bool is_editable;
diff --git a/source/blender/makesrna/intern/rna_pose.c b/source/blender/makesrna/intern/rna_pose.c
index 1f34d8f23d4..0591e877634 100644
--- a/source/blender/makesrna/intern/rna_pose.c
+++ b/source/blender/makesrna/intern/rna_pose.c
@@ -556,13 +556,18 @@ static void rna_PoseChannel_constraints_remove(ID *id, bPoseChannel *pchan, Repo
 	}
 }
 
-static int rna_PoseChannel_proxy_editable(PointerRNA *ptr)
+static int rna_PoseChannel_proxy_editable(PointerRNA *ptr, const char **r_info)
 {
 	Object *ob = (Object *)ptr->id.data;
 	bArmature *arm = ob->data;
 	bPoseChannel *pchan = (bPoseChannel *)ptr->data;
 	
-	return (ob->proxy && pchan->bone && (pchan->bone->layer & arm->layer_protected)) ? 0 : PROP_EDITABLE;
+	if (ob->proxy && pchan->bone && (pchan->bone->layer & arm->layer_protected)) {
+		*r_info = "Can't edit property of a proxy on a protected layer";
+		return 0;
+	}
+	
+	return PROP_EDITABLE;
 }
 
 static int rna_PoseChannel_location_editable(PointerRNA *ptr, int index)
diff --git a/source/blender/makesrna/intern/rna_sequencer.c b/source/blender/makesrna/intern/rna_sequencer.c
index c3a66058888..bb9c2a6c2fd 100644
--- a/source/blender/makesrna/intern/rna_sequencer.c
+++ b/source/blender/makesrna/intern/rna_sequencer.c
@@ -292,7 +292,7 @@ static int rna_Sequence_frame_length_get(PointerRNA *ptr)
 	return BKE_sequence_tx_get_final_right(seq, false) - BKE_sequence_tx_get_final_left(seq, false);
 }
 
-static int rna_Sequence_frame_editable(PointerRNA *ptr)
+static int rna_Sequence_frame_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	Sequence *seq = (Sequence *)ptr->data;
 	/* Effect sequences' start frame and length must be readonly! */
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index a7dab0f56f8..375d370097e 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -1645,7 +1645,7 @@ static void rna_FileBrowser_FSMenuEntry_name_set(PointerRNA *ptr, const char *va
 	ED_fsmenu_entry_set_name(fsm, value);
 }
 
-static int rna_FileBrowser_FSMenuEntry_name_get_editable(PointerRNA *ptr)
+static int rna_FileBrowser_FSMenuEntry_name_get_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	FSMenuEntry *fsm = ptr->data;
 
diff --git a/source/blender/makesrna/intern/rna_vfont.c b/source/blender/makesrna/intern/rna_vfont.c
index e9ba0c78439..c743751649c 100644
--- a/source/blender/makesrna/intern/rna_vfont.c
+++ b/source/blender/makesrna/intern/rna_vfont.c
@@ -44,7 +44,7 @@
 #include "WM_api.h"
 
 /* matching fnction in rna_ID.c */
-static int rna_VectorFont_filepath_editable(PointerRNA *ptr)
+static int rna_VectorFont_filepath_editable(PointerRNA *ptr, const char **UNUSED(r_info))
 {
 	VFont *vfont = ptr->id.data;
 	if (BKE_vfont_is_builtin(vfont)) {