Cleanup: Use enum for return values in context callbacks

Define enum `eContextResult` and use its values for returns, instead of
just returning 1, 0, or -1 (and always having some comment that explains
what -1 means).

This also cleans up the mixup between returning `0` and `false`, and `1`
and `true`. An inconsistency was discovered during this cleanup, and
marked with `TODO(sybren)`. It's not fixed here, as it would consititute
a functional change.

The enum isn't used everywhere, as enums in C and C++ can have different
storage sizes. To prevent issues, callback functions are still declared
as returning`int`. To at least make things easier to understand for
humans, I marked those with `int /*eContextResult*/`.

This is a followup of D9090, and is intended to unify how context
callbacks return values. This will make it easier to extend the approach
in D9090 to those functions.

No functional changes.

Differential Revision: https://developer.blender.org/D9095

1 files changed, 50 insertions, 48 deletions

diff --git a/source/blender/editors/space_buttons/buttons_context.c b/source/blender/editors/space_buttons/buttons_context.c
index a233e3a9edd..fabccecd533 100644
--- a/source/blender/editors/space_buttons/buttons_context.c
+++ b/source/blender/editors/space_buttons/buttons_context.c
@@ -780,17 +780,19 @@ const char *buttons_context_dir[] = {
     NULL,
 };
 
-int buttons_context(const bContext *C, const char *member, bContextDataResult *result)
+int /*eContextResult*/ buttons_context(const bContext *C,
+                                       const char *member,
+                                       bContextDataResult *result)
 {
   SpaceProperties *sbuts = CTX_wm_space_properties(C);
   ButsContextPath *path = sbuts ? sbuts->path : NULL;
 
   if (!path) {
-    return 0;
+    return CTX_RESULT_MEMBER_NOT_FOUND;
   }
 
   if (sbuts->mainb == BCONTEXT_TOOL) {
-    return 0;
+    return CTX_RESULT_MEMBER_NOT_FOUND;
   }
 
   /* here we handle context, getting data from precomputed path */
@@ -803,7 +805,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
     else {
       CTX_data_dir_set(result, buttons_context_dir);
     }
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "scene")) {
     /* Do not return one here if scene not found in path,
@@ -812,67 +814,67 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
   }
   if (CTX_data_equals(member, "world")) {
     set_pointer_type(path, result, &RNA_World);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "object")) {
     set_pointer_type(path, result, &RNA_Object);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "mesh")) {
     set_pointer_type(path, result, &RNA_Mesh);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "armature")) {
     set_pointer_type(path, result, &RNA_Armature);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "lattice")) {
     set_pointer_type(path, result, &RNA_Lattice);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "curve")) {
     set_pointer_type(path, result, &RNA_Curve);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "meta_ball")) {
     set_pointer_type(path, result, &RNA_MetaBall);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "light")) {
     set_pointer_type(path, result, &RNA_Light);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "camera")) {
     set_pointer_type(path, result, &RNA_Camera);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "speaker")) {
     set_pointer_type(path, result, &RNA_Speaker);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "lightprobe")) {
     set_pointer_type(path, result, &RNA_LightProbe);
-    return 1;
+    return CTX_RESULT_OK;
   }
 #ifdef WITH_HAIR_NODES
   if (CTX_data_equals(member, "hair")) {
     set_pointer_type(path, result, &RNA_Hair);
-    return 1;
+    return CTX_RESULT_OK;
   }
 #endif
 #ifdef WITH_PARTICLE_NODES
   if (CTX_data_equals(member, "pointcloud")) {
     set_pointer_type(path, result, &RNA_PointCloud);
-    return 1;
+    return CTX_RESULT_OK;
   }
 #endif
   if (CTX_data_equals(member, "volume")) {
     set_pointer_type(path, result, &RNA_Volume);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "material")) {
     set_pointer_type(path, result, &RNA_Material);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "texture")) {
     ButsContextTexture *ct = sbuts->texuser;
@@ -881,7 +883,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       CTX_data_pointer_set(result, &ct->texture->id, &RNA_Texture, ct->texture);
     }
 
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "material_slot")) {
     PointerRNA *ptr = get_pointer_type(path, &RNA_Object);
@@ -899,7 +901,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       }
     }
 
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "texture_user")) {
     ButsContextTexture *ct = sbuts->texuser;
@@ -913,7 +915,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       CTX_data_pointer_set(result, user->ptr.owner_id, user->ptr.type, user->ptr.data);
     }
 
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "texture_user_property")) {
     ButsContextTexture *ct = sbuts->texuser;
@@ -927,7 +929,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       CTX_data_pointer_set(result, NULL, &RNA_Property, user->prop);
     }
 
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "texture_node")) {
     ButsContextTexture *ct = sbuts->texuser;
@@ -938,9 +940,9 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
         CTX_data_pointer_set(result, &ct->user->ntree->id, &RNA_Node, ct->user->node);
       }
 
-      return 1;
+      return CTX_RESULT_OK;
     }
-    return -1; /* found but not available */
+    return CTX_RESULT_NO_DATA;
   }
   if (CTX_data_equals(member, "texture_slot")) {
     ButsContextTexture *ct = sbuts->texuser;
@@ -967,23 +969,23 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       }
     }
 
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "bone")) {
     set_pointer_type(path, result, &RNA_Bone);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "edit_bone")) {
     set_pointer_type(path, result, &RNA_EditBone);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "pose_bone")) {
     set_pointer_type(path, result, &RNA_PoseBone);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "particle_system")) {
     set_pointer_type(path, result, &RNA_ParticleSystem);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "particle_system_editable")) {
     if (PE_poll((bContext *)C)) {
@@ -992,7 +994,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
     else {
       CTX_data_pointer_set(result, NULL, &RNA_ParticleSystem, NULL);
     }
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "particle_settings")) {
     /* only available when pinned */
@@ -1000,7 +1002,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
 
     if (ptr && ptr->data) {
       CTX_data_pointer_set(result, ptr->owner_id, &RNA_ParticleSettings, ptr->data);
-      return 1;
+      return CTX_RESULT_OK;
     }
 
     /* get settings from active particle system instead */
@@ -1009,11 +1011,11 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
     if (ptr && ptr->data) {
       ParticleSettings *part = ((ParticleSystem *)ptr->data)->part;
       CTX_data_pointer_set(result, ptr->owner_id, &RNA_ParticleSettings, part);
-      return 1;
+      return CTX_RESULT_OK;
     }
 
     set_pointer_type(path, result, &RNA_ParticleSettings);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "cloth")) {
     PointerRNA *ptr = get_pointer_type(path, &RNA_Object);
@@ -1022,9 +1024,9 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       Object *ob = ptr->data;
       ModifierData *md = BKE_modifiers_findby_type(ob, eModifierType_Cloth);
       CTX_data_pointer_set(result, &ob->id, &RNA_ClothModifier, md);
-      return 1;
+      return CTX_RESULT_OK;
     }
-    return -1; /* found but not available */
+    return CTX_RESULT_NO_DATA;
   }
   if (CTX_data_equals(member, "soft_body")) {
     PointerRNA *ptr = get_pointer_type(path, &RNA_Object);
@@ -1033,9 +1035,9 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       Object *ob = ptr->data;
       ModifierData *md = BKE_modifiers_findby_type(ob, eModifierType_Softbody);
       CTX_data_pointer_set(result, &ob->id, &RNA_SoftBodyModifier, md);
-      return 1;
+      return CTX_RESULT_OK;
     }
-    return -1; /* found but not available */
+    return CTX_RESULT_NO_DATA;
   }
 
   if (CTX_data_equals(member, "fluid")) {
@@ -1045,9 +1047,9 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       Object *ob = ptr->data;
       ModifierData *md = BKE_modifiers_findby_type(ob, eModifierType_Fluid);
       CTX_data_pointer_set(result, &ob->id, &RNA_FluidModifier, md);
-      return 1;
+      return CTX_RESULT_OK;
     }
-    return -1; /* found but not available */
+    return CTX_RESULT_NO_DATA;
   }
   if (CTX_data_equals(member, "collision")) {
     PointerRNA *ptr = get_pointer_type(path, &RNA_Object);
@@ -1056,13 +1058,13 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       Object *ob = ptr->data;
       ModifierData *md = BKE_modifiers_findby_type(ob, eModifierType_Collision);
       CTX_data_pointer_set(result, &ob->id, &RNA_CollisionModifier, md);
-      return 1;
+      return CTX_RESULT_OK;
     }
-    return -1; /* found but not available */
+    return CTX_RESULT_NO_DATA;
   }
   if (CTX_data_equals(member, "brush")) {
     set_pointer_type(path, result, &RNA_Brush);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "dynamic_paint")) {
     PointerRNA *ptr = get_pointer_type(path, &RNA_Object);
@@ -1071,19 +1073,19 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
       Object *ob = ptr->data;
       ModifierData *md = BKE_modifiers_findby_type(ob, eModifierType_DynamicPaint);
       CTX_data_pointer_set(result, &ob->id, &RNA_DynamicPaintModifier, md);
-      return 1;
+      return CTX_RESULT_OK;
     }
-    return -1; /* found but not available */
+    return CTX_RESULT_NO_DATA;
   }
   if (CTX_data_equals(member, "line_style")) {
     set_pointer_type(path, result, &RNA_FreestyleLineStyle);
-    return 1;
+    return CTX_RESULT_OK;
   }
   if (CTX_data_equals(member, "gpencil")) {
     set_pointer_type(path, result, &RNA_GreasePencil);
-    return 1;
+    return CTX_RESULT_OK;
   }
-  return 0; /* not found */
+  return CTX_RESULT_MEMBER_NOT_FOUND;
 }
 
 /************************* Drawing the Path ************************/