v0.3.3 - Fixed Keying & Onion issues

- The addon will now assert that the active object should be of mesh
  type. If not, the appropriate operators will be inactive

- Fixed issue that artists were not able to override keyed value in an
  existing keyframe

- Fixed #9 that the `Initialize Frame Handler` had to be manually
  invoked by artists periodically to avoid issues. This has been fixed
  by calling the frame handler every 180 seconds, and also after a file
  is loaded

- The panel will now display a warning if there are no active objects
  and also when the active object is not of MESH type

- The active object's validity is now checked properly for all operators
  that depends on it.

stopmagic/__init__.py

@@ -18,6 +18,7 @@
 
 from typing import List, Tuple
 import bpy
+import threading
 import re
 import os.path
 
@@ -28,7 +29,7 @@
 bl_info = {
     "name": "Stopmagic",
     "author": "Aldrin Mathew",
-    "version": (0, 3, 2),
+    "version": (0, 3, 3),
     "blender": (2, 91, 0),
     "location": "Sidebar > Stopmagic",
     "warning": "beta",
@@ -41,6 +42,17 @@
 addon_keymaps: List[Tuple[bpy.types.KeyMap, bpy.types.KeyMapItem]] = []
 
 
+@bpy.app.handlers.persistent
+def periodic_handler(_):
+    functions.frame_handler(None)
+    threading.Timer(
+        interval=180,
+        function=functions.frame_handler,
+        args=[None],
+        kwargs=None,
+    )
+
+
 def register() -> None:
     global addon_keymaps
     icons.register()
@@ -56,7 +68,7 @@ def register() -> None:
     operators.keyed_frame_previous.register()
     operators.upgrade_addon.register()
     operators.contributions.register()
-    bpy.app.handlers.load_post.append(functions.frame_handler)
+    bpy.app.handlers.load_post.append(periodic_handler)
     bpy.app.handlers.frame_change_post.clear()
     bpy.app.handlers.frame_change_post.append(functions.update_stopmagic)
     bpy.app.handlers.frame_change_pre.clear()

stopmagic/functions/__init__.py

@@ -10,3 +10,4 @@
 from .get_object_keyframes import *
 from .get_object_key_values import *
 from .handle_onion_constraints import *
+from .is_candidate_object import *

stopmagic/functions/handle_onion_skin.py

@@ -21,6 +21,7 @@ def handle_collections(past: bpy.types.Object, future: bpy.types.Object) -> None
     sm_collection.hide_select = True
 
 
+@bpy.app.handlers.persistent
 def handle_onion_skin(dummy):
     """Automatically handles Onion Skin objects and populates them with mesh data"""
     if bpy.context.view_layer.objects.active is not None:
@@ -284,14 +285,15 @@ def clear_onion_data():
         bpy.data.materials.remove(pmaterial, do_unlink=True)
     if fmaterial is not None:
         bpy.data.materials.remove(fmaterial, do_unlink=True)
-    if collection.get("objects") is not None:
-        for obj in collection.objects:
-            mesh = obj.data
-            obj.name = "removed"
-            bpy.context.scene.objects.unlink(obj)
-            bpy.data.meshes.remove(mesh, do_unlink=True)
-            bpy.data.objects.remove(obj, do_unlink=True)
-    bpy.data.collections.remove(collection)
-    bpy.ops.outliner.orphans_purge(
-        do_local_ids=True, do_linked_ids=False, do_recursive=False
-    )
+    if collection is not None:
+        if collection.get("objects") is not None:
+            for obj in collection.objects:
+                mesh = obj.data
+                obj.name = "removed"
+                bpy.context.scene.objects.unlink(obj)
+                bpy.data.meshes.remove(mesh, do_unlink=True)
+                bpy.data.objects.remove(obj, do_unlink=True)
+        bpy.data.collections.remove(collection)
+        bpy.ops.outliner.orphans_purge(
+            do_local_ids=True, do_linked_ids=False, do_recursive=False
+        )

stopmagic/functions/insert_mesh_keyframe.py

@@ -40,32 +40,35 @@ def insert_mesh_keyframe(obj: bpy.types.Object | Any) -> None:
 
 
 def insert_mesh_keyframe_ex(obj: bpy.types.Object) -> bool:
-    if obj.get("sm_id") is None:
-        obj["sm_id"] = new_object_id()
-    #
-    object_sm_id = obj["sm_id"]
-    ob_name_full = obj.name_full
-    mesh_index = get_next_mesh_index(obj)
-    mesh_name = ob_name_full + "_sm_" + str(mesh_index)
-    del_mesh = []
-    new_mesh = bpy.data.meshes.new_from_object(obj)
-    new_mesh.name = mesh_name
-    new_mesh["sm_id"] = object_sm_id
-    new_mesh["sm_datablock"] = mesh_index
-    obj.data = new_mesh
-    obj.data.use_fake_user = True
-    obj["sm_datablock"] = mesh_index
-    obj.keyframe_insert(
-        data_path='["sm_datablock"]', frame=bpy.context.scene.frame_current
-    )
-    for mesh in del_mesh:
-        mesh.use_fake_user = False
-    update_stopmagic(bpy.context.scene)
-    for mesh in del_mesh:
-        if mesh.users == 0:
-            bpy.data.meshes.remove(mesh)
-    #
-    return True
+    try:
+        if obj.get("sm_id") is None:
+            obj["sm_id"] = new_object_id()
+        #
+        object_sm_id = obj["sm_id"]
+        ob_name_full = obj.name_full
+        mesh_index = get_next_mesh_index(obj)
+        mesh_name = ob_name_full + "_sm_" + str(mesh_index)
+        del_mesh = []
+        new_mesh = bpy.data.meshes.new_from_object(obj)
+        new_mesh.name = mesh_name
+        new_mesh["sm_id"] = object_sm_id
+        new_mesh["sm_datablock"] = mesh_index
+        obj.data = new_mesh
+        obj.data.use_fake_user = True
+        obj["sm_datablock"] = mesh_index
+        obj.keyframe_insert(
+            data_path='["sm_datablock"]', frame=bpy.context.scene.frame_current
+        )
+        for mesh in del_mesh:
+            mesh.use_fake_user = False
+        update_stopmagic(bpy.context.scene)
+        for mesh in del_mesh:
+            if mesh.users == 0:
+                bpy.data.meshes.remove(mesh)
+        #
+        return True
+    except:
+        return False
 
 
 # Get the appropriate index for the mesh about to be created

stopmagic/functions/update_stopmagic.py

@@ -1,6 +1,7 @@
 import bpy
 
 
+@bpy.app.handlers.persistent
 def update_stopmagic(scene: bpy.types.Scene) -> None:
     for object in scene.objects:
         if object.get("sm_datablock") is None:

stopmagic/operators/add_mesh_keyframe.py

@@ -1,5 +1,5 @@
 import bpy
-from ..functions.insert_mesh_keyframe import *
+from stopmagic.functions import insert_mesh_keyframe, is_candidate_object
 
 
 class AddMeshKeyframe(bpy.types.Operator):
@@ -11,7 +11,7 @@ class AddMeshKeyframe(bpy.types.Operator):
 
     @classmethod
     def poll(cls, context):
-        return context.view_layer.objects.active is not None
+        return is_candidate_object(context)
 
     def execute(self, context: bpy.types.Context):
         if bpy.context.view_layer.objects.active is not None:

stopmagic/operators/keyed_frame_next.py

@@ -2,7 +2,7 @@
 from typing import List, Set
 import bpy
 
-from stopmagic.functions import get_object_keyframes
+from stopmagic.functions import get_object_keyframes, is_candidate_object
 
 
 class KeyedFrameNext(bpy.types.Operator):
@@ -14,14 +14,15 @@ class KeyedFrameNext(bpy.types.Operator):
 
     @classmethod
     def poll(cls, context: bpy.types.Context) -> bool:
-        return context.view_layer.objects.active is not None
+        return is_candidate_object(context)
 
     def execute(self, context: bpy.types.Context) -> Set[int] | Set[str]:
-        if bpy.context.view_layer.objects.active is not None:
+        if context.view_layer.objects.active is not None:
             keyframes = get_object_keyframes(context.view_layer.objects.active)
             if len(keyframes) > 0:
-                frame = bpy.context.scene.frame_current
-                keyframes = [k for k in keyframes if k > frame]
+                keyframes = [
+                    k for k in keyframes if k > bpy.context.scene.frame_current
+                ]
             if len(keyframes) > 0:
                 lowest = keyframes[0]
                 for num in keyframes:

stopmagic/operators/keyed_frame_previous.py

@@ -2,7 +2,7 @@
 from typing import List, Set
 import bpy
 
-from stopmagic.functions.get_object_keyframes import get_object_keyframes
+from stopmagic.functions import get_object_keyframes, is_candidate_object
 
 
 class KeyedFramePrevious(bpy.types.Operator):
@@ -14,14 +14,15 @@ class KeyedFramePrevious(bpy.types.Operator):
 
     @classmethod
     def poll(cls, context: bpy.types.Context) -> bool:
-        return context.view_layer.objects.active is not None
+        return is_candidate_object(context)
 
     def execute(self, context: bpy.types.Context) -> Set[int] | Set[str]:
-        if bpy.context.view_layer.objects.active is not None:
+        if context.view_layer.objects.active is not None:
             keyframes = get_object_keyframes(context.view_layer.objects.active)
             if len(keyframes) > 0:
-                frame = bpy.context.scene.frame_current
-                keyframes = [k for k in keyframes if k < frame]
+                keyframes = [
+                    k for k in keyframes if k < bpy.context.scene.frame_current
+                ]
             if len(keyframes) > 0:
                 highest = keyframes[0]
                 for num in keyframes:

stopmagic/operators/skip_frame_backward.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 from typing import Set
 import bpy
-from stopmagic.functions.insert_mesh_keyframe import insert_mesh_keyframe
+from stopmagic.functions import insert_mesh_keyframe, is_candidate_object
 
 
 class SkipFrameBackward(bpy.types.Operator):
@@ -13,7 +13,7 @@ class SkipFrameBackward(bpy.types.Operator):
 
     @classmethod
     def poll(cls, context: bpy.types.Context) -> bool:
-        return context.view_layer.objects.active is not None
+        return is_candidate_object(context)
 
     def execute(self, context: bpy.types.Context) -> Set[int] | Set[str]:
         count = 3

stopmagic/operators/skip_frame_forward.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 import bpy
-from stopmagic.functions.insert_mesh_keyframe import insert_mesh_keyframe
+from stopmagic.functions import insert_mesh_keyframe, is_candidate_object
 from typing import Set
 
 
@@ -13,7 +13,7 @@ class SkipFrameForward(bpy.types.Operator):
 
     @classmethod
     def poll(cls, context: bpy.types.Context) -> bool:
-        return context.view_layer.objects.active is not None
+        return is_candidate_object(context)
 
     def execute(self, context: bpy.types.Context) -> Set[int] | Set[str]:
         count = 3

stopmagic/panel.py

@@ -44,14 +44,19 @@ def draw(self, context: bpy.context):
                 box.label(
                     text="v"
                     + functions.addon_version(StopmagicPanel.bl_info)
-                    + "   >>   "
+                    + "  to  "
                     + addon_remote_version()
                 )
                 box.operator(
                     "stopmagic.upgrade_addon", text="Upgrade Addon", icon="URL"
                 )
                 self.layout.separator()
         # SECTION :: Keyframe Mesh
+        if not functions.is_candidate_object(context):
+            if context.view_layer.objects.active is not None:
+                self.layout.column().label(text="NO ACTIVE MESH OBJECT!!", icon="ERROR")
+            else:
+                self.layout.column().label(text="NO ACTIVE OBJECT!!", icon="ERROR")
         column = self.layout.column()
         column.scale_y = 1.5
         column.operator("object.keyframe_mesh", text="Keyframe Mesh")