code for growing search -backup old ops method

utils.py

@@ -133,6 +133,8 @@ def plane_on_bone(bone, arm=None, cam=None, set_rotation=True, mesh=True):
     else:
         ## Use mid bone to better follow movement
         mat.translation = arm.matrix_world @ ((bone.tail + bone.head) / 2) # Mid bone
+    
+    mat_scale = Matrix.Scale(10, 4) # maybe move above mesh condition
 
     if mesh:
         # get/create collection
@@ -155,7 +157,6 @@ def plane_on_bone(bone, arm=None, cam=None, set_rotation=True, mesh=True):
         return plane
 
     plane = plane_coords()
-    mat_scale = Matrix.Scale(10, 4) # maybe move above mesh condition
     return matrix_transform(plane, mat @ mat_scale)
 
 def create_plane(name='Plane', collection=None):
@@ -274,4 +275,63 @@ def get_gp_draw_plane(obj=None):
 
     plane_no.rotate(mat)
     
-    return plane_co, plane_no
+    return plane_co, plane_no
+
+
+## --- Animation
+
+def following_keys(forward=True, all_keys=False) -> list:# -> list[int] | list | None:
+    '''return a lsit of int or an empty list'''
+    direction = 1 if forward else -1
+    cur_frame = bpy.context.scene.frame_current
+    settings = bpy.context.scene.gp_interpo_settings
+    
+    if settings.mode == 'FRAME':
+        if all_keys:
+            scn = bpy.context.scene
+            if forward:
+                limit = scn.frame_preview_end if scn.use_preview_range else scn.frame_end
+            else:
+                limit = scn.frame_preview_start if scn.use_preview_range else scn.frame_start
+            
+            limit += direction # offset by one for limit to be in range
+
+            return list(range(cur_frame, limit, settings.padding * direction))
+
+        else:
+            return [cur_frame + (settings.padding * direction)]
+    
+    elif settings.mode == 'GPKEY':
+        layers = bpy.context.object.data.layers
+        frames = [f.frame_number for l in layers for f in l.frames]
+    
+    elif settings.mode == 'RIGKEY':
+        col = settings.target_collection
+        if not col:
+            col = bpy.context.scene.collection            
+        for arm in [o for o in col.all_objects if o.type == 'ARMATURE']:
+            if not arm.animation_data or not arm.animation_data.action:
+                continue
+            frames = [k.co.x for fc in arm.animation_data.action.fcurves for k in fc.keyframe_points]
+    
+    if not frames:
+        return []
+
+    # Sort frames (invert if looking backward)
+    frames.sort(reversed=not forward)
+
+    if all_keys:
+        frames = list(set(frames))
+        if forward:
+            frame_list = [int(f) for f in frames if f > cur_frame]
+        else:
+            frame_list =  [int(f) for f in frames if f < cur_frame]
+        return frame_list
+
+    if forward:
+        new = next((f for f in frames if f > cur_frame), None)
+    else:
+        new = next((f for f in frames if f < cur_frame), None)
+    if new is None:
+        return []
+    return [int(new)]