auto_walk/OP_setup_curve_path.py

import bpy, re
from . import fn

## step 1 : Create the curve and/or follow path constraint, snap to ground

class AW_OT_create_curve_path(bpy.types.Operator):
    bl_idname = "autowalk.create_curve_path"
    bl_label = "Create Curve"
    bl_description = "Create curve and add follow path constraint"
    bl_options = {"REGISTER", "UNDO"}

    @classmethod
    def poll(cls, context):
        return context.object and context.object.type == 'ARMATURE'

    def execute(self, context):
        # use root (or other specified bone) to find where to put the curve
        prefs = fn.get_addon_prefs()
        ob = context.object
        settings = context.scene.anim_cycle_settings
        bpy.ops.object.mode_set(mode='OBJECT', toggle=False)
        
        root_name = fn.get_root_name(context=context)
        root = ob.pose.bones.get(root_name)
        if not root:
            self.report({'ERROR'}, f'posebone {root_name} not found in armature {ob.name} check addon preferences to change name')
            return {"CANCELLED"}

        ## create curve at bone position
        loc = ob.matrix_world @ root.matrix.to_translation()
        root_axis_vec = fn.get_direction_vector_from_enum(settings.forward_axis)
        
        # get real world direction of the root
        world_forward = (root.matrix @ root_axis_vec) - root.matrix.to_translation()

        curve = fn.generate_curve(location=loc, direction=world_forward.normalized() * 10, name='curve_path', context=context)

        settings.path_to_follow = curve
        
        fn.create_follow_path_constraint(ob, curve)
         
        # refresh evaluation so constraint shows up correctly
        bpy.context.scene.frame_set(bpy.context.scene.frame_current)
        return {"FINISHED"}

class AW_OT_create_follow_path(bpy.types.Operator):
    bl_idname = "autowalk.create_follow_path"
    bl_label = "Create Follow Path Constraint"
    bl_description = "Create follow path targeting curve chosen in dedicated field"
    bl_options = {"REGISTER", "UNDO"}

    @classmethod
    def poll(cls, context):
        return context.object and context.object.type == 'ARMATURE' \
        and context.scene.anim_cycle_settings.path_to_follow

    def execute(self, context):
        ob = context.object
        curve = context.scene.anim_cycle_settings.path_to_follow
        err, const = fn.create_follow_path_constraint(ob, curve)
        if isinstance(err, str):
            self.report({'ERROR'}, err)
            return {"CANCELLED"}
        return {"FINISHED"}

class AW_OT_remove_follow_path(bpy.types.Operator):
    bl_idname = "autowalk.remove_follow_path"
    bl_label = "Remove Follow Path Constraint"
    bl_description = "Remove follow path on target bone"
    bl_options = {"REGISTER", "UNDO"}

    @classmethod
    def poll(cls, context):
        return context.object and context.object.type == 'ARMATURE'

    def execute(self, context):
        ob = context.object
        # curve = context.scene.anim_cycle_settings.path_to_follow
        tgt_bone = fn.get_addon_prefs().tgt_bone
        bone = ob.pose.bones.get(tgt_bone)
        if not bone:
            self.report({'ERROR'}, f'No bone "{tgt_bone}" found')
            return {"CANCELLED"}
        const = next((c for c in bone.constraints if c.type == 'FOLLOW_PATH'), None)
        if not const:
            self.report({'ERROR'}, f'No follow path constraint on "{tgt_bone}" found')
            return {"CANCELLED"}
        
        bone.constraints.remove(const)
        self.report({'INFO'}, f'removed follow_path constraint on bone "{tgt_bone}"')

        # Also remove offset action ? myabe give the choice

        return {"FINISHED"}



class AW_OT_snap_curve_to_ground(bpy.types.Operator):
    bl_idname = "autowalk.snap_curve_to_ground"
    bl_label = "Snap Curve"
    bl_description = "snap curve to ground determine in field"
    bl_options = {"REGISTER", "UNDO"}

    @classmethod
    def poll(cls, context):
        return context.object and context.object.type == 'ARMATURE'

    def execute(self, context):
        err = fn.snap_curve()
        if err:
            self.report({err[0]}, err[1])
            if err[0] == 'ERROR':
                return {"CANCELLED"}
        return {"FINISHED"}

class AW_OT_edit_curve(bpy.types.Operator):
    bl_idname = "autowalk.edit_curve"
    bl_label = "Edit Curve"
    bl_description = "Edit curve used as constraint for foot"
    bl_options = {"REGISTER", "INTERNAL", "UNDO"}

    @classmethod
    def poll(cls, context):
        return context.object and context.object.type == 'ARMATURE'

    def execute(self, context):
        b = context.active_pose_bone
        curve = None
        
        # test with selected bone
        if b and b.constraints:
            curve = next((c.target for c in b.constraints if c.type == 'FOLLOW_PATH' and c.target), None)
        
        # get from 'root' bone
        if not curve:
            curve, _const = fn.get_follow_curve_from_armature(context.object)
            if isinstance(curve, str):
                self.report({curve}, _const)
                if curve == 'ERROR':
                    return {"CANCELLED"}
        
        # set mode to object set curve as active and go Edit
        fn.go_edit_mode(curve)    
        # curve context.mode -> EDIT_CURVE
        
        # Deselect armature object
        b.id_data.select_set(False)
        return {"FINISHED"}

class AW_OT_go_to_object(bpy.types.Operator):
    bl_idname = "autowalk.go_to_object"
    bl_label = "Go To Object"
    bl_description = "Go to object in pose mode"
    bl_options = {"REGISTER", "INTERNAL"}
    
    obj_name : bpy.props.StringProperty(options={'SKIP_SAVE'})

    def execute(self, context):
        obj = context.scene.objects.get(self.obj_name)
        if not obj:
            self.report({'ERROR'}, f'Could not find object {self.obj_name} in scene objects')
            return {"CANCELLED"}
        bpy.ops.object.mode_set(mode='OBJECT', toggle=False)
        ## deselect all armatures (or all objects)
        for ob in context.scene.objects:
            if ob.type == 'ARMATURE':
                ob.select_set(False)
        
        obj.select_set(True)
        context.view_layer.objects.active = obj
        bpy.ops.object.mode_set(mode='POSE', toggle=False)

        self.report({'INFO'}, f'Back to pose mode {obj.name}')
        return {"FINISHED"}

class AW_OT_object_from_curve(bpy.types.Operator):
    bl_idname = "autowalk.object_from_curve"
    bl_label = "Back To Armature"
    bl_description = "Go in armature pose mode from current curve"
    bl_options = {"REGISTER", "INTERNAL", "UNDO"}

    @classmethod
    def poll(cls, context):
        return context.object and context.object.type == 'CURVE'

    def invoke(self, context, event):
        self.armatures = []
        curve = context.object
        for o in context.scene.objects:
            if o.type != 'ARMATURE':
                continue
            for pb in o.pose.bones:
                for c in pb.constraints:
                    if c.type == 'FOLLOW_PATH' and c.target and c.target == curve:
                        self.armatures.append((o, pb))
                        break
        
        if not self.armatures:
            self.report({'ERROR'}, 'No armature using this curve found')
            return {"CANCELLED"}
        
        curve.select_set(False)
        if len(self.armatures) > 1:
            return context.window_manager.invoke_props_popup(self, event) # execute on change

        # set pose mode on only object available
        obj, pb = self.armatures[0]
        bpy.ops.object.mode_set(mode='OBJECT', toggle=False)
        for ob in context.scene.objects:
            if ob.type == 'ARMATURE':
                ob.select_set(False)
        obj.select_set(True)
        context.view_layer.objects.active = obj
        bpy.ops.object.mode_set(mode='POSE', toggle=False)
        self.report({'INFO'}, f'Back to pose mode {obj.name} (constraint on {pb.name})')

        return self.execute(context)

    def draw(self, context):
        layout = self.layout
        for arm, pb in self.armatures:
            layout.operator('autowalk.go_to_object', text=f'{arm.name} ({pb.name})', icon='OUTLINER_OB_ARMATURE').obj_name = arm.name

    def execute(self, context):
        return {"FINISHED"}

classes=(
AW_OT_create_curve_path,
AW_OT_create_follow_path,
AW_OT_remove_follow_path,
AW_OT_snap_curve_to_ground,
AW_OT_edit_curve,
AW_OT_go_to_object,
AW_OT_object_from_curve, # use set_choice_id is used to set an index in object_from_curve pop up menu
)

def register():
    for cls in classes:
        bpy.utils.register_class(cls)

def unregister():
    for cls in reversed(classes):
        bpy.utils.unregister_class(cls)

# if __name__ == "__main__":
#     register()