blender_change_extreme_points_radius.py

import bpy

bl_info = {
    "name": "Change curve extreme points radius",
    "author": "Alexander Pluzhnikov",
    "version": (1, 0),
    "blender": (2, 80, 0),
    "location": "View3D",
    "description": "Change curve extreme points radius with UI dialog",
    "category": "3D View"
}


class SetRadiusProps(bpy.types.PropertyGroup):
    radius: bpy.props.IntProperty(
        name = "Radius",
        default = 1)


class OT_CurveExtremePointsRadius(bpy.types.Operator):
    bl_label = "Change extreme points radius"
    bl_description = "Change extreme points radius"
    bl_idname = "curve.change_extreme_points_radius"
    
    def execute(self, context):
        splines = self.__get_active_splines()
        props = bpy.context.scene.set_extreme_points_radius

        if (len(splines) == 0):
            self.report({ 'ERROR' }, 'No splines selected')
            return {'CANCELLED'}

        self.__change_radius(splines, props.radius)

        return {'FINISHED'}
    
    def invoke(self, context, event):
        return context.window_manager.invoke_props_dialog(self, width = 200)

    def draw(self, context):
        layout = self.layout
        props = bpy.context.scene.set_extreme_points_radius

        layout.prop(props, "radius")

    def __get_active_splines(self) -> list:
        obj_data = bpy.context.active_object.data
        splines = []

        for spline in obj_data.splines:
            spline_found = False

            for point in spline.bezier_points:
                if spline_found:
                    break

                if point.select_control_point:
                    splines.append(spline)
                    spline_found = True
                    continue
        
        return splines

    def __change_radius(self, splines: list, value: int):
        for spline in splines:
            points_count = len(spline.bezier_points)
            spline.bezier_points[0].radius = value
            spline.bezier_points[points_count - 1].radius = value


def show_change_curve_extreme_points_radius(self, context):
    self.layout.operator("curve.change_extreme_points_radius")


def register():
    bpy.utils.register_class(SetRadiusProps)
    bpy.utils.register_class(OT_CurveExtremePointsRadius)

    bpy.types.Scene.set_extreme_points_radius = bpy.props.PointerProperty(type = SetRadiusProps)
    bpy.types.VIEW3D_MT_edit_curve.append(show_change_curve_extreme_points_radius)


def unregister():
    bpy.utils.unregister_class(SetRadiusProps)
    bpy.utils.unregister_class(OT_CurveExtremePointsRadius)

    bpy.types.VIEW3D_MT_edit_curve.remove(show_change_curve_extreme_points_radius)

    del(bpy.types.Scene.set_extreme_points_radius)


if __name__ == "__main__":
    register()