freecad-cam/Mod/Measure/MeasureCOM.py
2026-02-01 01:59:24 +01:00

157 lines
4.9 KiB
Python

# /***************************************************************************
# * Copyright (c) 2023 David Friedli <david[at]friedli-be.ch> *
# * *
# * This file is part of FreeCAD. *
# * *
# * FreeCAD is free software: you can redistribute it and/or modify it *
# * under the terms of the GNU Lesser General Public License as *
# * published by the Free Software Foundation, either version 2.1 of the *
# * License, or (at your option) any later version. *
# * *
# * FreeCAD is distributed in the hope that it will be useful, but *
# * WITHOUT ANY WARRANTY; without even the implied warranty of *
# * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
# * Lesser General Public License for more details. *
# * *
# * You should have received a copy of the GNU Lesser General Public *
# * License along with FreeCAD. If not, see *
# * <https://www.gnu.org/licenses/>. *
# * *
# **************************************************************************/
import FreeCAD
from FreeCAD import Units, Placement
from UtilsMeasure import MeasureBasePython
from PySide.QtCore import QT_TRANSLATE_NOOP
__title__ = "Measure Center of Mass Object"
__author__ = "David Friedli"
__url__ = "http://www.freecad.org"
"""
The Measure cpp object defines a result and a placement property. The Python measure type
adds it's own specific properties. Once the object is recomputed the parent properties are updated
based on the specific python properties.
We'll need some kind of interface for the measure command which exposes "parseSelection", "isValidSelection" etc.
"""
def makeMeasureCOM(name="CenterOfMass"):
"""makeMeasureCOM(name): make a CenterofMass measurement"""
obj = FreeCAD.ActiveDocument.addObject("Measure::MeasurePython", name)
MeasureCOM(obj)
return obj
class MeasureCOM(MeasureBasePython):
"The MeasureCOM object"
def __init__(self, obj):
obj.Proxy = self
obj.addProperty(
"App::PropertyLinkSubGlobal",
"Element",
"",
QT_TRANSLATE_NOOP("App::Property", "Element to measure"),
)
obj.addProperty(
"App::PropertyPosition",
"Result",
"",
QT_TRANSLATE_NOOP("App::PropertyVector", "The result location"),
)
@classmethod
def isValidSelection(cls, selection):
if not len(selection) == 1:
return False
element = selection[0]
ob = element["object"]
subName = element["subName"]
if not ob:
return
sub = ob.getSubObject(subName)
if not sub:
return
if not hasattr(sub, "CenterOfMass"):
return
return True
@classmethod
def isPrioritySelection(cls, selection):
return False
@classmethod
def getInputProps(cls):
return ("Element",)
def getSubject(self, obj):
if not obj:
return ()
element = obj.Element
if not element:
return ()
ob = element[0]
if not ob:
return ()
return (ob,)
def parseSelection(self, obj, selection):
item = selection[0]
o = item["object"]
obj.Element = (o, item["subName"])
def getResultString(self, obj):
values = [Units.Quantity(v, Units.Length).getUserPreferred()[0] for v in obj.Result]
return "COM\nX: {}\nY: {}\nZ: {}".format(*values)
def execute(self, obj):
element = obj.Element
if not element:
return
ob = element[0]
subElements = element[1]
if subElements:
subName = subElements[0]
sub = ob.getSubObject(subName)
if not sub or not hasattr(sub, "CenterOfMass"):
return
com = sub.CenterOfMass
else:
# Get Center of Mass of the object
if not hasattr(ob, "Shape"):
return
shape = ob.Shape
if not hasattr(shape, "CenterOfMass"):
return
com = shape.CenterOfMass
obj.Result = com
placement = Placement()
placement.Base = com
obj.Placement = placement
def onChanged(self, obj, prop):
"""Do something when a property has changed"""
if prop == "Element":
self.execute(obj)