Scripted objects/cs: Difference between revisions

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{{docnav|PySide|Embedding FreeCAD}}


{{Docnav
|[[Topological_data_scripting|Topological data scripting]]
|[[Scenegraph|Scenegraph]]
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==Introduction==

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Kromě standardních objektových typů jako jsou anotace, sítě a díly, nabízí FreeCAD skvělou možnost vytváření objektů 100% vytvořených skritpy Pythonu, které se nazývají Pythonovské objekty. Tyto objekty se chovají stejně jako jiné objekty FreeCADu a jsou ukládány a načítány automaticky při ukládání a otevírání souboru.
Kromě standardních objektových typů jako jsou anotace, sítě a díly, nabízí FreeCAD skvělou možnost vytváření objektů 100% vytvořených skritpy Pythonu, které se nazývají Pythonovské objekty. Tyto objekty se chovají stejně jako jiné objekty FreeCADu a jsou ukládány a načítány automaticky při ukládání a otevírání souboru.
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Je třeba pochopit jednu zvláštnost, tyto objekty jsou ukládány ve FcStd souborech FreeCADu s pythonovským modulem [http://docs.python.org/2/library/json.html json]. Tento modul převede pythonovský objekt do řetězce, který je pak možno uložit v souboru. Při načítání naopak tento modul použije uložený řetězec ke znovuvytvoření původního objektu, při tom musí mít přístup ke zdrojovému kódu, který vytvoří objekt. To znamená, že když uložíte takový uživatelský objekt a pak jej otevíráte na počítači kde není pythonovský kód, tak nebude tento objekt vytvořen. Když tedy distribuujete takový objekt někomu jinému, musíte společně s ním distribuovat i pythonovský skript, který objekt vytváří.
Je třeba pochopit jednu zvláštnost, tyto objekty jsou ukládány ve FcStd souborech FreeCADu s pythonovským modulem [http://docs.python.org/2/library/json.html json]. Tento modul převede pythonovský objekt do řetězce, který je pak možno uložit v souboru. Při načítání naopak tento modul použije uložený řetězec ke znovuvytvoření původního objektu, při tom musí mít přístup ke zdrojovému kódu, který vytvoří objekt. To znamená, že když uložíte takový uživatelský objekt a pak jej otevíráte na počítači kde není pythonovský kód, tak nebude tento objekt vytvořen. Když tedy distribuujete takový objekt někomu jinému, musíte společně s ním distribuovat i pythonovský skript, který objekt vytváří.
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'''Note''': It is possible to pack python code inside a FreeCAD file using json serializing with an App::PropertyPythonObject, but that code can never directly be run, and therefore has little use for our purpose here.

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Pythonovský objekt má stejné pravidlo jako FreeCAD: Aplikace a GUI jsou odděleny do samostatných částí. Aplikační část, Document Object, definuje konstrukci objektu, zatímco část GUI, View Provider Object, definuje jak bude objekt zobrazen na displeji. View Provider Object, stejně jako další GUI objekty FreeCADu je dostupný pouze když FreeCAD běží se svým vlastním GUI. Pro vytvoření objektu je použitelných několik vlastností a metod. Vlastnosti musejí být některé z předdefinovaných typových vlastností, které nabízí FreeCAD a zobrazují se v dialogovém okně vlastností, takže mohou být uživatelem upravovány. Tímto způsobem jsou Pythonovské objekty správně a zcela parametrizovány. Můžete samostatně definovat vlastnosti objektu a jeho zobrazovacího objektu.
Pythonovský objekt má stejné pravidlo jako FreeCAD: Aplikace a GUI jsou odděleny do samostatných částí. Aplikační část, Document Object, definuje konstrukci objektu, zatímco část GUI, View Provider Object, definuje jak bude objekt zobrazen na displeji. View Provider Object, stejně jako další GUI objekty FreeCADu je dostupný pouze když FreeCAD běží se svým vlastním GUI. Pro vytvoření objektu je použitelných několik vlastností a metod. Vlastnosti musejí být některé z předdefinovaných typových vlastností, které nabízí FreeCAD a zobrazují se v dialogovém okně vlastností, takže mohou být uživatelem upravovány. Tímto způsobem jsou Pythonovské objekty správně a zcela parametrizovány. Můžete samostatně definovat vlastnosti objektu a jeho zobrazovacího objektu.
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== Basic example ==
'''Informace:''' Ve starších verzích jsme používali pythonovský modul [http://docs.python.org/release/2.5/lib/module-cPickle.html cPickle]. Nicméně tento modul spouští libovolný kód a to může být bezpečnostní problém. Proto jsme přešli k pythonovskému modulu json.


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Následující příklad najdete v souboru [http://free-cad.svn.sourceforge.net/viewvc/free-cad/trunk/src/Mod/TemplatePyMod/FeaturePython.py?view=markup src/Mod/TemplatePyMod/FeaturePython.py], společně s několika dalšími příklady:
Následující příklad najdete v souboru [http://free-cad.svn.sourceforge.net/viewvc/free-cad/trunk/src/Mod/TemplatePyMod/FeaturePython.py?view=markup src/Mod/TemplatePyMod/FeaturePython.py], společně s několika dalšími příklady:
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{{Code|code=
{{Code|code=
'''Examples for a feature class and its view provider.'''
'''Examples for a feature class and its view provider.'''
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obj.addProperty("App::PropertyLength","Height","Box", "Height of the box").Height=1.0
obj.addProperty("App::PropertyLength","Height","Box", "Height of the box").Height=1.0
obj.Proxy = self
obj.Proxy = self

def onChanged(self, fp, prop):
def onChanged(self, fp, prop):
'''Do something when a property has changed'''
'''Do something when a property has changed'''
FreeCAD.Console.PrintMessage("Change property: " + str(prop) + "\n")
FreeCAD.Console.PrintMessage("Change property: " + str(prop) + "\n")

def execute(self, fp):
def execute(self, fp):
'''Do something when doing a recomputation, this method is mandatory'''
'''Do something when doing a recomputation, this method is mandatory'''
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obj.addProperty("App::PropertyColor","Color","Box","Color of the box").Color=(1.0,0.0,0.0)
obj.addProperty("App::PropertyColor","Color","Box","Color of the box").Color=(1.0,0.0,0.0)
obj.Proxy = self
obj.Proxy = self

def attach(self, obj):
def attach(self, obj):
'''Setup the scene sub-graph of the view provider, this method is mandatory'''
'''Setup the scene sub-graph of the view provider, this method is mandatory'''
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self.scale = coin.SoScale()
self.scale = coin.SoScale()
self.color = coin.SoBaseColor()
self.color = coin.SoBaseColor()

data=coin.SoCube()
data=coin.SoCube()
self.shaded.addChild(self.scale)
self.shaded.addChild(self.scale)
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obj.addDisplayMode(self.wireframe,"Wireframe");
obj.addDisplayMode(self.wireframe,"Wireframe");
self.onChanged(obj,"Color")
self.onChanged(obj,"Color")

def updateData(self, fp, prop):
def updateData(self, fp, prop):
'''If a property of the handled feature has changed we have the chance to handle this here'''
'''If a property of the handled feature has changed we have the chance to handle this here'''
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self.scale.scaleFactor.setValue(float(l),float(w),float(h))
self.scale.scaleFactor.setValue(float(l),float(w),float(h))
pass
pass

def getDisplayModes(self,obj):
def getDisplayModes(self,obj):
'''Return a list of display modes.'''
'''Return a list of display modes.'''
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modes.append("Wireframe")
modes.append("Wireframe")
return modes
return modes

def getDefaultDisplayMode(self):
def getDefaultDisplayMode(self):
'''Return the name of the default display mode. It must be defined in getDisplayModes.'''
'''Return the name of the default display mode. It must be defined in getDisplayModes.'''
return "Shaded"
return "Shaded"

def setDisplayMode(self,mode):
def setDisplayMode(self,mode):
'''Map the display mode defined in attach with those defined in getDisplayModes.\
'''Map the display mode defined in attach with those defined in getDisplayModes.\
Since they have the same names nothing needs to be done. This method is optional'''
Since they have the same names nothing needs to be done. This method is optional'''
return mode
return mode

def onChanged(self, vp, prop):
def onChanged(self, vp, prop):
'''Here we can do something when a single property got changed'''
'''Here we can do something when a single property got changed'''
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c = vp.getPropertyByName("Color")
c = vp.getPropertyByName("Color")
self.color.rgb.setValue(c[0],c[1],c[2])
self.color.rgb.setValue(c[0],c[1],c[2])

def getIcon(self):
def getIcon(self):
'''Return the icon in XPM format which will appear in the tree view. This method is\
'''Return the icon in XPM format which will appear in the tree view. This method is\
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" ####### "};
" ####### "};
"""
"""

def __getstate__(self):
def __getstate__(self):
'''When saving the document this object gets stored using Python's json module.\
'''When saving the document this object gets stored using Python's json module.\
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to return a tuple of all serializable objects or None.'''
to return a tuple of all serializable objects or None.'''
return None
return None

def __setstate__(self,state):
def __setstate__(self,state):
'''When restoring the serialized object from document we have the chance to set some internals here.\
'''When restoring the serialized object from document we have the chance to set some internals here.\
Since no data were serialized nothing needs to be done here.'''
Since no data were serialized nothing needs to be done here.'''
return None
return None



def makeBox():
def makeBox():
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makeBox()
makeBox()

}}
}}


=== Things to note ===

If your object relies on being recomputed as soon as it is created, you must do this manually in the {{incode|__init__}} function as it is not called automatically. This example does not require it because the {{incode|onChanged}} method of the {{incode|Box}} class has the same effect as the {{incode|execute}} function, but the examples below rely on being recomputed before anything is displayed in the 3D view. In the examples, this is done manually with {{incode|ActiveDocument.recompute()}} but in more complex scenarios you need to decide where to recompute either the whole document or the FeaturePython object.

This example produces a number of exception stack traces in the report view window. This is because the {{incode|onChanged}} method of the {{incode|Box}} class is called each time a property is added in {{incode|__init__}}. When the first one is added, the Width and Height properties don't exist yet and so the attempt to access them fails.

An explanation of {{incode|__getstate__}} and {{incode|__setstate__}} is in the forum thread [https://forum.freecadweb.org/viewtopic.php?f=18&t=44009&start=10#p377892 obj.Proxy.Type is a dict, not a string].

== Available methods ==

See [[FeaturePython_methods|FeaturePython methods]] for the complete reference.

== Available properties ==

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== Dostupné vlastnosti ==
== Dostupné vlastnosti ==
Vlastnosti jsou skutečné základní kameny pythonovských objektů. Jejich prostřednictvím je uživatel schopen pracovat s objektem. Po vytvoření Pythonovského objektu v dokumentu ( obj=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Box") ), obdržíte seznam dostupných vlastností zadáním:
Vlastnosti jsou skutečné základní kameny pythonovských objektů. Jejich prostřednictvím je uživatel schopen pracovat s objektem. Po vytvoření Pythonovského objektu v dokumentu ( obj=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Box") ), obdržíte seznam dostupných vlastností zadáním:
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{{Code|code=
{{Code|code=
obj.supportedProperties()
obj.supportedProperties()
}}
}}

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Dostanete seznam dostupných vlastností:
Dostanete seznam dostupných vlastností:
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{{Code|code=

App::PropertyBool
* [[FeaturePython Custom Properties#App::PropertyAcceleration|App::PropertyAcceleration]]
App::PropertyBoolList
* [[FeaturePython Custom Properties#App::PropertyAngle|App::PropertyAngle]]
App::PropertyFloat
* [[FeaturePython Custom Properties#App::PropertyArea|App::PropertyArea]]
App::PropertyFloatList
* [[FeaturePython Custom Properties#App::PropertyBool|App::PropertyBool]]
App::PropertyFloatConstraint
* [[FeaturePython Custom Properties#App::PropertyBoolList|App::PropertyBoolList]]
App::PropertyQuantity
* [[FeaturePython Custom Properties#App::PropertyColor|App::PropertyColor]]
App::PropertyQuantityConstraint
* [[FeaturePython Custom Properties#App::PropertyColorList|App::PropertyColorList]]
App::PropertyAngle
* [[FeaturePython Custom Properties#App::PropertyDirection|App::PropertyDirection]]
App::PropertyDistance
* [[FeaturePython Custom Properties#App::PropertyDistance|App::PropertyDistance]]
App::PropertyLength
* [[FeaturePython Custom Properties#App::PropertyEnumeration|App::PropertyEnumeration]]
App::PropertySpeed
* [[FeaturePython Custom Properties#App::PropertyExpressionEngine|App::PropertyExpressionEngine]]
App::PropertyAcceleration
* [[FeaturePython Custom Properties#App::PropertyFile|App::PropertyFile]]
App::PropertyForce
* [[FeaturePython Custom Properties#App::PropertyFileIncluded|App::PropertyFileIncluded]]
App::PropertyPressure
* [[FeaturePython Custom Properties#App::PropertyFloat|App::PropertyFloat]]
App::PropertyInteger
* [[FeaturePython Custom Properties#App::PropertyFloatConstraint|App::PropertyFloatConstraint]]
App::PropertyIntegerConstraint
* [[FeaturePython Custom Properties#App::PropertyFloatList|App::PropertyFloatList]]
App::PropertyPercent
* [[FeaturePython Custom Properties#App::PropertyFont|App::PropertyFont]]
App::PropertyEnumeration
* [[FeaturePython Custom Properties#App::PropertyForce|App::PropertyForce]]
App::PropertyIntegerList
* [[FeaturePython Custom Properties#App::PropertyFrequency|App::PropertyFrequency]]
App::PropertyIntegerSet
* [[FeaturePython Custom Properties#App::PropertyInteger|App::PropertyInteger]]
App::PropertyMap
* [[FeaturePython Custom Properties#App::PropertyIntegerConstraint|App::PropertyIntegerConstraint]]
App::PropertyString
* [[FeaturePython Custom Properties#App::PropertyIntegerList|App::PropertyIntegerList]]
App::PropertyUUID
* [[FeaturePython Custom Properties#App::PropertyIntegerSet|App::PropertyIntegerSet]]
App::PropertyFont
* [[FeaturePython Custom Properties#App::PropertyLength|App::PropertyLength]]
App::PropertyStringList
App::PropertyLink
* [[FeaturePython Custom Properties#App::PropertyLink|App::PropertyLink]]
* [[FeaturePython Custom Properties#App::PropertyLinkChild|App::PropertyLinkChild]]
App::PropertyLinkSub
* [[FeaturePython Custom Properties#App::PropertyLinkGlobal|App::PropertyLinkGlobal]]
App::PropertyLinkList
* [[FeaturePython Custom Properties#App::PropertyLinkHidden|App::PropertyLinkHidden]]
App::PropertyLinkSubList
* [[FeaturePython Custom Properties#App::PropertyLinkList|App::PropertyLinkList]]
App::PropertyMatrix
* [[FeaturePython Custom Properties#App::PropertyLinkListChild|App::PropertyLinkListChild]]
App::PropertyVector
* [[FeaturePython Custom Properties#App::PropertyLinkListGlobal|App::PropertyLinkListGlobal]]
App::PropertyVectorList
* [[FeaturePython Custom Properties#App::PropertyLinkListHidden|App::PropertyLinkListHidden]]
App::PropertyPlacement
* [[FeaturePython Custom Properties#App::PropertyLinkSub|App::PropertyLinkSub]]
App::PropertyPlacementLink
* [[FeaturePython Custom Properties#App::PropertyLinkSubChild|App::PropertyLinkSubChild]]
App::PropertyPlacementList
* [[FeaturePython Custom Properties#App::PropertyLinkSubGlobal|App::PropertyLinkSubGlobal]]
App::PropertyColor
* [[FeaturePython Custom Properties#App::PropertyLinkSubHidden|App::PropertyLinkSubHidden]]
App::PropertyColorList
* [[FeaturePython Custom Properties#App::PropertyLinkSubList|App::PropertyLinkSubList]]
App::PropertyMaterial
* [[FeaturePython Custom Properties#App::PropertyLinkSubListChild|App::PropertyLinkSubListChild]]
App::PropertyPath
* [[FeaturePython Custom Properties#App::PropertyLinkSubListGlobal|App::PropertyLinkSubListGlobal]]
App::PropertyFile
* [[FeaturePython Custom Properties#App::PropertyLinkSubListHidden|App::PropertyLinkSubListHidden]]
App::PropertyFileIncluded
* [[FeaturePython Custom Properties#App::PropertyMap|App::PropertyMap]]
App::PropertyPythonObject
* [[FeaturePython Custom Properties#App::PropertyMaterial|App::PropertyMaterial]]
Part::PropertyPartShape
* [[FeaturePython Custom Properties#App::PropertyMaterialList|App::PropertyMaterialList]]
Part::PropertyGeometryList
* [[FeaturePython Custom Properties#App::PropertyMatrix|App::PropertyMatrix]]
Part::PropertyShapeHistory
* [[FeaturePython Custom Properties#App::PropertyPath|App::PropertyPath]]
Part::PropertyFilletEdges
* [[FeaturePython Custom Properties#App::PropertyPercent|App::PropertyPercent]]
Sketcher::PropertyConstraintList
* [[FeaturePython Custom Properties#App::PropertyPersistentObject|App::PropertyPersistentObject]]
}}
* [[FeaturePython Custom Properties#App::PropertyPlacement|App::PropertyPlacement]]
* [[FeaturePython Custom Properties#App::PropertyPlacementLink|App::PropertyPlacementLink]]
* [[FeaturePython Custom Properties#App::PropertyPlacementList|App::PropertyPlacementList]]
* [[FeaturePython Custom Properties#App::PropertyPosition|App::PropertyPosition]]
* [[FeaturePython Custom Properties#App::PropertyPrecision|App::PropertyPrecision]]
* [[FeaturePython Custom Properties#App::PropertyPressure|App::PropertyPressure]]
* [[FeaturePython Custom Properties#App::PropertyPythonObject|App::PropertyPythonObject]]
* [[FeaturePython Custom Properties#App::PropertyQuantity|App::PropertyQuantity]]
* [[FeaturePython Custom Properties#App::PropertyQuantityConstraint|App::PropertyQuantityConstraint]]
* [[FeaturePython Custom Properties#App::PropertySpeed|App::PropertySpeed]]
* [[FeaturePython Custom Properties#App::PropertyString|App::PropertyString]]
* [[FeaturePython Custom Properties#App::PropertyStringList|App::PropertyStringList]]
* [[FeaturePython Custom Properties#App::PropertyUUID|App::PropertyUUID]]
* [[FeaturePython Custom Properties#App::PropertyVacuumPermittivity|App::PropertyVacuumPermittivity]]
* [[FeaturePython Custom Properties#App::PropertyVector|App::PropertyVector]]
* [[FeaturePython Custom Properties#App::PropertyVectorDistance|App::PropertyVectorDistance]]
* [[FeaturePython Custom Properties#App::PropertyVectorList|App::PropertyVectorList]]
* [[FeaturePython Custom Properties#App::PropertyVolume|App::PropertyVolume]]
* [[FeaturePython Custom Properties#App::PropertyXLink|App::PropertyXLink]]
* [[FeaturePython Custom Properties#App::PropertyXLinkList|App::PropertyXLinkList]]
* [[FeaturePython Custom Properties#App::PropertyXLinkSub|App::PropertyXLinkSub]]
* [[FeaturePython Custom Properties#App::PropertyXLinkSubList|App::PropertyXLinkSubList]]
* [[FeaturePython Custom Properties#Mesh::PropertyCurvatureList|Mesh::PropertyCurvatureList]]
* [[FeaturePython Custom Properties#Mesh::PropertyMeshKernel|Mesh::PropertyMeshKernel]]
* [[FeaturePython Custom Properties#Mesh::PropertyNormalList|Mesh::PropertyNormalList]]
* [[FeaturePython Custom Properties#Part::PropertyFilletEdges|Part::PropertyFilletEdges]]
* [[FeaturePython Custom Properties#Part::PropertyGeometryList|Part::PropertyGeometryList]]
* [[FeaturePython Custom Properties#Part::PropertyPartShape|Part::PropertyPartShape]]
* [[FeaturePython Custom Properties#Part::PropertyShapeHistory|Part::PropertyShapeHistory]]
* [[FeaturePython Custom Properties#Path::PropertyPath|Path::PropertyPath]]
* [[FeaturePython Custom Properties#Path::PropertyTool|Path::PropertyTool]]
* [[FeaturePython Custom Properties#Path::PropertyTooltable|Path::PropertyTooltable]]
* [[FeaturePython Custom Properties#Sketcher::PropertyConstraintList|Sketcher::PropertyConstraintList]]
* [[FeaturePython Custom Properties#Spreadsheet::PropertyColumnWidths|Spreadsheet::PropertyColumnWidths]]
* [[FeaturePython Custom Properties#Spreadsheet::PropertyRowHeights|Spreadsheet::PropertyRowHeights]]
* [[FeaturePython Custom Properties#Spreadsheet::PropertySheet|Spreadsheet::PropertySheet]]
* [[FeaturePython Custom Properties#Spreadsheet::PropertySpreadsheetQuantity|Spreadsheet::PropertySpreadsheetQuantity]]
* [[FeaturePython Custom Properties#TechDraw::PropertyCenterLineList|TechDraw::PropertyCenterLineList]]
* [[FeaturePython Custom Properties#TechDraw::PropertyCosmeticEdgeList|TechDraw::PropertyCosmeticEdgeList]]
* [[FeaturePython Custom Properties#TechDraw::PropertyCosmeticVertexList|TechDraw::PropertyCosmeticVertexList]]
* [[FeaturePython Custom Properties#TechDraw::PropertyGeomFormatList|TechDraw::PropertyGeomFormatList]]


Když do uživatelského objektu přidáváte vlastnosti dejte pozor na::
Když do uživatelského objektu přidáváte vlastnosti dejte pozor na::
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}}
}}


==Property Type==

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==Typ vlastnosti==
==Typ vlastnosti==
Standardně mohou být vlastnosti upravovány. Je ale možné nastavit vlastnosti pouze ke čtení, třeba když má jenom zobrazovat výstup výsledku metody. Je možné také vlastnost skrýt.
Standardně mohou být vlastnosti upravovány. Je ale možné nastavit vlastnosti pouze ke čtení, třeba když má jenom zobrazovat výstup výsledku metody. Je možné také vlastnost skrýt.
Typ vlastnosti může být nastaven použitím
Typ vlastnosti může být nastaven použitím
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{{Code|code=
{{Code|code=
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16 -- Prop_NoRecompute, Modified property doesn't touch its container for recompute
16 -- Prop_NoRecompute, Modified property doesn't touch its container for recompute


You can find these different property types defined in the [https://github.com/FreeCAD/FreeCAD/blob/master/src/App/PropertyContainer.h source code C++ header for PropertyContainer].


== Other more complex example ==
You can find these different property types defined in the [https://github.com/FreeCAD/FreeCAD/blob/master/src/App/PropertyContainer.h source code C++ header for PropertyContainer]


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== Další složitější příklady ==
== Další složitější příklady ==
Tento příklad používá [[Part Module/cs|Modul Díl]] k vytvoření osmistěnu a potom vytvoří pomocí Pivy jeho reprezentaci v Coinu.
Tento příklad používá [[Part_Workbench/cs|Modul Díl]] k vytvoření osmistěnu a potom vytvoří pomocí Pivy jeho reprezentaci v Coinu.
</div>
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v5 = FreeCAD.Vector(fp.Length/2,fp.Width/2,fp.Height/2)
v5 = FreeCAD.Vector(fp.Length/2,fp.Width/2,fp.Height/2)
v6 = FreeCAD.Vector(fp.Length/2,fp.Width/2,-fp.Height/2)
v6 = FreeCAD.Vector(fp.Length/2,fp.Width/2,-fp.Height/2)

# Make the wires/faces
# Make the wires/faces
f1 = self.make_face(v1,v2,v5)
f1 = self.make_face(v1,v2,v5)
Line 317: Line 396:


self.data=coin.SoCoordinate3()
self.data=coin.SoCoordinate3()
self.face=coin.SoIndexedLineSet()
self.face=coin.SoIndexedFaceSet()


self.shaded.addChild(self.scale)
self.shaded.addChild(self.scale)
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self.data.point.set1Value(cnt,i.X,i.Y,i.Z)
self.data.point.set1Value(cnt,i.X,i.Y,i.Z)
cnt=cnt+1
cnt=cnt+1

self.face.coordIndex.set1Value(0,0)
self.face.coordIndex.set1Value(0,0)
self.face.coordIndex.set1Value(1,1)
self.face.coordIndex.set1Value(1,1)
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}}
}}


== Making objects selectable ==

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== Zpřístupnění objektu k výběru ==
== Zpřístupnění objektu k výběru ==
Chcete-li aby bylo možné objekt vybrat nebo alespoň jeho část, kliknutím na něj v pohledu, musíte včlenit jeho Coin konstrukci do uzlu SoFCSelection. Má-li objekt komplexní zobrazení s widgety, anotacemi atd., můžete chtít včlenit do SoFCSelection pouze nějakou část. Všechno co je SoFCSelection je průběžně skenováno FreeCADem pro detekci výběru/předvýběru, takže je rozumné nepřetěžovat jej zbytečným skenováním. Tady je co byste měli zahrnout do self.face z příkladu nahoře.
Chcete-li aby bylo možné objekt vybrat nebo alespoň jeho část, kliknutím na něj v pohledu, musíte včlenit jeho Coin konstrukci do uzlu SoFCSelection. Má-li objekt komplexní zobrazení s widgety, anotacemi atd., můžete chtít včlenit do SoFCSelection pouze nějakou část. Všechno co je SoFCSelection je průběžně skenováno FreeCADem pro detekci výběru/předvýběru, takže je rozumné nepřetěžovat jej zbytečným skenováním. Tady je co byste měli zahrnout do self.face z příkladu nahoře.
</div>

Once the parts of the scenegraph that are to be selectable are inside SoFCSelection nodes, you then need to provide two methods to handle the selection path. The selection path can take the form of a string giving the names of each element in the path, or of an array of scenegraph objects. The two methods you provide are {{incode|getDetailPath}}, which converts from a string path to an array of scenegraph objects, and {{incode|getElementPicked}}, which takes an element which has been clicked on in the scenegraph and returns its string name (note, not its string path).

Here is the molecule example above, adapted to make the elements of the molecule selectable:


{{Code|code=
{{Code|code=
class Molecule:
selectionNode = coin.SoType.fromName("SoFCSelection").createInstance()
def __init__(self, obj):
selectionNode.documentName.setValue(FreeCAD.ActiveDocument.Name)
''' Add two point properties '''
selectionNode.objectName.setValue(obj.Object.Name) # here obj is the ViewObject, we need its associated App Object
obj.addProperty("App::PropertyVector","p1","Line","Start point")
selectionNode.subElementName.setValue("Face")
obj.addProperty("App::PropertyVector","p2","Line","End point").p2=FreeCAD.Vector(5,0,0)
selectNode.addChild(self.face)

...
obj.Proxy = self
self.shaded.addChild(selectionNode)

self.wireframe.addChild(selectionNode)
def onChanged(self, fp, prop):
if prop == "p1" or prop == "p2":
''' Print the name of the property that has changed '''
fp.Shape = Part.makeLine(fp.p1,fp.p2)

def execute(self, fp):
''' Print a short message when doing a recomputation, this method is mandatory '''
fp.Shape = Part.makeLine(fp.p1,fp.p2)

class ViewProviderMolecule:
def __init__(self, obj):
''' Set this object to the proxy object of the actual view provider '''
obj.Proxy = self
self.ViewObject = obj
sep1=coin.SoSeparator()
sel1 = coin.SoType.fromName('SoFCSelection').createInstance()
# sel1.policy.setValue(coin.SoSelection.SHIFT)
sel1.ref()
sep1.addChild(sel1)
self.trl1=coin.SoTranslation()
sel1.addChild(self.trl1)
sel1.addChild(coin.SoSphere())
sep2=coin.SoSeparator()
sel2 = coin.SoType.fromName('SoFCSelection').createInstance()
sel2.ref()
sep2.addChild(sel2)
self.trl2=coin.SoTranslation()
sel2.addChild(self.trl2)
sel2.addChild(coin.SoSphere())
obj.RootNode.addChild(sep1)
obj.RootNode.addChild(sep2)
self.updateData(obj.Object, 'p2')
self.sel1 = sel1
self.sel2 = sel2

def getDetailPath(self, subname, path, append):
vobj = self.ViewObject
if append:
path.append(vobj.RootNode)
path.append(vobj.SwitchNode)

mode = vobj.SwitchNode.whichChild.getValue()
if mode >= 0:
mode = vobj.SwitchNode.getChild(mode)
path.append(mode)
sub = Part.splitSubname(subname)[-1]
if sub == 'Atom1':
path.append(self.sel1)
elif sub == 'Atom2':
path.append(self.sel2)
else:
path.append(mode.getChild(0))
return True

def getElementPicked(self, pp):
path = pp.getPath()
if path.findNode(self.sel1) >= 0:
return 'Atom1'
if path.findNode(self.sel2) >= 0:
return 'Atom2'
raise NotImplementedError

def updateData(self, fp, prop):
"If a property of the handled feature has changed we have the chance to handle this here"
# fp is the handled feature, prop is the name of the property that has changed
if prop == "p1":
p = fp.getPropertyByName("p1")
self.trl1.translation=(p.x,p.y,p.z)
elif prop == "p2":
p = fp.getPropertyByName("p2")
self.trl2.translation=(p.x,p.y,p.z)

def __getstate__(self):
return None

def __setstate__(self,state):
return None

def makeMolecule():
FreeCAD.newDocument()
a=FreeCAD.ActiveDocument.addObject("Part::FeaturePython","Molecule")
Molecule(a)
ViewProviderMolecule(a.ViewObject)
FreeCAD.ActiveDocument.recompute()
}}
}}


== Working with simple shapes ==
Jednoduše vytvoříte uzel SoFCSelection, potom přidáte konstrukční uzly a potom přidáte hlavní uzel misto přímého přidávání konstrukčních uzlů.


<div class="mw-translate-fuzzy">
== Práce s jednoduchými tvary ==
== Práce s jednoduchými tvary ==
Jestliže z parametrického objektu vychází jednoduchý tvar, není nutné používat zobrazovací objekt. Tvar bude zobrazován použitím standardního zobrazování tvarů ve FreeCADu.
Jestliže z parametrického objektu vychází jednoduchý tvar, není nutné používat zobrazovací objekt. Tvar bude zobrazován použitím standardního zobrazování tvarů ve FreeCADu.
</div>


{{Code|code=
{{Code|code=
Line 506: Line 679:
obj.addProperty("App::PropertyVector","p2","Line","End point").p2=FreeCAD.Vector(100,0,0)
obj.addProperty("App::PropertyVector","p2","Line","End point").p2=FreeCAD.Vector(100,0,0)
obj.Proxy = self
obj.Proxy = self

def execute(self, fp):
def execute(self, fp):
'''"Print a short message when doing a recomputation, this method is mandatory" '''
'''"Print a short message when doing a recomputation, this method is mandatory" '''
Line 526: Line 699:
}}
}}


== Scenegraph Structure ==
<div class="mw-translate-fuzzy">
{{docnav/cs|[[PySide/cs|PySide]]|[[Embedding FreeCAD/cs|Vkládání FreeCADu]]}}
</div>


You may have noticed that the examples above construct their scenegraphs in slightly different ways. Some use {{incode|obj.addDisplayMode(node, "modename")}} while others use {{incode|obj.SwitchNode.getChild(x).addChild(y)}}.
- [http://forum.freecadweb.org/viewtopic.php?f=22&t=13740 Python object attributes lost at load]


Each feature in a FreeCAD document is based the following scenegraph structure:
- [http://forum.freecadweb.org/viewtopic.php?t=12139 New FeaturePython is grey]


{{Code|code=
- [https://forum.freecadweb.org/viewtopic.php?f=18&t=13460&start=20#p109709 Eigenmode frequency always 0?]
RootNode
\- SwitchNode
\- Shaded
- Wireframe
- etc
}}


The {{incode|SwitchNode}} displays only one of its children, depending on which display mode is selection in FreeCAD.
- [https://forum.freecadweb.org/viewtopic.php?f=22&t=21330 how to implement python feature's setEdit properly?]


The examples which use {{incode|addDisplayMode}} are constructing their scenegraphs solely out of coin3d scenegraph elements. Under the covers, {{incode|addDisplayMode}} adds a new child to the {{incode|SwitchNode}}; the name of that node will match the display mode it was passed.
In addition to the examples presented here have a look at FreeCAD source code [https://github.com/FreeCAD/FreeCAD/blob/master/src/Mod/TemplatePyMod/FeaturePython.py src/Mod/TemplatePyMod/FeaturePython.py] for more examples.


The examples which use {{incode|SwitchNode.getChild(x).addChild}} also construct part of their geometry using functions from the Part workbench, such as {{incode|1=fp.Shape = Part.makeLine(fp.p1,fp.p2)}}. This constructs the different display mode scenegraphs under the {{incode|SwitchNode}}; when we later come to add coin3d elements to the scenegraph, we need to add them to the existing display mode scenegraphs using {{incode|addChild}} rather than creating a new child of the {{incode|SwitchNode}}.
{{docnav|PySide|Embedding FreeCAD}}


When using {{incode|addDisplayMode()}} to add geometry to the scenegraph, each display mode should have its own node which is passed to {{incode|addDisplayMode()}}; don't reuse the same node for this. Doing so will confuse the selection mechanism. It's okay if each display mode's node has the same geometry nodes added below it, just the root of each display mode needs to be distinct.
{{Userdocnavi}}

Here is the above molecule example, adapted to be drawn only with Coin3D scenegraph objects instead of using objects from the Part workbench:

{{Code|code=
import Part
from pivy import coin

class Molecule:
def __init__(self, obj):
''' Add two point properties '''
obj.addProperty("App::PropertyVector","p1","Line","Start point")
obj.addProperty("App::PropertyVector","p2","Line","End point").p2=FreeCAD.Vector(5,0,0)

obj.Proxy = self

def onChanged(self, fp, prop):
pass

def execute(self, fp):
''' Print a short message when doing a recomputation, this method is mandatory '''
pass

class ViewProviderMolecule:
def __init__(self, obj):
''' Set this object to the proxy object of the actual view provider '''
self.constructed = False
obj.Proxy = self
self.ViewObject = obj

def attach(self, obj):
material = coin.SoMaterial()
material.diffuseColor = (1.0, 0.0, 0.0)
material.emissiveColor = (1.0, 0.0, 0.0)
drawStyle = coin.SoDrawStyle()
drawStyle.pointSize.setValue(10)
drawStyle.style = coin.SoDrawStyle.LINES
wireframe = coin.SoGroup()
shaded = coin.SoGroup()
self.wireframe = wireframe
self.shaded = shaded

self.coords = coin.SoCoordinate3()
self.coords.point.setValues(0, 2, [FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(1, 0, 0)])
wireframe += self.coords
wireframe += drawStyle
wireframe += material
shaded += self.coords
shaded += drawStyle
shaded += material

g = coin.SoGroup()
sel1 = coin.SoType.fromName('SoFCSelection').createInstance()
sel1.style = 'EMISSIVE_DIFFUSE'
p1 = coin.SoType.fromName('SoIndexedPointSet').createInstance()
p1.coordIndex.set1Value(0, 0)
sel1 += p1
g += sel1
wireframe += g
shaded += g

g = coin.SoGroup()
sel2 = coin.SoType.fromName('SoFCSelection').createInstance()
sel2.style = 'EMISSIVE_DIFFUSE'
p2 = coin.SoType.fromName('SoIndexedPointSet').createInstance()
p2.coordIndex.set1Value(0, 1)
sel2 += p2
g += sel2
wireframe += g
shaded += g

g = coin.SoGroup()
sel3 = coin.SoType.fromName('SoFCSelection').createInstance()
sel3.style = 'EMISSIVE_DIFFUSE'
p3 = coin.SoType.fromName('SoIndexedLineSet').createInstance()
p3.coordIndex.setValues(0, 2, [0, 1])
sel3 += p3
g += sel3
wireframe += g
shaded += g

obj.addDisplayMode(wireframe, 'Wireframe')
obj.addDisplayMode(shaded, 'Shaded')

self.sel1 = sel1
self.sel2 = sel2
self.sel3 = sel3
self.constructed = True
self.updateData(obj.Object, 'p2')

def getDetailPath(self, subname, path, append):
vobj = self.ViewObject
if append:
path.append(vobj.RootNode)
path.append(vobj.SwitchNode)

mode = vobj.SwitchNode.whichChild.getValue()
FreeCAD.Console.PrintWarning("getDetailPath: mode {} is active\n".format(mode))
if mode >= 0:
mode = vobj.SwitchNode.getChild(mode)
path.append(mode)
sub = Part.splitSubname(subname)[-1]
print(sub)
if sub == 'Atom1':
path.append(self.sel1)
elif sub == 'Atom2':
path.append(self.sel2)
elif sub == 'Line':
path.append(self.sel3)
else:
path.append(mode.getChild(0))
return True

def getElementPicked(self, pp):
path = pp.getPath()
if path.findNode(self.sel1) >= 0:
return 'Atom1'
if path.findNode(self.sel2) >= 0:
return 'Atom2'
if path.findNode(self.sel3) >= 0:
return 'Line'
raise NotImplementedError

def updateData(self, fp, prop):
"If a property of the handled feature has changed we have the chance to handle this here"
# fp is the handled feature, prop is the name of the property that has changed
if not self.constructed:
return
if prop == "p1":
p = fp.getPropertyByName("p1")
self.coords.point.set1Value(0, p)
elif prop == "p2":
p = fp.getPropertyByName("p2")
self.coords.point.set1Value(1, p)

def getDisplayModes(self, obj):
return ['Wireframe', 'Shaded']

def getDefaultDisplayMode(self):
return 'Shaded'

def setDisplayMode(self, mode):
return mode

def __getstate__(self):
return None

def __setstate__(self,state):
return None

def makeMolecule():
FreeCAD.newDocument()
a=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Molecule")
Molecule(a)
b=ViewProviderMolecule(a.ViewObject)
a.touch()
FreeCAD.ActiveDocument.recompute()
return a,b

a,b = makeMolecule()
}}

== Part Design scripted objects ==

When making scripted objects in Part Design the process is similar to the scripted objects discussed above, but with a few additional considerations. We must handle 2 shape properties, one for the shape we see in the 3D view and another for the shape used by the pattern tools, such as polar pattern features. The object shapes also needs to be fused to any existing material already in the Body (or cut from it in the case of Subtractive features). And we must account for the placement and attachment of our objects a little bit differently.

Part Design scripted solid object features should be based on either PartDesign::FeaturePython, PartDesign::FeatureAdditivePython, or PartDesign::FeatureSubtractivePython rather than Part::FeaturePython. Only the Additive and Subtractive variants can be used in pattern features, and if based on Part::FeaturePython when the user drops the object into a Part Design Body it becomes a BaseFeature rather than being treated by the Body as a native Part Design object. Note: all of these are expected to be solids, so if you are making a non-solid feature it should be based on Part::FeaturePython or else the next feature in the tree will attempt to fuse to as a solid and it will fail.

Here is a simple example of making a Tube primitive, similar to the Tube primitive in Part Workbench except this one will be a Part Design solid feature object. For this we will 2 separate files: pdtube.FCMacro and pdtube.py. The .FCMacro file will be executed by the user to create the object. The .py file will hold the class definitions, imported by the .FCMacro. The reason for doing it this way is to maintain the parametric nature of the object after restarting FreeCAD and opening a document containing one of our Tubes.

First, the class definition file:

{{Code|code=
# -*- coding: utf-8 -*-
#classes should go in pdtube.py
import FreeCAD, FreeCADGui, Part
class PDTube:
def __init__(self,obj):
obj.addProperty("App::PropertyLength","Radius1","Tube","Radius1").Radius1 = 5
obj.addProperty("App::PropertyLength","Radius2","Tube","Radius2").Radius2 = 10
obj.addProperty("App::PropertyLength","Height","Tube","Height of tube").Height = 10
self.makeAttachable(obj)
obj.Proxy = self

def makeAttachable(self, obj):

if int(FreeCAD.Version()[1]) >= 19:
obj.addExtension('Part::AttachExtensionPython')
else:
obj.addExtension('Part::AttachExtensionPython', obj)

obj.setEditorMode('Placement', 0) #non-readonly non-hidden

def execute(self,fp):
outer_cylinder = Part.makeCylinder(fp.Radius2, fp.Height)
inner_cylinder = Part.makeCylinder(fp.Radius1, fp.Height)
if fp.Radius1 == fp.Radius2: #just make cylinder
tube_shape = outer_cylinder
elif fp.Radius1 < fp.Radius2:
tube_shape = outer_cylinder.cut(inner_cylinder)
else: #invert rather than error out
tube_shape = inner_cylinder.cut(outer_cylinder)

if not hasattr(fp, "positionBySupport"):
self.makeAttachable(fp)
fp.positionBySupport()
tube_shape.Placement = fp.Placement

#BaseFeature (shape property of type Part::PropertyPartShape) is provided for us
#with the PartDesign::FeaturePython and related classes, but it might be empty
#if our object is the first object in the tree. it's a good idea to check
#for its existence in case we want to make type Part::FeaturePython, which won't have it

if hasattr(fp, "BaseFeature") and fp.BaseFeature != None:
if "Subtractive" in fp.TypeId:
full_shape = fp.BaseFeature.Shape.cut(tube_shape)
else:
full_shape = fp.BaseFeature.Shape.fuse(tube_shape)
full_shape.transformShape(fp.Placement.inverse().toMatrix(), True) #borrowed from gears workbench
fp.Shape = full_shape
else:
fp.Shape = tube_shape
if hasattr(fp,"AddSubShape"): #PartDesign::FeatureAdditivePython and
#PartDesign::FeatureSubtractivePython have this
#property but PartDesign::FeaturePython does not
#It is the shape used for copying in pattern features
#for example in making a polar pattern
tube_shape.transformShape(fp.Placement.inverse().toMatrix(), True)
fp.AddSubShape = tube_shape

class PDTubeVP:
def __init__(self, obj):
'''Set this object to the proxy object of the actual view provider'''
obj.Proxy = self

def attach(self,vobj):
self.vobj = vobj

def updateData(self, fp, prop):
'''If a property of the handled feature has changed we have the chance to handle this here'''
pass

def getDisplayModes(self,obj):
'''Return a list of display modes.'''
modes=[]
modes.append("Flat Lines")
modes.append("Shaded")
modes.append("Wireframe")
return modes

def getDefaultDisplayMode(self):
'''Return the name of the default display mode. It must be defined in getDisplayModes.'''
return "Flat Lines"

def setDisplayMode(self,mode):
'''Map the display mode defined in attach with those defined in getDisplayModes.\
Since they have the same names nothing needs to be done. This method is optional'''
return mode

def onChanged(self, vp, prop):
'''Here we can do something when a single property got changed'''
#FreeCAD.Console.PrintMessage("Change property: " + str(prop) + "\n")
pass

def getIcon(self):
'''Return the icon in XPM format which will appear in the tree view. This method is\
optional and if not defined a default icon is shown.'''
return """
/* XPM */
static const char * ViewProviderBox_xpm[] = {
"16 16 6 1",
" c None",
". c #141010",
"+ c #615BD2",
"@ c #C39D55",
"# c #000000",
"$ c #57C355",
" ........",
" ......++..+..",
" .@@@@.++..++.",
" .@@@@.++..++.",
" .@@ .++++++.",
" ..@@ .++..++.",
"###@@@@ .++..++.",
"##$.@@$#.++++++.",
"#$#$.$$$........",
"#$$####### ",
"#$$#$$$$$# ",
"#$$#$$$$$# ",
"#$$#$$$$$# ",
" #$#$$$$$# ",
" ##$$$$$# ",
" ####### "};
"""

def __getstate__(self):
'''When saving the document this object gets stored using Python's json module.\
Since we have some un-serializable parts here -- the Coin stuff -- we must define this method\
to return a tuple of all serializable objects or None.'''
return None

def __setstate__(self,state):
'''When restoring the serialized object from document we have the chance to set some internals here.\
Since no data were serialized nothing needs to be done here.'''
return None
}}

And now the macro file to create the object:

{{Code|code=
# -*- coding: utf-8 -*-

#pdtube.FCMacro
import pdtube
#above line needed if the class definitions above are place in another file: PDTube.py
#this is needed if the tube object is to remain parametric after restarting FreeCAD and loading
#a document containing the object

body = FreeCADGui.ActiveDocument.ActiveView.getActiveObject("pdbody")
if not body:
FreeCAD.Console.PrintError("No active body.\n")
else:
from PySide import QtGui
window = FreeCADGui.getMainWindow()
items = ["Additive","Subtractive","Neither additive nor subtractive"]
item,ok =QtGui.QInputDialog.getItem(window,"Select tube type","Select whether you want additive, subtractive, or neither:",items,0,False)
if ok:
if item == items[0]:
className = "PartDesign::FeatureAdditivePython"
elif item == items[1]:
className = "PartDesign::FeatureSubtractivePython"
else:
className = "PartDesign::FeaturePython" #not usable in pattern features, such as polar pattern

tube = FreeCAD.ActiveDocument.addObject(className,"Tube")
pdtube.PDTube(tube)
pdtube.PDTubeVP(tube.ViewObject)
body.addObject(tube) #optionally we can also use body.insertObject() for placing at particular place in tree
}}


<div class="mw-translate-fuzzy">
<div class="mw-translate-fuzzy">
{{docnav/cs|[[PySide/cs|PySide]]|[[Embedding FreeCAD/cs|Vkládání FreeCADu]]}}
[[Category:Poweruser Documentation/cs|Kategorie:Dokumentace pokročilého uživatele]]
[[Category:Python Code/cs|Kategorie:Python kódy]]
</div>
</div>


Additional pages:
[[Category:Python Code]]
* [[Scripted_objects_saving_attributes|Scripted objects saving attributes]]
* [[Scripted_objects_migration|Scripted objects migration]]
* [[Scripted objects with attachment|Scripted objects with attachment]]
* [[Viewprovider|Viewproviders]]


Interesting forum threads about scripted objects:

* [http://forum.freecadweb.org/viewtopic.php?f=22&t=13740 Python object attributes lost at load]
* [http://forum.freecadweb.org/viewtopic.php?t=12139 New FeaturePython is grey]
* [https://forum.freecadweb.org/viewtopic.php?f=18&t=44009 Explanation on __getstate__ and __setstate__], [https://docs.python.org/3/library/pickle.html#object.__getstate__ official documentation]
* [https://forum.freecadweb.org/viewtopic.php?f=18&t=13460&start=20#p109709 Eigenmode frequency always 0?]
* [https://forum.freecadweb.org/viewtopic.php?f=22&t=21330 how to implement python feature's setEdit properly?]

In addition to the examples presented here have a look at FreeCAD source code [https://github.com/FreeCAD/FreeCAD/blob/master/src/Mod/TemplatePyMod/FeaturePython.py src/Mod/TemplatePyMod/FeaturePython.py] for more examples.


{{Docnav
|[[Topological_data_scripting|Topological data scripting]]
|[[Scenegraph|Scenegraph]]
}}


{{Powerdocnavi{{#translation:}}}}
{{clear}}
[[Category:Developer Documentation{{#translation:}}]]
[[Category:Python Code{{#translation:}}]]

Revision as of 17:04, 11 June 2022

Introduction

Kromě standardních objektových typů jako jsou anotace, sítě a díly, nabízí FreeCAD skvělou možnost vytváření objektů 100% vytvořených skritpy Pythonu, které se nazývají Pythonovské objekty. Tyto objekty se chovají stejně jako jiné objekty FreeCADu a jsou ukládány a načítány automaticky při ukládání a otevírání souboru.

Je třeba pochopit jednu zvláštnost, tyto objekty jsou ukládány ve FcStd souborech FreeCADu s pythonovským modulem json. Tento modul převede pythonovský objekt do řetězce, který je pak možno uložit v souboru. Při načítání naopak tento modul použije uložený řetězec ke znovuvytvoření původního objektu, při tom musí mít přístup ke zdrojovému kódu, který vytvoří objekt. To znamená, že když uložíte takový uživatelský objekt a pak jej otevíráte na počítači kde není pythonovský kód, tak nebude tento objekt vytvořen. Když tedy distribuujete takový objekt někomu jinému, musíte společně s ním distribuovat i pythonovský skript, který objekt vytváří.

Note: It is possible to pack python code inside a FreeCAD file using json serializing with an App::PropertyPythonObject, but that code can never directly be run, and therefore has little use for our purpose here.

Pythonovský objekt má stejné pravidlo jako FreeCAD: Aplikace a GUI jsou odděleny do samostatných částí. Aplikační část, Document Object, definuje konstrukci objektu, zatímco část GUI, View Provider Object, definuje jak bude objekt zobrazen na displeji. View Provider Object, stejně jako další GUI objekty FreeCADu je dostupný pouze když FreeCAD běží se svým vlastním GUI. Pro vytvoření objektu je použitelných několik vlastností a metod. Vlastnosti musejí být některé z předdefinovaných typových vlastností, které nabízí FreeCAD a zobrazují se v dialogovém okně vlastností, takže mohou být uživatelem upravovány. Tímto způsobem jsou Pythonovské objekty správně a zcela parametrizovány. Můžete samostatně definovat vlastnosti objektu a jeho zobrazovacího objektu.

Basic example

Základní příklad

Následující příklad najdete v souboru src/Mod/TemplatePyMod/FeaturePython.py, společně s několika dalšími příklady:

'''Examples for a feature class and its view provider.'''

import FreeCAD, FreeCADGui
from pivy import coin

class Box:
    def __init__(self, obj):
        '''Add some custom properties to our box feature'''
        obj.addProperty("App::PropertyLength","Length","Box","Length of the box").Length=1.0
        obj.addProperty("App::PropertyLength","Width","Box","Width of the box").Width=1.0
        obj.addProperty("App::PropertyLength","Height","Box", "Height of the box").Height=1.0
        obj.Proxy = self

    def onChanged(self, fp, prop):
        '''Do something when a property has changed'''
        FreeCAD.Console.PrintMessage("Change property: " + str(prop) + "\n")

    def execute(self, fp):
        '''Do something when doing a recomputation, this method is mandatory'''
        FreeCAD.Console.PrintMessage("Recompute Python Box feature\n")

class ViewProviderBox:
    def __init__(self, obj):
        '''Set this object to the proxy object of the actual view provider'''
        obj.addProperty("App::PropertyColor","Color","Box","Color of the box").Color=(1.0,0.0,0.0)
        obj.Proxy = self

    def attach(self, obj):
        '''Setup the scene sub-graph of the view provider, this method is mandatory'''
        self.shaded = coin.SoGroup()
        self.wireframe = coin.SoGroup()
        self.scale = coin.SoScale()
        self.color = coin.SoBaseColor()

        data=coin.SoCube()
        self.shaded.addChild(self.scale)
        self.shaded.addChild(self.color)
        self.shaded.addChild(data)
        obj.addDisplayMode(self.shaded,"Shaded");
        style=coin.SoDrawStyle()
        style.style = coin.SoDrawStyle.LINES
        self.wireframe.addChild(style)
        self.wireframe.addChild(self.scale)
        self.wireframe.addChild(self.color)
        self.wireframe.addChild(data)
        obj.addDisplayMode(self.wireframe,"Wireframe");
        self.onChanged(obj,"Color")

    def updateData(self, fp, prop):
        '''If a property of the handled feature has changed we have the chance to handle this here'''
        # fp is the handled feature, prop is the name of the property that has changed
        l = fp.getPropertyByName("Length")
        w = fp.getPropertyByName("Width")
        h = fp.getPropertyByName("Height")
        self.scale.scaleFactor.setValue(float(l),float(w),float(h))
        pass

    def getDisplayModes(self,obj):
        '''Return a list of display modes.'''
        modes=[]
        modes.append("Shaded")
        modes.append("Wireframe")
        return modes

    def getDefaultDisplayMode(self):
        '''Return the name of the default display mode. It must be defined in getDisplayModes.'''
        return "Shaded"

    def setDisplayMode(self,mode):
        '''Map the display mode defined in attach with those defined in getDisplayModes.\
                Since they have the same names nothing needs to be done. This method is optional'''
        return mode

    def onChanged(self, vp, prop):
        '''Here we can do something when a single property got changed'''
        FreeCAD.Console.PrintMessage("Change property: " + str(prop) + "\n")
        if prop == "Color":
            c = vp.getPropertyByName("Color")
            self.color.rgb.setValue(c[0],c[1],c[2])

    def getIcon(self):
        '''Return the icon in XPM format which will appear in the tree view. This method is\
                optional and if not defined a default icon is shown.'''
        return """
            /* XPM */
            static const char * ViewProviderBox_xpm[] = {
            "16 16 6 1",
            "   c None",
            ".  c #141010",
            "+  c #615BD2",
            "@  c #C39D55",
            "#  c #000000",
            "$  c #57C355",
            "        ........",
            "   ......++..+..",
            "   .@@@@.++..++.",
            "   .@@@@.++..++.",
            "   .@@  .++++++.",
            "  ..@@  .++..++.",
            "###@@@@ .++..++.",
            "##$.@@$#.++++++.",
            "#$#$.$$$........",
            "#$$#######      ",
            "#$$#$$$$$#      ",
            "#$$#$$$$$#      ",
            "#$$#$$$$$#      ",
            " #$#$$$$$#      ",
            "  ##$$$$$#      ",
            "   #######      "};
            """

    def __getstate__(self):
        '''When saving the document this object gets stored using Python's json module.\
                Since we have some un-serializable parts here -- the Coin stuff -- we must define this method\
                to return a tuple of all serializable objects or None.'''
        return None

    def __setstate__(self,state):
        '''When restoring the serialized object from document we have the chance to set some internals here.\
                Since no data were serialized nothing needs to be done here.'''
        return None

def makeBox():
    FreeCAD.newDocument()
    a=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Box")
    Box(a)
    ViewProviderBox(a.ViewObject)

makeBox()

Things to note

If your object relies on being recomputed as soon as it is created, you must do this manually in the __init__ function as it is not called automatically. This example does not require it because the onChanged method of the Box class has the same effect as the execute function, but the examples below rely on being recomputed before anything is displayed in the 3D view. In the examples, this is done manually with ActiveDocument.recompute() but in more complex scenarios you need to decide where to recompute either the whole document or the FeaturePython object.

This example produces a number of exception stack traces in the report view window. This is because the onChanged method of the Box class is called each time a property is added in __init__. When the first one is added, the Width and Height properties don't exist yet and so the attempt to access them fails.

An explanation of __getstate__ and __setstate__ is in the forum thread obj.Proxy.Type is a dict, not a string.

Available methods

See FeaturePython methods for the complete reference.

Available properties

Dostupné vlastnosti

Vlastnosti jsou skutečné základní kameny pythonovských objektů. Jejich prostřednictvím je uživatel schopen pracovat s objektem. Po vytvoření Pythonovského objektu v dokumentu ( obj=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Box") ), obdržíte seznam dostupných vlastností zadáním:

obj.supportedProperties()

Dostanete seznam dostupných vlastností:

Když do uživatelského objektu přidáváte vlastnosti dejte pozor na::

  • Nepoužívejte znaky "<" a ">" v popisu vlastnosti (odděluje to části XML v souboru .fcstd)
  • Vlastnosti jsou uloženy podle abecedy ve .fcstd souboru. Máte-li ve vlastnostech tvar (shape), jakékoliv jméno vlastnosti, které je za "Shape" podle abecedy, bude nataženo až po tvaru, což může zapříčinit neočekávané chování.

A complete list of property attributes can be seen in the PropertyStandard C++ header file. For instance, if you want to allow the user to enter only a limited range of values (e.g. using PropertyIntegerConstraint), in Python you will assign a tuple containing not only the property value, but also the lower and upper limit as well as the stepsize, as below:

prop = (value, lower, upper, stepsize)

Property Type

Typ vlastnosti

Standardně mohou být vlastnosti upravovány. Je ale možné nastavit vlastnosti pouze ke čtení, třeba když má jenom zobrazovat výstup výsledku metody. Je možné také vlastnost skrýt. Typ vlastnosti může být nastaven použitím

obj.setEditorMode("MyPropertyName", mode)

kde mode je malá celočíselná hodnota, které může být nastavena na:

 0 -- defaultní mód, čtení  i zápis
 1 -- pouze čtení
 2 -- skryto

The EditorModes are not set at FreeCAD file reload. This could to be done by the __setstate__ function. See http://forum.freecadweb.org/viewtopic.php?f=18&t=13460&start=10#p108072. By using the setEditorMode the properties are only read only in PropertyEditor. They could still be changed from python. To really make them read only the setting has to be passed directly inside the addProperty function. See http://forum.freecadweb.org/viewtopic.php?f=18&t=13460&start=20#p109709 for an example.

Using the direct setting in the addProperty function, you also have more possibilities. In particular, an interesting one is mark a property as an output property. This way FreeCAD won't mark the feature as touched when changing it (so no need to recompute).

Example of output property (see also https://forum.freecadweb.org/viewtopic.php?t=24928):

obj.addProperty("App::PropertyString","MyCustomProperty","","",8)

The property types that can be set at last parameter of the addProperty function are:

 0 -- Prop_None, No special property type
 1 -- Prop_ReadOnly, Property is read-only in the editor
 2 -- Prop_Transient, Property won't be saved to file
 4 -- Prop_Hidden, Property won't appear in the editor
 8 -- Prop_Output, Modified property doesn't touch its parent container
 16 -- Prop_NoRecompute, Modified property doesn't touch its container for recompute

You can find these different property types defined in the source code C++ header for PropertyContainer.

Other more complex example

Další složitější příklady

Tento příklad používá Modul Díl k vytvoření osmistěnu a potom vytvoří pomocí Pivy jeho reprezentaci v Coinu.

První je samotné vytvoření dokumentu:

import FreeCAD, FreeCADGui, Part
import pivy
from pivy import coin

class Octahedron:
  def __init__(self, obj):
     "Add some custom properties to our box feature"
     obj.addProperty("App::PropertyLength","Length","Octahedron","Length of the octahedron").Length=1.0
     obj.addProperty("App::PropertyLength","Width","Octahedron","Width of the octahedron").Width=1.0
     obj.addProperty("App::PropertyLength","Height","Octahedron", "Height of the octahedron").Height=1.0
     obj.addProperty("Part::PropertyPartShape","Shape","Octahedron", "Shape of the octahedron")
     obj.Proxy = self

  def execute(self, fp):
     # Define six vetices for the shape
     v1 = FreeCAD.Vector(0,0,0)
     v2 = FreeCAD.Vector(fp.Length,0,0)
     v3 = FreeCAD.Vector(0,fp.Width,0)
     v4 = FreeCAD.Vector(fp.Length,fp.Width,0)
     v5 = FreeCAD.Vector(fp.Length/2,fp.Width/2,fp.Height/2)
     v6 = FreeCAD.Vector(fp.Length/2,fp.Width/2,-fp.Height/2)

     # Make the wires/faces
     f1 = self.make_face(v1,v2,v5)
     f2 = self.make_face(v2,v4,v5)
     f3 = self.make_face(v4,v3,v5)
     f4 = self.make_face(v3,v1,v5)
     f5 = self.make_face(v2,v1,v6)
     f6 = self.make_face(v4,v2,v6)
     f7 = self.make_face(v3,v4,v6)
     f8 = self.make_face(v1,v3,v6)
     shell=Part.makeShell([f1,f2,f3,f4,f5,f6,f7,f8])
     solid=Part.makeSolid(shell)
     fp.Shape = solid

  # helper mehod to create the faces
  def make_face(self,v1,v2,v3):
     wire = Part.makePolygon([v1,v2,v3,v1])
     face = Part.Face(wire)
     return face

Pak máme objekt pro zobrazení (view provider object), zodpovědný za zobrazení objektu ve 3D:

class ViewProviderOctahedron:
  def __init__(self, obj):
     "Set this object to the proxy object of the actual view provider"
     obj.addProperty("App::PropertyColor","Color","Octahedron","Color of the octahedron").Color=(1.0,0.0,0.0)
     obj.Proxy = self

  def attach(self, obj):
     "Setup the scene sub-graph of the view provider, this method is mandatory"
     self.shaded = coin.SoGroup()
     self.wireframe = coin.SoGroup()
     self.scale = coin.SoScale()
     self.color = coin.SoBaseColor()

     self.data=coin.SoCoordinate3()
     self.face=coin.SoIndexedFaceSet()

     self.shaded.addChild(self.scale)
     self.shaded.addChild(self.color)
     self.shaded.addChild(self.data)
     self.shaded.addChild(self.face)
     obj.addDisplayMode(self.shaded,"Shaded");
     style=coin.SoDrawStyle()
     style.style = coin.SoDrawStyle.LINES
     self.wireframe.addChild(style)
     self.wireframe.addChild(self.scale)
     self.wireframe.addChild(self.color)
     self.wireframe.addChild(self.data)
     self.wireframe.addChild(self.face)
     obj.addDisplayMode(self.wireframe,"Wireframe");
     self.onChanged(obj,"Color")

  def updateData(self, fp, prop):
     "If a property of the handled feature has changed we have the chance to handle this here"
     # fp is the handled feature, prop is the name of the property that has changed
     if prop == "Shape":
        s = fp.getPropertyByName("Shape")
        self.data.point.setNum(6)
        cnt=0
        for i in s.Vertexes:
           self.data.point.set1Value(cnt,i.X,i.Y,i.Z)
           cnt=cnt+1

        self.face.coordIndex.set1Value(0,0)
        self.face.coordIndex.set1Value(1,1)
        self.face.coordIndex.set1Value(2,2)
        self.face.coordIndex.set1Value(3,-1)

        self.face.coordIndex.set1Value(4,1)
        self.face.coordIndex.set1Value(5,3)
        self.face.coordIndex.set1Value(6,2)
        self.face.coordIndex.set1Value(7,-1)

        self.face.coordIndex.set1Value(8,3)
        self.face.coordIndex.set1Value(9,4)
        self.face.coordIndex.set1Value(10,2)
        self.face.coordIndex.set1Value(11,-1)

        self.face.coordIndex.set1Value(12,4)
        self.face.coordIndex.set1Value(13,0)
        self.face.coordIndex.set1Value(14,2)
        self.face.coordIndex.set1Value(15,-1)

        self.face.coordIndex.set1Value(16,1)
        self.face.coordIndex.set1Value(17,0)
        self.face.coordIndex.set1Value(18,5)
        self.face.coordIndex.set1Value(19,-1)

        self.face.coordIndex.set1Value(20,3)
        self.face.coordIndex.set1Value(21,1)
        self.face.coordIndex.set1Value(22,5)
        self.face.coordIndex.set1Value(23,-1)

        self.face.coordIndex.set1Value(24,4)
        self.face.coordIndex.set1Value(25,3)
        self.face.coordIndex.set1Value(26,5)
        self.face.coordIndex.set1Value(27,-1)

        self.face.coordIndex.set1Value(28,0)
        self.face.coordIndex.set1Value(29,4)
        self.face.coordIndex.set1Value(30,5)
        self.face.coordIndex.set1Value(31,-1)

  def getDisplayModes(self,obj):
     "Return a list of display modes."
     modes=[]
     modes.append("Shaded")
     modes.append("Wireframe")
     return modes

  def getDefaultDisplayMode(self):
     "Return the name of the default display mode. It must be defined in getDisplayModes."
     return "Shaded"

  def setDisplayMode(self,mode):
     return mode

  def onChanged(self, vp, prop):
     "Here we can do something when a single property got changed"
     FreeCAD.Console.PrintMessage("Change property: " + str(prop) + "\n")
     if prop == "Color":
        c = vp.getPropertyByName("Color")
        self.color.rgb.setValue(c[0],c[1],c[2])

  def getIcon(self):
     return """
        /* XPM */
        static const char * ViewProviderBox_xpm[] = {
        "16 16 6 1",
        "    c None",
        ".   c #141010",
        "+   c #615BD2",
        "@   c #C39D55",
        "#   c #000000",
        "$   c #57C355",
        "        ........",
        "   ......++..+..",
        "   .@@@@.++..++.",
        "   .@@@@.++..++.",
        "   .@@  .++++++.",
        "  ..@@  .++..++.",
        "###@@@@ .++..++.",
        "##$.@@$#.++++++.",
        "#$#$.$$$........",
        "#$$#######      ",
        "#$$#$$$$$#      ",
        "#$$#$$$$$#      ",
        "#$$#$$$$$#      ",
        " #$#$$$$$#      ",
        "  ##$$$$$#      ",
        "   #######      "};
        """

  def __getstate__(self):
     return None

  def __setstate__(self,state):
     return None

A nakonec, když je objekt i jeho zobrazení definováno, stačí ho už jen zavolat:

FreeCAD.newDocument()
a=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Octahedron")
Octahedron(a)
ViewProviderOctahedron(a.ViewObject)

Making objects selectable

Zpřístupnění objektu k výběru

Chcete-li aby bylo možné objekt vybrat nebo alespoň jeho část, kliknutím na něj v pohledu, musíte včlenit jeho Coin konstrukci do uzlu SoFCSelection. Má-li objekt komplexní zobrazení s widgety, anotacemi atd., můžete chtít včlenit do SoFCSelection pouze nějakou část. Všechno co je SoFCSelection je průběžně skenováno FreeCADem pro detekci výběru/předvýběru, takže je rozumné nepřetěžovat jej zbytečným skenováním. Tady je co byste měli zahrnout do self.face z příkladu nahoře.

Once the parts of the scenegraph that are to be selectable are inside SoFCSelection nodes, you then need to provide two methods to handle the selection path. The selection path can take the form of a string giving the names of each element in the path, or of an array of scenegraph objects. The two methods you provide are getDetailPath, which converts from a string path to an array of scenegraph objects, and getElementPicked, which takes an element which has been clicked on in the scenegraph and returns its string name (note, not its string path).

Here is the molecule example above, adapted to make the elements of the molecule selectable:

class Molecule:
    def __init__(self, obj):
        ''' Add two point properties '''
        obj.addProperty("App::PropertyVector","p1","Line","Start point")
        obj.addProperty("App::PropertyVector","p2","Line","End point").p2=FreeCAD.Vector(5,0,0)

        obj.Proxy = self

    def onChanged(self, fp, prop):
        if prop == "p1" or prop == "p2":
            ''' Print the name of the property that has changed '''
            fp.Shape = Part.makeLine(fp.p1,fp.p2)

    def execute(self, fp):
        ''' Print a short message when doing a recomputation, this method is mandatory '''
        fp.Shape = Part.makeLine(fp.p1,fp.p2)

class ViewProviderMolecule:
    def __init__(self, obj):
        ''' Set this object to the proxy object of the actual view provider '''
        obj.Proxy = self
        self.ViewObject = obj
        sep1=coin.SoSeparator()
        sel1 = coin.SoType.fromName('SoFCSelection').createInstance()
        # sel1.policy.setValue(coin.SoSelection.SHIFT)
        sel1.ref()
        sep1.addChild(sel1)
        self.trl1=coin.SoTranslation()
        sel1.addChild(self.trl1)
        sel1.addChild(coin.SoSphere())
        sep2=coin.SoSeparator()
        sel2 = coin.SoType.fromName('SoFCSelection').createInstance()
        sel2.ref()
        sep2.addChild(sel2)
        self.trl2=coin.SoTranslation()
        sel2.addChild(self.trl2)
        sel2.addChild(coin.SoSphere())
        obj.RootNode.addChild(sep1)
        obj.RootNode.addChild(sep2)
        self.updateData(obj.Object, 'p2')
        self.sel1 = sel1
        self.sel2 = sel2

    def getDetailPath(self, subname, path, append):
        vobj = self.ViewObject
        if append:
            path.append(vobj.RootNode)
            path.append(vobj.SwitchNode)

            mode = vobj.SwitchNode.whichChild.getValue()
            if mode >= 0:
                mode = vobj.SwitchNode.getChild(mode)
                path.append(mode)
                sub = Part.splitSubname(subname)[-1]
                if sub == 'Atom1':
                    path.append(self.sel1)
                elif sub == 'Atom2':
                    path.append(self.sel2)
                else:
                    path.append(mode.getChild(0))
        return True

    def getElementPicked(self, pp):
        path = pp.getPath()
        if path.findNode(self.sel1) >= 0:
            return 'Atom1'
        if path.findNode(self.sel2) >= 0:
            return 'Atom2'
        raise NotImplementedError

    def updateData(self, fp, prop):
        "If a property of the handled feature has changed we have the chance to handle this here"
        # fp is the handled feature, prop is the name of the property that has changed
        if prop == "p1":
            p = fp.getPropertyByName("p1")
            self.trl1.translation=(p.x,p.y,p.z)
        elif prop == "p2":
            p = fp.getPropertyByName("p2")
            self.trl2.translation=(p.x,p.y,p.z)

    def __getstate__(self):
        return None

    def __setstate__(self,state):
        return None

def makeMolecule():
    FreeCAD.newDocument()
    a=FreeCAD.ActiveDocument.addObject("Part::FeaturePython","Molecule")
    Molecule(a)
    ViewProviderMolecule(a.ViewObject)
    FreeCAD.ActiveDocument.recompute()

Working with simple shapes

Práce s jednoduchými tvary

Jestliže z parametrického objektu vychází jednoduchý tvar, není nutné používat zobrazovací objekt. Tvar bude zobrazován použitím standardního zobrazování tvarů ve FreeCADu.

import FreeCAD as App
import FreeCADGui
import FreeCAD
import Part
class Line:
    def __init__(self, obj):
        '''"App two point properties" '''
        obj.addProperty("App::PropertyVector","p1","Line","Start point")
        obj.addProperty("App::PropertyVector","p2","Line","End point").p2=FreeCAD.Vector(1,0,0)
        obj.Proxy = self

    def execute(self, fp):
        '''"Print a short message when doing a recomputation, this method is mandatory" '''
        fp.Shape = Part.makeLine(fp.p1,fp.p2)

a=FreeCAD.ActiveDocument.addObject("Part::FeaturePython","Line")
Line(a)
a.ViewObject.Proxy=0 # just set it to something different from None (this assignment is needed to run an internal notification)
FreeCAD.ActiveDocument.recompute()

Same code with use ViewProviderLine

import FreeCAD as App
import FreeCADGui
import FreeCAD
import Part

class Line:
    def __init__(self, obj):
         '''"App two point properties" '''
         obj.addProperty("App::PropertyVector","p1","Line","Start point")
         obj.addProperty("App::PropertyVector","p2","Line","End point").p2=FreeCAD.Vector(100,0,0)
         obj.Proxy = self

    def execute(self, fp):
        '''"Print a short message when doing a recomputation, this method is mandatory" '''
        fp.Shape = Part.makeLine(fp.p1,fp.p2)

class ViewProviderLine:
   def __init__(self, obj):
      ''' Set this object to the proxy object of the actual view provider '''
      obj.Proxy = self

   def getDefaultDisplayMode(self):
      ''' Return the name of the default display mode. It must be defined in getDisplayModes. '''
      return "Flat Lines"

a=FreeCAD.ActiveDocument.addObject("Part::FeaturePython","Line")
Line(a)
ViewProviderLine(a.ViewObject)
App.ActiveDocument.recompute()

Scenegraph Structure

You may have noticed that the examples above construct their scenegraphs in slightly different ways. Some use obj.addDisplayMode(node, "modename") while others use obj.SwitchNode.getChild(x).addChild(y).

Each feature in a FreeCAD document is based the following scenegraph structure:

RootNode
 \- SwitchNode
     \- Shaded
      - Wireframe
      - etc

The SwitchNode displays only one of its children, depending on which display mode is selection in FreeCAD.

The examples which use addDisplayMode are constructing their scenegraphs solely out of coin3d scenegraph elements. Under the covers, addDisplayMode adds a new child to the SwitchNode; the name of that node will match the display mode it was passed.

The examples which use SwitchNode.getChild(x).addChild also construct part of their geometry using functions from the Part workbench, such as fp.Shape = Part.makeLine(fp.p1,fp.p2). This constructs the different display mode scenegraphs under the SwitchNode; when we later come to add coin3d elements to the scenegraph, we need to add them to the existing display mode scenegraphs using addChild rather than creating a new child of the SwitchNode.

When using addDisplayMode() to add geometry to the scenegraph, each display mode should have its own node which is passed to addDisplayMode(); don't reuse the same node for this. Doing so will confuse the selection mechanism. It's okay if each display mode's node has the same geometry nodes added below it, just the root of each display mode needs to be distinct.

Here is the above molecule example, adapted to be drawn only with Coin3D scenegraph objects instead of using objects from the Part workbench:

import Part
from pivy import coin

class Molecule:
    def __init__(self, obj):
        ''' Add two point properties '''
        obj.addProperty("App::PropertyVector","p1","Line","Start point")
        obj.addProperty("App::PropertyVector","p2","Line","End point").p2=FreeCAD.Vector(5,0,0)

        obj.Proxy = self

    def onChanged(self, fp, prop):
        pass

    def execute(self, fp):
        ''' Print a short message when doing a recomputation, this method is mandatory '''
        pass

class ViewProviderMolecule:
    def __init__(self, obj):
        ''' Set this object to the proxy object of the actual view provider '''
        self.constructed = False
        obj.Proxy = self
        self.ViewObject = obj

    def attach(self, obj):
        material = coin.SoMaterial()
        material.diffuseColor = (1.0, 0.0, 0.0)
        material.emissiveColor = (1.0, 0.0, 0.0)
        drawStyle = coin.SoDrawStyle()
        drawStyle.pointSize.setValue(10)
        drawStyle.style = coin.SoDrawStyle.LINES
        wireframe = coin.SoGroup()
        shaded = coin.SoGroup()
        self.wireframe = wireframe
        self.shaded = shaded

        self.coords = coin.SoCoordinate3()
        self.coords.point.setValues(0, 2, [FreeCAD.Vector(0, 0, 0), FreeCAD.Vector(1, 0, 0)])
        wireframe += self.coords
        wireframe += drawStyle
        wireframe += material
        shaded += self.coords
        shaded += drawStyle
        shaded += material

        g = coin.SoGroup()
        sel1 = coin.SoType.fromName('SoFCSelection').createInstance()
        sel1.style = 'EMISSIVE_DIFFUSE'
        p1 = coin.SoType.fromName('SoIndexedPointSet').createInstance()
        p1.coordIndex.set1Value(0, 0)
        sel1 += p1
        g += sel1
        wireframe += g
        shaded += g

        g = coin.SoGroup()
        sel2 = coin.SoType.fromName('SoFCSelection').createInstance()
        sel2.style = 'EMISSIVE_DIFFUSE'
        p2 = coin.SoType.fromName('SoIndexedPointSet').createInstance()
        p2.coordIndex.set1Value(0, 1)
        sel2 += p2
        g += sel2
        wireframe += g
        shaded += g

        g = coin.SoGroup()
        sel3 = coin.SoType.fromName('SoFCSelection').createInstance()
        sel3.style = 'EMISSIVE_DIFFUSE'
        p3 = coin.SoType.fromName('SoIndexedLineSet').createInstance()
        p3.coordIndex.setValues(0, 2, [0, 1])
        sel3 += p3
        g += sel3
        wireframe += g
        shaded += g

        obj.addDisplayMode(wireframe, 'Wireframe')
        obj.addDisplayMode(shaded, 'Shaded')

        self.sel1 = sel1
        self.sel2 = sel2
        self.sel3 = sel3
        self.constructed = True
        self.updateData(obj.Object, 'p2')

    def getDetailPath(self, subname, path, append):
        vobj = self.ViewObject
        if append:
            path.append(vobj.RootNode)
            path.append(vobj.SwitchNode)

            mode = vobj.SwitchNode.whichChild.getValue()
            FreeCAD.Console.PrintWarning("getDetailPath: mode {} is active\n".format(mode))
            if mode >= 0:
                mode = vobj.SwitchNode.getChild(mode)
                path.append(mode)
                sub = Part.splitSubname(subname)[-1]
                print(sub)
                if sub == 'Atom1':
                    path.append(self.sel1)
                elif sub == 'Atom2':
                    path.append(self.sel2)
                elif sub == 'Line':
                    path.append(self.sel3)
                else:
                    path.append(mode.getChild(0))
        return True

    def getElementPicked(self, pp):
        path = pp.getPath()
        if path.findNode(self.sel1) >= 0:
            return 'Atom1'
        if path.findNode(self.sel2) >= 0:
            return 'Atom2'
        if path.findNode(self.sel3) >= 0:
            return 'Line'
        raise NotImplementedError

    def updateData(self, fp, prop):
        "If a property of the handled feature has changed we have the chance to handle this here"
        # fp is the handled feature, prop is the name of the property that has changed
        if not self.constructed:
            return
        if prop == "p1":
            p = fp.getPropertyByName("p1")
            self.coords.point.set1Value(0, p)
        elif prop == "p2":
            p = fp.getPropertyByName("p2")
            self.coords.point.set1Value(1, p)

    def getDisplayModes(self, obj):
        return ['Wireframe', 'Shaded']

    def getDefaultDisplayMode(self):
        return 'Shaded'

    def setDisplayMode(self, mode):
        return mode

    def __getstate__(self):
        return None

    def __setstate__(self,state):
        return None

def makeMolecule():
    FreeCAD.newDocument()
    a=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Molecule")
    Molecule(a)
    b=ViewProviderMolecule(a.ViewObject)
    a.touch()
    FreeCAD.ActiveDocument.recompute()
    return a,b

a,b = makeMolecule()

Part Design scripted objects

When making scripted objects in Part Design the process is similar to the scripted objects discussed above, but with a few additional considerations. We must handle 2 shape properties, one for the shape we see in the 3D view and another for the shape used by the pattern tools, such as polar pattern features. The object shapes also needs to be fused to any existing material already in the Body (or cut from it in the case of Subtractive features). And we must account for the placement and attachment of our objects a little bit differently.

Part Design scripted solid object features should be based on either PartDesign::FeaturePython, PartDesign::FeatureAdditivePython, or PartDesign::FeatureSubtractivePython rather than Part::FeaturePython. Only the Additive and Subtractive variants can be used in pattern features, and if based on Part::FeaturePython when the user drops the object into a Part Design Body it becomes a BaseFeature rather than being treated by the Body as a native Part Design object. Note: all of these are expected to be solids, so if you are making a non-solid feature it should be based on Part::FeaturePython or else the next feature in the tree will attempt to fuse to as a solid and it will fail.

Here is a simple example of making a Tube primitive, similar to the Tube primitive in Part Workbench except this one will be a Part Design solid feature object. For this we will 2 separate files: pdtube.FCMacro and pdtube.py. The .FCMacro file will be executed by the user to create the object. The .py file will hold the class definitions, imported by the .FCMacro. The reason for doing it this way is to maintain the parametric nature of the object after restarting FreeCAD and opening a document containing one of our Tubes.

First, the class definition file:

# -*- coding: utf-8 -*-
#classes should go in pdtube.py
import FreeCAD, FreeCADGui, Part
class PDTube:
    def __init__(self,obj):
        obj.addProperty("App::PropertyLength","Radius1","Tube","Radius1").Radius1 = 5
        obj.addProperty("App::PropertyLength","Radius2","Tube","Radius2").Radius2 = 10
        obj.addProperty("App::PropertyLength","Height","Tube","Height of tube").Height = 10
        self.makeAttachable(obj)
        obj.Proxy = self

    def makeAttachable(self, obj):

        if int(FreeCAD.Version()[1]) >= 19:
            obj.addExtension('Part::AttachExtensionPython')
        else:
            obj.addExtension('Part::AttachExtensionPython', obj)

        obj.setEditorMode('Placement', 0) #non-readonly non-hidden

    def execute(self,fp):
        outer_cylinder = Part.makeCylinder(fp.Radius2, fp.Height)
        inner_cylinder = Part.makeCylinder(fp.Radius1, fp.Height)
        if fp.Radius1 == fp.Radius2: #just make cylinder
            tube_shape = outer_cylinder
        elif fp.Radius1 < fp.Radius2:
            tube_shape = outer_cylinder.cut(inner_cylinder)
        else: #invert rather than error out
            tube_shape = inner_cylinder.cut(outer_cylinder)

        if not hasattr(fp, "positionBySupport"):
            self.makeAttachable(fp)
        fp.positionBySupport()
        tube_shape.Placement = fp.Placement

        #BaseFeature (shape property of type Part::PropertyPartShape) is provided for us
        #with the PartDesign::FeaturePython and related classes, but it might be empty
        #if our object is the first object in the tree.  it's a good idea to check
        #for its existence in case we want to make type Part::FeaturePython, which won't have it

        if hasattr(fp, "BaseFeature") and fp.BaseFeature != None:
            if "Subtractive" in fp.TypeId:
                full_shape = fp.BaseFeature.Shape.cut(tube_shape)
            else:
                full_shape = fp.BaseFeature.Shape.fuse(tube_shape)
            full_shape.transformShape(fp.Placement.inverse().toMatrix(), True) #borrowed from gears workbench
            fp.Shape = full_shape
        else:
            fp.Shape = tube_shape
        if hasattr(fp,"AddSubShape"): #PartDesign::FeatureAdditivePython and
                                      #PartDesign::FeatureSubtractivePython have this
                                      #property but PartDesign::FeaturePython does not
                                      #It is the shape used for copying in pattern features
                                      #for example in making a polar pattern
            tube_shape.transformShape(fp.Placement.inverse().toMatrix(), True)
            fp.AddSubShape = tube_shape

class PDTubeVP:
    def __init__(self, obj):
        '''Set this object to the proxy object of the actual view provider'''
        obj.Proxy = self

    def attach(self,vobj):
        self.vobj = vobj

    def updateData(self, fp, prop):
        '''If a property of the handled feature has changed we have the chance to handle this here'''
        pass

    def getDisplayModes(self,obj):
        '''Return a list of display modes.'''
        modes=[]
        modes.append("Flat Lines")
        modes.append("Shaded")
        modes.append("Wireframe")
        return modes

    def getDefaultDisplayMode(self):
        '''Return the name of the default display mode. It must be defined in getDisplayModes.'''
        return "Flat Lines"

    def setDisplayMode(self,mode):
        '''Map the display mode defined in attach with those defined in getDisplayModes.\
                Since they have the same names nothing needs to be done. This method is optional'''
        return mode

    def onChanged(self, vp, prop):
        '''Here we can do something when a single property got changed'''
        #FreeCAD.Console.PrintMessage("Change property: " + str(prop) + "\n")
        pass

    def getIcon(self):
        '''Return the icon in XPM format which will appear in the tree view. This method is\
                optional and if not defined a default icon is shown.'''
        return """
            /* XPM */
            static const char * ViewProviderBox_xpm[] = {
            "16 16 6 1",
            "   c None",
            ".  c #141010",
            "+  c #615BD2",
            "@  c #C39D55",
            "#  c #000000",
            "$  c #57C355",
            "        ........",
            "   ......++..+..",
            "   .@@@@.++..++.",
            "   .@@@@.++..++.",
            "   .@@  .++++++.",
            "  ..@@  .++..++.",
            "###@@@@ .++..++.",
            "##$.@@$#.++++++.",
            "#$#$.$$$........",
            "#$$#######      ",
            "#$$#$$$$$#      ",
            "#$$#$$$$$#      ",
            "#$$#$$$$$#      ",
            " #$#$$$$$#      ",
            "  ##$$$$$#      ",
            "   #######      "};
            """

    def __getstate__(self):
        '''When saving the document this object gets stored using Python's json module.\
                Since we have some un-serializable parts here -- the Coin stuff -- we must define this method\
                to return a tuple of all serializable objects or None.'''
        return None

    def __setstate__(self,state):
        '''When restoring the serialized object from document we have the chance to set some internals here.\
                Since no data were serialized nothing needs to be done here.'''
        return None

And now the macro file to create the object:

# -*- coding: utf-8 -*-

#pdtube.FCMacro
import pdtube
#above line needed if the class definitions above are place in another file: PDTube.py
#this is needed if the tube object is to remain parametric after restarting FreeCAD and loading
#a document containing the object

body = FreeCADGui.ActiveDocument.ActiveView.getActiveObject("pdbody")
if not body:
    FreeCAD.Console.PrintError("No active body.\n")
else:
    from PySide import QtGui
    window = FreeCADGui.getMainWindow()
    items = ["Additive","Subtractive","Neither additive nor subtractive"]
    item,ok =QtGui.QInputDialog.getItem(window,"Select tube type","Select whether you want additive, subtractive, or neither:",items,0,False)
    if ok:
        if item == items[0]:
            className = "PartDesign::FeatureAdditivePython"
        elif item == items[1]:
            className = "PartDesign::FeatureSubtractivePython"
        else:
            className = "PartDesign::FeaturePython" #not usable in pattern features, such as polar pattern

        tube = FreeCAD.ActiveDocument.addObject(className,"Tube")
        pdtube.PDTube(tube)
        pdtube.PDTubeVP(tube.ViewObject)
        body.addObject(tube) #optionally we can also use body.insertObject() for placing at particular place in tree

Additional pages:

Interesting forum threads about scripted objects:

In addition to the examples presented here have a look at FreeCAD source code src/Mod/TemplatePyMod/FeaturePython.py for more examples.