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<languages/>
<languages/>

{{Docnav/de
|[[Topological_data_scripting/de|Topologische Daten skripten]]
|[[Scenegraph/de|Szenengraph]]
}}


{{TOCright}}
{{TOCright}}


<span id="Introduction"></span>
==Einführung==
==Einführung==


Neben den Standard Objekttypen wie Anmerkungen, Netze und Teileobjekte bietet FreeCAD auch die erstaunliche Möglichkeit, 100% python geschriebene Objekte zu erstellen, die als Python Funktionen bezeichnet werden. Diese Objekte verhalten sich genau wie jedes andere FreeCAD Objekt und werden beim Speichern/Laden von Dateien automatisch gespeichert und wiederhergestellt.
Neben den Standard-Objekttypen wie Beschriftungen, Netze und Bauteilobjekte bietet FreeCAD auch die erstaunliche Möglichkeit, 100% mit Python geschriebene parametrische Objekte zu erstellen, die als [[App_FeaturePython|Python-Objekt]] (App FeaturePython-Objekt) bezeichnet werden. Diese Objekte verhalten sich genau wie jedes andere FreeCAD-Objekt und werden beim Speichern/Laden von Dateien automatisch gespeichert und wiederhergestellt.

Eine Besonderheit muss beachtet werden: Aus Sicherheitsgründen enthalten FreeCAD Dateien niemals eingebetteten Code. Der Python Code, den du zum Erstellen von parametrischen Objekten schreibst, wird niemals innerhalb einer Datei gespeichert. Das bedeutet, dass, wenn du eine Datei, die ein solches Objekt enthält, auf einem anderen Rechner öffnest, wenn dieser Python Code auf diesem Rechner nicht verfügbar ist, das Objekt nicht vollständig neu erstellt wird. Wenn du solche Objekte an andere weitergibst, musst du auch dein Python Skript weitergeben, z. B. als [[Macros/de|Makro]].

'''Hinweis''': Es ist möglich, Python Code in eine FreeCAD Datei zu packen, indem man json mit einem App::PropertyPythonObject serialisiert, aber dieser Code kann nie direkt ausgeführt werden und hat daher für unseren Zweck hier wenig Nutzen.


[[App_FeaturePython/de|Python-Objekte]] folgen der gleichen Regel wie alle FreeCAD Funktionen: Sie sind in App- und einen GUI-Teile getrennt. Der App-Teil, das Dokument-Objekt, definiert die Geometrie unseres Objekts, während sein GUI-Teil, das View-Provider-Objekt, definiert, wie das Objekt auf dem Bildschirm daegestellt wird. Das Ansichtsprovider-Objekt ist, wie jede andere FreeCAD-Funktion, nur verfügbar, wenn FreeCAD in seiner eigenen GUI ausgeführt wird. Es stehen mehrere Eigenschaften und Methoden zur Verfügung, um ein Objekt zu erstellen. Die Eigenschaften müssen zu einem der vordefinierten Eigenschaftstypen gehören, die FreeCAD anbietet und werden im Eigenschaften Ansichtsfenster angezeigt, damit sie vom Benutzer bearbeitet werden können. Auf diese Weise sind FeaturePython-Objekte wirklich und vollständig parametrisch. Du kannst Eigenschaften für das Objekt und sein Ansichtsobjekt getrennt definieren.
Eine Besonderheit muss verstanden werden, diese Objekte werden in FreeCAD FcStd Dateien mit dem Python Modul [https://docs.python.org/3/library/json.html json] gespeichert. Dieses Modul wandelt ein Python Objekt in eine Zeichenkette um, so dass es der gespeicherten Datei hinzugefügt werden kann. Beim Laden verwendet das json Modul diese Zeichenfolge, um das ursprüngliche Objekt wieder zu erzeugen, vorausgesetzt, es hat Zugriff auf den Quellcode, der das Objekt erzeugt hat. Das heißt, wenn Sie ein solches benutzerdefiniertes Objekt speichern und es auf einem Rechner öffnen, auf dem der Python Code, der das Objekt erzeugt hat, nicht vorhanden ist, wird das Objekt nicht neu erstellt. Wenn Sie solche Objekte an andere verteilen, müssen Sie das Python Skript, das das Objekt erzeugt hat, zusammen verteilen.


<span id="Basic_example"></span>
Python Funktionen folgen der gleichen Regel wie alle FreeCAD Funktionen: Sie sind in App- und einen GUI Teile getrennt. Der App-Teil, das Dokument-Objekt, definiert die Geometrie unseres Objekts, während sein GUI-Teil, das View-Provider-Objekt, definiert, wie das Objekt auf dem Bildschirm gezeichnet wird. Das Ansichtsprovider-Objekt ist, wie jede andere FreeCAD-Funktion, nur verfügbar, wenn Sie FreeCAD in seiner eigenen GUI ausführen. Es stehen mehrere Eigenschaften und Methoden zur Verfügung, um Ihr Objekt zu erstellen. Die Eigenschaften müssen zu einem der vordefinierten Eigenschaftstypen gehören, die FreeCAD anbietet, und werden im Eigenschaften-Ansichtsfenster angezeigt, damit sie vom Benutzer bearbeitet werden können. Auf diese Weise sind FeaturePython Objekte wirklich und vollständig parametrisch. Sie können Eigenschaften für das Objekt und sein Ansichtsobjekt getrennt definieren.
==Grundlegendes Beispiel==


Das folgende Beispiel ist zusammen mit einigen anderen Beispielen in der Datei [https://github.com/FreeCAD/FreeCAD/blob/master/src/Mod/TemplatePyMod/FeaturePython.py src/Mod/TemplatePyMod/FeaturePython.py] zu finden:
'''Tip:''' In früheren Versionen haben wir das Python Modul [http://docs.python.org/release/2.5/lib/module-cPickle.html cPickle] verwendet. Dieses Modul führt jedoch willkürlichen Code aus und verursacht damit ein Sicherheitsproblem. Daher sind wir zu Pythons json Modul übergegangen.


== Grundlegendes Beispiel ==
Das folgende Beispiel ist zusammen mit einigen anderen Beispielen in der [https://github.com/FreeCAD/FreeCAD/blob/master/src/Mod/TemplatePyMod/FeaturePython.py src/Mod/TemplatePyMod/FeaturePython.py] Datei zu finden:
{{Code|code=
{{Code|code=
'''Examples for a feature class and its view provider.'''
'''Examples for a feature class and its view provider.'''
Line 24: Line 33:
def __init__(self, obj):
def __init__(self, obj):
'''Add some custom properties to our box feature'''
'''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", "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", "Width", "Box", "Width of the box").Width = 1.0
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'''
Line 40: Line 49:
def __init__(self, obj):
def __init__(self, obj):
'''Set this object to the proxy object of the actual view provider'''
'''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.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'''
Line 49: Line 58:
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)
self.shaded.addChild(self.color)
self.shaded.addChild(self.color)
self.shaded.addChild(data)
self.shaded.addChild(data)
obj.addDisplayMode(self.shaded,"Shaded");
obj.addDisplayMode(self.shaded, "Shaded");
style=coin.SoDrawStyle()
style=coin.SoDrawStyle()
style.style = coin.SoDrawStyle.LINES
style.style = coin.SoDrawStyle.LINES
Line 61: Line 70:
self.wireframe.addChild(self.color)
self.wireframe.addChild(self.color)
self.wireframe.addChild(data)
self.wireframe.addChild(data)
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'''
Line 70: Line 79:
w = fp.getPropertyByName("Width")
w = fp.getPropertyByName("Width")
h = fp.getPropertyByName("Height")
h = fp.getPropertyByName("Height")
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.'''
Line 79: Line 88:
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'''
Line 94: Line 103:
if prop == "Color":
if prop == "Color":
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\
Line 126: Line 135:
" ####### "};
" ####### "};
"""
"""

def __getstate__(self):
def dumps(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.\
Since we have some un-serializable parts here -- the Coin stuff -- we must define this method\
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.'''
to return a tuple of all serializable objects or None.'''
return None
return None

def __setstate__(self,state):
def loads(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():
FreeCAD.newDocument()
FreeCAD.newDocument()
a=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Box")
a=FreeCAD.ActiveDocument.addObject("App::FeaturePython", "Box")
Box(a)
Box(a)
ViewProviderBox(a.ViewObject)
ViewProviderBox(a.ViewObject)


makeBox()
makeBox()

}}
}}

=== Things to note ===
=== 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.
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.
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.


Eine Erklärung von {{incode|__getstate__}} und {{incode|__setstate__}} findest du im Forumsbeitrag [https://forum.freecadweb.org/viewtopic.php?f=18&t=44009&start=10#p377892 obj.Proxy.Type ist ein Verzeichnis, keine Zeichenfolge].
Eine Erklärung zu {{incode|__getstate__}} und {{incode|__setstate__}}, die durch {{incode|dumps}} und {{incode|loads}} ersetzt wurden, befindet sich im Forumsbeitrag [https://forum.freecadweb.org/viewtopic.php?f=18&t=44009&start=10#p377892 obj.Proxy.Type is a dict, not a string].


{{incode|obj.addProperty(...)}} returns {{incode|obj}}, so that the value of the property can be set on the same line:
== Verfügbare Methoden ==
Siehe [[FeaturePython_methods/de|FunktionPython Methoden]] für die vollständige Referenz.

== Verfügbare Eigenschaften ==

Eigenschaften sind die wahren Bausteine von FeaturePython-Gegenständen. Durch ist der Benutzer im Stande, mit einem Objekt zu interagieren und es zu ändern. Nach dem Erstellen eines neuen FeaturePython-Objekts in Ihrem Dokument( a=FreeCAD.ActiveDocument.addObject("App::FeaturePython","Box") ), können eine Liste der verfügbaren Eigenschaften bekommen, indem Sie folgendes eingeben:


{{Code|code=
{{Code|code=
obj.addProperty("App::PropertyLength", "Length", "Box", "Length of the box").Length = 1.0
obj.supportedProperties()
}}
Sie werden eine Liste von verfügbaren Eigenschaften bekommen mit:
{{Code|code=
App::PropertyBool
App::PropertyBoolList
App::PropertyFloat
App::PropertyFloatList
App::PropertyFloatConstraint
App::PropertyQuantity
App::PropertyQuantityConstraint
App::PropertyAngle
App::PropertyDistance
App::PropertyLength
App::PropertySpeed
App::PropertyAcceleration
App::PropertyForce
App::PropertyPressure
App::PropertyInteger
App::PropertyIntegerConstraint
App::PropertyPercent
App::PropertyEnumeration
App::PropertyIntegerList
App::PropertyIntegerSet
App::PropertyMap
App::PropertyString
App::PropertyUUID
App::PropertyFont
App::PropertyStringList
App::PropertyLink
App::PropertyLinkSub
App::PropertyLinkList
App::PropertyLinkSubList
App::PropertyMatrix
App::PropertyVector
App::PropertyVectorList
App::PropertyPlacement
App::PropertyPlacementLink
App::PropertyPlacementList
App::PropertyColor
App::PropertyColorList
App::PropertyMaterial
App::PropertyPath
App::PropertyFile
App::PropertyFileIncluded
App::PropertyPythonObject
Part::PropertyPartShape
Part::PropertyGeometryList
Part::PropertyShapeHistory
Part::PropertyFilletEdges
Sketcher::PropertyConstraintList
}}
}}


Which is equivalent to:
Beim Hinzufügen von Eigenschaften zu benutzerdefinierten Objekte, achten Sie bitte auf folgendes:

* Verwenden Sie keine Zeichen "<" oder ">" in den Eigenschaftes-Beschreibungen (das würde den XML-Teil in der .Fcstd-Datei zerbrechen)
* Eigenschaften werden alphabetisch in einer .fcstd Datei gespeichert. Wenn Sie eine Form("Shape") in Ihren Eigenschaften haben, wird jede Eigenschaft, deren Name in alphabetischen Reihenfolge nach "Shape" kommt, auch nach der Form geladen, was zu seltsamen Verhaltensweisen führen kann.

A complete list of property attributes can be seen in the [https://github.com/FreeCAD/FreeCAD/blob/master/src/App/PropertyStandard.h 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:


{{Code|code=
{{Code|code=
obj.addProperty("App::PropertyLength", "Length", "Box", "Length of the box")
prop = (value, lower, upper, stepsize)
obj.Length = 1.0
}}
}}


<span id="Other_more_complex_example"></span>
==Eigenschaftstyp==
==Andere komplexere Beispiele==
Standardmäßig können die Eigenschaften aktualisiert werden. Es ist möglich, die Eigenschaften schreibgeschützt zu machen, zum Beispiel für den Fall, dass man das Ergebnis einer Methode anzeigen möchte. Es ist auch möglich, die Eigenschaft auszublenden.
Der Eigenschaftstyp kann festgelegt werden mit

{{Code|code=
obj.setEditorMode("MyPropertyName", mode)
}}

wobei mode ein kurzer int ist, der gesetzt werden kann auf:
0 -- Standardmodus, Lesen und Schreiben
1 -- Nur-Lesen
2 -- Versteckt

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):

{{Code|code=
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 [https://github.com/FreeCAD/FreeCAD/blob/master/src/App/PropertyContainer.h source code C++ header for PropertyContainer]


Dieses Beispiel verwendet das [[Part_Workbench/de|Part-Modul]], um ein Oktaeder zu erstellen und dann seine Coin-Darstellung mit pivy.
== Andere komplexere Beispiele ==
Dieses Beispiel macht vom [[Part_Module/de|Part Modul]] Gebrauch, um ein Oktaeder zu schaffen, erstellt dann seine coin Darstellung mit pivy.


Das Erste ist das Documentobjekt selbst:
Das Erste ist das Documentobjekt selbst:
Line 289: Line 206:
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 327: Line 244:


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)
Line 354: Line 271:
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)
Line 445: Line 362:
"""
"""


def __getstate__(self):
def dumps(self):
return None
return None


def __setstate__(self,state):
def loads(self,state):
return None
return None
}}
}}
Line 461: Line 378:
}}
}}


<span id="Making_objects_selectable"></span>
== Objekte auswählbar machen ==
== Objekte auswählbar machen ==

Wenn du dein Objekt oder zumindest einen Teil davon durch Anklicken im Ansichtsfenster auswählbar machen möchtest, musst du seine coin Geometrie in einen SoFCSelection Knoten aufnehmen. Wenn dein Objekt eine komplexe Darstellung hat, mit Widgets, Anmerkungen usw., möchtest du vielleicht nur einen Teil davon in eine SoFCSelection einschließen. Alles, was eine SoFCSelection ist, wird von FreeCAD ständig gescannt, um Auswahl/Vorwahl zu erkennen, daher ist es sinnvoll, es nicht mit unnötigem Scannen zu überlasten.
Wenn du dein Objekt oder zumindest einen Teil davon durch Anklicken im Ansichtsfenster auswählbar machen möchtest, musst du seine Coin-Geometrie in einen SoFCSelection-Knoten aufnehmen. Wenn dein Objekt eine komplexe Darstellung hat, mit Widgets, Anmerkungen usw., möchtest du vielleicht nur einen Teil davon in eine SoFCSelection einschließen. Alles, was eine SoFCSelection ist, wird von FreeCAD ständig gescannt, um Auswahl/Vorwahl zu erkennen, daher ist es sinnvoll, es nicht mit unnötigem Scannen zu überlasten.


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).
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).


Hier ist das obige Molekülbeispiel, angepasst, um die Elemente des Moleküls auswählbar zu machen:
Hier ist das obige Molekülbeispiel, angepasst, um die Elemente des Moleküls auswählbar zu machen:

{{Code|code=
{{Code|code=
class Molecule:
class Molecule:
Line 537: Line 457:
return 'Atom2'
return 'Atom2'
raise NotImplementedError
raise NotImplementedError



def updateData(self, fp, prop):
def updateData(self, fp, prop):
Line 549: Line 468:
self.trl2.translation=(p.x,p.y,p.z)
self.trl2.translation=(p.x,p.y,p.z)


def __getstate__(self):
def dumps(self):
return None
return None


def __setstate__(self,state):
def loads(self,state):
return None
return None


Line 563: Line 482:
}}
}}


== Arbeiten mit einfachen Formen ==
== Working with simple shapes ==

Erstellen Sie einfach einen SoFCSelection Knoten, dann fügen Sie Ihre Geometrie-Knoten dazu hinzu, dann fügen Sie alles zu Ihrem Hauptknoten hinzu, anstatt Ihre Geometrie-Knoten direkt einzufügen. Die Form wird mittels der FreeCAD Standard-Form-Darstellung angezeigt:
Wenn ein parametrisches Objekt einfach nur eine Form ausgibt, muss man keinen View-Provider-Objekt verwenden. Die Form wird mit FreeCADs Standard-Form-Darstellung angezeigt.


{{Code|code=
{{Code|code=
Line 602: Line 522:
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 623: Line 543:


== Scenegraph Structure ==
== Scenegraph Structure ==

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)}}.
Du hast vielleicht bemerkt, dass die obigen Beispiele deine Szenengraphen auf leicht unterschiedliche Weise aufbauen. Einige verwenden {{incode|obj.addDisplayMode(node, "modename")}}, während andere {{incode|obj.SwitchNode.getChild(x).addChild(y)}} verwenden.


Each feature in a FreeCAD document is based the following scenegraph structure:
Each feature in a FreeCAD document is based the following scenegraph structure:
Line 763: Line 684:
return 'Line'
return 'Line'
raise NotImplementedError
raise NotImplementedError



def updateData(self, fp, prop):
def updateData(self, fp, prop):
Line 786: Line 706:
return mode
return mode


def __getstate__(self):
def dumps(self):
return None
return None


def __setstate__(self,state):
def loads(self,state):
return None
return None


Line 804: Line 724:
}}
}}


== 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 dumps(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 loads(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
}}

== Available object types ==

The list of all object types you can create with {{incode|FreeCAD.ActiveDocument.addObject()}} can be obtained with {{incode|FreeCAD.ActiveDocument.supportedTypes()}}. Only object types with a name ending in {{incode|Python}} can be used for scripted objects. These are listed here (for FreeCAD v0.21):
* {{incode|App::DocumentObjectGroupPython}}
* {{incode|App::FeaturePython}}
* {{incode|App::GeometryPython}}
* {{incode|App::LinkElementPython}}
* {{incode|App::LinkGroupPython}}
* {{incode|App::LinkPython}}
* {{incode|App::MaterialObjectPython}}
* {{incode|App::PlacementPython}}
* {{incode|Part::CustomFeaturePython}}
* {{incode|Part::FeaturePython}}
* {{incode|Part::Part2DObjectPython}}
* {{incode|Path::FeatureAreaPython}}
* {{incode|Path::FeatureAreaViewPython}}
* {{incode|Path::FeatureCompoundPython}}
* {{incode|Path::FeaturePython}}
* {{incode|Path::FeatureShapePython}}
* {{incode|Sketcher::SketchObjectPython}}
* {{incode|TechDraw::DrawComplexSectionPython}}
* {{incode|TechDraw::DrawLeaderLinePython}}
* {{incode|TechDraw::DrawPagePython}}
* {{incode|TechDraw::DrawRichAnnoPython}}
* {{incode|TechDraw::DrawTemplatePython}}
* {{incode|TechDraw::DrawTilePython}}
* {{incode|TechDraw::DrawTileWeldPython}}
* {{incode|TechDraw::DrawViewPartPython}}
* {{incode|TechDraw::DrawViewPython}}
* {{incode|TechDraw::DrawViewSectionPython}}
* {{incode|TechDraw::DrawViewSymbolPython}}
* {{incode|TechDraw::DrawWeldSymbolPython}}

<span id="Available_methods"></span>
==Vorhandene Methoden==

Siehe [[FeaturePython_methods/de|FeaturePython Methoden]] für eine vollständige Referenz.

<span id="Available_properties"></span>
==Vorhandene Eigenschaften==

Eigenschaften sind die wahren Bausteine von FeaturePython-Objekten. Durch sie kann man mit einem Objekt interagieren und es ändern. Nach dem Erstellen eines neuen FeaturePython-Objekts in einem Dokument, kann man eine Liste der vorhandenen Eigenschaften bekommen:

{{Code|code=
obj = FreeCAD.ActiveDocument.addObject("App::FeaturePython", "Box")
obj.supportedProperties()
}}

Siehe [[FeaturePython_Custom_Properties/de|FunktionsPython benutzerdefinierte Eigenschaften]] für einen Überblick:

Beim Hinzufügen von Eigenschaften zu benutzerdefinierten Objekten bitte folgendes beachten:
* Nicht die Zeichen {{Incode|<}} oder {{Incode| >}} in den Beschreibungen der Eigenschaften verwenden (das würde die XML-Teile in der .FCStd-Datei auseinanderbrechen)
* Eigenschaften werden alphabetisch in einer .FCStd-Datei gespeichert. Befindet sich eine Form (shape) in den Eigenschaften, wird jede Eigenschaft, deren Name in alphabetischen Reihenfolge nach "Shape" kommt, auch NACH der Form geladen, was zu seltsamen Verhaltensweisen führen kann.

Die Eigenschaften sind in der C++ header-Datei [https://github.com/FreeCAD/FreeCAD/blob/master/src/App/PropertyStandard.h PropertyStandard.h] festgelegt.

<span id="Property_types"></span>
===Arten von Eigenschaften===

Standardmäßig können Eigenschaften aktualisiert werden, aber es ist möglich, die Eigenschaften auf schreibgeschützt zu setzen, wenn man zum Beispiel das Ergebnis einer Methode anzeigen möchte. Es ist auch möglich, eine Eigenschaft auszublenden. Die Art der Eigenschaft kann festgelegt werden mit:

{{Code|code=
obj.setEditorMode("MyPropertyName", mode)
}}

wobei mode ein kurzer int ist, der gesetzt werden kann auf:
0 -- Standardmodus, Lesen und Schreiben
1 -- Nur-Lesen
2 -- Versteckt

The mode can also be set using a list of strings, e.g. {{incode|obj.setEditorMode("Placement", ["ReadOnly", "Hidden"])}}.

The EditorModes are not set at FreeCAD file reload. This could to be done by the {{Incode|loads}} function. See http://forum.freecadweb.org/viewtopic.php?f=18&t=13460&start=10#p108072. By using the {{Incode|setEditorMode}} the properties are only read-only in the [[Property_editor|Property editor]]. They can still be changed from Python. To really make them read-only the setting has to be passed directly inside the {{Incode|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 {{Incode|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):

{{Code|code=
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
32 -- Prop_NoPersist, Property won't be saved to file at all

The property types are defined in the [https://github.com/FreeCAD/FreeCAD/blob/master/src/App/PropertyContainer.h PropertyContainer C++ header file].

== Available extensions ==

The list of available extensions can be obtained with {{incode|grep -RI EXTENSION_PROPERTY_SOURCE_TEMPLATE}} in the repository of the source code and is given here (for FreeCAD v0.21).

For objects:
* {{incode|App::GeoFeatureGroupExtensionPython}}
* {{incode|App::GroupExtensionPython}}
* {{incode|App::LinkBaseExtensionPython}}
* {{incode|App::LinkExtensionPython}}
* {{incode|App::OriginGroupExtensionPython}}
* {{incode|Part::AttachExtensionPython}}
* {{incode|TechDraw::CosmeticExtensionPython}}

For view objects:
* {{incode|Gui::ViewProviderExtensionPython}}
* {{incode|Gui::ViewProviderGeoFeatureGroupExtensionPython}}
* {{incode|Gui::ViewProviderGroupExtensionPython}}
* {{incode|Gui::ViewProviderOriginGroupExtensionPython}}
* {{incode|PartGui::ViewProviderAttachExtensionPython}}
* {{incode|PartGui::ViewProviderSplineExtensionPython}}

There exist other extensions but they do not work as-is:
* {{incode|App::ExtensionPython}}
* {{incode|TechDrawGui::ViewProviderCosmeticExtensionPython}}
* {{incode|TechDrawGui::ViewProviderDrawingViewExtensionPython}}
* {{incode|TechDrawGui::ViewProviderPageExtensionPython}}
* {{incode|TechDrawGui::ViewProviderTemplateExtensionPython}}

<span id="Further_information"></span>
== Weitere Informationen ==
== Weitere Informationen ==


Line 813: Line 1,033:


Interessante Forenbeiträge über geskriptete Objekte:
Interessante Forenbeiträge über geskriptete Objekte:

* [http://forum.freecadweb.org/viewtopic.php?f=22&t=13740 Python object attributes lost at load]
* [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]
* [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=44009 Explanation on dumps and loads], [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=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?]
* [https://forum.freecadweb.org/viewtopic.php?f=22&t=21330 how to implement python feature's setEdit properly?]
Line 821: Line 1,042:
Zusätzlich zu den hier vorgestellten Beispielen solltedz du einen Blick in den FreeCAD Quellcode [https://github.com/FreeCAD/FreeCAD/blob/master/src/Mod/TemplatePyMod/FeaturePython.py src/Mod/TemplatePyMod/FeaturePython.py] für weitere Beispiele werfen.
Zusätzlich zu den hier vorgestellten Beispielen solltedz du einen Blick in den FreeCAD Quellcode [https://github.com/FreeCAD/FreeCAD/blob/master/src/Mod/TemplatePyMod/FeaturePython.py src/Mod/TemplatePyMod/FeaturePython.py] für weitere Beispiele werfen.



{{Docnav/de
|[[Topological_data_scripting/de|Topologische Daten skripten]]
|[[Scenegraph/de|Szenengraph]]
}}


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

Latest revision as of 14:37, 3 February 2024

Other languages:

Einführung

Neben den Standard-Objekttypen wie Beschriftungen, Netze und Bauteilobjekte bietet FreeCAD auch die erstaunliche Möglichkeit, 100% mit Python geschriebene parametrische Objekte zu erstellen, die als Python-Objekt (App FeaturePython-Objekt) bezeichnet werden. Diese Objekte verhalten sich genau wie jedes andere FreeCAD-Objekt und werden beim Speichern/Laden von Dateien automatisch gespeichert und wiederhergestellt.

Eine Besonderheit muss beachtet werden: Aus Sicherheitsgründen enthalten FreeCAD Dateien niemals eingebetteten Code. Der Python Code, den du zum Erstellen von parametrischen Objekten schreibst, wird niemals innerhalb einer Datei gespeichert. Das bedeutet, dass, wenn du eine Datei, die ein solches Objekt enthält, auf einem anderen Rechner öffnest, wenn dieser Python Code auf diesem Rechner nicht verfügbar ist, das Objekt nicht vollständig neu erstellt wird. Wenn du solche Objekte an andere weitergibst, musst du auch dein Python Skript weitergeben, z. B. als Makro.

Hinweis: Es ist möglich, Python Code in eine FreeCAD Datei zu packen, indem man json mit einem App::PropertyPythonObject serialisiert, aber dieser Code kann nie direkt ausgeführt werden und hat daher für unseren Zweck hier wenig Nutzen.

Python-Objekte folgen der gleichen Regel wie alle FreeCAD Funktionen: Sie sind in App- und einen GUI-Teile getrennt. Der App-Teil, das Dokument-Objekt, definiert die Geometrie unseres Objekts, während sein GUI-Teil, das View-Provider-Objekt, definiert, wie das Objekt auf dem Bildschirm daegestellt wird. Das Ansichtsprovider-Objekt ist, wie jede andere FreeCAD-Funktion, nur verfügbar, wenn FreeCAD in seiner eigenen GUI ausgeführt wird. Es stehen mehrere Eigenschaften und Methoden zur Verfügung, um ein Objekt zu erstellen. Die Eigenschaften müssen zu einem der vordefinierten Eigenschaftstypen gehören, die FreeCAD anbietet und werden im Eigenschaften Ansichtsfenster angezeigt, damit sie vom Benutzer bearbeitet werden können. Auf diese Weise sind FeaturePython-Objekte wirklich und vollständig parametrisch. Du kannst Eigenschaften für das Objekt und sein Ansichtsobjekt getrennt definieren.

Grundlegendes Beispiel

Das folgende Beispiel ist zusammen mit einigen anderen Beispielen in der Datei src/Mod/TemplatePyMod/FeaturePython.py zu finden: 

'''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 dumps(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 loads(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.

Eine Erklärung zu __getstate__ und __setstate__, die durch dumps und loads ersetzt wurden, befindet sich im Forumsbeitrag obj.Proxy.Type is a dict, not a string.

obj.addProperty(...) returns obj, so that the value of the property can be set on the same line: 

obj.addProperty("App::PropertyLength", "Length", "Box", "Length of the box").Length = 1.0

Which is equivalent to: 

obj.addProperty("App::PropertyLength", "Length", "Box", "Length of the box")
obj.Length = 1.0

Andere komplexere Beispiele

Dieses Beispiel verwendet das Part-Modul, um ein Oktaeder zu erstellen und dann seine Coin-Darstellung mit pivy.

Das Erste ist das Documentobjekt selbst: 

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

Dann haben wir das View Provider Objekt, das für die Darstellung des Objekts in der 3D Szene verantwortlich ist: 

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 dumps(self):
     return None

  def loads(self,state):
     return None

Schließlich, sobald unser Objekt und sein Viewobjekt definiert sind, müssen wir sie nur noch aufrufen (Der Code der Octahedron Klasse und der Viewprovider Klasse könnte direkt in die FreeCAD Python Konsole kopiert werden): 

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

Objekte auswählbar machen

Wenn du dein Objekt oder zumindest einen Teil davon durch Anklicken im Ansichtsfenster auswählbar machen möchtest, musst du seine Coin-Geometrie in einen SoFCSelection-Knoten aufnehmen. Wenn dein Objekt eine komplexe Darstellung hat, mit Widgets, Anmerkungen usw., möchtest du vielleicht nur einen Teil davon in eine SoFCSelection einschließen. Alles, was eine SoFCSelection ist, wird von FreeCAD ständig gescannt, um Auswahl/Vorwahl zu erkennen, daher ist es sinnvoll, es nicht mit unnötigem Scannen zu überlasten.

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).

Hier ist das obige Molekülbeispiel, angepasst, um die Elemente des Moleküls auswählbar zu machen: 

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 dumps(self):
        return None

    def loads(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

Wenn ein parametrisches Objekt einfach nur eine Form ausgibt, muss man keinen View-Provider-Objekt verwenden. Die Form wird mit FreeCADs Standard-Form-Darstellung angezeigt. 

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()

Gleicher Code unter Verwendung von 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

Du hast vielleicht bemerkt, dass die obigen Beispiele deine Szenengraphen auf leicht unterschiedliche Weise aufbauen. Einige verwenden obj.addDisplayMode(node, "modename"), während andere obj.SwitchNode.getChild(x).addChild(y) verwenden.

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 dumps(self):
        return None

    def loads(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 dumps(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 loads(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

Available object types

The list of all object types you can create with FreeCAD.ActiveDocument.addObject() can be obtained with FreeCAD.ActiveDocument.supportedTypes(). Only object types with a name ending in Python can be used for scripted objects. These are listed here (for FreeCAD v0.21):

  • App::DocumentObjectGroupPython
  • App::FeaturePython
  • App::GeometryPython
  • App::LinkElementPython
  • App::LinkGroupPython
  • App::LinkPython
  • App::MaterialObjectPython
  • App::PlacementPython
  • Part::CustomFeaturePython
  • Part::FeaturePython
  • Part::Part2DObjectPython
  • Path::FeatureAreaPython
  • Path::FeatureAreaViewPython
  • Path::FeatureCompoundPython
  • Path::FeaturePython
  • Path::FeatureShapePython
  • Sketcher::SketchObjectPython
  • TechDraw::DrawComplexSectionPython
  • TechDraw::DrawLeaderLinePython
  • TechDraw::DrawPagePython
  • TechDraw::DrawRichAnnoPython
  • TechDraw::DrawTemplatePython
  • TechDraw::DrawTilePython
  • TechDraw::DrawTileWeldPython
  • TechDraw::DrawViewPartPython
  • TechDraw::DrawViewPython
  • TechDraw::DrawViewSectionPython
  • TechDraw::DrawViewSymbolPython
  • TechDraw::DrawWeldSymbolPython

Vorhandene Methoden

Siehe FeaturePython Methoden für eine vollständige Referenz.

Vorhandene Eigenschaften

Eigenschaften sind die wahren Bausteine von FeaturePython-Objekten. Durch sie kann man mit einem Objekt interagieren und es ändern. Nach dem Erstellen eines neuen FeaturePython-Objekts in einem Dokument, kann man eine Liste der vorhandenen Eigenschaften bekommen: 

obj = FreeCAD.ActiveDocument.addObject("App::FeaturePython", "Box")
obj.supportedProperties()

Siehe FunktionsPython benutzerdefinierte Eigenschaften für einen Überblick:

Beim Hinzufügen von Eigenschaften zu benutzerdefinierten Objekten bitte folgendes beachten:

  • Nicht die Zeichen < oder > in den Beschreibungen der Eigenschaften verwenden (das würde die XML-Teile in der .FCStd-Datei auseinanderbrechen)
  • Eigenschaften werden alphabetisch in einer .FCStd-Datei gespeichert. Befindet sich eine Form (shape) in den Eigenschaften, wird jede Eigenschaft, deren Name in alphabetischen Reihenfolge nach "Shape" kommt, auch NACH der Form geladen, was zu seltsamen Verhaltensweisen führen kann.

Die Eigenschaften sind in der C++ header-Datei PropertyStandard.h festgelegt.

Arten von Eigenschaften

Standardmäßig können Eigenschaften aktualisiert werden, aber es ist möglich, die Eigenschaften auf schreibgeschützt zu setzen, wenn man zum Beispiel das Ergebnis einer Methode anzeigen möchte. Es ist auch möglich, eine Eigenschaft auszublenden. Die Art der Eigenschaft kann festgelegt werden mit: 

obj.setEditorMode("MyPropertyName", mode)

wobei mode ein kurzer int ist, der gesetzt werden kann auf: 

0 -- Standardmodus, Lesen und Schreiben
1 -- Nur-Lesen
2 -- Versteckt

The mode can also be set using a list of strings, e.g. obj.setEditorMode("Placement", ["ReadOnly", "Hidden"]).

The EditorModes are not set at FreeCAD file reload. This could to be done by the loads 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 the Property editor. They can 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
 32 -- Prop_NoPersist, Property won't be saved to file at all

The property types are defined in the PropertyContainer C++ header file.

Available extensions

The list of available extensions can be obtained with grep -RI EXTENSION_PROPERTY_SOURCE_TEMPLATE in the repository of the source code and is given here (for FreeCAD v0.21).

For objects:

  • App::GeoFeatureGroupExtensionPython
  • App::GroupExtensionPython
  • App::LinkBaseExtensionPython
  • App::LinkExtensionPython
  • App::OriginGroupExtensionPython
  • Part::AttachExtensionPython
  • TechDraw::CosmeticExtensionPython

For view objects:

  • Gui::ViewProviderExtensionPython
  • Gui::ViewProviderGeoFeatureGroupExtensionPython
  • Gui::ViewProviderGroupExtensionPython
  • Gui::ViewProviderOriginGroupExtensionPython
  • PartGui::ViewProviderAttachExtensionPython
  • PartGui::ViewProviderSplineExtensionPython

There exist other extensions but they do not work as-is:

  • App::ExtensionPython
  • TechDrawGui::ViewProviderCosmeticExtensionPython
  • TechDrawGui::ViewProviderDrawingViewExtensionPython
  • TechDrawGui::ViewProviderPageExtensionPython
  • TechDrawGui::ViewProviderTemplateExtensionPython

Weitere Informationen

Weitere Seiten:

Interessante Forenbeiträge über geskriptete Objekte:

Zusätzlich zu den hier vorgestellten Beispielen solltedz du einen Blick in den FreeCAD Quellcode src/Mod/TemplatePyMod/FeaturePython.py für weitere Beispiele werfen.


Power user documentation
Retrieved from "http://wiki.freecad.org/index.php?title=Scripted_objects/de&oldid=1361855"