Draft/Arch related changes

* Add Draft_LinkArray and Draft_PathLinkArray that uses link for both
  data and visualization, which supports linking external objects

* Add link group support for draft snap

* Fix ArchWindows expression ambiguity

src/Mod/Arch/ArchWindow.py

@@ -358,7 +358,7 @@ def doorFrame(s,width,height,h1,w1,o1):
                 s.renameConstraint(58,'Frame8')
                 s.renameConstraint(59,'Frame9')
                 s.renameConstraint(60,'F10')
-                s.setExpression('Constraints.F10','-Constraints.Frame5')
+                s.setExpression('.Constraints.F10','-.Constraints.Frame5')
             fw = str(w2)
             if w2 == w1:
                 fw = "0.00+V"

src/Mod/Draft/DraftSnap.py

@@ -234,8 +234,8 @@ def snap(self,screenpos,lastpoint=None,active=True,constrain=False,noTracker=Fal
             self.trackLine.p1(lastpoint)
 
         # checking if parallel to one of the edges of the last objects or to a polar direction
+        eline = None
         if active:
-            eline = None
             point,eline = self.snapToPolar(point,lastpoint)
             point,eline = self.snapToExtensions(point,lastpoint,constrain,eline)
 
@@ -273,14 +273,21 @@ def cycleSnapObject(self):
 
     def snapToObject(self, lastpoint, active, constrain, eline, point, oldActive):
         # we have an object to snap to
-        snaps = []
 
-        obj = FreeCAD.ActiveDocument.getObject(self.snapInfo['Object'])
+        parent = self.snapInfo.get('ParentObject',None)
+        if parent:
+            subname = self.snapInfo['SubName']
+            obj = parent.getSubObject(subname,retType=1)
+        else:
+            obj = FreeCAD.ActiveDocument.getObject(self.snapInfo['Object'])
+            parent = obj
+            subname = self.snapInfo['Component']
         if not obj:
-            self.spoint = self.cstr(lastpoint, constrain, point)
+            self.spoint = cstr(point)
             self.running = False
             return self.spoint
 
+        snaps = []
         self.lastSnappedObject = obj
 
         if hasattr(obj.ViewObject,"Selectable"):
@@ -303,11 +310,10 @@ def snapToObject(self, lastpoint, active, constrain, eline, point, oldActive):
             # active snapping
             comp = self.snapInfo['Component']
 
-            if obj.isDerivedFrom("Part::Feature"):
+            shape = Part.getShape(parent,subname,
+                        needSubElement=True,noElementMap=True)
 
-                # applying global placements
-                shape = obj.Shape.copy()
-                shape.Placement = obj.getGlobalPlacement()
+            if not shape.isNull():
 
                 snaps.extend(self.snapToSpecials(obj,lastpoint,eline))
 

src/Mod/Draft/DraftTools.py

@@ -4805,6 +4805,10 @@ def proceed(self):
 class Array(Modifier):
     """The Shape2DView FreeCAD command definition"""
 
+    def __init__(self,useLink=False):
+        Modifier.__init__(self)
+        self.useLink = useLink
+
     def GetResources(self):
         return {'Pixmap'  : 'Draft_Array',
                 'MenuText': QtCore.QT_TRANSLATE_NOOP("Draft_Array", "Array"),
@@ -4827,14 +4831,29 @@ def proceed(self):
             obj = FreeCADGui.Selection.getSelection()[0]
             FreeCADGui.addModule("Draft")
             self.commit(translate("draft","Array"),
-                        ['obj = Draft.makeArray(FreeCAD.ActiveDocument.'+obj.Name+',FreeCAD.Vector(1,0,0),FreeCAD.Vector(0,1,0),2,2)',
+                        ['obj = Draft.makeArray(FreeCAD.ActiveDocument.{},FreeCAD.Vector(1,0,0),FreeCAD.Vector(0,1,0),2,2,useLink={})'.format(obj.Name,self.useLink),
                          'Draft.autogroup(obj)',
                          'FreeCAD.ActiveDocument.recompute()'])
         self.finish()
 
+class LinkArray(Array):
+    "The Shape2DView FreeCAD command definition"
+
+    def __init__(self):
+        Array.__init__(self,True)
+
+    def GetResources(self):
+        return {'Pixmap'  : 'Draft_LinkArray',
+                'MenuText': QtCore.QT_TRANSLATE_NOOP("Draft_LinkArray", "LinkArray"),
+                'ToolTip': QtCore.QT_TRANSLATE_NOOP("Draft_LinkArray", "Creates a polar or rectangular link array from a selected object")}
+
 class PathArray(Modifier):
     """The PathArray FreeCAD command definition"""
 
+    def __init__(self,useLink=False):
+        Modifier.__init__(self)
+        self.useLink = useLink
+
     def GetResources(self):
         return {'Pixmap'  : 'Draft_PathArray',
                 'MenuText': QtCore.QT_TRANSLATE_NOOP("Draft_PathArray", "PathArray"),
@@ -4863,11 +4882,22 @@ def proceed(self):
             defCount = 4
             defAlign = False
             FreeCAD.ActiveDocument.openTransaction("PathArray")
-            Draft.makePathArray(base,path,defCount,defXlate,defAlign,pathsubs)
+            Draft.makePathArray(base,path,defCount,defXlate,defAlign,pathsubs,useLink=self.useLink)
             FreeCAD.ActiveDocument.commitTransaction()
             FreeCAD.ActiveDocument.recompute()                                  # feature won't appear until recompute.
         self.finish()
 
+class PathLinkArray(PathArray):
+    "The PathLinkArray FreeCAD command definition"
+
+    def __init__(self):
+        PathArray.__init__(self,True)
+
+    def GetResources(self):
+        return {'Pixmap'  : 'Draft_PathLinkArray',
+                'MenuText': QtCore.QT_TRANSLATE_NOOP("Draft_PathLinkArray", "PathLinkArray"),
+                'ToolTip': QtCore.QT_TRANSLATE_NOOP("Draft_PathLinkArray", "Creates links of a selected object along a selected path.")}
+
 class PointArray(Modifier):
     """The PointArray FreeCAD command definition"""
 
@@ -5851,8 +5881,10 @@ def IsActive(self):
 FreeCADGui.addCommand('Draft_WireToBSpline',WireToBSpline())
 FreeCADGui.addCommand('Draft_Draft2Sketch',Draft2Sketch())
 FreeCADGui.addCommand('Draft_Array',Array())
+FreeCADGui.addCommand('Draft_LinkArray',LinkArray())
 FreeCADGui.addCommand('Draft_Clone',Draft_Clone())
 FreeCADGui.addCommand('Draft_PathArray',PathArray())
+FreeCADGui.addCommand('Draft_PathLinkArray',PathLinkArray())
 FreeCADGui.addCommand('Draft_PointArray',PointArray())
 FreeCADGui.addCommand('Draft_Heal',Heal())
 FreeCADGui.addCommand('Draft_Mirror',Mirror())

src/Mod/Draft/DraftTrackers.py

@@ -723,6 +723,7 @@ def __init__(self,pos=Vector(0,0,0),name=None,idx=0,objcol=None,\
         else:
             selnode = coin.SoType.fromName("SoFCSelection").createInstance()
             if name:
+                selnode.useNewSelection = False
                 selnode.documentName.setValue(FreeCAD.ActiveDocument.Name)
                 selnode.objectName.setValue(name)
                 selnode.subElementName.setValue("EditNode"+str(idx))

src/Mod/Draft/InitGui.py

@@ -85,8 +85,8 @@ def QT_TRANSLATE_NOOP(scope, text):
                         "Draft_Edit", "Draft_Edit_Improved",
                         "Draft_WireToBSpline", "Draft_AddPoint",
                         "Draft_DelPoint", "Draft_Shape2DView",
-                        "Draft_Draft2Sketch", "Draft_Array",
-                        "Draft_PathArray", "Draft_PointArray", "Draft_Clone",
+                        "Draft_Draft2Sketch", "Draft_Array", "Draft_LinkArray",
+                        "Draft_PathArray", "Draft_PathLinkArray", "Draft_PointArray", "Draft_Clone",
                         "Draft_Drawing", "Draft_Mirror", "Draft_Stretch"]
         self.treecmdList = ["Draft_ApplyStyle", "Draft_ToggleDisplayMode",
                             "Draft_AddToGroup", "Draft_SelectGroup",

src/Mod/Draft/Resources/Draft.qrc

@@ -44,11 +44,13 @@
         <file>icons/Draft_Wipe.svg</file>
         <file>icons/Draft_Draft2Sketch.svg</file>
         <file>icons/Draft_Array.svg</file>
+        <file>icons/Draft_LinkArray.svg</file>
         <file>icons/Draft_Cursor.svg</file>
         <file>icons/Draft_Dot.svg</file>
         <file>icons/Draft_Point.svg</file>
         <file>icons/Draft_Snap.svg</file>
         <file>icons/Draft_PathArray.svg</file>
+        <file>icons/Draft_PathLinkArray.svg</file>
         <file>icons/Draft_PointArray.svg</file>
         <file>icons/Draft_VisGroup.svg</file>
         <file>icons/Snap_Lock.svg</file>