ViewFromPlacement: fixes

* fix Lattice2 not loading on FC v0.17
* fix look-around when "Rotate At Cursor" is on in preferences.

lattice2ViewFromPlacement.py

@@ -26,12 +26,77 @@ __author__ = "DeepSOIC"
 __url__ = ""
 
 import FreeCAD as App
+if App.GuiUp:
+    import FreeCADGui as Gui
 
 from lattice2Common import *
 import lattice2BaseFeature as LBF
 import lattice2CompoundExplorer as LCE
 
-import Show
+try:
+    import Show
+except ImportError:
+    Show = None
+try:
+    from Show.SceneDetail import SceneDetail
+except ImportError:
+    SceneDetail = None
+    
+from copy import copy
+
+class SDParameter(SceneDetail if SceneDetail is not None else object):
+    """SDParameter(param_path, param_name, param_type, param_val = None): Plugin for TempoVis for changing a parameter."""
+    class_id = 'SDParameter'
+    mild_restore = True
+    param_path = ''
+    param_name = ''
+    param_type = ''
+    
+    def __init__(self, param_path, param_name, param_type, param_val = None):
+        self.key = '{param_path}/[{param_type}]{param_name}'.format(**vars())
+        self.param_path = param_path
+        self.param_name = param_name
+        self.param_type = param_type
+        if param_val is not None:
+            self.data = param_val
+            
+    def scene_value(self):
+        import FreeCAD as App
+        hgrp = App.ParamGet(self.param_path)
+        getter, def1, def2 = {
+            'Bool'    : (hgrp.GetBool    , True, False),
+            'Float'   : (hgrp.GetFloat   , 1.0, 2.0   ),
+            'Int'     : (hgrp.GetInt     , 1, 2       ),
+            'String'  : (hgrp.GetString  , 'a', 'b'   ),
+            'Unsigned': (hgrp.GetUnsigned, 1, 2       ),
+        }[self.param_type]
+        val1 = getter(self.param_name, def1)
+        val2 = getter(self.param_name, def2)
+        absent = val1 == def1 and val2 == def2
+        return val1 if not absent else None
+    
+    def apply_data(self, val):
+        import FreeCAD as App
+        hgrp = App.ParamGet(self.param_path)
+        setter = {
+            'Bool'    : (hgrp.SetBool    ),
+            'Float'   : (hgrp.SetFloat   ),
+            'Int'     : (hgrp.SetInt     ),
+            'String'  : (hgrp.SetString  ),
+            'Unsigned': (hgrp.SetUnsigned),
+        }[self.param_type]
+        deleter = {
+            'Bool'    : (hgrp.RemBool    ),
+            'Float'   : (hgrp.RemFloat   ),
+            'Int'     : (hgrp.RemInt     ),
+            'String'  : (hgrp.RemString  ),
+            'Unsigned': (hgrp.RemUnsigned),
+        }[self.param_type]
+        if val is None:
+            deleter(self.param_name)
+        else:
+            setter(self.param_name, val)
+
 
 def getSelectedPlacement(obj, sub):
     leaves = LCE.AllLeaves(obj.Shape)
@@ -54,6 +119,8 @@ def getSelectedPlacement(obj, sub):
 # --------------------------------Gui commands----------------------------------
 
 _library = {} #instances of TempoVis, per document
+_old_par = None #original value of DragAtCursor parameter
+_stack_len = 0 #how many times did we tried to modify the parameter
 
 class CommandViewFromPlacement:
     def GetResources(self):
@@ -66,6 +133,9 @@ class CommandViewFromPlacement:
     def Activated(self):
         import FreeCADGui as Gui
 
+        global _stack_len
+        global _old_par
+
         oldTV =  _library.pop(App.ActiveDocument.Name, None)
         if oldTV is None:            
             V = App.Vector
@@ -83,7 +153,15 @@ class CommandViewFromPlacement:
                 #prepare
                 tv = Show.TempoVis(App.ActiveDocument)
                 tv.saveCamera()
-                
+                if SceneDetail is not None:
+                    tv.modify(SDParameter('User parameter:BaseApp/Preferences/View','DragAtCursor','Bool', False))
+                else:
+                    dt = SDParameter('User parameter:BaseApp/Preferences/View','DragAtCursor','Bool', False)
+                    if _stack_len == 0:
+                        _old_par = dt.scene_value()
+                    _stack_len += 1 
+                    dt.apply_data(dt.data)
+                    
                 #set up camera
                 Gui.ActiveDocument.ActiveView.setCameraType('Perspective')
                 from pivy import coin
@@ -107,12 +185,17 @@ class CommandViewFromPlacement:
             if Gui.ActiveDocument.ActiveView.getCameraType() == 'Perspective':
                 cam = Gui.ActiveDocument.ActiveView.getCameraNode()
                 cam.heightAngle = abs(cam.heightAngle.getValue()) #workaround
+            if SceneDetail is None:
+                _stack_len -= 1 
+                if _stack_len == 0:
+                    dt = SDParameter('User parameter:BaseApp/Preferences/View','DragAtCursor','Bool', False)
+                    dt.apply_data(_old_par)
             
     def IsActive(self):
-        if not App.ActiveDocument: return False
-        return True
+        if Show is None: return False
+        return hasattr(Gui.activeView(), 'getCameraNode')
             
-if FreeCAD.GuiUp:
+if App.GuiUp:
     FreeCADGui.addCommand('Lattice2_ViewFromPlacement', CommandViewFromPlacement())
 
 exportedCommands = [