Merge pull request #586 from acq4/parametertree-updates

Parametertree updates

pyqtgraph/parametertree/Parameter.py

@@ -162,7 +162,11 @@ class Parameter(QtCore.QObject):
             'title': None,
             #'limits': None,  ## This is a bad plan--each parameter type may have a different data type for limits.
         }
+        value = opts.get('value', None)
+        name = opts.get('name', None)
         self.opts.update(opts)
+        self.opts['value'] = None  # will be set later.
+        self.opts['name'] = None
         
         self.childs = []
         self.names = {}   ## map name:child
@@ -172,17 +176,19 @@ class Parameter(QtCore.QObject):
         self.blockTreeChangeEmit = 0
         #self.monitoringChildren = False  ## prevent calling monitorChildren more than once
         
-        if 'value' not in self.opts:
+        if not isinstance(name, basestring):
-            self.opts['value'] = None
-        
-        if 'name' not in self.opts or not isinstance(self.opts['name'], basestring):
             raise Exception("Parameter must have a string name specified in opts.")
-        self.setName(opts['name'])
+        self.setName(name)
         
         self.addChildren(self.opts.get('children', []))
         
-        if 'value' in self.opts and 'default' not in self.opts:
+        self.opts['value'] = None
-            self.opts['default'] = self.opts['value']
+        if value is not None:
+            self.setValue(value)
+
+        if 'default' not in self.opts:
+            self.opts['default'] = None
+            self.setDefault(self.opts['value'])
     
         ## Connect all state changed signals to the general sigStateChanged
         self.sigValueChanged.connect(lambda param, data: self.emitStateChanged('value', data))
@@ -647,15 +653,16 @@ class Parameter(QtCore.QObject):
         """Return a child parameter. 
         Accepts the name of the child or a tuple (path, to, child)
 
-        Added in version 0.9.9. Ealier versions used the 'param' method, which is still
+        Added in version 0.9.9. Earlier versions used the 'param' method, which is still
-        implemented for backward compatibility."""
+        implemented for backward compatibility.
+        """
         try:
             param = self.names[names[0]]
         except KeyError:
-            raise Exception("Parameter %s has no child named %s" % (self.name(), names[0]))
+            raise KeyError("Parameter %s has no child named %s" % (self.name(), names[0]))
         
         if len(names) > 1:
-            return param.param(*names[1:])
+            return param.child(*names[1:])
         else:
             return param
 

pyqtgraph/parametertree/SystemSolver.py

@@ -1,5 +1,7 @@
 from ..pgcollections import OrderedDict
 import numpy as np
+import copy
+
 
 class SystemSolver(object):
     """
@@ -73,6 +75,12 @@ class SystemSolver(object):
         self.__dict__['_currentGets'] = set()
         self.reset()
         
+    def copy(self):
+        sys = type(self)()
+        sys.__dict__['_vars'] = copy.deepcopy(self.__dict__['_vars'])
+        sys.__dict__['_currentGets'] = copy.deepcopy(self.__dict__['_currentGets'])
+        return sys
+
     def reset(self):
         """
         Reset all variables in the solver to their default state.
@@ -167,6 +175,16 @@ class SystemSolver(object):
         elif constraint == 'fixed':
             if 'f' not in var[3]:
                 raise TypeError("Fixed constraints not allowed for '%s'" % name)
+            # This is nice, but not reliable because sometimes there is 1 DOF but we set 2
+            # values simultaneously. 
+            # if var[2] is None:
+            #     try:
+            #         self.get(name)
+            #         # has already been computed by the system; adding a fixed constraint
+            #         # would overspecify the system.
+            #         raise ValueError("Cannot fix parameter '%s'; system would become overconstrained." % name)
+            #     except RuntimeError:
+            #         pass
             var[2] = constraint
         elif isinstance(constraint, tuple):
             if 'r' not in var[3]:
@@ -177,7 +195,7 @@ class SystemSolver(object):
             raise TypeError("constraint must be None, True, 'fixed', or tuple. (got %s)" % constraint)
         
         # type checking / massaging
-        if var[1] is np.ndarray:
+        if var[1] is np.ndarray and value is not None:
             value = np.array(value, dtype=float)
         elif var[1] in (int, float, tuple) and value is not None:
             value = var[1](value)
@@ -187,7 +205,7 @@ class SystemSolver(object):
             raise ValueError("Setting %s = %s violates constraint %s" % (name, value, var[2]))
 
         # invalidate other dependent values
-        if var[0] is not None:
+        if var[0] is not None or value is None:
             # todo: we can make this more clever..(and might need to) 
             # we just know that a value of None cannot have dependencies
             # (because if anyone else had asked for this value, it wouldn't be 
@@ -237,6 +255,31 @@ class SystemSolver(object):
         for k in self._vars:
             getattr(self, k)
                 
+    def checkOverconstraint(self):
+        """Check whether the system is overconstrained. If so, return the name of
+        the first overconstrained parameter.
+
+        Overconstraints occur when any fixed parameter can be successfully computed by the system.
+        (Ideally, all parameters are either fixed by the user or constrained by the
+        system, but never both).
+        """
+        for k,v in self._vars.items():
+            if v[2] == 'fixed' and 'n' in v[3]:
+                oldval = v[:]
+                self.set(k, None, None)
+                try:
+                    self.get(k)
+                    return k
+                except RuntimeError:
+                    pass
+                finally:
+                    self._vars[k] = oldval
+
+        return False
+
+
+
+
     def __repr__(self):
         state = OrderedDict()
         for name, var in self._vars.items():

pyqtgraph/parametertree/parameterTypes.py

@@ -463,11 +463,14 @@ class GroupParameter(Parameter):
     """
     itemClass = GroupParameterItem
     
+    sigAddNew = QtCore.Signal(object, object)  # self, type
+
     def addNew(self, typ=None):
         """
         This method is called when the user has requested to add a new item to the group.
+        By default, it emits ``sigAddNew(self, typ)``.
         """
-        raise Exception("Must override this function in subclass.")
+        self.sigAddNew.emit(self, typ)
     
     def setAddList(self, vals):
         """Change the list of options available for the user to add to the group."""
@@ -605,6 +608,7 @@ class ActionParameterItem(ParameterItem):
         ParameterItem.__init__(self, param, depth)
         self.layoutWidget = QtGui.QWidget()
         self.layout = QtGui.QHBoxLayout()
+        self.layout.setContentsMargins(0, 0, 0, 0)
         self.layoutWidget.setLayout(self.layout)
         self.button = QtGui.QPushButton(param.name())
         #self.layout.addSpacing(100)