Commit 1c94d1b8 authored by Luke Campagnola's avatar Luke Campagnola
Browse files

Updated parametertree documentation

parent 0ee255ac
......@@ -14,14 +14,39 @@ def registerParameterType(name, cls, override=False):
class Parameter(QtCore.QObject):
"""Tree of name=value pairs (modifiable or not)
Tree of name=value pairs (modifiable or not)
- Value may be integer, float, string, bool, color, or list selection
- Optionally, a custom widget may be specified for a property
- Any number of extra columns may be added for other purposes
- Any values may be reset to a default value
- Parameters may be grouped / nested
- Parameter may be subclassed to provide customized behavior.
For more Parameter types, see ParameterTree.parameterTypes module.
=================================== =========================================================
sigStateChanged(self, change, info) Emitted when anything changes about this parameter at
The second argument is a string indicating what changed
('value', 'childAdded', etc..)
The third argument can be any extra information about
the change
sigTreeStateChanged(self, changes) Emitted when any child in the tree changes state
(but only if monitorChildren() is called)
the format of *changes* is [(param, change, info), ...]
sigValueChanged(self, value) Emitted when value is finished changing
sigValueChanging(self, value) Emitted immediately for all value changes,
including during editing.
sigChildAdded(self, child, index) Emitted when a child is added
sigChildRemoved(self, child) Emitted when a child is removed
sigParentChanged(self, parent) Emitted when this parameter's parent has changed
sigLimitsChanged(self, limits) Emitted when this parameter's limits have changed
sigDefaultChanged(self, default) Emitted when this parameter's default value has changed
sigNameChanged(self, name) Emitted when this parameter's name has changed
sigOptionsChanged(self, opts) Emitted when any of this parameter's options have changed
=================================== =========================================================
## name, type, limits, etc.
## can also carry UI hints (slider vs spinbox, etc.)
......@@ -244,25 +269,33 @@ class Parameter(QtCore.QObject):
def defaultValue(self):
"""Return the default value for this parameter."""
return self.opts['default']
def setDefault(self, val):
"""Set the default value for this parameter."""
if self.opts['default'] == val:
self.opts['default'] = val
self.sigDefaultChanged.emit(self, val)
def setToDefault(self):
"""Set this parameter's value to the default."""
if self.hasDefault():
def hasDefault(self):
"""Returns True if this parameter has a default value."""
return 'default' in self.opts
def valueIsDefault(self):
"""Returns True if this parameter's value is equal to the default value."""
return self.value() == self.defaultValue()
def setLimits(self, limits):
"""Set limits on the acceptable values for this parameter.
The format of limits depends on the type of the parameter and
some parameters do not make use of limits at all."""
if 'limits' in self.opts and self.opts['limits'] == limits:
self.opts['limits'] = limits
......@@ -270,10 +303,20 @@ class Parameter(QtCore.QObject):
return limits
def writable(self):
Returns True if this parameter's value can be changed by the user.
Note that the value of the parameter can *always* be changed by
calling setValue().
return not self.opts.get('readonly', False)
def setOpts(self, **opts):
"""For setting any arbitrary options."""
Set any arbitrary options on this parameter.
The exact behavior of this function will depend on the parameter type, but
most parameters will accept a common set of options: value, name, limits,
default, readonly, removable, renamable, visible, and enabled.
changed = collections.OrderedDict()
for k in opts:
if k == 'value':
......@@ -344,6 +387,7 @@ class Parameter(QtCore.QObject):
return child
def removeChild(self, child):
"""Remove a child parameter."""
name =
if name not in self.names or self.names[name] is not child:
raise Exception("Parameter %s is not my child; can't remove." % str(child))
......@@ -355,22 +399,27 @@ class Parameter(QtCore.QObject):
def clearChildren(self):
"""Remove all child parameters."""
for ch in self.childs[:]:
def children(self):
"""Return a list of this parameter's children."""
## warning -- this overrides QObject.children
return self.childs[:]
def parentChanged(self, parent):
"""This method is called when the parameter's parent has changed.
It may be useful to extend this method in subclasses."""
self._parent = parent
self.sigParentChanged.emit(self, parent)
def parent(self):
"""Return the parent of this parameter."""
return self._parent
def remove(self):
"""Remove self from parent's child list"""
"""Remove this parameter from its parent's child list"""
parent = self.parent()
if parent is None:
raise Exception("Cannot remove; no parent.")
......@@ -396,13 +445,21 @@ class Parameter(QtCore.QObject):
yield ch
def __getitem__(self, names):
"""Get the value of a child parameter"""
"""Get the value of a child parameter. The name may also be a tuple giving
the path to a sub-parameter::
value = param[('child', 'grandchild')]
if not isinstance(names, tuple):
names = (names,)
return self.param(*names).value()
def __setitem__(self, names, value):
"""Set the value of a child parameter"""
"""Set the value of a child parameter. The name may also be a tuple giving
the path to a sub-parameter::
param[('child', 'grandchild')] = value
if isinstance(names, basestring):
names = (names,)
return self.param(*names).setValue(value)
......@@ -424,6 +481,7 @@ class Parameter(QtCore.QObject):
return "<%s '%s' at 0x%x>" % (self.__class__.__name__,, id(self))
def __getattr__(self, attr):
## Leaving this undocumented because I might like to remove it in the future..
#print type(self), attr
if attr in self.names:
return self.param(attr)
......@@ -442,9 +500,12 @@ class Parameter(QtCore.QObject):
self.items[item] = None
def hide(self):
"""Hide this parameter. It and its children will no longer be visible in any ParameterTree
widgets it is connected to."""
def show(self, s=True):
"""Show this parameter. """
self.opts['visible'] = s
self.sigOptionsChanged.emit(self, {'visible': s})
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