Skip to content
Snippets Groups Projects
Commit 8f56ea79 authored by Paul McCarthy's avatar Paul McCarthy
Browse files

First steps towards de-Tkinterising the properties code. Things are broken.

parent 6aa199df
No related branches found
No related tags found
No related merge requests found
Hide whitespace changes
Inline Side-by-side
fsl/__init__.py 0 → 100644
+ 0
− 0
View file @ 8f56ea79
fsl/props/__init__.py
+ 5
− 6
View file @ 8f56ea79
#!/usr/bin/env python #!/usr/bin/env python
# #
# __init__.py - Sets up the tkprop package namespace. # __init__.py - Sets up the fsl.props package namespace.
# #
# Author: Paul McCarthy <pauldmccarthy@gmail.com> # Author: Paul McCarthy <pauldmccarthy@gmail.com>
# #
from tkprop.properties import \ from fsl.props.properties import \
TkVarProxy, \
PropertyBase, \ PropertyBase, \
HasProperties HasProperties
from tkprop.properties_types import \ from fsl.props.properties_types import \
Boolean, \ Boolean, \
Int, \ Int, \
Double, \ Double, \
...@@ -20,10 +19,10 @@ from tkprop.properties_types import \ ...@@ -20,10 +19,10 @@ from tkprop.properties_types import \
Choice, \ Choice, \
List List
from tkprop.widgets import \ from fsl.props.widgets import \
makeWidget makeWidget
from tkprop.build import \ from fsl.props.build import \
buildGUI, \ buildGUI, \
ViewItem, \ ViewItem, \
Button, \ Button, \
......
fsl/props/properties.py
+ 99
− 158
View file @ 8f56ea79
#!/usr/bin/env python #!/usr/bin/env python
# #
# properties.py - Tkinter control variables encapsulated inside Python # properties.py - Python descriptors of various types.
# descriptors.
# #
# This module should not be imported directly - import the tkprops # This module should not be imported directly - import the fsl.props
# package instead. Property type definitions are in properties_types.py. # package instead. Property type definitions are in properties_types.py.
# #
# Usage: # Usage:
...@@ -126,64 +125,56 @@ ...@@ -126,64 +125,56 @@
# author: Paul McCarthy <pauldmccarthy@gmail.com> # author: Paul McCarthy <pauldmccarthy@gmail.com>
# #
import types import types
import logging as log import logging as log
import Tkinter as tk
class TkVarProxy(object): class PropertyValue(object):
""" """
Proxy object which encapsulates a Tkinter control variable. One or Proxy object which encapsulates a single value for a property.
more TkVarProxy objects is created for every property of a One or more PropertyValue objects is created for every property
HasProperties instance. of a HasProperties instance.
""" """
def __init__(self, tkProp, owner, tkVarType, value, name=None): def __init__(self, prop, owner, value, name=None):
""" """
Creates an instance of the specified tkVarType, and sets a
trace on it.
Parameters: Parameters:
- tkProp: The PropertyBase object which manages this - prop: The PropertyBase object which manages this
TkVarProxy. PropertyValue.
- owner: The HasProperties object, the owner of the - owner: The HasProperties object, the owner of the
tkProp property. prop property.
- tkVarType: The type of Tkinter control variable that - value: Initial value.
this TkVarProxy encapsulates. - name: Variable name - if not provided, a default,
- value: Initial value. unique name is created.
- name: Variable name - if not provided, a default,
unique name is created.
""" """
if name is None: name = '{}_{}'.format(tkProp.label, id(self)) if name is None: name = '{}_{}'.format(prop.label, id(self))
self.tkVarType = tkVarType self.prop = prop
self.tkProp = tkProp
self.owner = owner self.owner = owner
self.changeListeners = {}
self.name = name self.name = name
self.changeListeners = {}
self._value = value
self._valid = None
self._lastValue = value self._lastValue = value
self._lastValid = None self._lastValid = None
self.tkVar = tkVarType(value=value, name=name)
self.traceName = self.tkVar.trace('w', self._traceCb)
def addListener(self, name, callback): def addListener(self, name, callback):
""" """
Adds a listener for this variable. When the variable value Adds a listener for this value. When the value changes, the
changes, the listener callback function is called. Listener listener callback function is called. Listener notification
notification may also be programmatically triggered via the may also be programmatically triggered via the
PropertyBase.forceValidation method. The callback function PropertyBase.forceValidation method. The callback function
must accept these arguments: must accept these arguments:
value - The property value value - The property value
valid - Whether the value is valid or invalid valid - Whether the value is valid or invalid
instance - The HasProperties instance instance - The HasProperties instance
tkProp - The PropertyBase instance prop - The PropertyBase instance
name - The name of this TkVarProxy name - The name of this PropertyValue
If you are only interested in the value, you can define your If you are only interested in the value, you can define your
callback function like 'def callback(value, *a): ...' callback function like 'def callback(value, *a): ...'
...@@ -205,56 +196,45 @@ class TkVarProxy(object): ...@@ -205,56 +196,45 @@ class TkVarProxy(object):
self.changeListeners[instance].pop(name, None) self.changeListeners[instance].pop(name, None)
def get(self):
"""
Returns the current property value.
"""
return self._value
def _getVarValue(self):
def set(self, newValue):
""" """
Returns the current value of the Tkinter control Sets the property value. The property is validated, and any
variable being managed by this TkVarProxy object. registered listeners are notified.
""" """
# This is silly. Tkinter allows Boolean/Int/Double self._value = newValue
# variables to be set to invalid values (e.g. it
# allows DoubleVars to be set to strings containing
# non numeric characters). But then, later calls to
# get() will fail, as they will attempt to convert
# the invalid value to a boolean/int/double. So here
# we attempt to get the current value in the normal
# way ...
try: value = self.tkVar.get()
# and if that fails, we manually look up the value log.debug('Variable {} changed: {}'.format(self.name, newValue))
# via the current tk context, thus avoiding the
# failing type cast. Ugly.
except: value = self.tkVar._tk.globalgetvar(self.name)
# More silliness related to above silliness. All # Validate the new value and notify any registered listeners
# variables in Tk, be they IntVars, BooleanVars, or self.validateAndNotify()
# whatever, are stored as strings, and cannot have no
# value. If you try to set a Tk variable to None, it # Notify the property owner that this property has changed
# will be converted to a string, and stored as 'None', self.owner._propChanged(self.prop)
# which is quite different. So I'm following the
# convention that an empty string, for any of the
# variable types, is equivalent to None.
if value == '': value = None
return value
def validateAndNotify(self): def validateAndNotify(self):
""" """
Passes the current variable value to the validate() Passes the current value to the validate() method
method of the PropertyBase object which owns this of the PropertyBase object which owns this PropertyValue.
TkVarProxy. If the value, or the validity of that If the value, or the validity of that value, has changed
value, has changed since the last validation, any since the last validation, any listeners which have been
listeners which have been registered with this registered with this PropertyValue object are notified.
TkVarProxy object are notified..
""" """
value = self._getVarValue() value = self.get()
valid = True valid = True
listeners = self.changeListeners.items() listeners = self.changeListeners.items()
try: self.tkProp.validate(self.owner, value) try: self.prop.validate(self.owner, value)
except ValueError: valid = False except ValueError: valid = False
# Listeners are only notified if the value or its # Listeners are only notified if the value or its
...@@ -272,74 +252,46 @@ class TkVarProxy(object): ...@@ -272,74 +252,46 @@ class TkVarProxy(object):
log.debug('Notifying listener on {}: {}'.format(self.name, name)) log.debug('Notifying listener on {}: {}'.format(self.name, name))
try: func(value, valid, self.owner, self.tkProp, self.name) try: func(value, valid, self.owner, self.prop, self.name)
except Exception as e: except Exception as e:
log.debug('Listener on {} ({}) raised exception: {}'.format( log.debug('Listener on {} ({}) raised exception: {}'.format(
self.name, name, e)) self.name, name, e))
def _traceCb(self, *args):
"""
Called whenever the Tkinter control variable value is changed.
Notifies any registered listeners, and the HasProperties
property owner, of the change.
"""
newValue = self._getVarValue()
log.debug('Variable {} changed: {}'.format(self.name, newValue))
# Validate the new value and notify any registered listeners
self.validateAndNotify()
# Notify the property owner that this property has changed
self.owner._propChanged(self.tkProp)
def __del__(self):
"""
Remove the trace on the Tkinter variable.
"""
self.tkVar.trace_vdelete('w', self.traceName)
class PropertyBase(object): class PropertyBase(object):
""" """
The base class for properties. Subclasses should: The base class for properties. For every object which has this
PropertyBase object as a property, one or more PropertyValue
instances are created and attached as an attribute of the parent.
Subclasses should:
- Ensure that PropertyBase.__init__ is called. - Ensure that PropertyBase.__init__ is called.
- Override the validate method to implement any built in - Override the validate method to implement any built in
validation rules, ensuring that the PropertyBase.validate validation rules, ensuring that the PropertyBase.validate
method is called. method is called first.
- Override __get__ and __set__ for any required implicit - Override __get__ and __set__ for any required implicit
casting/data transformation rules (see casting/data transformation rules (see
properties_types.String for an example). properties_types.String for an example).
- Override _makeTkVar if creation of the TkVarProxy needs - Override _makePropVal if creation of the PropertyValue
to be controlled (see properties_types.Choice for an needs to be controlled (see properties_types.Choice for
example). an example).
- Override getTkVar for properties which consist of - Override getPropVal for properties which consist of
more than one TkVarProxy object more than one PropertyValue object
(see properties_types.List for an example). (see properties_types.List for an example).
- Override whatever you want for advanced usage (see - Override whatever you want for advanced usage (see
properties_types.List for an example). properties_types.List for an example).
""" """
def __init__(self, tkVarType, default, required=False, validateFunc=None): def __init__(self, default, required=False, validateFunc=None):
""" """
The tkvartype parameter should be one of the Tkinter.*Var Parameters:
classes. For every object (the parent) which has this
PropertyBase object as a property, one or more TkVarProxy
instances are created and attached as an attribute of the
parent. Parameters:
- tkVarType: Tkinter control variable class. May be
None for properties which manage multiple
TkVarProxy objects.
- default: Default/initial value. - default: Default/initial value.
...@@ -357,7 +309,6 @@ class PropertyBase(object): ...@@ -357,7 +309,6 @@ class PropertyBase(object):
new value is invalid. new value is invalid.
""" """
self.label = None self.label = None
self.tkVarType = tkVarType
self.default = default self.default = default
self.required = required self.required = required
self.validateFunc = validateFunc self.validateFunc = validateFunc
...@@ -367,7 +318,7 @@ class PropertyBase(object): ...@@ -367,7 +318,7 @@ class PropertyBase(object):
def addListener(self, instance, name, callback): def addListener(self, instance, name, callback):
""" """
Register a listener with this property. When the property value Register a listener with this property. When the property value
changes, the listener will be notified. See TkVarProxy.addListener changes, the listener will be notified. See PropertyValue.addListener
for required callback function signature. for required callback function signature.
""" """
...@@ -398,20 +349,20 @@ class PropertyBase(object): ...@@ -398,20 +349,20 @@ class PropertyBase(object):
This will result in any registered listeners being notified. This will result in any registered listeners being notified.
""" """
varProxies = instance.getTkVar(self.label) propVals = instance.getPropVal(self.label)
# getTkVar returns either a TkVarProxy object, or a # getPropVal returns either a PropertyValue object,
# list of TkVarProxy objects (it should do, anyway). # or a list of them (it should do, anyway).
if isinstance(varProxies, TkVarProxy): if isinstance(propVals, PropertyValue):
varProxies = [varProxies] propVals = [propVals]
for var in varProxies: for val in propVals:
var.validateAndNotify() val.validateAndNotify()
def _varChanged(self, value, valid, instance, tkProp, name): def _varChanged(self, value, valid, instance, prop, name):
""" """
This function is registered with the TkVarProxy object (or This function is registered with the PropertyValue object (or
objects) which are managed by this PropertyBase instance. objects) which are managed by this PropertyBase instance.
It notifies any listeners which have been registered to It notifies any listeners which have been registered to
this property, (and to the associated HasProperties instance). this property, (and to the associated HasProperties instance).
...@@ -425,18 +376,17 @@ class PropertyBase(object): ...@@ -425,18 +376,17 @@ class PropertyBase(object):
log.debug('Notifying listener on {}: {}'.format(self.label, lName)) log.debug('Notifying listener on {}: {}'.format(self.label, lName))
func(value, valid, instance, tkProp, name) func(value, valid, instance, prop, name)
def _makeTkVar(self, instance): def _makePropVal(self, instance):
""" """
Creates a TkVarProxy object, and attaches it to the given Creates a PropertyValue object, and attaches it to the given
instance. Also registers this PropertyBase instance as a instance. Also registers this PropertyBase instance as a
listener on the TkVarProxy object. listener on the PropertyValue object.
""" """
instval = TkVarProxy( instval = PropertyValue(self, instance, self.default, self.label)
self, instance, self.tkVarType, self.default, self.label)
instance.__dict__[self.label] = instval instance.__dict__[self.label] = instval
listenerName = 'PropertyBase_{}_{}'.format(self.label, id(instval)) listenerName = 'PropertyBase_{}_{}'.format(self.label, id(instval))
...@@ -446,11 +396,11 @@ class PropertyBase(object): ...@@ -446,11 +396,11 @@ class PropertyBase(object):
return instval return instval
def getTkVar(self, instance): def getPropVal(self, instance):
""" """
Return the TkVarProxy object (or objects) for this property, Return the PropertyValue object (or objects) for this property,
associated with the given HasProperties instance. Properties associated with the given HasProperties instance. Properties
which contain multiple TkVarProxy objects should override which contain multiple PropertyValue objects should override
this method to return a list of said objects. this method to return a list of said objects.
""" """
return instance.__dict__[self.label] return instance.__dict__[self.label]
...@@ -489,38 +439,29 @@ class PropertyBase(object): ...@@ -489,38 +439,29 @@ class PropertyBase(object):
""" """
If called on the HasProperties class, and not on an instance, If called on the HasProperties class, and not on an instance,
returns this PropertyBase object. Otherwise, returns the value returns this PropertyBase object. Otherwise, returns the value
contained in the TkVarProxy variable which is attached to the contained in the PropertyValue variable which is attached to the
instance. instance.
""" """
if instance is None: if instance is None:
return self return self
instval = instance.__dict__.get(self.label, None) instval = self.getPropVal(instance)
if instval is None: instval = self._makeTkVar(instance)
if instval is None: instval = self._makePropVal(instance)
# See comments in TkVarProxy._getVarValue
# for a brief overview of this silliness.
try: val = instval.tkVar.get()
except: val = instval.tkVar._tk.globalgetvar(instval.tkVar._name)
if val == '': val = None
return val return instval.get()
def __set__(self, instance, value): def __set__(self, instance, value):
""" """
Set the Tkinter variable, attached to the given instance, to Set the value of this property, as attached to the given
the given value. instance, to the given value.
""" """
# See comments in TkVarProxy._getVarValue
# for a brief overview of this silliness.
if value is None: value = ''
instval = self.getTkVar(instance) instval = self.getPropVal(instance)
instval.tkVar.set(value) instval.set(value)
class PropertyOwner(type): class PropertyOwner(type):
...@@ -562,18 +503,18 @@ class HasProperties(object): ...@@ -562,18 +503,18 @@ class HasProperties(object):
return inst return inst
def getTkProp(self, propName): def getProp(self, propName):
""" """
Return the tkprop PropertyBase object for the given property. Return the PropertyBase object for the given property.
""" """
return getattr(self.__class__, propName) return getattr(self.__class__, propName)
def getTkVar(self, propName): def getPropVal(self, propName):
""" """
Return the TkVarProxy object(s) for the given property. Return the PropertyValue object(s) for the given property.
""" """
return self.getTkProp(propName).getTkVar(self) return self.getProp(propName).getPropVal(self)
def getAllProperties(self): def getAllProperties(self):
...@@ -618,7 +559,7 @@ class HasProperties(object): ...@@ -618,7 +559,7 @@ class HasProperties(object):
return errors return errors
def _propChanged(self, cProp): def _propChanged(self, changedProp):
""" """
Called whenever any property value changes. Forces validation Called whenever any property value changes. Forces validation
for all other properties, and notification of their registered for all other properties, and notification of their registered
...@@ -632,7 +573,7 @@ class HasProperties(object): ...@@ -632,7 +573,7 @@ class HasProperties(object):
propNames, props = self.getAllProperties() propNames, props = self.getAllProperties()
for prop in props: for prop in props:
if prop == cProp: continue if prop == changedProp: continue
prop.forceValidation(self) prop.forceValidation(self)
......
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment