PythonBrowser¶
A PyObjC Example without documentation
Sources¶
PythonBrowser.py¶
"""PythonBrowser.py -- a module and/or demo program implementing a Python
object browser.
It can be used in two ways:
1) as a standalone demo app that shows how to use the NSOutlineView class
2) as a module to add an object browser to your app.
For the latter usage, include PythonBrowser.nib in your app bundle,
make sure that PythonBrowser.py and PythonBrowserModel.py can be found
on sys.path, and call
PythonBrowser.PythonBrowserWindowController(aBrowsableObject)
from your app. The object to be browsed can't be a number, a string or
None, any other kind of object is fine.
To build the demo program, run this line in Terminal.app:
$ python setup.py py2app -A
This creates a directory "dist" containing PythonBrowser.app. (The
-A option causes the files to be symlinked to the .app bundle instead
of copied. This means you don't have to rebuild the app if you edit the
sources or nibs.)
"""
import sys
import Cocoa
import objc
from PythonBrowserModel import PythonBrowserModel
# class defined in PythonBrowser.nib
class PythonBrowserWindowController(Cocoa.NSWindowController):
outlineView = objc.IBOutlet()
def __new__(cls, obj):
# "Pythonic" constructor
return cls.alloc().initWithObject_(obj)
def initWithObject_(self, obj):
self = self.initWithWindowNibName_("PythonBrowser")
self.setWindowTitleForObject_(obj)
self.model = PythonBrowserModel.alloc().initWithObject_(obj)
self.outlineView.setDataSource_(self.model)
self.outlineView.setDelegate_(self.model)
self.outlineView.setTarget_(self)
self.outlineView.setDoubleAction_(b"doubleClick:")
self.window().makeFirstResponder_(self.outlineView)
self.showWindow_(self)
# The window controller doesn't need to be retained (referenced)
# anywhere, so we pretend to have a reference to ourselves to avoid
# being garbage collected before the window is closed. The extra
# reference will be released in self.windowWillClose_()
self.retain()
return self
def windowWillClose_(self, notification):
# see comment in self.initWithObject_()
self.autorelease()
def setWindowTitleForObject_(self, obj):
if hasattr(obj, "__name__"):
title = f"PythonBrowser -- {type(obj).__name__}: {obj.__name__}"
else:
title = f"PythonBrowser -- {type(obj).__name__}"
self.window().setTitle_(title)
def setObject_(self, obj):
self.setWindowTitleForObject_(obj)
self.model.setObject_(obj)
self.outlineView.reloadData()
@objc.IBAction
def doubleClick_(self, sender):
# Open a new browser window for each selected expandable item
for row in self.outlineView.selectedRowEnumerator():
item = self.outlineView.itemAtRow_(row)
if item.isExpandable():
PythonBrowserWindowController(item.object)
@objc.IBAction
def pickRandomModule_(self, sender):
"""Test method, hooked up from the "Pick Random Module" menu in
MainMenu.nib, to test changing the browsed object after the window
has been created."""
from random import choice
mod = None
while mod is None:
mod = sys.modules[choice(sys.modules.keys())]
self.setObject_(mod)
class PythonBrowserAppDelegate(Cocoa.NSObject):
def applicationDidFinishLaunching_(self, notification):
self.newBrowser_(self)
@objc.IBAction
def newBrowser_(self, sender):
# The PythonBrowserWindowController instance will retain itself,
# so we don't (have to) keep track of all instances here.
PythonBrowserWindowController(sys)
if __name__ == "__main__":
from PyObjCTools import AppHelper
AppHelper.runEventLoop()
PythonBrowserModel.py¶
"""PythonBrowserModel.py -- module implementing the data model for PythonBrowser."""
import sys
from operator import getitem, setitem
from AppKit import NSBeep
from Foundation import NSObject
class PythonBrowserModel(NSObject):
"""This is a delegate as well as a data source for NSOutlineViews."""
def initWithObject_(self, obj):
self = self.init()
self.setObject_(obj)
return self
def setObject_(self, obj):
self.root = PythonItem("<root>", obj, None, None)
# NSOutlineViewDataSource methods
def outlineView_numberOfChildrenOfItem_(self, view, item):
if item is None:
item = self.root
return len(item)
def outlineView_child_ofItem_(self, view, child, item):
if item is None:
item = self.root
return item.getChild_(child)
def outlineView_isItemExpandable_(self, view, item):
if item is None:
item = self.root
return item.isExpandable()
def outlineView_objectValueForTableColumn_byItem_(self, view, col, item):
if item is None:
item = self.root
return getattr(item, col.identifier())
def outlineView_setObjectValue_forTableColumn_byItem_(self, view, value, col, item):
assert col.identifier() == "value"
if item.value == value:
return
try:
obj = eval(value, {})
except: # noqa: E722, B001
NSBeep()
print("Error:", sys.exc_info())
print(" :", repr(value))
else:
item.setValue_(obj)
# delegate method
def outlineView_shouldEditTableColumn_item_(self, view, col, item):
return item.isEditable()
# objects of these types are not eligible for expansion in the outline view
try:
SIMPLE_TYPES = (str, unicode, int, long, float, complex)
except NameError:
SIMPLE_TYPES = (str, int, float, complex)
def getInstanceVarNames(obj):
"""Return a list the names of all (potential) instance variables."""
# Recipe from Guido
slots = {}
if hasattr(obj, "__dict__"):
slots.update(obj.__dict__)
if hasattr(obj, "__class__"):
slots["__class__"] = 1
cls = getattr(obj, "__class__", type(obj))
if hasattr(cls, "__mro__"):
for base in cls.__mro__:
for name, value in base.__dict__.items():
if (
hasattr(value, "__get__")
and not callable(value)
and hasattr(obj, name)
):
slots[name] = 1
if "__dict__" in slots:
del slots["__dict__"]
slots = sorted(slots.keys())
return slots
class NiceError:
"""Wrapper for an exception so we can display it nicely in the browser."""
def __init__(self, exc_info):
self.exc_info = exc_info
def __repr__(self):
from traceback import format_exception_only
lines = format_exception_only(*self.exc_info[:2])
assert len(lines) == 1
error = lines[0].strip()
return "*** error *** %s" % error
class PythonItem(NSObject):
"""Wrapper class for items to be displayed in the outline view."""
# We keep references to all child items (once created). This is
# necessary because NSOutlineView holds on to PythonItem instances
# without retaining them. If we don't make sure they don't get
# garbage collected, the app will crash. For the same reason this
# class _must_ derive from NSObject, since otherwise autoreleased
# proxies will be fed to NSOutlineView, which will go away too soon.
def __new__(cls, *args, **kwargs):
# "Pythonic" constructor
return cls.alloc().init()
def __init__(self, name, obj, parent, setvalue):
self.realName = name
self.name = str(name)
self.parent = parent
self._setValue = setvalue
self.type = type(obj).__name__
try:
self.value = repr(obj)[:256]
assert isinstance(self.value, str)
except: # noqa: E722, B001
self.value = repr(NiceError(sys.exc_info()))
self.object = obj
self.childrenEditable = 0
if isinstance(obj, dict):
self.children = list(obj.keys())
self.children.sort()
self._getChild = getitem
self._setChild = setitem
self.childrenEditable = 1
elif obj is None or isinstance(obj, SIMPLE_TYPES):
self._getChild = None
self._setChild = None
elif isinstance(obj, (list, tuple)):
self.children = range(len(obj))
self._getChild = getitem
self._setChild = setitem
if isinstance(obj, list):
self.childrenEditable = 1
else:
self.children = getInstanceVarNames(obj)
self._getChild = getattr
self._setChild = setattr
self.childrenEditable = 1
self._childRefs = {}
def setValue_(self, value):
self._setValue(self.parent, self.realName, value)
self.__init__(self.realName, value, self.parent, self._setValue)
def isEditable(self):
return self._setValue is not None
def isExpandable(self):
return self._getChild is not None
def getChild_(self, child):
if child in self._childRefs:
return self._childRefs[child]
name = self.children[child]
try:
obj = self._getChild(self.object, name)
except: # noqa: E722, B001
obj = NiceError(sys.exc_info())
if self.childrenEditable:
childObj = PythonItem(name, obj, self.object, self._setChild)
else:
childObj = PythonItem(name, obj, None, None)
self._childRefs[child] = childObj
return childObj
def __len__(self):
return len(self.children)
setup.py¶
"""
Script for building the example.
Usage:
python3 setup.py py2app
"""
from setuptools import setup
setup(
app=["PythonBrowser.py"],
data_files=["MainMenu.nib", "PythonBrowser.nib"],
setup_requires=["py2app", "pyobjc-framework-Cocoa"],
)