WhereIsMyMac

This example shows how to use the CoreLocation framework and is a translation in Python of the example at “Cocoa with Love”

Sources

WhereIsMyMacAppDelegate.py

"""
This file is a translation from Objective-C. The original
copy-right:

//  Copyright 2009 Matt Gallagher. All rights reserved.
//
//  Permission is given to use this source code file, free of charge, in any
//  project, commercial or otherwise, entirely at your risk, with the condition
//  that any redistribution (in part or whole) of source code must retain
//  this copyright and permission notice. Attribution in compiled projects is
//  appreciated but not required.
"""

import objc
import Cocoa
import CoreLocation
import WebKit
from CoreLocation import *
import math

class WhereIsMyMacAppDelegate (Cocoa.NSObject):
    window = objc.ivar()
    webView = objc.IBOutlet()
    locationManager = objc.ivar()
    locationLabel = objc.IBOutlet()
    accuracyLabel = objc.IBOutlet()



    def applicationDidFinishLaunching_(self, notification):
        self.locationManager = CoreLocation.CLLocationManager.alloc().init()
        self.locationManager.setDelegate_(self)
        self.locationManager.startUpdatingLocation()

    @classmethod
    def latitudeRangeForLocation_(self, aLocation):
        M = 6367000.0; # approximate average meridional radius of curvature of earth
        metersToLatitude = 1.0 / ((math.pi / 180.0) * M);
        accuracyToWindowScale = 2.0;

        return aLocation.horizontalAccuracy() * metersToLatitude * accuracyToWindowScale;

    @classmethod
    def longitudeRangeForLocation_(self, aLocation):
        latitudeRange = WhereIsMyMacAppDelegate.latitudeRangeForLocation_(aLocation)

        return latitudeRange * math.cos(aLocation.coordinate().latitude * math.pi / 180.0)


    @objc.IBAction
    def openInDefaultBrowser_(self, sender):
        currentLocation = locationManager.location()

        externalBrowserURL = Cocoa.NSURL.URLWithString_(
                "http://maps.google.com/maps?ll=%f,%f&spn=%f,%f"%(
                    currentLocation.coordinate.latitude,
                    currentLocation.coordinate.longitude,
                    WhereIsMyMacAppDelegate.latitudeRangeForLocation_(currentLocation),
                    WhereIsMyMacAppDelegate.longitudeRangeForLocation_(currentLocation)))

        Cocoa.NSWorkspace.sharedWorkspace.openURL_(externalBrowserURL)

    def locationManager_didUpdateToLocation_fromLocation_(self,
            manager, newLocation, oldLocation):

        # Ignore updates where nothing we care about changed
        if newLocation is None:
            return
        if oldLocation is None:
            pass
        elif (newLocation.coordinate().longitude == oldLocation.coordinate().longitude and
                newLocation.coordinate().latitude == oldLocation.coordinate().latitude and
                newLocation.horizontalAccuracy() == oldLocation.horizontalAccuracy()):
            return

        # Load the HTML for displaying the Google map from a file and replace the
        # format placeholders with our location data
        path = Cocoa.NSBundle.mainBundle().pathForResource_ofType_("HTMLFormatString", "html")
        with open(path, 'r') as fp:
            htmlString = fp.read() % (
                newLocation.coordinate().latitude,
                newLocation.coordinate().longitude,
                WhereIsMyMacAppDelegate.latitudeRangeForLocation_(newLocation),
                WhereIsMyMacAppDelegate.longitudeRangeForLocation_(newLocation))

        # Load the HTML in the WebView and set the labels
        self.webView.mainFrame().loadHTMLString_baseURL_(htmlString, None)
        self.locationLabel.setStringValue_("%f, %f"%(
                newLocation.coordinate().latitude, newLocation.coordinate().longitude))
        self.accuracyLabel.setStringValue_("%f"%(newLocation.horizontalAccuracy(),))

    def locationManager_didFailWithError_(self, manager, error):
        self.webView.mainFrame.loadHTMLString_baseURL_(
                Cocoa.NSLocalizedString("Location manager failed with error: %s", nil) % (
                    error.localizedDescription()), None)
        self.locationLabel.setStringValue_("")
        self.accuracyLabel.setStringValue_("")

    def applicationWillTerminate_(self, aNotification):
        self.locationManager.stopUpdatingLocation()

main.py

from PyObjCTools import AppHelper

import WhereIsMyMacAppDelegate

AppHelper.runEventLoop()

setup.py

"""
Script for building the example.

Usage:
    python3 setup.py py2app
"""
from setuptools import setup

setup(
    name="WhereIsMyMac",
    app=["main.py"],
    data_files=[
        "English.lproj",
        "HTMLFormatString.html"
    ],
    setup_requires=[
        "py2app",
        "pyobjc-framework-Cocoa",
        "pyobjc-framework-CoreLocation",
    ]
)

Resources