Handle Installation to Virtual Environments for macOS, and Windows (#34)

Added a bdist_wheel command inside of a try block.  This ensure that
normal system wide installations, which don't include the wheel module,
are not impacted.

For virtual environment the wheel module will be present, and this will
override it for the virtual environment installation.  This should
ensure that jars are downloaded for both standard, and virtual
environment installations.

Author: pfifer

setup.py

@@ -83,10 +83,36 @@
 
 class MavenJarDownloader:
 
-    def __init__(self, destdir=JAR_DIRECTORY, packages=REMOTE_MAVEN_PACKAGES):
+    def __init__(self, on_completion, destdir=JAR_DIRECTORY, packages=REMOTE_MAVEN_PACKAGES):
+        self.on_completion = on_completion
         self.destdir = destdir
         self.packages = packages
 
+    def warning_string(self, missing_jars=[]):
+        s = '''The following jars were not installed because they were not
+present in this package at the time of installation:'''
+        for jar in missing_jars:
+            s += '\n  {jar}'.format(jar=jar)
+        s += '''
+This doesn't affect the rest of the installation, but may make it more
+difficult for you to run the sample app and get started.
+
+You should consider running:
+
+    python setup.py download_jars
+    python setup.py install
+
+Which will download the required jars and rerun the install.
+'''
+        return s
+
+    def download_and_check(self):
+        self.download_files()
+        self.on_completion()
+        missing_jars = self.missing_jars()
+        if len(missing_jars) > 0:
+            print(self.warning_string(missing_jars))
+
     def package_destination(self, artifcat_id, version):
         return '{artifcat_id}-{version}.jar'.format(artifcat_id=artifcat_id, version=version)
 
@@ -156,23 +182,8 @@ def run(self):
 
 class InstallThenCheckForJars(install):
 
-    def warning_string(self, missing_jars=[]):
-        s = '''The following jars were not installed because they were not
-present in this package at the time of installation:'''
-        for jar in missing_jars:
-            s += '\n  {jar}'.format(jar=jar)
-        s += '''
-This doesn't affect the rest of the installation, but may make it more
-difficult for you to run the sample app and get started.
-
-You should consider running:
-
-    python setup.py download_jars
-    python setup.py install
-
-Which will download the required jars and rerun the install.
-'''
-        return s
+    def do_install(self):
+        install.run(self)
 
     def run(self):
         """
@@ -181,14 +192,48 @@ def run(self):
         in this package. If they aren't present we warn the user and give
         them some advice on how to retry getting the jars.
         """
-        downloader = MavenJarDownloader()
-        downloader.download_files()
-        install.run(self)
-        missing_jars = downloader.missing_jars()
-        if len(missing_jars) > 0:
-            print(self.warning_string(missing_jars))
+        downloader = MavenJarDownloader(self.do_install)
+        downloader.download_and_check()
+
+
+try:
+    from wheel.bdist_wheel import bdist_wheel
+
+
+    class BdistWheelWithJars(bdist_wheel):
+        """
+        This overrides the bdist_wheel command, that handles building a binary wheel of the package.
+        Currently, as far as I can tell, binary wheel creation only occurs during the virtual environment creation.
+        The package that bdist_wheel comes from isn't a modeled dependency of this package, but is required for virtual
+        environment creation.
+        """
+
+        def do_run(self):
+            bdist_wheel.run(self)
+
+        def run(self):
+            downloader = MavenJarDownloader(self.do_run)
+            downloader.download_and_check()
+
+except ImportError:
+    pass
 
 if __name__ == '__main__':
+    commands = {
+        'download_jars': DownloadJarsCommand,
+        'install': InstallThenCheckForJars,
+    }
+    try:
+        #
+        # BdistWheelWithJars will only be present if the wheel package is present, and that is present during
+        # virtual environment creation.
+        # It's important to note this is a hack.  There doesn't appear to be a way to execute hooks around wheel
+        # creation by design.  See https://github.com/pypa/packaging-problems/issues/64 for more information.
+        #
+        commands['bdist_wheel'] = BdistWheelWithJars
+    except NameError:
+        pass
+
     setup(
         name=PACKAGE_NAME,
         version=PACKAGE_VERSION,
@@ -202,10 +247,7 @@ def run(self):
             'samples': ['sample.properties'],
         },
         install_requires=PYTHON_REQUIREMENTS,
-        cmdclass={
-            'download_jars': DownloadJarsCommand,
-            'install': InstallThenCheckForJars,
-        },
+        cmdclass=commands,
         url="https://github.com/awslabs/amazon-kinesis-client-python",
         keywords="amazon kinesis client library python",
         zip_safe=False,