Add get_platform to kivy live

src/bitmessagekivy/get_platform.py

@@ -0,0 +1,31 @@
+# pylint: disable=no-else-return, too-many-return-statements
+
+"""To check the platform"""
+
+from sys import platform as _sys_platform
+from os import environ
+
+
+def _get_platform():
+    kivy_build = environ.get("KIVY_BUILD", "")
+    if kivy_build in {"android", "ios"}:
+        return kivy_build
+    elif "P4A_BOOTSTRAP" in environ:
+        return "android"
+    elif "ANDROID_ARGUMENT" in environ:
+        return "android"
+    elif _sys_platform in ("win32", "cygwin"):
+        return "win"
+    elif _sys_platform == "darwin":
+        return "macosx"
+    elif _sys_platform.startswith("linux"):
+        return "linux"
+    elif _sys_platform.startswith("freebsd"):
+        return "linux"
+    return "unknown"
+
+
+platform = _get_platform()
+
+if platform not in ("android", "unknown"):
+    environ["KIVY_CAMERA"] = "opencv"