build: native notifications on Mac OS

Also refactors the notification function to introduce some single
responsibility.

python/servo/build_commands.py

@@ -1,9 +1,10 @@
 from __future__ import print_function, unicode_literals
 
-import sys
 import os
 import os.path as path
 import subprocess
+import sys
+
 from time import time
 
 from mach.decorators import (
@@ -14,56 +15,86 @@ from mach.decorators import (
 
 from servo.command_base import CommandBase, cd
 
+
 def is_headless_build():
     return int(os.getenv('SERVO_HEADLESS', 0)) == 1
 
-# Function to generate desktop notification once build is completed & limit exceeded!
-def notify(elapsed):
-    if elapsed < 30:
-        return
 
-    if sys.platform.startswith('linux'):
+def notify_linux(title, text):
     try:
         import dbus
         bus = dbus.SessionBus()
-            notify_obj = bus.get_object('org.freedesktop.Notifications', '/org/freedesktop/Notifications')
+        notify_obj = bus.get_object("org.freedesktop.Notifications", "/org/freedesktop/Notifications")
-            method = notify_obj.get_dbus_method('Notify', 'org.freedesktop.Notifications')
+        method = notify_obj.get_dbus_method("Notify", "org.freedesktop.Notifications")
-            method('Servo Build System', 0, '', ' Servo build complete!', '', [], [], -1)
+        method(title, 0, "", text, "", [], [], -1)
     except:
-            print("[Warning] Could not generate notification! Please make sure that the python dbus module is installed!")
+        raise Exception("Please make sure that the Python dbus module is installed!")
 
-    elif sys.platform.startswith('win'):
+
-        try:
+def notify_win(title, text):
     from ctypes import Structure, windll, POINTER, sizeof
     from ctypes.wintypes import DWORD, HANDLE, WINFUNCTYPE, BOOL, UINT
+
     class FLASHWINDOW(Structure):
         _fields_ = [("cbSize", UINT),
                     ("hwnd", HANDLE),
                     ("dwFlags", DWORD),
                     ("uCount", UINT),
                     ("dwTimeout", DWORD)]
+
     FlashWindowExProto = WINFUNCTYPE(BOOL, POINTER(FLASHWINDOW))
     FlashWindowEx = FlashWindowExProto(("FlashWindowEx", windll.user32))
     FLASHW_CAPTION = 0x01
     FLASHW_TRAY = 0x02
     FLASHW_TIMERNOFG = 0x0C
+
     params = FLASHWINDOW(sizeof(FLASHWINDOW),
                         windll.kernel32.GetConsoleWindow(),
                         FLASHW_CAPTION | FLASHW_TRAY | FLASHW_TIMERNOFG, 3, 0)
     FlashWindowEx(params)
-        except:
-            print("[Warning] Could not generate notification! Please make sure that the required libraries are installed!")
 
-    elif sys.platform.startswith('darwin'):
+
+def notify_darwin(title, text):
+    import AppKit, Foundation, objc
+
+    NSUserNotification = objc.lookUpClass("NSUserNotification")
+    NSUserNotificationCenter = objc.lookUpClass("NSUserNotificationCenter")
+
+    note = NSUserNotification.alloc().init()
+    note.setTitle_(title)
+    note.setInformativeText_(text)
+
+    now = Foundation.NSDate.dateWithTimeInterval_sinceDate_(0, Foundation.NSDate.date())
+    note.setDeliveryDate_(now)
+
+    centre = NSUserNotificationCenter.defaultUserNotificationCenter()
+    centre.scheduleNotification_(note)
+
+
+def notify_build_done(elapsed):
+    """Generate desktop notification when build is complete and the
+    elapsed build time was longer than 30 seconds."""
+    if elapsed > 30:
+        notify("Servo build", "Completed in %0.2fs" % elapsed)
+
+
+def notify(title, text):
+    """Generate a desktop notification using appropriate means on
+    supported platforms Linux, Windows, and Mac OS.  On unsupported
+    platforms, this function acts as a no-op."""
+    platforms = {
+        "linux": notify_linux,
+        "win": notify_win,
+        "darwin": notify_darwin
+    }
+    func = platforms.get(sys.platform)
+
+    if func is not None:
         try:
-            from distutils.spawn import find_executable
+            func(title, text)
-            notifier = find_executable('terminal-notifier')
+        except Exception as e:
-            if not notifier:
+            extra = getattr(e, "message", "")
-                raise Exception('`terminal-notifier` not found')
+            print("[Warning] Could not generate notification!%s" % extra, file=sys.stderr)
-            subprocess.call([notifier, '-title', 'Servo Build System',
-                             '-group', 'servobuild', '-message', 'Servo build complete!'])
-        except:
-            print("[Warning] Could not generate notification! Make sure that `terminal-notifier is installed!")
 
 
 @CommandProvider
@@ -159,7 +190,7 @@ class MachCommands(CommandBase):
         elapsed = time() - build_start
 
         # Generate Desktop Notification if elapsed-time > some threshold value
-        notify(elapsed)
+        notify_build_done(elapsed)
 
         print("Build completed in %0.2fs" % elapsed)
         return status
@@ -195,7 +226,7 @@ class MachCommands(CommandBase):
         elapsed = time() - build_start
 
         # Generate Desktop Notification if elapsed-time > some threshold value
-        notify(elapsed)
+        notify_build_done(elapsed)
 
         print("CEF build completed in %0.2fs" % elapsed)
 
@@ -233,7 +264,7 @@ class MachCommands(CommandBase):
         elapsed = time() - build_start
 
         # Generate Desktop Notification if elapsed-time > some threshold value
-        notify(elapsed)
+        notify_build_done(elapsed)
 
         print("Gonk build completed in %0.2fs" % elapsed)