Created attachment 283886 [details] [review]
quartz: Conditionally check for backingScaleFactor

The backingScaleFactor selector was introduced in 10.7, so we need to
check for its existence in order to support older framework versions.

This doesn't seem to do the trick yet. You actually get a compile time error (not just runtime):

gtkapplication-quartz-menu.c: In function '-[GNSMenuItem didChangeIcon]':
gtkapplication-quartz-menu.c:271: warning: 'NSScreen' may not respond to '-backingScaleFactor'
gtkapplication-quartz-menu.c:271: warning: (Messages without a matching method signature
gtkapplication-quartz-menu.c:271: warning: will be assumed to return 'id' and accept
gtkapplication-quartz-menu.c:271: warning: '...' as arguments.)
gtkapplication-quartz-menu.c:271: error: incompatible type for argument 1 of 'roundf'

Created attachment 283896 [details] [review]
quartz: Add compile-time checks

In case we are compiling on a framework version < 10.7.

Review of attachment 283896 [details] [review]:

See comments inline

::: gtk/gtkapplication-quartz-menu.c
@@ +264,3 @@
       theme = gtk_icon_theme_get_default ();
 
+#if defined(MAC_OS_X_VERSION_10_7) && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7)

To use these macros, I think you need to #include <AvailabilityMacros.h>

@@ +270,2 @@
       if (![[NSScreen mainScreen] respondsToSelector:@selector(backingScaleFactor)])
         scale = 1.0f;

scale is actually defined as an integer

@@ +273,3 @@
         scale = roundf ([[NSScreen mainScreen] backingScaleFactor]);
+#else
+      scale = 1.0f;

idem

There are a few different ways to avoid the "may not respond" warning. The simplest is to call performSelector: instead of sending the selector message directly. You might need to cast the result to avoid the type error.

Another is to wrap it in #ifdef AVAILABLE_MAC_OS_X_VERSION_10_7_AND_LATER. Since the linker generally won't let you run a Gtk app on an OS version earlier than the one you built it on, that works just as well as the respondsToSelector test.

A particularly clever, perhaps too clever, way is shown in gdk/quartz/gdkwindow-quartz.c:

@protocol CanSetStyleMask
- (void)setStyleMask:(int)mask;
@end

...

      if ([impl->toplevel respondsToSelector:@selector(setStyleMask:)])
        {
          NSString *title = [impl->toplevel title];

          [(id<CanSetStyleMask>)impl->toplevel setStyleMask:new_mask];

Created attachment 284280 [details] [review]
quartz: Add availability check for >= 10.7 API

This adds both a compile time check for the SDK version being compiled against, as well as a runtime check in the case the resulting binary is run against an older SDK.

I've tested the above patch, and I think it does everything:

1) No need to include AvailabilityMacros, it's already being included by Cocoa
2) Uses the straightforward AVAILABLE_MAC_OS_X_VERSION_10_7_AND_LATER for compile time check
3) Uses respondsToSelector for runtime check (even though unlikely this would happen, it's still the right thing to do)
4) No clever tricks needed :)

*** Bug 737561 has been marked as a duplicate of this bug. ***

Attachment 284280 [details] pushed as de96cea - quartz: Add availability check for >= 10.7 API