Write SDK version to binary when compiling from command line (macOS) - objective-c

I am trying to detect whether the system is in dark mode.
I have already tried reading AppleInterfaceStyle from the user defaults i.e.
NSString *interfaceStyle = [[NSUserDefaults standardUserDefaults] stringForKey:#"AppleInterfaceStyle"];
BOOL isDark = [#"dark" caseInsensitiveCompare:interfaceStyle] == NSOrderedSame;
which works most of the time but has issues in Auto mode on Catalina.
Now from what I have read is that the more robust approach is to check the effectiveAppearance of NSApplication which looks like this:
NSApplication *app = [NSApplication sharedApplication];
NSAppearance *appearance = app.effectiveAppearance;
NSAppearanceName appearanceName = [appearance bestMatchFromAppearancesWithNames:#[NSAppearanceNameAqua, NSAppearanceNameDarkAqua]];
BOOL isDark = [appearanceName isEqualToString:NSAppearanceNameDarkAqua];
The problem with this approach is that the application I am writing this for manually sets its appearance property, which prevents the effectiveAppearance from using the system appearance.
I tried settings app.appearance = nil before checking the effectiveAppearance but it didn't help.
Now there also is [NSAppearance currentAppearance] which uses the appearance of the current thread. I'm not quite sure what this value resolves to if the thread hasn't set the value explicitly.
My big problem here is that I have no access to a machine running macOS to check my code, so I would highly appreciate if someone knows what to do here.
Edit: It looks like the issue is that the library isn’t compile against the correct version of the SDK. Or at least that version isn’t written to the library information.
From the documentation:
If you build your app against an earlier SDK but still want to support Dark Mode, include the NSRequiresAquaSystemAppearance key (with a value of NO) in your app's Info.plist file. Do so only if your app's appearance looks correct when running in macOS 10.14 and later with Dark Mode enabled.
I am already specifying the version through -mmacosx-version-min=10.14. From what I have found this issue is basically the same that I have, but I don’t quite understand what the solution is from the commit.
I guess it has something to do with the -isysroot and -platform_version. But I didn’t find any good reference for what they do and how they work.
My updated question would be:
How do -isysroot and -platform_version work and how do I use them to enable SDK specific functionality with my binaries?

The solution is quite simple. When manually compiling from the command line -mmacosx-version-min=10.14 needs to get passed to the compiler and the linker.

Related

Fetch preferences / permissions for NSUserNotificationCenter

I'm currently trying to set up a notification service using the old NSUserNotification API on macOSX (not iOS) in objective c++.
The catch is that I would need to know the system preferences associated with notifications that the user set (and preferably during the rest of runtime too) to determine if my notifications are actually seen. The application is meant to get the users attention in some way to guarantee things like reminders don't go unnoticed, so the thing I want to avoid is a notification delivered that silently doesn't produce any sound nor image on the screen whatsoever without the application knowing. If the notification is not allowed the application should handle it in some other way.
I am working on a macOS 10.14 Mojave machine. My overall code with NSUserNotificationCenter works fine with a custom Delegate that implements shouldDeliver, didActivate etc. Its just that I am currently assuming the user didn't press the "frick off" button on my notifications.
Unfortunately, NSUserNotificationCenter and related classes don't appear to feature a function that determines the permissions the way the new API (UNUserNotificationCenter) does. I have been trying to resolve this for a few hours so I was wondering if anyone else has found a solution to this. I can't really use the new API since this is strictly for back-compatibility in favour of the possibly rather prevalent amount of people who don't use mojave yet.
Things I have tried to make it work so far:
Try and see if there is a .plist somewhere where these settings are stored, in the User-specific Library folder as well as the general Library folder.
Try and find said .plist using CFPreferencesCopyKeyList and related methods. Apparently I don't really know the right domain name.
This answer from 2012 which appears to be outdated since I cannot locate the database on my machine anymore. Might be due to me using a mojave machine, or the file has since moved somewhere else.
Try and determine whether we can retro-actively check our permissions by checking a NSUserNotification's "presented" property on didDeliverNotification, shouldPresentNotification in the delegate. Unfortunately as stated in NSUserNotificationCenter itself it still behaves the same whether the preferences allow notifications or not.
Some code I tried includes the following:
CFPreferencesCopyKeyList((CFStringRef) #"com.apple.systemPreferences.plist", kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
CFPreferencesCopyKeyList((CFStringRef) #"com.apple.systemPreferences.plist", kCFPreferencesAnyUser, kCFPreferencesAnyHost);
//Unfortunately returns null with any combination of com.apple.notificationcenter.plist, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost
CFPreferencesCopyKeyList((CFStringRef) #"com.apple.notificationcenter", kCFPreferencesAnyUser, kCFPreferencesAnyHost);
On my system (only macOS High Sierra), it looks like the file you're after is:
~/Library/Preferences/com.apple.ncprefs.plist
That would correspond to a combination of kCFPreferencesCurrentUser, and kCFPreferencesAnyHost. (For the record, kCFPreferencesCurrentUser + kCFPreferencesCurrentHost equates to pref files in the ~/Library/Preferences/ByHost/ folder).
I don't think any settings would be stored in the local domain (by that I mean in the root /Library/Preferences/ folder).
I was able to get a list of apps and settings using the following code:
[[NSUserDefaults standardUserDefaults] addSuiteNamed:#"com.apple.ncprefs"];
NSArray *apps = [[NSUserDefaults standardUserDefaults] objectForKey:#"apps"];
NSLog(#"[%# %#] apps == %#", NSStringFromClass([self class]), NSStringFromSelector(_cmd), apps);
NOTE: this will not work if your app is sanboxed, as access to other pref files like that will be denied.

Enable WebGL in the Mac OS application on WebKit

I am writing an application for Mac OS - browser on WebKit to use for the some site on WebGL. All is ready, the application correctly displays normal HTML sites, but WebGL doesn't work. How can enable WebGL in my app?
Once you have a WebView, there is an undocumented method which can enable WebGL:
WebPreferences *p = [webView preferences];
if ([p respondsToSelector:#selector(setWebGLEnabled:)]) {
[p setWebGLEnabled:YES];
}
In this example I have protected it with respondsToSelector: to ensure the code will not abort if later versions remove this specific option.
Note that I understand that an application containing code using undocumented interfaces may be rejected if submitted to Apple's Mac App Store.
Another option is to use a different embedded renderer which officially supports WebGL (where Apple's WebKit as demonstrated in Safari only has it as a developer option, presumably intended to be experimental). Since both Firefox and Chrome support WebGL, have a look at Gecko and Chromium Embedded Framework. (Note: I have not been able to confirm whether whether embedded Gecko supports WebGL.)
In Mavericks, this is the correct code.
WebPreferences *preferences = [_webview preferences];
if([preferences respondsToSelector:#selector(setWebGLEnabled:)]){
[preferences performSelector:#selector(setWebGLEnabled:) withObject:[NSNumber numberWithBool:YES]];
}
You need to call performSelector otherwise you'll get a compile error.
I figured out how to do this without using an undocumented method. You need to set the user preference WebKitWebGLEnabled to #YES for your app. To have the setting apply the first time the app is run, it needs to be set early, before the WebView is initialized. In my case, the WebView instance is loaded from the main nib file, so that's very early indeed. I added this code to Supporting Files/main.m:
[[NSUserDefaults standardUserDefaults] setObject:#YES
forKey:#"WebKitWebGLEnabled"];
Please note, since no undocumented method is called, I assume this code is within app store guidelines, but my app hasn't been reviewed yet!

How to intercept reading of plist values in Objective-C code?

We're using the new Urban Airship iOS plugin for PhoneGap.
In the plugin's plist file, we're supposed to enter the app-specific keys needed to enable push notifications.
The problem is we have two versions, free and paid, of the same app, but the plist file only accommodates one version.
Essentially, we need to modify the Objective-C code to read different plist values, depending on whether it's the free or premium version.
We currently manage both versions with the same code base and Xcode project. Unless we change the plugin code, it seems like we need to create a new Xcode project, which we don't want to do.
How do we adjust Urban Airship's Objective-C files to read different values from the plsit file?
Sorry to keep you waiting, I wanted to give you a very detailed answer instead of rushing last night :) So here we go.
First in your project we need to add a new target. Go to your project settings and right click your target. Click duplicate.
You'll get a new target probably named Target-copy. You'll also get a new info.plist file just for that target.
Next we're going to edit our Pro version's Built Settings. Scroll or search and find Apple LLVM compiler 4.0 Preprocessing. Add to both your Debug and Release configurations. I normally just go with the simple PRO=1. You also need to add PRO=0 to your lite version or it will be undefined when you try to build that version.
Now lets look at how to add a custom plist like I'm sure you'll need. First create two folders. Its important these are folders not groups. In each folder we can create a plist with the exact same filename.
Since Now you can add something to each of them. I just added a key property and a value pro string / lite string. Finally to the code. In the sample project I made I simple overrode viewDidLoad but obviously this will work anywhere. Since the plists have the same name you can load them with one line of code. They'll never get mixed up because they are only copied to their respective target. If you need to do code level based logic you can use the PRO preprocessor we made.
- (void)viewDidLoad
{
[super viewDidLoad];
// This will load the proper plist automatically.
NSLog(#"Plist Value: %#",[[NSDictionary dictionaryWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"Property List" ofType:#"plist"]] objectForKey:#"property"]);
// Also remember we set up a preprocessor PRO. you can use it as well.
if (PRO) {
NSLog(#"Only Show for Pro");
} else {
NSLog(#"Only Show for Lite");
}
NSLog(#"This will show for both");
}
This is the method I use for all my lite/pro version apps so I can share a common codebase without copying it between projects or other complicated systems. It has worked pretty well for me so far :) Happy Coding!
Source
Figured someone may be able to use the project to look at so here it is on GitHub.

Why is checking [NSMetadataQuery class] crashing on iOS 4.2.1?

I'm attempting to use this approach, described by Marco Arment, for checking if a class exists before using it. With the correct settings, classes are automatically weak-linked when it's appropriate. As Marco describes, "you can safely subclass or have pointers to whatever you want (as long as you’re careful not to instantiate them when they’re not available)".
My app runs fine on iOS 5. I've followed the conditions mentioned at the link:
Base SDK is Latest iOS (iOS 5.1)
Deployment Target is iOS 4.0
Compiler for C/C++/Objective-C is Apple LLVM compiler 3.1 (also tried LLVM GCC 4.2)
Any time I reference NSMetadataQuery I'm making sure the class exists first:
if ([NSMetadataQuery class] != nil) …
Despite all this my app crashes immediately on launch if I try to run it on an iPod touch with iOS 4.2.1:
dyld: Symbol not found: _OBJC_CLASS_$_NSMetadataQuery
I've tried commenting out all the code any my app runs fine. As soon as I add back in a single reference to NSMetadataQuery, it crashes. I've even tried this:
if ([NSMetadataQuery class] != nil) NSLog(#"OK");
Simply including that line, and no other reference to NSMetadataQuery, crashes the app. Even more strange, checking for other iOS 5 classes doesn't cause any problems:
if ([UIDictationPhrase class] != nil) NSLog(#"OK");
That works fine, as expected.
I have been able to work around the problem using the uglier NSClassFromString() to make sure the class exists, but I'd love to know why the other approach isn't working.
I don't have an explanation to this but I ran into the same problem as you. No matter what I/you do, NSMetadataQuery just won't be weak linked...
Refer to this answer, which is really the best one in another question:
https://stackoverflow.com/a/8426591/129202
In short, other auto weak linking seems to work, it's just NSMetadataQuery* that you have to remove from source and replace with id. Instantiate the class with NSClassFromString() etc. No hiccups on other classes like UIDocument however so you can safely use those in the normal sweat free way.
NSMetadataQuery is available in iOS 5.0 and above, so any versions below that has no clue as to what it is. By merely using it in your code, the class name will be added to a symbol table and looked-up when the app launches.

OSX / Xcode / Objective-C: How to detect the version of Flash Player installed?

I need to take different action depending on the version of Flash Player installed on OS X (due to a Flash bug). Is there a way to programmatically ascertain the version number?
I am using WebKit for this, BTW.
EDIT:
I also tried
NSBundle* myBundle = [NSBundle bundleWithPath: #"/Library/Internet Plug-Ins/Flash Player.plugin/Contents/Info.plist"];
And although the pathname exists. "myBundle" is always nil.
You just need to use anything that will let you at the CFBundleVersion of the currently installed plugin. Something like this works in a shell scripting environment:
/usr/libexec/PlistBuddy -c 'Print CFBundleVersion' /Library/Internet\ Plug-Ins/Flash\ Player.plugin/Contents/Info.plist
There might be a way to search the system's list of installed applications for a bundle ID matching com.macromedia.Flash Player.plugin and pull out the bundle version from the system record, as well.
EDIT: It looks like both NSWorkspace and Launch Services just map items to bundle IDs of relevant apps, and then will map a bundle ID to a URL or FSRef. So ultimately, with this approach, you have to grab the appropriate bundle and pull out the version from there.
There's likely also a way to get this information from some JavaScript code running within the webview. Adobe's SWFObject seems to make this quite easy, for example. For more, see "Detecting Flash Player versions and embedding SWF files with SWFObject 2".
Just leave off the Contents/Info.plist part; you need to get the bundle, not its Info.plist:
NSBundle* flashBundle = [NSBundle bundleWithPath: #"/Library/Internet Plug-Ins/Flash Player.plugin"];
NSString flashVersion = flashBundle.infoDictionary[(id)kCFBundleVersionKey];
Remember to cover the case when there is no Flash Player installed.