Xcode 10.1 is not officially supported on Catalina and Big Sur. I recommend installing Xcode 12.4 and checking if that fixes things.

If you want an answer, you need to show the code that pauses the workout and the timer when using the Foundation timer.

Hacking with Swift(hackingwithswift.com) has a free 100 day course on SwiftUI.

You created an action to go from A to B. Create a second action to go from B to A. Create an SKAction sequence with the two actions and run the sequence. let sequence = SKAction.sequence([firstAction, secondAction]) sprite.run(sequence) firstAction and secondAction are the actions you created to move from A to B and B to A. sprite is the sprite node to move with the action sequence.

Using the Core Text framework is going to be the easiest way to create a PDF with large amounts of text. Core Text has a function to determine how much text can fit on a page, CTFramesetterSuggestFrameSizeWithConstraints. It's been a while since I used Core Text, but the following article shows how to create a PDF with Core Text and Quartz (Core Graphics): meandmark.com/blog/2016/08/creating-pdfs-with-core-text-and-quartz/

In a followup reply, the OP provided the following error message: duplicate symbol '_main' in:   /Users/lamiaalkhunini/Library/Developer/Xcode/DerivedData/c-awfbaiszjqjdyzfyhvlstvnfmpbe/Build/Intermediates.noindex/c.build/Debug/c.build/Objects-normal/x86_64/l.o   /Users/lamiaalkhunini/Library/Developer/Xcode/DerivedData/c-awfbaiszjqjdyzfyhvlstvnfmpbe/Build/Intermediates.noindex/c.build/Debug/c.build/Objects-normal/x86_64/ll.o ld: 1 duplicate symbol for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) The duplicate symbol _main told me there were two main functions in the project. I didn't guess it from the original question.

The error message says you have two main functions in your project. You can have only one. When you create the project, Xcode includes a main.cpp file that has a main function. If you add a second main function, you are going to get an error. Remove one of the two main functions. If you added your own C++ file to the project, delete the main.cpp function Xcode included with the project.

If you create a Command Line Tool project and click the Run (Play) button, does the project build and run? List the steps you are taking to create and run the project, including the code you typed. Also list the actual error message you get. The text you posted does not contain the error message. I also recommend coming up with a different name for your project than c.

SceneKit does not support Android.

When I select the Info.plist file from the project navigator, select an item in the property list, and right click, I can choose Add Row. When I move the cursor over an item in the property, Add (+) and Remove (-) buttons appear next to the item. Clicking the Add button adds a new item. If neither of these things work for you, you will have to provide more detailed information, such as the steps you are taking to add an item to the property list.

Are you sure the Text statement is correct? Does the code compile if you provide a static string, such as the following: Text("Today") If the Text statement is correct and you still get a compiler error, you are going to have to supply more code for anyone to help you. Show the code for the SwiftUI view.

The isDateInToday function is part of the Foundation framework. You should be calling that function (like in your last code snippet) and not writing your own version of the function. If you are getting a compiler error about a missing isDateInToday function, import the Foundation framework in your Swift code. import Foundation

You created the MeetingRow view to display one meeting, but instead of having a property for the one meeting to display, you have a @FetchRequest property that contains a set of meetings. A meeting has a meetingName property, but a set of meetings does not. The set contains meetings so you get a compiler error. To fix the error, get rid of the meetings property and add a meeting property of type Meeting. Your Text item will look like the following: Text(meeting.meetingName ?? "nil")

Your SwiftUI document struct holds the data and handles the saving to a file and loading the data from the file. Your SwiftUI content view has a property for the document. Usually this property uses the @Binding property wrapper. The content view will have the UIView (using UIViewRepresentable) as part of its body. The UIView needs a property to access to whatever data it needs to do the PencilKit drawing. This data is part of the document. Without more information about your document and data model, no one is going to be able to give you a more detailed answer to this question.

In Xcode 12 Apple consolidated several iOS application project templates into an App template. Choose the App template for your project. If you really want the old template, you will have to install Xcode 11. The Xcode Releases site (xcodereleases.com) has download links for every Xcode version Apple has ever released.