I would like to print a NSTextStorage on multiple pages and add annotations to the side margins corresponding to certain text ranges. For example, for all occurrences of # at the start of a line, the side margin should show an automatically increasing number.
My idea was to create a NSLayoutManager and dynamically add NSTextContainer instances to it until all text is laid out. The layoutManager would then allow me to get the bounding rectangle of the interesting text ranges so that I can draw the corresponding numbers at the same height inside the side margin. This approach works well on macOS, but I'm having some issues on iOS.
When running the code below in an iPad Simulator, I would expect that the print preview shows 3 pages, the first with the numbers 0-1, the second with the numbers 2-3, and the last one with the number 4. Instead the first page shows the number 4, the second one the numbers 2-4, and the last one the numbers 0-4. It's as if the pages are inverted, and each page shows the text starting at the correct location but always ending at the end of the complete text (and not the range assigned to the relative textContainer).
I've created FB17026419.
class ViewController: UIViewController {
override func viewDidAppear(_ animated: Bool) {
let printController = UIPrintInteractionController.shared
let printPageRenderer = PrintPageRenderer()
printPageRenderer.pageSize = CGSize(width: 100, height: 100)
printPageRenderer.textStorage = NSTextStorage(string: (0..<5).map({ "\($0)" }).joined(separator: "\n"), attributes: [.font: UIFont.systemFont(ofSize: 30)])
printController.printPageRenderer = printPageRenderer
printController.present(animated: true) { _, _, error in
if let error = error {
print(error.localizedDescription)
}
}
}
}
class PrintPageRenderer: UIPrintPageRenderer, NSLayoutManagerDelegate {
var pageSize: CGSize!
var textStorage: NSTextStorage!
private let layoutManager = NSLayoutManager()
private var textViews = [UITextView]()
override var numberOfPages: Int {
if !Thread.isMainThread {
return DispatchQueue.main.sync { [self] in
numberOfPages
}
}
printFormatters = nil
layoutManager.delegate = self
textStorage.addLayoutManager(layoutManager)
if textStorage.length > 0 {
let glyphRange = layoutManager.glyphRange(forCharacterRange: NSRange(location: textStorage.length - 1, length: 0), actualCharacterRange: nil)
layoutManager.textContainer(forGlyphAt: glyphRange.location, effectiveRange: nil)
}
var page = 0
for textView in textViews {
let printFormatter = textView.viewPrintFormatter()
addPrintFormatter(printFormatter, startingAtPageAt: page)
page += printFormatter.pageCount
}
return page
}
func layoutManager(_ layoutManager: NSLayoutManager, didCompleteLayoutFor textContainer: NSTextContainer?, atEnd layoutFinishedFlag: Bool) {
if textContainer == nil {
addPage()
}
}
private func addPage() {
let textContainer = NSTextContainer(size: pageSize)
layoutManager.addTextContainer(textContainer)
let textView = UITextView(frame: CGRect(origin: .zero, size: pageSize), textContainer: textContainer)
textViews.append(textView)
}
}
Selecting any option will automatically load the page
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When creating a default macOS document-based Xcode project and using the code below (and wiring the File menu's Print item to printDocument: instead of the default print:, which does nothing), opening the print panel causes PrintView.knowsPageRange(_:) to be called twice.
Is this a bug? My app populates PrintView dynamically, and for large documents it can be quite inefficient to populate it once, only for the contents to be immediately discarded and populated again.
A workaround that came to my mind would be to check if the print options have changed, though I'm not sure if it's a reliable indicator that the print preview is effectively the same.
I created FB17018494.
class Document: NSDocument {
override func makeWindowControllers() {
addWindowController(NSStoryboard(name: NSStoryboard.Name("Main"), bundle: nil).instantiateController(withIdentifier: NSStoryboard.SceneIdentifier("Document Window Controller")) as! NSWindowController)
}
override func printOperation(withSettings printSettings: [NSPrintInfo.AttributeKey : Any]) throws -> NSPrintOperation {
return NSPrintOperation(view: PrintView(frame: CGRect(x: 0, y: 0, width: 100, height: 100)), printInfo: NSPrintInfo(dictionary: printSettings))
}
}
class PrintView: NSView {
override func knowsPageRange(_ range: NSRangePointer) -> Bool {
print("knowsPageRange")
range.pointee = NSRange(location: 1, length: 1)
return true
}
}
Topic:
UI Frameworks
SubTopic:
AppKit
Xcode downloaded a crash report for my app which I don't quite understand. It seems the following line caused the crash:
myEntity.image = newImage
where myEntity is of type MyEntity:
class MyEntity: NSObject, Identifiable {
@objc dynamic var image: NSImage!
...
}
The code is called on the main thread. According to the crash report, thread 0 makes that assignment, and at the same time thread 16 is calling [NSImageView asynchronousPreparation:prepareResultUsingParameters:].
What could cause such a crash? Could I be doing something wrong or is this a bug in macOS?
crash.crash
It seems that NSTextView has an issue with deleting text and setting any attribute at the same time, when it also has a textContainerInset.
With the code below, after 1 second, the empty line in the text view is automatically deleted and the first line is colored red. The top part of the last line remains visible at its old position. Selecting the whole text and then deselecting it again makes the issue disappear.
Is there a workaround?
I've created FB16897003.
class ViewController: NSViewController {
@IBOutlet var textView: NSTextView!
override func viewDidAppear() {
textView.textContainerInset = CGSize(width: 0, height: 8)
let _ = textView.layoutManager
textView.textStorage!.setAttributedString(NSAttributedString(string: "1\n\n2\n3\n4"))
textView.textStorage!.addAttribute(.foregroundColor, value: NSColor.labelColor, range: NSRange(location: 0, length: textView.textStorage!.length))
DispatchQueue.main.asyncAfter(deadline: .now() + 1) { [self] in
textView.selectedRange = NSRange(location: 3, length: 0)
textView.deleteBackward(nil)
textView.textStorage!.beginEditing()
textView.textStorage!.addAttribute(.foregroundColor, value: NSColor.red, range: NSRange(location: 0, length: 2))
textView.textStorage!.endEditing()
}
}
}
I was just having a look at some crash reports downloaded by Xcode, and I noticed the same wrong pattern I already mentioned here: the crash reports indicate that method A calls method B, which is impossible.
In the first crash report below, method MainViewController.showSettings seems to be called by ConfirmMoveViewController.openSourceInFinder, which is impossible. ConfirmMoveViewController.openSourceInFinder is a context menu action in a modal window, and MainViewController.showSettings is in a completely different window and the two methods have no relation whatsoever.
In the second crash report below, MainViewController.setSortMode is triggered by the press of a button (and nothing else) but seems to be called by OtherViewController.copy that can be triggered by a context menu (or keyboard shortcut). The two methods have no relation whatsoever. The rest of the stack trace confirm that it's indeed the button that was pressed.
This seems to me like a quite serious bug in how macOS creates crash reports.
1.crash
2.crash
I'm building a game with a client-server architecture. Using GKMatch.chooseBestHostingPlayer(_:) rarely works. When I started testing it today, it worked once at the very beginning, and since then it always succeeds on one client and returns nil on the other client. I'm testing with a Mac and an iPhone. Sometimes it fails on the Mac, sometimes on the iPhone. On the device that it succeeds on, the provided host can be the device itself or the other one.
I created FB9583628 in August 2021, but after the Feedback Assistant team replied that they are not able to reproduce it, the feedback never went forward.
import SceneKit
import GameKit
#if os(macOS)
typealias ViewController = NSViewController
#else
typealias ViewController = UIViewController
#endif
class GameViewController: ViewController, GKMatchmakerViewControllerDelegate, GKMatchDelegate {
var match: GKMatch?
var matchStarted = false
override func viewDidLoad() {
super.viewDidLoad()
GKLocalPlayer.local.authenticateHandler = authenticate
}
private func authenticate(_ viewController: ViewController?, _ error: Error?) {
#if os(macOS)
if let viewController = viewController {
presentAsSheet(viewController)
} else if let error = error {
print(error)
} else {
print("authenticated as \(GKLocalPlayer.local.gamePlayerID)")
let viewController = GKMatchmakerViewController(matchRequest: defaultMatchRequest())!
viewController.matchmakerDelegate = self
GKDialogController.shared().present(viewController)
}
#else
if let viewController = viewController {
present(viewController, animated: true)
} else if let error = error {
print(error)
} else {
print("authenticated as \(GKLocalPlayer.local.gamePlayerID)")
let viewController = GKMatchmakerViewController(matchRequest: defaultMatchRequest())!
viewController.matchmakerDelegate = self
present(viewController, animated: true)
}
#endif
}
private func defaultMatchRequest() -> GKMatchRequest {
let request = GKMatchRequest()
request.minPlayers = 2
request.maxPlayers = 2
request.defaultNumberOfPlayers = 2
request.inviteMessage = "Ciao!"
return request
}
func matchmakerViewControllerWasCancelled(_ viewController: GKMatchmakerViewController) {
print("cancelled")
}
func matchmakerViewController(_ viewController: GKMatchmakerViewController, didFailWithError error: Error) {
print(error)
}
func matchmakerViewController(_ viewController: GKMatchmakerViewController, didFind match: GKMatch) {
self.match = match
match.delegate = self
startMatch()
}
func match(_ match: GKMatch, player: GKPlayer, didChange state: GKPlayerConnectionState) {
print("\(player.gamePlayerID) changed state to \(String(describing: state))")
startMatch()
}
func startMatch() {
let match = match!
if matchStarted || match.expectedPlayerCount > 0 {
return
}
print("starting match with local player \(GKLocalPlayer.local.gamePlayerID) and remote players \(match.players.map({ $0.gamePlayerID }))")
match.chooseBestHostingPlayer { host in
print("host is \(String(describing: host?.gamePlayerID))")
}
}
}
All the threads only contain system calls. The crashed thread only contains a single call to my app's code which is main.swift:13.
What could cause such a crash?
crash.crash
All the threads only contain system calls. The crashed thread only contains a single call to my app's code which is main.swift:13.
What could cause such a crash?
crash.crash
I was just comparing the build settings of two of my apps to try to understand why they behave differently (one of them uses the full screen on iPad, and the other one has small top and bottom black borders, although that's not the issue I want to discuss now). I saw that the option CLANG_CXX_LANGUAGE_STANDARD is set to gnu++0x for the older project, while it's set to gnu++17 for the newer one. The documentation lists different possible values and also a default one:
Compiler Default: Tells the compiler to use its default C++ language dialect. This is normally the best choice unless you have specific needs. (Currently equivalent to GNU++98.)
If it really is the best choice (normally), why is it not used when creating a new default Xcode project? Or is it better to select a newer compiler version (GNU++98 sounds quite old compared to GNU++17)? Also, does this affect Swift code?
This crash report for one of my apps was downloaded by Xcode. Apparently the app crashed while releasing an object of type Scan.File, which is a Swift class held in an array in the Scan.Directory class. I'm not doing any manual reference counting or low-level stuff with that object.
What could cause such a crash?
crash.crash
On macOS, the Finder allows to connect to a server and store the login credentials. When creating a bookmark to a file on a server and resolving it again, the server is mounted automatically (unless I provide the option URL.BookmarkResolutionOptions.withoutMounting).
I just tried connecting to my Mac from my iPad via SMB in the Files app and storing a bookmark to a file on the server, but disconnecting the server and trying to resolve the bookmark throws the error (I translated the English text from Italian):
Error Domain=NSFileProviderErrorDomain Code=-2001 "No file provider was found with the identifier "com.apple.SMBClientProvider.FileProvider"'" UserInfo={NSLocalizedDescription=No file provider was found with the identifier "com.apple.SMBClientProvider.FileProvider"., NSUnderlyingError=0x302a1a340 {Error Domain=NSFileProviderErrorDomain Code=-2013 "(null) "}}
Every time I disconnect and reconnect to the server, selecting the same file returns a different path. The first time I got
/private/var/mobile/Library/LiveFiles/com.apple.filesystems.smbclientd/WtFD3Ausername/path/to/file.txt
The next time WtFD3A changed to EqHc2g and so on.
Is it not possible to automatically mount a server when resolving a bookmark on iOS?
The following code allows to reproduce the issue:
struct ContentView: View {
@State private var isPresentingFilePicker = false
@AppStorage("bookmarkData") private var bookmarkData: Data?
@State private var url: URL?
@State private var stale = false
@State private var error: Error?
var body: some View {
VStack {
Button("Open") {
isPresentingFilePicker = true
}
if let url = url {
Text(url.path)
} else if bookmarkData != nil {
Text("couldn't resolve bookmark data")
} else {
Text("no bookmark data")
}
if stale {
Text("bookmark is stale")
}
if let error = error {
Text("\(error)")
.foregroundStyle(.red)
}
}
.padding()
.fileImporter(isPresented: $isPresentingFilePicker, allowedContentTypes: [.data]) { result in
do {
let url = try result.get()
if url.startAccessingSecurityScopedResource() {
bookmarkData = try url.bookmarkData()
}
} catch {
self.error = error
}
}
.onChange(of: bookmarkData, initial: true) { _, bookmarkData in
if let bookmarkData = bookmarkData {
do {
url = try URL(resolvingBookmarkData: bookmarkData, bookmarkDataIsStale: &stale)
} catch {
self.error = error
}
}
}
}
}
On macOS, we have didMountNotification but there doesn't seem to be an equivalent for iOS. Is there a way to be notified when a volume is mounted on iOS? I would like to use it in my iOS app I'm currently porting from macOS, which starts a synchronization from the volume (which has been previously selected in a NSOpenPanel) as soon as it's mounted.
Some time ago I read somewhere that one can get a file icon on iOS like this:
UIDocumentInteractionController(url: url).icons.last!)
but this always returns the following image for every file:
Today I tried the following, which always returns nil:
(try? url.resourceValues(forKeys: [.effectiveIconKey]))?.allValues[.effectiveIconKey] as? UIImage
Is there any way to get a file icon on iOS?
You can try the above methods in this sample app:
struct ContentView: View {
@State private var isPresentingFilePicker = false
@State private var url: URL?
var body: some View {
VStack {
Button("Open") {
isPresentingFilePicker = true
}
if let url = url {
Image(uiImage: UIDocumentInteractionController(url: url).icons.last!)
if let image = (try? url.resourceValues(forKeys: [.effectiveIconKey]))?.allValues[.effectiveIconKey] as? UIImage {
Image(uiImage: image)
} else {
Text("none")
}
}
}
.padding()
.fileImporter(isPresented: $isPresentingFilePicker, allowedContentTypes: [.data]) { result in
do {
let url = try result.get()
if url.startAccessingSecurityScopedResource() {
self.url = url
}
} catch {
preconditionFailure(error.localizedDescription)
}
}
}
}
The following code works when compiling for macOS:
print(NSMutableDictionary().isEqual(to: NSMutableDictionary()))
but produces a compiler error when compiling for iOS:
'NSMutableDictionary' is not convertible to '[AnyHashable : Any]'
NSDictionary.isEqual(to:) has the same signature on macOS and iOS. Why does this happen? Can I use NSDictionary.isEqual(_:) instead?
All the threads only contain system calls. The crashed thread only contains a single call to my app's code which is main.swift:12.
What could cause such a crash?
crash.txt