Overview

Post

Replies

Boosts

Views

Created

Multipeer Connectivity support
Greetings.I have an app today that uses multipeer connectivity extensively. Currently, when the user switches away from the app, MPC disconnects the session(s) - this is by design apparently (per other feedback). I'd like to hear if anyone has experimented with iOS9 multitasking / multipeer and whether MPC sessions can stay alive?Thanks
6
1
3.7k
Jul ’15
P3 Display to XYZ Color Space Conversion
When I use the ColorSync Utility to convert Display P3 color (1, 0, 0) to an XYZ color, the result is (0.5151, 0.2412, -0.0011). I expected that result because that is identical to the red colorant tristimulus value in the Display P3.icc file.When I use the CGColor converted method to do the same, the XYZ color is approximately (0.5151, 0.2412, 0.0). Note that the third element is 0.0 whereas it is -0.0011 when using the ColorSync Utility. I have printed out the Z component to 16 digits of precision, and Z is all 0s. It appears that the CGColor converted method is clamping the result from 0 to 1.My questions are:1. Which conversion is correct? The ColorSync utility or the CGColor converted method?2. I am not a color specialist, but I thought that the XYZ components should never be negative. If so, is the colorant tristimulus value in the Display P3.icc file wrong?3. Because CGColor clamped the Z component to 0, the XYZ color cannot be converted back exactly or closely to the Display P3 color (1, 0, 0). I would have expected to be able to go back and forth between the two color spaces when starting from a valid P3 Display color especially since the XYZ color space completely encompasses the P3 Display color space. Is that not true?4. Is (1, 0, 0) an invalid Display P3 color? If so, I can understand the peculiar results. I'm not sure how I would know if a Display P3 color is valid or not. (I only know that the component values must be from 0 to 1.) I think it is valid because Apple uses that color in the UIColor API Reference in an example.
3
0
3.4k
Oct ’16
Discovering HID Service over BLE
Hello All,I am trying to communicate with BLE device which is using HID service through my iOS App using Core Bluetooth.While discovering all Services , i cannot look HID Service but i can look other services. As per previous versions , Core Bluetooth doesn't expose HID peripheral service capabilities to apps.Currently i am using Xcode 8 and iOS 10 version for development. Is there any update on exposing HID peripheral service in latest versions. If yes, how can i achive this?I will appreciate any help!!
3
0
3k
Dec ’16
DELETE/PUT in AppleMusic API
Hi,Since today, we are no more able to do DELETE/PUT request on the Apple Music API.So, we can't update a playlist details, delete a playlist, delete tracks in playlist, delete tracks in library...Old methods allowed are now returning only an HTTP Code 403.Why this change in the Apple Music API ? We can hope that will be back soon ?
20
2
9.9k
Aug ’18
Internal error, NEHotspotConfigurationErrorDomain
Hello eveybody,Currently I'm working on an app which connects to a device. During testing I encounter an internal error of NEHotspotConfigurationErrorDomain. See the log snippet:Domain=NEHotspotConfigurationErrorDomain Code=8 "internal error." UserInfo={NSLocalizedDescription=internal error.}This error appears randomly. In one day I encountered it three times. The only solution I can think of is catching this error somehow and then telling the user to restart the device.After this error appears, the wifi functionality of iOS in all third party apps seems to be broken. Only restarting helps as far as I know. Also there seems to be nothing we as app developers can do about it. Therefor I wonder if there is some way to prevent this error somehow? The only solution I can think of is catching this error somehow and then telling the user to restart the device.Also since there is not much information about this error on the web, it would be really nice if someone can clarify whats going on with this error.Regards.
16
0
10k
Aug ’18
com.apple.hiservices-xpcservice (Not Responding)
Previously discussed in beta:https://forums.developer.apple.com/message/330295This process stops responding every day it seems, I'm running 10.14.3 (18D109)When the process hangs, its Open Files and Ports include the following:txt /Library/Preferences/Logging/.plist-cache.ZP6RP0OT txt /private/var/db/timezone/tz/2018i.1.0/icutz/icutz44l.dat txt /usr/share/icu/icudt62l.dat txt /private/var/folders/35/dgpwsg457w17gs77hssnrbnw0000gn/0/com.apple.LaunchServices-231-v2.csstoreThose are not open when the service is running (before it hangs)Would like to know how frequently this hangs for everyone else and get steps to troubleshoot if possible.
21
2
39k
Feb ’19
Notarization: "Team isn't configured for notarization"
I've tried to notarize my app recently and got the error:{ "logFormatVersion": 1, "jobId": "...", "status": "Rejected", "statusSummary": "Team is not yet configured for notarization", "statusCode": 7000, "archiveFilename": "myapp.dmg", "uploadDate": "2019-06-20T06:24:53Z", "sha256": "...", "ticketContents": null, "issues": null }I've never heard about "team configuration for notarization" previously. What are the steps to resolve that issue?Thanks in advance.
52
0
19k
Jun ’19
[iOS Safari] Fullscreen API on a non-video element
webkitEnterFullScreen API is supported on iOS for video element, but not for a div element. Also as a fullscreen demo website shown, Safari on macOS supports div element but not on iOS. Is there any plan to add the support in iOS? If not is there any way to fullscreen a div element or make it run as fullscreen on Safari iOS?
31
12
31k
May ’20
Shape detection for other apps?
When selecting a stroke path for object on PKCanvas, the option "Snap to Shape" appears. I understand this function is still in beta and has not made available natively to other PencilKit app. Is there a way using Stroke API to call this function directly after the user hold pencil for half a second when stroke is done drawing, just like how it behaves in native apps?
4
0
2.4k
Jun ’20
Issue with multiple touches with "Defer System Gestures" on, with iOS
I'm developing a rhythm game for iOS which has four buttons spanning the width of the screen in portrait. I noticed that my testers were having some missed inputs on the buttons on the left and right due to the fact that iOS, by default, tries to ignore accidental touches on the edges of the screen. So I enabled "Defer System Gestures" on the left and right edges, but then quickly started to notice a new, very specific, issue. Description of the issue If you have finger #1 touching and holding anywhere in the middle of the screen, and finger #2 touches on the far right or left edge of the screen just below the horizontal position of finger #1, those touches are inconsistently not recognized. If finger #1 is not present, this issue does not occur. If finger #2 is above or well below finger #1, this issue also does not occur. A dead zone is created on the right and left edges of the screen just below the horizontal position of the first touch. Here is a rough representative example of where touches #1 and #2 need to be for this issue to manifest, in case the text above is not clear. |				| |				| |				| |				| |	 1		| |			 2| |				| It just so happens that this issue is causing major usability problems with my game, as it results in what the user sees as sporadic and inconsistent response when the game calls for two notes to be played at the same time. Steps to recreate the issue Here are the steps if you want to recreate the problem yourself using the "Create New Gesture" pane in "Assistive Touch" (Note that this problem is not specific to the Settings app, but rather is an issue across the system—however this panel defers system gestures and shows where touches are being read, so it is a great place to demonstrate): (1) Go to Settings > Accessibility > Touch > Assistive Touch > Create New Gesture...; (2) With one finger, touch the middle of the screen and hold it through step 3; (3) With a second finger, tap 4 times along the right (or left) edge of the screen in the following places: (a) well above the vertical position of the first touch, (b) just above the vertical position of the first touch, (c) just below the vertical position of the first touch, and (d) well below the vertical position of the first touch; (4) Notice how, more than half the time, touch (c) does not register. I have found that this problem is more replicatable when the first touch is on the lower half of the screen, but I have been able to replicate it when the finger is higher as well, just not as consistently. Here are the four positions described in the steps above: Position a: both touches register |				| |				| |				| |			 2| |	 1		| |				| |				| Position b: both touches usually register |				| |				| |				| |				| |	 1	 2| |				| |				| Position c: only touch 1 registers |				| |				| |				| |				| |	 1		| |			 2| |				| Position d: both touches register |				| |				| |				| |				| |	 1		| |				| |			 2| Is there anything I can do to resolve this behavior? My app requires gesture deferment to be on for the expected experience by the user, and this bug is causing other issues for my testers that kind of need to be resolved before I can confidently release the game.
2
2
1.3k
Sep ’20
Enrolled in Small Business Program - Still takes ~30% cut.
As the title says, I am enrolled in the small business program but Apple still takes about 30% of my sales. Most of my sales are from Swedish customers, not sure if this matters. For instance I have an app with sales of: $109 After apples cut I am left with: $74 74/109 = 0.68. Why is this? I have non consumable IAP in my app.
7
0
5.7k
May ’21
iOS Background Execution Limits
I regularly see questions, both here on the Apple Developer Forums and in my Day Job™ at DTS, that are caused by a fundamental misunderstanding of how background execution works on iOS. These come in many different variants, for example: How do I keep my app running continuously in the background? If I schedule a timer, how do I get it to fire when the screen is locked? How do I run code in the background every 15 minutes? How do I set up a network server that runs in the background? How can my app provide an IPC service to another one of my apps while it’s in the background? How can I resume my app in the background if it’s been ‘force quit’ by the user? The short answer to all of these is You can’t. iOS puts strict limits on background execution. Its default behaviour is to suspend your app shortly after the user has moved it to the background; this suspension prevents the process from running any code. There’s no general-purpose mechanism for: Running code continuously in the background Running code at some specific time in the background Running code periodically at a guaranteed interval Resuming in the background in response to a network or IPC request [1] However, iOS does provide a wide range of special-purpose mechanisms for accomplishing specific user goals. For example: If you’re building a music player, use the audio background mode to continue playing after the user has moved your app to the background. If you’re building a timer app, check out the AlarmKit framework. On older systems, use a local notification to notify the user when your timer has expired. If you’re building a video player app, use AVFoundation’s download support. Keep in mind that the above is just a short list of examples. There are many other special-purpose background execution mechanisms, so you should search the documentation for something appropriate to your needs. IMPORTANT Each of these mechanisms fulfils a specific purpose. Do not attempt to use them for some other purpose. Before using a background API, read clause 2.5.4 of the App Review Guidelines. Additionally, iOS provides some general-purpose mechanisms for background execution: To resume your app in the background in response to an event on your server, use a background notification (aka a ‘silent’ push). For more information, see Pushing background updates to your App. To request a small amount of background execution time to refresh your UI, use the BGAppRefreshTaskRequest class. To request extended background execution time, typically delivered overnight when the user is asleep, use the BGProcessingTaskRequest class. To continue user-visible work after the user has left your app, use the BGContinuedProcessingTask class. To prevent your app from being suspended for a short period of time so that you can complete some user task, use a UIApplication background task. For more information on this, see UIApplication Background Task Notes. To download or upload a large HTTP resource, use an URLSession background session. All of these mechanisms prevent you from abusing them to run arbitrary code in the background. As an example, consider the URLSession resume rate limiter. For more information about these limitations, and background execution in general, I strongly recommend that you watch WWDC 2020 Session 10063 Background execution demystified [2]. It’s an excellent resource. Specifically, this talk addresses a common misconception about the app refresh mechanism (BGAppRefreshTaskRequest and the older background fetch API). Folks assume that app refresh will provide regular background execution time. That’s not the case. The system applies a range of heuristics to decide which apps get app refresh time and when. This is a complex issue, one that I’m not going to try to summarise here, but the take-home message is that, if you expect that the app refresh mechanism will grant you background execution time, say, every 15 minutes, you’ll be disappointed. In fact, there are common scenarios where it won’t grant you any background execution time at all! Watch the talk for the details. [1] iOS 26 introduced support for general-purpose IPC, in the form of enhanced security helper extensions. However, these can only be invoked by the container app, and that means there’s no background execution benefit. [2] Sadly the video is currently not available from Apple. I’ve left the link in place just in case it comes back. When the user ‘force quits’ an app by swiping up in the multitasking UI, iOS interprets that to mean that the user doesn’t want the app running at all. So: If the app is running, iOS terminates it. iOS also sets a flag that prevents the app from being launched in the background. That flag gets cleared when the user next launches the app manually. This gesture is a clear statement of user intent; there’s no documented way for your app to override the user’s choice. Note In some circumstances iOS will not honour this flag. The exact cases where this happens are not documented and have changed over time. Finally, if you have questions about background execution that aren’t covered by the resources listed here, please open a new thread on the forums with the details. Put it in a reasonable subtopic and tag it appropriately for the technology you’re using; if nothing specific springs to mind, use Background Tasks. Also, make sure to include details about the specific problem you’re trying to solve because, when it comes to background execution, the devil really is in the details. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" Change history: 2026-01-09 Added a reference to AlarmKit. Added a reference to BGContinuedProcessingTask. Add a footnote about IPC and another one about WWDC 2020 Session 10063. Made other minor editorial changes. 2024-03-21 Added a discussion of ‘force quit’. 2023-05-11 Added a paragraph that explains a common misconception about the app refresh mechanism. Made other minor editorial changes. 2021-08-12 Added more entries to the common questions list, this time related to networking and IPC. Made minor editorial changes. 2021-07-26 Extended the statement about what’s not possible to include “running code periodically at a guaranteed interval”. 2021-07-22 First posted.
0
0
26k
Jul ’21