Why doesn't Xcode suggest #synchronized? - objective-c

I only rarely use #synchronized, but as far as I can remember (meaning around Xcode 3.2 or something), it never suggested #synchronized when using the auto-completion, and still never does.
I do get suggestions when typing '#', like #autorelease, #encode, #selector and so forth.
Is there any known reason for this ? I wasn't able to find any related topic. It's been bugging me, because it gives me the feeling that this is not a valid method to handle concurrency in iOS.

#synchronized does not appear when using auto-completion because Apple has not mapped that keyword to any code sense implementation.
Per Apple's suggestion, I have filed a bug report.
However, I can offer an auto-complete solution.
You may create an #synchronized snippet that can be auto-completed or drag and dropped into your code.
Copy/paste the code below into one of your Xcode documents.
Select the new code and drag it to your snippets library.
Double-click the new snippet and click edit.
Enter #synchronized for the completion shortcut.
For more info: http://nshipster.com/xcode-snippets/
#synchronized(anObj) {
// Everything between the braces is protected by the #synchronized directive.
}

Related

Intellisense - deduce right Class by its methods

I'm used to work with NetBeans and now I'm trying IntelliJ. So my question is: Does IntelliJ has a way to get right class by its methods?
For example, in NetBeans if I write:
glGenBu // Intellisense will kick in and will suggest me
to use GL15.glGenBuffers() method from GL15 class
This will automatically import the right library.
This is very handy because I'm working with LWJGL and it has a bad way to manage OpenGL methods ('GLXX' where XX is the version of OpenGL and all methods that appeared in that version are stored in that class) and I never remember the right class where my desired method is.
Thank you.
Pressing Ctrl+Space when you already see completion list will show more suggestions, with static methods from the entire project among them. See https://www.jetbrains.com/help/idea/auto-completing-code.html for more details.

iOS9 storyboard what is unhandled action (handleNonLaunchSpecificActions)?

I've noticed the following error popping up in the console when running my app on iOS 9 when using a storyboard. I'm using xCode7. Is this something I need to be concerned about?
-[UIApplication _handleNonLaunchSpecificActions:forScene:withTransitionContext:completion:] ** unhandled action -> <FBSSceneSnapshotAction: 0x176bfb20> {
handler = remote;
info = <BSSettings: 0x176a5d90> {
(1) = 5;
};
}
There is nothing wrong with your code. This is a logging message internal to Apple, and you should file a radar about it.
There are two hints that show that this is probably Apple's code:
The underscore leading the method name _handleNonLaunchSpecificActions:forScene:withTransitionContext:completion is a convention indicating that the method is private/internal to the class that it's declared in. (See this comment.)
It's reasonable to guess that the two letter prefix in FBSSceneSnapshotAction is shorthand for FrontBoard, which according to Rene Ritchie in "iOS 9 wish-list: Guest Mode" is part of the whole family of software related to launching apps:
With iOS 8, Apple refactored its system manager, SpringBoard, into several smaller, more focused components. In addition to BackBoard, which was already spun off to handle background tasks, they added Frontboard for foreground tasks. They also added PreBoard to handle the Lock screen under secure, encrypted conditions. [...]
I have no idea what the BS prefix in BSSettings is for, but
BS is shorthand for BackBoard Settings, and an analysis of this log message would indicate that it's not anything you did, and you should file a radar with steps to reproduce the logging message.
If you want to try and grab a stack trace, you can implement the category linked to here. Some would argue that overriding private API is a bad idea, but in this case a temporary injection to grab a stack trace can't be too harmful.
EDIT:
But, we still want to know what this action is. So I put a breakpoint on -[UIApplication _handleNonLaunchSpecificActions:forScene:withTransitionContext:completion] and started printing out register values and found a class called FBSceneImpl which had a whole bunch of information about my application:
We are able to find out which private method is called next (stored in the program counter, instruction pointer, register 15.)
I tried finding the un-handled FBSceneSnapshotAction referenced in the log, but no dice. Then, I subclassed UIApplication, and overrode _handleNonLaunchSpecificActions:forScene:withTransitionContext:completion. Now I was able to get at the action directly, but still, we don't know what it is.
Then, I looked at the FBSceneSnapshotAction again. Turns out it has a superclass called BSAction.
Then I wrote a tool similar to RuntimeBrowser and looked up all of the subclasses of BSAction. It turns out that there's quite a list of them:
The two method names we have (one from the log and one from the program counter on the devices) indicate that these actions are used under the hood for passing actions around the system.
Some actions are probably sent up to the app delegate's callbacks, while others are handled internally.
What's happening here is that there is an action that wasn't handled correctly and the system is noting it. We weren't supposed to see it, apparently.
AFAIK, the info above is related to iOS during snapshot the screen (i suppose for double click home multitask related behaviour).I deeply investigated my application and seems that it does not get any side behaviours. You can safely ignore it, for now.
You can use the following gist simple category to test yourself against the calls to the above function:
I have figured it out, it will happen when you have IBAction method declared in .h or .m file but you have not bind it to any control.
.m example:
- (IBAction)click:(id)sender{
}
but not assigned this method to any control in storyboard.
haven't find out why it happens in my app, but at least you can catch the exception, if you want to keep this from popping up in your log pane. It's not a solution, but it might give you more insight why it is happing by inspecting any of the arguments that are passed in the catch.
swift 2 version:
import UIKit
extension UIApplication {
func _handleNonLaunchSpecificActions(arg1: AnyObject, forScene arg2: AnyObject, withTransitionContext arg3: AnyObject, completion completionHandler: () -> Void) {
//whatever you want to do in this catch
print("handleNonLaunchSpecificActions catched")
}
}

Xcode: "Spurious Update" console warning?

I'm writing a pretty straightforward ObjC app. (The only minor complexity is that it uses an external library called Chilkat for some basic networking, but I don't think that that's relevant.)
Occasionally, my project spontaneously pops up this warning message:
May 14 01:24:01 Neovenator-2.local Project[22645] : void
CGSUpdateManager::log() const: conn 0x4b29b: spurious update.
And I have no idea how to handle or even interpret it. There's nothing in my project called CGSUpdateManager, and my project doesn't call a log() function anywhere. I can't even reliably reproduce it, but it's popped up often enough to raise my interest level.
Searches at both Google and here for the term "spurious update" reveals a lightly scattered set of conversation, but nothing relevant to my project. Meanwhile, a Google search for "CGSUpdateManager" reveals it's something to do with Swift, which I'm not using at all.
Can anyone help me understand what this means? Or should I just disregard it?
Make sure to call super in viewDidLoad, viewWillAppear and viewWillDisappear.
Sorry, my code with correct Highlight/indentation:
- (void)setNeedsDisplay
{
//#if 1 //TEST (suppose we are only called by us)
if(wvImageRep_DoRebuild)
//#endif
[super setNeedsDisplay]; // "spurious update" ?
}
It's an example (#see my full response), it helped me

iOS 5 TableView crashes

Something got changed at the new SDK and my code suddenly isn't working.
I created a new empty project and created only a UITableView in it.
I used the same code as i've been used to, except the compiler said that i do not need to use autorelease anymore, so i removed it.
Oh, and I replaced retain with strong as i was recommended.
When I run the app it shows the TableView like it should look, but the minute i touch anywhere on screen, like scrolling for example, it crashes with EXC_BAD_ACCESS error.
What do I miss??
You should post some more informations on where your program crashed! But I don't think the mentioned compiler warnings are the reason. You should have tried to run your project with the compiler by turning of ARC (automatic reference count) and see what happens. If you can go back, do that first.
Also maybe there went something wrong with the changes you made because of ARC . If you have not done the changes with the Xcode refactoring tool I recommend you doing so.
Therefor select in the Xcode Menu:
Edit > Refactor > Convert to Objectiv-C ARC...
It will go through your code and apply the changes. Apple recommends though that your project should work without crashes and warnings before using it.

Does Xcode support regions?

Does Xcode support anything akin to Visual Studio style #region directives for arbitrary code folding?
No, you can only fold code on various defined scoping levels in Xcode.
You can use little tricks to make navigating via the function menu easier, though.
#pragma mark
Allows you to create a grouping where the label following mark will show up in the function menu. If the label is a hyphen, a separator is inserted into the function menu.
Also, the following labels in comments will show up in the function menu:
// MARK:
// TODO:
// FIXME:
// !!!:
// ???:
Obviously since #pragma mark is not really portable, if you're building a portable application and need it to work with a compiler that doesn't just ignore #pragma directives that it doesn't understand, the comment-style mark is a decent alternative.
I am going to hell for this but here goes:
At the top of a given file, put
#define FOLD 1
Wherever you want to fold something, wrap it in an if block like so:
if(FOLD) {
// your code to hide
// more code
}
That will let you fold it away out of sight.
That won't work in the place you want it most, that is, around groups of functions or methods.
It may be useful inside a long, linear method with no internal conditionals or loops, but such methods aren't common in general Mac OS X UI code, though if you're writing some big numeric or graphics-crunching code it could help group things.
And the if(fold) is entirely superfluous. Just use the braces inside a method or function and Xcode will fold them.
Try this way :
//region title1
{
//region Subtitl1
{
}
//region Subtitl2
{
}
}
It can do like that :
Without support for .Net style regions, being able to collapse all your functions at the same time is the next best thing.
command-option-shift-left arrow
to collapse all.
command-option-shift-right arrow
to expand all.
Xcode will remember the last state of collapsed functions.
A useful option in XCode 12 (maybe before), is an option in preferences "Code Folding Ribbon"
When you check it, the source code looks like this
When you hover the mouse over this ribbon, you get foldable regions based on brackets, like this
When you click the Ribbon, it folds the bracket region, like this
Its not as the regions in Visual Studio, where you can place them wherever you want, but they're good enough to tidy up your code files.
To answer your question...No. And It drives me nuts.
If you have the opportunity/ability you can use AppCode for this. I've been using it for a few years and it usually beats Xcode in many areas.
Also I specifically use AppCode because of these features:
Ability to use regions
Searching classes, text and usages is MUCH faster.
Refactoring is also faster.
Cleaner and more customizable UI.
Tabs are handled (in my opinion) much better than in Xcode.
FOLDING. You can actually change what levels of folding you want. Why Apple thought there should be no quick-key to fold extensions is beyond me. And fold ribbons? Really Apple? Yes they're pretty and all but most professionals use hotkeys for everything.
Better GIT integration.
Support for live updates in SwiftUI
If you use other Jetbrains IDE's like PyCharm or Android Studio the UI is exactly the same.
Some downsides of AppCode:
Some things that work in Xcode aren't supported
Visual #colorLiteral(). When using them they don't show a color picker.
No Storyboard support. Annoying to have to open up Xcode. If you write your UI in code this is a moot point.
Editing .plist files isn't as nice. Doable, but not nice.
Initial indexing can take a while.
Cost. But I would argue the time savings in just navigation will compensate for this.
Kind of a lot for a simple question but I think it's nice having alternatives.
Put your desired code inside brackets { }, and it will become a folding zone.
But you have to keep in mind that brackets also define variables scope, so this code should not have variables declarations which will be used outside these brackets.
One nice solution I just found:
Put your project into one big namespace.
Close and reopen this namespace for the individual sections of your source file:
namespace myproj { // members of class MyClassA
void MyClassA::dosomething()
{
}
void MyClassA::dosomethingelse()
{
}
} // members of class MyClassA
namespace myproj { // members of MyClassB
void MyClassB::dosomething()
{
}
void MyClassB::dosomethingelse()
{
}
} // members of MyClassB