How would I go about locking a screen like Keychain does, meaning preventing all access to Dock, menubar, desktop, etc. Basically just a black screen that I can add a password field to, for the user to return to the desktop? I am well aware of the Carbon method, but I want the NSApplication method because this is an all Cocoa application.
Thanks~
If you can get away with not writing this code yourself, all for the better. It is usually a terrible idea to write your own code to lock the screen, considering the number of vulnerabilities that have been found in screen locking code over the years. If you have a Carbon call that can do it, go ahead and use that... don't worry about the "purity" of your Cocoa code.
However, if you decide to write this yourself, here's what you do:
First, capture all the screens using CoreGraphics. See: http://developer.apple.com/mac/library/documentation/GraphicsImaging/Conceptual/QuartzDisplayServicesConceptual/Articles/DisplayCapture.html
Next, create a new NSWindow and put it in front of the window that's used for capturing the screens. You'll have to call a CG function to get the "order" of the black window covering each screen, and order the new window in front of that. Normally, the black window has an order so far forward that everything is behind it. Put a password field in the window. Do NOT use an ordinary text field or write your own code for password input. The password input field has a ton of special code in it so you can't copy text out of it, and other programs can't listen to keystrokes while you're typing into a password field. So use the one that Apple provides.
Last, put the computer in "kiosk mode". This mode allows you to disable alt-tab, user switching, the menubar and dock, and even the ability to force quit. See: http://developer.apple.com/mac/library/technotes/KioskMode/Introduction/Introduction.html
It's not a lot of code, it just uses a few different APIs so you'll spend most of your time bouncing between API docs. I suggest writing the screen lock code as its own application (just add a new application target to your Xcode project) and then put the screen locker inside your application bundle. This used to be (as of 10.4) how Apple Remote Desktop implemented the "Lock Screen" functionality, but I can't find the app anymore.
I believe the Cocoa replacement to the SetSystemUIMode API was not introduced until 10.6.
If you can live with Snow-Leopard-only code, the answer is - setPresentationOptions: on NSApplication.
Related
A quick search of Apple's Human Interface Guidelines and Developer Library yields an unequivocal guideline:
Users, and not apps, place menu bar extras in the menu bar.
Anecdotal data backs that up: submitting an app where - upon quit of a dock process/main view, the extra is left running - yields a tidy rejection.
Now - I'm a User experience designer (UXD) who typically plays, I mean, works in the mobile and web space. So please pardon my lack of Obj C chops, thanks.
I understand well the guideline and behavior/pattern: apps like Skitch, Wunderlist, Evernote, et al however very clearly leave the extra (often termed HelperApp) running in the menu bar on quit of main app. They all, do offer explicit user toggle of this w/i preferences.
There's no additional Human Interface Guidelines w/ specifics around handling this requirement for user control. Must this be included in onboarding? Dialog at 1st quit? Again: I can speak to best behavior UX wise, but my (very senior) dev wants the mandate - how are others not getting rejected?
Focus: what means of user control is/are mandated to avoid rejection?
Known/given: include in preferences
Other: ???
After hours of searching online and Apple Dev guidelines, I humbly bring this question here. There simply isn't time to play a carnival game of requirements: guess, get rejected, repeat. Thanks in advance.
Do you have a button somewhere in your user interface that adds the menu extra to the menu bar? Or does your app just do it automatically without the user telling it to do so?
I think that's the distinction, your app must only add an extra when instructed to do so. Also if the primary purpose of your app is to create a menu extra (eg, I have one that puts a calendar in the menu bar) then just launching the app is an implicit instruction, so it can be added automatically.
Ultimately, this rule really is vague and can't be clarified. What it comes down to, is that there should not be many menu extras in a user's menu bar unless the user explicitly chooses to have them. So unless your app really needs a menu extra, you must disable it by default.
If you think the reviewer should have allowed your app through then reply to the rejection explaining your position. I've had an app change to approved once after doing that.
If they still reject your app, then you can appeal the app rejection.
Alternatively, just disable the menu extra by default and have a button somewhere to add it to the menu bar.
Also, all of this assumes you are using NSStatusItem and not the "real" menu extra system — which is a private API. Only NSStatusItem menu extras can be placed in the app store as far as I know.
I'm working on wrapping some Cocoa functionality in an Objective-C library that will be called from a cross-platform C library. One of my goals is to provide someone who does development in C on Linux with the ability to deploy to OSX without having to get into XCode, nib files, etc. I want them to be able to compile and link their code on OSX using the command line tools, and end up with a regular resizeable main window with the usual buttons and so on, an application menu and a dock icon that looks and behaves as expected, etc.
I'm working on OSX 10.8.5. I have XCode 5.0 installed. Here's my gcc --version output:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.0 (clang-500.2.76) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin12.5.0
Thread model: posix
I've figured out how to present a main window, how to set up the application menu, and various other things, programmatically, without using XCode or any nib or plist, but I've run into a problem with the dock icon.
I set a custom dock icon image by calling:
[NSApp setApplicationIconImage:dockImage];
When the user quits the app, the dock icon image reverts to something else (some kind of default application icon or view), briefly, before going away. How can I prevent that from happening without using XCode to create a nib or a plist?
I've tried setting the activation policy of NSApp to prohibitted in the app delegate's applicationShouldTerminate method, to try to hide the dock icon before this switch back occurs. That didn't help, it does hide the window and the dock icon, but the dock icon still switches back to the default icon, briefly, as part of the process of hiding. I confirmed this by returning NSTerminateLator, and confirming that setting the activation policy to prohibited does cause the dock and the icon to hide even though the app is not terminating, and not setting it leaves it unhidden.
I've tried subclassing NSApplication and overriding the setApplicationIconImage call. I have confirmed that it is being called a second time, by something other than my code (well, or not directly by my code, anyway), just before the program exits. I've tried preventing the second call to it from working by calling the super function the first time, but not the second time, and I've confirmed that code in that function can prevent my code from changing the application icon, but that didn't fix the problem. It still happens anyway, somehow.
I've also tried removing the application badge, like this:
[[window dockTile] setShowsApplicationBadge: NO];
just in case it was something to do with that, but that didn't work. The docs say that app badges are no longer relevant as of 10.6, but I was grasping at straws.
Being stumped on the programmatic front, I'm now trying to find out how to package an .app from scratch,without using XCode, and see if maybe I can create a plist from scratch that has a reference to application image in it. But a programmatic solution would be preferable, as I'd really like to minimize what goes into the OSX-specific packaging of a deployment.
Another possibility might be to use XCode once, to produce a very generic, bare-bones .app that my deployment scripts copy and alter.
Please don't shoot my question down as being "too broad" or "not constructive" or something like that. I realize I'm reinventing wheels that already exist in various forms, but there's no law against trying to build a better mouse trap, or just a different or even a worse one, for that matter. I realize I'm trying to fix a problem that a lot of people would consider inconsequential, but XCode-produced apps don't have this problem, and I really don't want the tools I'm creating to produce any user-visible artifacts like that. I'm not intending to diss Apple's tool chain or invite debate about whether or not what I'm pursuing should be pursued. I have a specific, technical problem that I'm looking for solution to that is within the constraints of my goals.
I am developing an app that allows the user to make certain changes to tiles on the Windows 8 start screen. When a change has been made within the app, the user will be shown a "View my changes" button. Clicking the button should bring the user back to the start screen.
I have looked into different ways of closing/suspending the app programmatically (and thus taking the user to the start screen), but I have not found a way to achieve this using WinJS. Throwing an exception closes the app, but this seems like a very dirty workaround. Any suggestions?
I'm assuming you are creating secondary tiles and want to show the users what they look like? #mydogisbox is right in that this kind of functionality has probably been deliberatly excluded.
I'd recommend to just do an in-app 'view changes' of whatever changes to secondary tiles the user might have made. In general, I'd argue that this would be a better user experience because you will keep the user engaged within your application and not be essentially kicking them out of the experience.
Here's a though question:
I need to find out when the user double-clicked the OS X desktop, but not icons on it.
Now, I have thought of the following solutions, though I am not sure if they are doable:
Using desktop icons position (not sure how to get them), and the size of the desktop icons, we could theoretically check once the user double-clicks on the desktop, if it is inside one of the icon areas. Contra: Might not be flawless as some icons might be transparent or not taking up the entire icon size.
Maybe there is a variable that tells us if a icon from the desktop has been clicked? Then we could just check if that variable has been activated when the user double-clicked the last time the desk.
I am certainly still open to other (better) solutions, but they need to be sandboxable for the Mac App Store.
This is probably not going to be appropriate for the Mac App Store, for a number of reasons.
First, how are you going to intercept clicks outside your window? There are a few different mechanisms for this (e.g., event taps), but none of them are allowed in sandboxed apps. And that's intentional, and for a good reason—you're not supposed to be interfering with other apps or with the OS.
On top of that, it's hard to imagine that whatever you're trying to do wouldn't count as non-standard UI/HIG stuff, which is another reason for rejection.
But, assuming none of that were a problem, and you could intercept clicks on the desktop, there's no documented way to get all the icons on the desktop, so you have to read the .DS_store file directly, which means relying on private implementation information, which is another thing you're not allowed to do.
Finally, you have to get access to that .DS_store file. Unless you're expecting the user to drag the (invisible) file or its parent directory to your app or select it in an NSOpenPanel or something, the only way to get such access from inside the sandbox is via a temporary exception entitlement. Which you can't use unless you can justify to the reviewer why you need it as a workaround for a bug or limitation in the OS. So, what's your justification going to be?
I am a newbie in Mac application development. I want to write a GUI application in Cocoa using Interface Builder. I want multiple screens i.e. when one button on a screen is clicked, another screen should be displayed. How can I activate a new screen at button click event?
I would heartily recommend Aaron Hilegass's book Cocoa Programming for Mac OS X. It took me from feeling like everything was impossible to being relatively competent in the space of a few short weeks. I was very impressed with it.
Apple's documentation is amazingly good, but it takes a while to get used to the style, and you will need to know which objects actually exist before you can look up how to use them, which is where Aaron's book comes in.
Your library may have a copy of it, or be able to order one for you if they don't.
I think you mean windows, not screens. Screens are the displays (monitors) on which all the user's windows from all the user's applications appear.
And I second Jonathan's recommendation of the Hillegass book.
The button has a target. That should link to the new window. As its action you can tell the window to show itself.
Take a look at:
http://developer.apple.com/DOCUMENTATION/Cocoa/Conceptual/WinPanel/WinPanel.html
I think what you want is the type of interface like that seen in Coda, or System Preferences where there is a toolbar on the top of the screen that can be used to select between the content of the window.
The simplest method I have found is to use BWToolkit.
Another method is to use a series of views, and switch between them when the toolbar is clicked. I've found one description here, but that's not the one I used first (which may have been originally in Ruby Cocoa, IIRC).
NSTabView.