Application.Current.Exit() exits the app programmatically, but I need to simulate the same effect as when you press back out of you app, ie usually suspending it. Is it possible?
(yes I know you usually shouldn't mess around with this but it's for a very specific purpose)
No, it's not possible to exit an app programmatically without terminating it.
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I am essentially trying to create something like a launcher for an Unreal application. The expected behavior that I was looking for is that when I launch an application the launcher would minimize or hide in the background and then whenever you close the application the launcher would then be restored.
I can successfully get the launcher to launch the other app and minimize itself but, for some reason my method for re-maximizing it doesn't seem to work. However, I was able to get it to work if I keep the app on screen(& not in focus) but, at a small size. It just seems that minimizing or hiding the app causes this method not to work
Essentially, I am using FPlatformProcess::CreateProc and grabbing the processID and then listening to see if the application is running. If it quits running then I (try to) restore the window.
My guess is there is something happening that is most likely pausing the app for some reason. I should also note that I overrode the UGameViewportClient class so that it doesn't pause the game even if it loses focus and that doesn't seem to work either.
I could possibly modify some code on the other application but, I want to keep that at a minimum. Any help would be greatly appreciated.
I was able to get a hold of one of the Engine developers with my question. Essentially, there are two options for doing something like this. First, you can use the MessageBus class and establish a connection between the two game instances. The drawback to this method however, is that it isn't really possible to detect crashes and things of that nature.
The second method (the approach I took) is to create a watchdog program in something like Visual Basic that you can use to set up a listener to a process exiting. This also allows you to set up other things like listening for application crashes or sending logs to developers.
I'm a developer and a long-time Windows user with an obsession about making my system as convenient to use as possible.
Yesterday I thought about something that has always annoyed me in Windows and that I've taken for granted, and I realized that I have a better idea for how it could work, and I'm now wondering whether it's possible to tweak Windows to work like that.
The thing that annoys me is when windows steal focus. For example, I could be running an installer for some program. While it's working, I'll switch to my browser and browse, maybe entering some text into an email in my browser. Then suddenly the installer finishes and its window steals the focus. Now I'm in the middle of writing an email, so I might press a key that happens to be bound to a button on that installer, and then that button gets invoked, doing some action that I never intended to happen!
This is doubly annoying to me because I'm using a multiple-desktop program called DexPot, and when a window steals focus, it also brings itself to the desktop I'm currently on, which can be really annoying, because then I have to put it back into its original desktop.
How my ideal solution to this problem would work: Every time a window tries to steal focus, we intercept that, and don't let it. We show something like a toaster message saying "Foobar installer wants focus, press Win-Whatever to switch to it". If and when you press the key combo, it switches to the window.
The question is: Is there an easy way to tweak Windows to make this happen? I know very little about Windows programming. I do know AHK and if it's possible with that, that'd be great.
No, there isn't an easy way to add this behavior, but Windows tries to do this automatically.
In theory apps shouldn't be able to steal the foreground while you're actively using another app. Unfortunatly there are some scenarios where Windows can't tell the difference between legitimate user actions that should change the foreground and unwanted foreground-theft. The window manager generally tightens up the holes a bit with each new version of Windows, but also needs to make sure that apps can come to the foreground when the user wants them to, even if that desire is expressed indirectly.
For example, a process launched by the current foreground process can put a window into the foreground. This is necessary so that when a user launches a window from Explorer the newly launched process can open its main window. This permission only lasts until the next user input, so if an application is slow to launch and you start working on an email the app may lose its foreground permissions before it can use them.
See the SetForegroundWindow function documentation for a list of requirements for a process to be able to set a window into the foreground.
There are also apps which specifically make use of these requirements to steal the permission (by joining the foreground queue or synthsising user input to themselves), but I suspect in your installer scenario it is accidental.
I'm not sure what exactly is going on, but I suspect that the problem comes from the installer running as a service and accidentally stealing the foreground permission when it tries to launch the app on your current desktop.
It would be theoretically possible for an external process to hook into the foreground system to override this and show your confirmation toast, but it would be tricky to get right and would require significant low level code (I'd probably start with a CbtHook). It would not be possible in a scripting package like AHK (assuming you mean AutoHotKey) but would need to be native C/C++ code injected into every running process.
In my mac application I am supporting full screen by changing system resolution of the device. And I am resetting back to old resolution if the user switches from full screen to windowed mode or if user quits the app and I need to handle force quit case also.
1. Is there any API or callback which tells the application if the user presses cmd+opt+esc(force quit).
2. Any other way to handle this?
I know in NSApplicaction there is an option to disable force quit([NSApplication setPresentationOptions: NSApplicationPresentationDisableForceQuit]) but instead of disabling it I want to handle force quit event.
The general consensus is that force quit sends a SIGKILL ("consensus" as I don't know any Apple documentation that states this, but it is the logical answer). A SIGKILL cannot be caught so you cannot do cleanup directly. An alternative is to run a helper application which monitors you main app and does the cleanup, the main app can terminate the helper on normal exit. See also this question.
I'm writing a Cocoa application that installs itself as an menulet in the menu bar (i.e. like the volume or battery icons). When the program crashes, it isn't possible to use the Force-Quit dialog, because it doesn't show up in the list. Of course, I can still kill it using the command-line, but my users don't know how to do that. Is there any way to fix this, say by making the program show up in the Force-Quit dialog?
(Note: the app is Leopard only).
To be honest, the proper solution is to make sure your app never hangs or crashes for users. This should be your #1 priority, rather than figuring out how to let users deal with crashes and hangs. Obviously it isn't always possible to make sure your app never breaks in these ways, but it should definitely be the exception rather than the rule.
On another note, MenuExtras is a private API which I hope you aren't using to create your "menulet". Rather, the public class NSStatusItem (part of Cocoa) is the Apple-approved, recommended way to install icons into your menu bar.
Not really an answer, but hopefully helpful still ...
I think that most people who know how to force quit also know they can kill a process in the activity monitor. Just make sure it's not named '93AZkZ' or something.
You could provide a PreferencePane for your application that can send the proper signal to it, if you want to allow users an easy way to shut it down or restart it. This is the pattern that MySQL uses on OS X.
I don't really know where to begin. Let's start with the stupid questions:
What language should I use for this? What is suited for the task at hand?
Next, the real ones:
Is there a way to stop the screensaver from starting, short of changing the cursor position? If not, will changing the cursor position even work?
SetThreadExecutionState will prevent the screensaver from coming on or the machine from automatically going to sleep if you pass the ES_CONTINUOUS and ES_DISPLAY_REQUIRED flags.
I wrote an app awhile ago that does exactly what you are asking for. It runs as an icon in the System Tray, not the Taskbar, and uses a global message hook to disable the WM_SYSCOMMAND/SC_SCREENSAVE notification from reaching any applications. If that notification does not reach the DefWindowProc() function, the screen saver will never run.
Your program does not need to be visible in the task bar at all.
You don't even need a program at all, if you can disable the screensaver in the registry.
What you want to do can perhaps be achieved by sending a MOUSE_MOVE event to the desktop window. If you want to use C# (the only language I am current with right now), you can look at this article, but maybe a simple C program using the WinAPI is better suited for this task.
.NET will easily allow you to put an application in the system tray (checkout the NotifyIcon object in System.Windows.Forms.Controls).
I believe you can use the SetCursorPos (http://msdn.microsoft.com/en-us/library/ms648394(VS.85).aspx) API call to prevent the screen saver, just make sure you set them to the current location so you don't actually move the mouse.