I am making a vim-style "window manager" that takes text input, much like Alfred or Spotlight in Mavericks (in a floating panel).
The problem I'm having is when I call activateWithOptions: on a running application it steals focus from my window. I was hoping the problem would be solved by simply bring my app to the foreground again, however it seems the activation is running on a separate thread, and I end up activating my app before the original app gets activated.
I have tried reactivating when I receive NSWorkspaceDidActivateApplicationNotification, but that doesn't work either.
Ideally I'd like to pause execution until the application is focused for multiple reasons, since that would be the window I manipulate further.
Does anyone have any suggestions?
Related
I have a Winforms app with a main form where a multiline text box is updated during a long running process.
I would like to be able to use the ALT-TAB facility of Windows to switch away from the Visual Studio 2012 IDE to watch the form being updated as the app runs.
Is there some option that controls this? If I have other apps running such as Notepad I can toggle away from the IDE but navigating in this way to the running Winforms app seems to be disabled.
Last time I debugged an app like this I recall this sort of switching worked but sometimes there was a lag in the rendering of the screen.
The winforms app is not multithreaded.
Any ideas?
The winforms app is not multithreaded.
Which means you're doing all your lengthy processing on the UI thread. And that, in turn, means that during that processing, your app is ignoring all the messages Windows is sending it, like the "hey, somebody just Alt+Tabbed to you, so bring yourself to the front" message.
You either need to sprinkle your code with frequent calls to Application.DoEvents (not recommended, but could work if you don't intend to maintain this app long-term), or move your long-running logic into a background thread so your UI thread can stay responsive to messages.
I have written a WinForms driver safety application for a windows tablet device that will blank the screen (display a full screen blank topmost window) when it detects that the car is moving at say more that 15km/h (using the tablets GPS).
The software has worked fine under Windows 7 but I'm struggling a bit to get it working under Windows 8. My first challenge is to display the blank screen when the Metro start menu is currently displayed. So if the user has the Metro start menu displayed and the car starts moving > 15 km/h my blank screen should display... I need to steal the focus from the metro interface and display my blank window on the desktop.
To test this I wrote a simple vb.net app in 2010. It had a form with a timer firing every 3 seconds. In the Tick event I had the code:
Beep()
Me.Activate()
When I ran this with the debugger and pressed the windows key to show the Metro Start Menu, it worked... The focus switched back to the desktop (and my window). However, when I ran this without the debugger and did the same thing I could hear the beeps but the focus never switched back to the desktop.
Any ideas why the behaviour would be different? Any ideas on how I replicate the same behaviour I get when the debugger is attached?
I have tried a few things like AppActivate, setting the form TopMost, BringToFront but unfortunately this hasn't worked.
The only half solution I have come up with is to send a windows button keystroke but this has other issues.
Windows specifically tries to prevent applications from stealing the foreground from other apps. See the SetForegroundWindow documentation for commentary on this and the factors that can let an application come to the foreground (all of the methods you are trying essentially come down to a SetForegroundWindow call).
Note that one of the explicit blocking circumstances is "The foreground process is not a Modern Application or the Start Screen."
This works for you when debugging because "The process is being debugged" is one of the cases which explicitly allows foreground privileges.
Because this is a generally user-unfriendly thing to do there isn't a good general purpose way to bypass this behaviour and steal the foreground.
Likewise, normal apps cannot run on top of Modern applications or the start screen.
You may be better off locking the system by calling the LockWorkStation function.
VS2012's default C# "Metro style" project templates include code in App.xaml.cs (in the OnLaunched override) to restore the application state after a suspend-and-terminate. This code only runs when LaunchActivatedEventArgs.PreviousExecutionState is Terminated, i.e., "The app was terminated after being suspended."
How can I force my app to be suspended and terminated, so I can test this suspend/resume functionality in my app?
Things I've tried that don't work:
If I use the "close app" gesture (drag from the top of the screen to the bottom), then the next run's PreviousExecutionState is ClosedByUser.
If I kill the app -- either using Task Manager, or (if I was debugging) with the "stop" button on the VS toolbar -- then the next run's PreviousExecutionState is NotRunning. This is true even if Task Manager showed the app as "Suspended" before I ended task, so clearly it's more nuanced than the description of "terminated after being suspended".
You'd think I could just switch away from my app, and then open lots of other Metro-style apps until my app eventually gets kicked out. But even if I open every single Metro-style app that ships with the Windows 8 Release Preview, that's apparently not enough memory pressure to make Windows terminate my app. (I assume Windows would be less likely to terminate an app that was being debugged, so I launched my app from the Start screen -- no debugger -- before I tried this.)
It does appear that, if I switch away from my app and type into a StackOverflow window for several minutes, that my app will eventually get terminated, so perhaps there's a time-based component to it. But if I have to wait five or ten minutes every time for my app to terminate, that's a pretty slow testing cycle.
Given that this is something developers will have to test, you'd think there would be a nice, easy way for a dev to force an app to suspend-and-terminate. Is there some kind of stress-test app that comes with Visual Studio that will force enough memory pressure? Is there some menu item in Visual Studio that will force termination of my app? How are we supposed to test this?
In Visual Studio 2012, when you're debugging, there are "Suspend", "Resume" and "Suspend and Shutdown" buttons. By default, you should see the buttons while you are debugging your app. See this article for more info on debugging process lifecycle.
I had trouble finding the Suspend control because VS wasn't showing a second row of toolbars for me. As it turns out, this is on the "Debug Location" toolbar. Make sure you have this toolbar turned on and then you should be able to find the Suspend control (and it does work to solve the OP's problem).
If they don't show by default, go to TOOLS -> CUSTOMIZE, and under the Toolbars tab, check the box that says "Debug Location"
I was looking for VS 2013, just in case others came for the same reason.
Source:
http://blogs.msdn.com/b/visualstudio/archive/2012/08/23/new-visual-studio-2012-debugging-features-for-the-windows-8-app-lifecycle-model.aspx
a busy cat http://blogs.msdn.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-01-29-92-metablogapi/2210.image_5F00_thumb_5F00_1FBA9C1E.png
Can a WinRT app continue to run while Screen Off?
I know that a WinRT application can create a Background Task that periodically executes even when the application is not running. Handy, but not what I am asking. What I am asking is, when the user clicks the power button and invokes Connected Standby, is there anything an app can do to remain active. Can it ask for some special capability?
Example - in Windows Phone there is a handy Running and Walking app that keeps track of "where you are" while it is running - then tallies your distances, etc. Even when the screen is off! Turn the screen on and the "where was I" map is up-to-date. Is this type of application possible in WinRT?
I've been looking into the same thing recently, and unfortunately it seems that what you want to do isn't possible with WinRT.
Why don't you use Background task to simulate what you are trying to achieve. When the user starts the app again, you could have the info populated to the latest data by looking at the store where the background process updated. Just a thought.
Within my Cocoa app, I call NSWorkspace's openFile: method to open some file with its default application.
Sometimes this works just fine, and the other application gets focus, as it should.
But alas, sometimes (the occurrence of which seems to be totally random), after the focus goes briefly to the other application, it goes quickly back to my Cocoa app. This is unwanted.
Any ideas what the causes could be?
Note: I have also tried the openFile:withApplication:andDeactivate:, passing YES to the last argument. This doesn't work either. The strange random occurrences of focus going back to my Cocoa app persist.
I'm unable to reproduce this now. Not sure what the problem was.