I'm currently developing a cross-plataform virtual keyboard. In linux i was able to do whatever i want, but in Windows i'm having problems to prevent the widget to obtain the keyboard focus.
In linux, using the window flag
Qt::X11BypassWindowManagerHint
the widget never gets the keyboard input, but of course, that flag does not work on Windows
Is there something equivalent to that flag or some method i can use instead?
any ideas would be appreciated
thanks in advance
I posted an answer to a similar question over in Make a floating QDockWidget unfocusable. On Win32 you don't really have the choice of bypassing the window manager completely, but you should be able to get most of the behavior you want by intercepting nativeEvent to handle WM_MOUSEACTIVATE.
I would try to ignore the event. I believe you need to ignore FocusIn on the main application window - not sure about the actual event, you might need to prototype it. You can do ignore events by either installing an event filter or manually re-implementing one of the event methods (possibly event itself). I don't know which is the preferred way though but I'd attempt the event filter first for this task: http://doc.trolltech.com/4.6/qobject.html#eventFilter
I've never tried to capture the keyboard focus event, but I have been able to successfully ignore escape keys in a QDialog to prevent users from accidentally closing the window. I believe it should be possible.
Related
I am not sure how to ask the question so here is a picture of some idea that came to mind
So for example, when you run my "custom launcher" it displays a window with a couple buttons on the side which you can assign values to. When you click on a button, the appropriate program will run in the big panel on the right (in window mode).
This is all from the user's perspective of course. They will just see that the program they want to run appears in that panel. The actual implementation may have nothing to do with "one program running inside another program"
My own use case is limited to windows desktop platforms only, but if it is possible to generalize it that would be nice as well.
Is this actually possible? Can I write such a program that will run another program inside a panel? The program that's launched may be someone else's, such as MS paint or calculator.
Just to expand on my comment above, here is an approach that may work for you: Fake it :)
When you launch the program, intercept all windows messages to the program that control it's position on screen. That way it 'appears' to be fixed in place, but in reality it's still attached to the normal Windows desktop.
Here's some light reading for you:
Windows Event Hooks
A hook is a mechanism by which an application can intercept events,
such as messages, mouse actions, and keystrokes. A function that
intercepts a particular type of event is known as a hook procedure. A
hook procedure can act on each event it receives, and then modify or
discard the event.
I would recommend against it in a commercial application because you are modifying the behavior of software you don't own - that software may make assumptions about what its parent window is, but for experimentation there's the SetParent Win32 function.
I'm trying to write an application that prevents certain key signals from propagating beyond the OS in OSX. To clarify, I want to make it so that it almost seems to the user that the key they are pushing on their keyboard is broken. So, the associated letter won't show up in a textarea, the key won't activate a function in another application, etc. Any ideas? Thanks in advance.
You probably want to look into Quartz Event Taps. Note that your process will need to be running with "root" privileges to intercept events at the system level.
See also OSX Quartz Event Taps: event types and how to edit events
I have an ATL app where I want to handle WM_POWERBROADCAST. I have a CMainDlg (CAxDialogImpl) in whose MSG_MAP I defined the handler.
BEGIN_MSG_MAP(CMainDlg)
...
MESSAGE_HANDLER(WM_POWERBROADCAST, OnPowerChange)
...
END_MSG_MAP()
However, the handler isn't invoked when I do things that should invoke it, for instance change power settings or put the machine to sleep.
Any ideas about what might be going on, and how to fix this? Does CMainDlg not get notified of power events, for some reason?
I suspect your dialog not being a top level window (WS_POPUP styled).
Just tested with a WTL AppWizard non modal dialog app that WM_POWERBROADCAST is received (without any registration) on AC plugged/unplugged.
Did you register to receive the power events?
To add to answers above, you might want to use Spy++ tool to make sure the messages of interest are posted to your application in first place. You will also see which windows they are posted to, and if it is your window where you are waiting for this message.
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.
I'm writing a routine to provide user definable keyboard short-cuts for any menu item in my Windows Mobile 5 application, which is in C++/MFC. To do this I am getting all of the available menu command IDs, and using the CWnd::PostMessage(WM_COMMAND,MyMenuID) to post it to the application. I use this technique to good effect elsewhere for inter-thread comms, but not with menu command IDs. Any ideas why this doesn't work. The app is document view, and I have tried posting to the CMainFrame and CView derived windows. I could write a god awful switch statement but I feel posting a message should work.
Edit: Ok, i've tried a number of things, including suggestions from this post, to no avail. Big ugly switch statement it is for now, I'll update again if i find anything better.
The only reason I can think of is the message is going to the wrong window. Don't forget that not all menu commands are always processed by a particular window. Some menu commands like Cut are usually processed by a view window. Others are processed by frame windows and some possibly by the application object.
Hope this helps.