Ctrl+Escape is a global Windows shortcut for opening main system menu. But I would like my Qt application to use this shortcut without triggering Windows main menu. I know it is probably a bad idea to override system shortcuts in general, but I would like to use this shortcut is a very limited use case.
This usecase is as follows. I have a popup window containing several rows or items. This window is opened by Ctrl+Tab and while the user holds Ctrl and keep pressing Tab, the current rows are cycled through. When the user releases Ctrl, the current row is used for some operation... But sometimes it happens that user presses Ctrl+Tab and then realizes he does not want to continue. He usually presses Escape while still holding Ctrl. And then it triggers Windows system menu and normal user gets confused, choleric user get angry... which is a bad thing. In other words I would like to be able to close the popup window when user presses Ctrl+Escape. How to do that? It is even possible?
If I write the code using this shortcut like any other short, it does not work and it always triggers Windows main menu.
As I understand it, Qt will typically not receive the key event if the underlying window system has intercepted it. For example even QtCreator cannot override system-wide shortcuts.
This question is almost a duplicate of: C++/Qt Global Hotkeys
While that question is asking specifically to capture shortcuts in a hidden/background application, I think the basic concept is the same -- capture shortcuts before the window system processes them.
From that answer, UGlobalHotkey seems pretty good, and the How to use System-Wide Hotkeys in your Qt application blog post could be useful for your limited-use case (but read the comments on that blog post about fixing the example).
Also found:
https://github.com/mitei/qglobalshortcut
https://github.com/Skycoder42/QHotkey (looks like a more detailed version of above)
Related
I have a program that has some rather bad window handling. I can provide scripting to the client portion of the application but have no control over the non-client portion, apart from some simple movement/resizing commands (that don't help).
The main problem is that when the windows "maximize" button is pressed the WS_MAXIMIZE style is not set. The window is positioned correctly, and helpfully respects the taskbar settings but the application icon/title and "windows buttons" are misplaced and the borders show up on any other screens.
Using winspy++ I was able to set the WS_MAXIMIZE style fixing these graphical annoyances. but this also led into a secondary issue. The "restore" button also does nothing, when pressed it simply reverts the style and does not take the application back to it's pre-maximized position and size.
I was going to make a launcher for this program in Python anyway, to handle some .ini stuff and alterable executable parameters.
I would like to extend this launcher to silently run behind the application, fixing these issues.
These things were intended to be handled by the operating system and the developers of the application do not seem to be focused on working on these problems, but more on increasing the library of application scripting and porting to other systems.
My assumption is that when the launcher is commanded to run the program it needs to have access to the thread/process so that it can poll the position and size of the application window and set the appropriate style when it is required, and more importantly (I guess), have access to it's memory.
Example: [-8,-8] to [1374,776] on a 1366x768 screen with a minimized taskbar.
If there is an asynchronous method to detect when the window has been moved/resized/windows buttons pressed, that would be preferable to polling every step.
Supplying the window with "restore" information to make use of the restore button seems a bit less trivial. I have been reading as much reference as I can find but have not found anything on this. Where is this memory stored? How do I access it? Is it read-only, and only set by the OS?
I'm new to Python, and SO, so I apologize if my question doesn't fit here, I've tried.
I'm trying to use GTK3 and Cairo from Python for a minimal plotting application where the on-screen display of Cairo's output is for user convenience.
The typical usage is that I run a command, a plot pops up on screen and is also written to file, and I want to be able to dismiss the window as quickly as possible, ideally just a "q" keypress but also the common Ctrl-W and Ctrl-Q in addition to the default Alt-F4 (does anyone really use that regularly?!?).
I also want as little UI clutter in the window as possible: ideally just the standard window surround, no menus, toolbars, etc.
So... how can I bind my "q", "Ctrl-Q", etc. keybindings to Gtk.main_quit without having to a) create a cluttersome drop-down menu bar and b) go though the heavyweight Gtk.UIManager focused on by the Python Gtk+ 3 documentation here: http://python-gtk-3-tutorial.readthedocs.org/en/latest/menus.html . I hope this is possible, and doesn't require a lot of code (at least not as much as to set up all the menus!), but I can't find an example anywhere online: maybe I'm just searching for the wrong terms, being a GTK newbie.
Unfortunately there doesn't seem to be any documentation on making such a minimal accelerator setup, and the code to configure accelerator keys seems to differ a great deal between GTK2 and 3... thanks for helping.
Connect a signal to your main frame Win.connect('key-press-event', self.on_key_function) and in on_key_function (self, widget, event) check the value of event.keyval. For ESC is 65307 if you like hardcoded. Also, for key combinations, event.state report shift, alt(meta), and so on: if Gdk.ModifierType.CONTROL_MASK & event.state:do_something if ctrl is pressed
You could have separate stataments for left-ctrl, right-alt; be sure not to try to capture predefined key combinations, thay may be consumed by window manager.
A IDE with a good introspection will help you a lot, just write Gdk (previously imported) and autocompletion will popup a lot of functions/clases, most of them with a self-explanatory name.
Don't use key-press-event and keyval, it won't work for users with non-Latin keyboard layouts. GTK+ does a great job internally to match keyvals to hardware keys, this functionality is exposed via accelerators (often shortened as accel in the API) and bindings.
I have a root window with a panel on it. Then there is this function, in which I create a TopLevel (another window) for asking input from user. I'm trying to find some way to make it compulsory for user to either enter input and click OK or cancel to dismiss the window before being able to access the root window. It's like when an error message pops up, you can't just ignore it and do other things in the root window. Does anyone have any suggestion for me?
Have a look at Dialog Windows. You can use widget.wait_window(window) to achieve this.
You can do what is called a grab, which forces all events into the window of your choice. There are several methods for managing grab, including grab_set and grab_release.
For an example, see NiceGrab.
When working with grabs, exercise extreme care. It's possible to lock up your computer if you do a global grab and then have a bug that prevents you from releasing it. During development I will often implement a timer that kills the program after a minute or so, so if I lock everything up it will be automatically released after a short wait.
Is there any way I can create a UAC-like environment in Python? I want to basically lock the workstation without actually using the Windows lock screen. The user should not be able to do anything except, say, type a password to unlock the workstation.
You cannot do this without cooperation with operating system. Whatever you do, Ctrl-Alt-Del will allow the user to circumvent your lock.
The API call you're looking for Win32-wise is a combination of CreateDesktop and SetThreadDesktop.
In terms of the internals of Vista+ desktops, MSDN covers this, as does this blog post. This'll give you the requisite background to know what you're doing.
In terms of making it look like the UAC dialog - well, consent.exe actually takes a screenshot of the desktop and copies it to the background of the new desktop; otherwise, the desktop will be empty.
As the other answerer has pointed out - Ctrl+Alt+Delete will still work. There's no way around that - at least, not without replacing the keyboard driver, anyway.
As to how to do this in Python - it looks like pywin32 implements SetThreadDesktop etc. I'm not sure how compatible it is with Win32; if you find it doesn't work as you need, then you might need a python extension to do it. They're not nearly as hard to write as they sound.
You might be able to get the effect you desire using a GUI toolkit that draws a window that covers the entire screen, then do a global grab of the keyboard events. I'm not sure if it will catch something like ctrl-alt-del on windows, however.
For example, with Tkinter you can create a main window, then call the overrideredirect method to turn off all window decorations (the standard window titlebar and window borders, assuming your window manager has such things). You can query the size of the monitor, then set this window to that size. I'm not sure if this will let you overlay the OSX menubar, though. Finally, you can do a grab which will force all input to a specific window.
How effective this is depends on just how "locked out" you want the user to be. On a *nix/X11 system you can pretty much completely lock them out (so make sure you can remotely log in while testing, or you may have to forcibly reboot if your code has a bug). On windows or OSX the effectiveness might be a little less.
I would try with pygame, because it can lock mouse to itself and thus keep all input to itself, but i wouldn't call this secure without much testing, ctr-alt-del probably escape it, can't try on windows right now.
(not very different of Bryan Oakley's answer, except with pygame)
I saw here a solution, but i don't want wait until the key is pressed. I want to get the last key pressed.
The related question may help you, as #S.Lott mentioned: Detect in python which keys are pressed
I am writting in, though to give yu advice: don't worry about that.
What kind of program are you trying to produce?
Programas running on a terminal usually don't have an interface in which getting "live" keystrokes is interesting. Not nowadays. For programs running in the terminal, you should worry about a usefull command line User Interfase, using the optparse or other modules.
For interative programs, you should use a GUI library and create a decent UI for your users, instead of reinventing the wheel.Which wouldb eb etter for what you ar trying to do? Theuser click on an icon,a window opens on the screen, witha couple of buttons on it, and half a dozen or so menu options packed under a "File" menu as all the otehr windws on the screen - or - a black terminal opens up, with an 80's looking text interface with some blue-highlighted menu options and so on?. You can use Tkinter for simple windowed applications, as it comes pre-installed with Python + Windows, so that yoru users don't have to worry about installign aditional libraries.
Rephrasing it just to be clear: Any program that requires a user interface should either se a GUI library, or have a WEB interface. It is a waste of your time, and that of your users, to try and create a UI operating over the terminal - we are not in 1989 any more.
If you absolutely need a text interface, you should look at the ncurses library then. Better than trying to reinvent the wheel.
http://code.activestate.com/recipes/134892/
i think it's what you need
ps ooops, i didn't see it's the same solution you rejected...why, btw?
edit:
do you know:
from msvcrt import getch
it works only in windows, however...
(and it is generalised in the above link)
from here: http://www.daniweb.com/forums/thread115282.html