Came across a problem which google searches could not help me with. I have a little SDL application that runs at 60 fps. Everything is working fine, however, it pauses/stops running when the window is dragged ( 640 X 480 window ). Is there a flag or something that can be set in the SDL window to prevent this from happening? Or is this unavoidable?
Windows uses a modal event loop for dragging windows, which blocks your main UI thread.
More discussion (and suggested workarounds, such as drawing from a second thread): http://www.sfml-dev.org/forum/viewtopic.php?p=8384&sid=632116a07a569edee43331076e028071
OpenTk apparently has code designed to address this, maybe you can reuse some of it: http://www.opentk.com/node/1218
Related
My goal is to take screenshots off an application while the laptop screen is off, but instead the screenshot will always be the same as just before turning off the screen. It does not redraw itself once the screen is off, and remains frozen.
I'm obtaining a screenshot using printwindow from Python (using method described here: Python Screenshot of inactive window PrintWindow + win32gui
This method works nicely as long as I have my laptop screen on, but if I turn it off, it simply returns the last image before the screen turned off. I've tried using win32gui.RedrawWindow, hoping that this would force a redraw, but I haven't gotten it to work, even trying all the different flags. I've also tried getting screenshots via pyautogui, but this also has the same problem. Is there any way to redraw the application while the laptop screen is off?
It would be nice if there were a straightforward way to do what you want to do, but unfortunately it's just not possible without some convoluted low-level work.
In the underlying WinAPI, native windows redraw themselves only when they receive WM_PAINT messages, and they only receive WM_PAINT messages if they are visible. They don't get the messages if they're behind another window, or if they're dragged off screen, or minimized, or their visibility is set to False. They also aren't visible when the screen is off. Since they aren't visible, they simply never get told to redraw themselves. That's why the screen capture image doesn't change after the screen is turned off.
There is no command you can issue that will override this -- it is implemented as a fundamental part of the windowing paradigm.
One solution is to have the application paint itself in something that's not a window (e.g., a dialog box) and capture that rather than capturing the screen. You could also modify the application by overriding OnPaint and using a timer to invalidate and call your OnPaint function periodically (since WM_PAINT messages won't be received).
If it were me I'd override OnPaint, make my application draw itself to a background context bitmap rather than the normal window, then use a timer to invalidate and redraw periodically and just take the bitmap of the background context whenever I wanted to capture the output.
If you don't own the code for the applications that are running, you may still be able to get applications to redraw themselves by running everything in a virtual machine. I've done that successfully for headless computing in the past, but it was many OS versions ago and things may be different now, so YMMV...
Information on manual screenshots under VMWare is here.
Information on programmatic screenshots under Hyper-V is here.
I have two monitors attached to my Desktop session in linux. I'd like to have a gtk window pop-up on the screen where the mouse cursor is. Sometimes it would be monitor 1, sometimes monitor 2. The pop-up is easy enough, but how can I determine which monitor contains the mouse pointer? I've run across various examples shelling out of python to call xrandr but I was hoping for a more integrative approach in Python.
Its pretty dependent on your setup which is why an "integrative" approach is fairly difficult. Multiple monitors on X is quite a mess.
Assuming you are using twinview, the X screen is essentially just 1 screen anyway, so how does the monitor matter?
from Xlib import display
data = display.Display().screen().root.query_pointer()._data
locationtuple = (data["root_x"], data["root_y"])
That should work if you are using Twinview.
A real newbie question here.
I'm using IDLE 2.7.2 on OSX 10.7.2 and reading Zelle's Python:Programming. I haven't programmed since the 80's, so after going through the command line stuff, I'm excited to dive into Objects. I grab his graphics.py file and copy it into documents (this seems like the default location for IDLE) and start up IDLE.
He then suggests a few commands into the shell:
from graphics import *
win = GraphWin() #which opens a graphics window with no problem
He then goes on to have you draw some lines and shapes in the window. Those graphics show up just fine in the window.
Here's my problem. If I try to mouse over the graphics window, I get the Mac pinwheel. Moving the window doesn't help. So the window seems like it's crashing (though IDLE is doing fine), but strangely, if I keep entering commands into IDLE, the shapes keep drawing normally in the window.
Am I doing something wrong? Is this normal? Thanks,
Henry
Idle runs the python commands you enter in another process, so it's reasonable to expect this "lock up" behavior to be different between the program controlled window and Idle.
What's probably going on, though is that everything is fine, but you have not yet started the event loop in the program you're typing in. The operating system notices that the program is not emptying out its event queue when you mouse over it (which creates lots of events) and it's helpfully informing you (by way of the pinwheel) that the program seems to be busy.
You will likely reach a point later in the tutorial where you do start the event loop, and the pinwheel will magically go away.
I am developing an application that will run on Linux to run fullscreen all the time (no menus or trays or anything will be visible).
The application is going to be developed in Python, not that that matters as far as the window manager, but what I am having a hard time with is choosing a window manager.
I need something with the smallest possible footprint, that will let me run a graphical Python app and have an mplayer window at the same time, at widescreen resolutions (widescreen, 16:10,16:9, etc). Other than that, it doesn't need a lot of features, but the end footprint size is the most important thing I'll be looking at.
What window manager would you recommend?
EDIT: There won't be any interaction with the application needed.
You don't actually need any window manager or display manager. All you need to do is open your initial window with the same geometry as the root window. I suppose you could even draw directly into the root window if you wanted.
If you are using some display library it probably has an easy way to open a full screen window. For example using a recent enough version of SDL through pygame you can do
pygame.display.init()
surface = pygame.display.set_mode((0,0),pygame.FULLSCREEN,0)
to get a window that fills the entire screen. This will work even if there is no window manager running.
As for mplayer, it accepts the -geometry flag, so you can use something like mplayer -geometry 640x480+20+20 to display the mplayer window 20 pixels from the top 20 pixels from the left and with a size of 640x480 pixels.
You probably meant window manager. Display manages are KDM, GDM and the like. Windoe managers, to name, GNOME, Xfce, KDE, ratpoison, fvwm, twm, blackbox are a few. ratpoison gives full screen to the application that is in the foreground but demands heavy keyboard interaction (hence the name ratpoison) and no mouse interaction at all.
I assume you'll be running both your python GUI and mplayer in some sort of geometries combination that shows both at the same time, filling the screen.
As commented, you should not need a window manager to achieve that. You could have your python GUI app get command-line parameters for setting its window geometry and also call fullscreen mplayer with the -geometry parameter. That should fill the screen as expected, without any window decorations.
Now you could have the startx script called for the user running it all and have a custom ~/.xinitrc script doing something like:
#!/bin/sh
exec python my_gui_app --whatever-sets-geom &
exec mplayer -fs video.avi
If yout pyhon app will instead be launching mplayer then just leave the first 'exex' call (remove the '&') and have it call mplayer as desired with the expected dimensions in '-fs' mode.
Please note you may need to use something like the 'xset' program to disable monitor blanking due to energy savings, hide the cursor (although IIRC that's something mplayer does for its own window), and things like that.
Also, somethimes running, for example, GTK apps on a bare X display may end up using an "ugly" theme, so you may need to have the toolkit style configuration taken care of someway.
I am doing something similar on my "set-top box" and I don't use any window manager.
It boots debian, and from inittab I auto-login the user that runs the display. That user's .profile starts X, which runs .xinitrc, which starts my python app that runs as a network server in front of mplayer (running mplayer in -slave mode).
My python app does not have a GUI element - only mplayer runs on the X display. But in your case, it should be no different. As I mentioned in a comment to another answer, you may want to look into how you can reparent mplayer's window to give you greater control over its placement and/or movement/size.
Doing it this way avoided a display manager and a window manager. This simplifies the solution, boots faster and uses a smaller footprint (it runs of an SD card, with heaps of room to spare).
I realize this is an old question, but I use openbox on my system, I have created a custom config file that disables all mouse keyboard shortcuts, and removes borders etc on the applications.
In the openbox config i even created some secret shortcuts that can run fx. an xterm for debugging live on the box.
The openbox documentation was very helpful in figuring everything out, I did the config in about 30 minutes.
I'm writing a python script that runs in the background and takes screenshots of another application that is active. Then it analyses the screenshots and now it should overlay a certain image over the active app or the screen. I still need to be able to make mouse and keyboard inputs in the active app.
So I need a way to overlay/paint on another window or on the screen, and still keep the other window the active window so that I can make inputs.
I would prefer to do that with python in Mac OS, but if it isn't possible, other languages and even Windows (if really necessary) would also be ok.
Can anybody help me?
Thanks in advance!
http://www.michaelfogleman.com/2009/12/drawing-on-the-windows-desktop-using-python-and-wxpython/
Seems to do what you want, but is windows only, as are some other answers to similar questions here on stackoverflow