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Change desktop wallpaper on certain monitor? [duplicate]

I'm using:
ctypes.windll.user32.SystemParametersInfoA(SPI_SETDESKWALLPAPER,
0, "picturefile", 0)
To change the wallpaper.
But I'm wondering if there's any simple way to put different wallpapers on each screen.
This feature isn't standard in windows though, but there are external applications like ultramon that do this. Anyone know how that works?
The way I thought it might work if I join the two images together into one and then make that the wallpaper, but then I still need a way to span one image accross both screens.
Also, how could I grab some info about the monitor setup, the resolution of each screen and their placement? Like what you see in the gui display settings in windows, but in numbers.

After joining the images together into a big image, you have to set the wallpaper mode to tiled to make it so the image spans the desktop (otherwise it will restart on each monitor).
Couple of ways to do this:
a) Using IActiveDesktop (which does not require Active Desktop to be used, don't worry). This is nicest as on Win7 the new wallpaper will fade in.
You create an IActiveDesktop / CLSID_ActiveDesktop COM object and then call SetWallpaper, SetWallpaperOptions and finally ApplyChanges. (As I'm not a Python dev, I'm not sure exactly how you access the COM object, sorry.)
OR:
b) Via the registry. This isn't as nice, but works well enough.
Under HKEY_CURRENT_USER\Control Panel\Desktop set:
TileWallpaper to (REG_SZ) 1 (i.e. the string "1" not the number 1)
WallpaperStyle to (REG_SZ) 0 (i.e. the string "0" not the number 0)
Then call SystemParameterInfo(SPI_SETDESKTOPWALLPAPER...) as you do already.
.
By the way, the code I'm looking at, which uses IActiveDesktop and falls back on the registry if that fails, passes SPIF_UPDATEINIFILE | SPIF_SENDCHANGE as the last argument to SystemParameterInfo; you're currently passing 0 which could be wrong.
EnumDisplayMonitors is the Win32 API for getting details on the monitors, including their screen sizes and positions relative to each other.
That API returns its results via a callback function that you have to provide. (It calls it once for each monitor.) I am not a Python developer so I'm not sure how you can call such a function from Python.
A quick Google for "Python EnumWindows" (EnumWindows being a commonly-used API which returns results in the same way) finds people talking about that, and using a Lambda function for the callback, so it looks like it's possible but I'll leave it to someone who knows more about Python.
Note: Remember to cope with monitors that aren't right next to each other or aren't aligned with each other. Your compiled image may need to have blank areas to make things line up right on all the monitors. If you move one of the monitors around and do a PrtScn screenshot of the whole desktop you'll see what I mean in the result.

Take all input in Python (like UAC)

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)

Interactive movie / video processing with PyQT / OpenCV

I am starting out on a project in which I need to build a customized annotation tool for movies and video. Some person (not technically minded) will need to pop open a GUI that I create, open either a video file or a directory of frames that result from chopping up a video file, and then use a window (much like QuickTime or VLC player, etc., i.e. a video window with a simple slider bar allowing the user to move back and forth at will). In this window, the user will be able to click on interesting points, give them semantic labels and meta-data (such as whether or not the point is occluded by something else in the picture), and then basically "press go" and start a tracker. The tracker will follow the points, frame by frame and the user can press the space bar or something to move forward and backward. The idea is to allow the human to intervene any time the tracker gets confused, but hopefully the tracker works well enough that humans don't have to hand-label every frame in an entire multi-thousand frame video sequence.
I am planning to do this all in Python, (a) because it is the language I know best for non-trivial programming, (b) I have easy access to both OpenCV Python (for image processing algorithms) and PyQt which seems to have a powerful enough GUI toolbox for what I want to do and (c) some other aspects of this same project are being developed by other programmers to work in Python and with MySQL databases. Python just seems like the natural choice to streamline it all together.
I am experienced using computer vision algorithms for the tracking, and I am reasonably sure that I can figure out simple PyQt GUI devices for making points clickable, buttons, entering simple text data, etc. However, the part I am having trouble understanding is how to actually construct my own video window with a slider bar that either moves ahead according to a frame's number or else is actually manipulating a video file. Can I leverage other movie players like VLC from within PyQt when programming in Python? Any suggestions or links that describe similar movie/video editing GUIs and how to develop them at home would be greatly appreciated.

Qt(PyQt) has a good multimedia support via Phonon module. You can easily use that module to achieve Video window, it can provide an easy-to-use video player and you can get playing position etc.

Creating an image editing application in Python

I need a tile/sprite editor kind of like Pixen, but I couldn't find one for Windows so I thought it might be a good exercise for me to try and put one together. I use Python, so are there any libraries out there that are suited to the task of putting together a simple tile/sprite editor?

You just need a gui toolkit (gtk, qt, wx) a image library (PIL) and 500 hours of free time ...

Have you looked at the Python Imaging Library (PIL)?

So, the fact is that creating a complex app with a nice UI takes time - I am just expanding a little bit on the answer by THC4k.
PIL, at least PIL alone is useless for this: it does have some functions to manipulate images, but the complicate task here is creating and tunning your desired UI.
That's where the widgets toolkits come in: You would have to pick a toolkit platform that can offer you buttons, images, load and save the image files, maybe some specialzed widgets you can use to create your color swatches, etc.
both GTK+ and QT4.5 have a liberal license, are very complete and very unpythonic on their use :-(
(While you are at it, when using these libraries and toolkits our app can easily be multiplatform: you don't have to make it windows specific, it is equally easy to create an app that will run on Windows, Linux and Mac using python and either GTK+ or Qt4)
One thing I would suggest is for you to learn to proper use GIMP: it is an Image editor, and certainly it will lack a lot of tools you are needing for sprites: but you can expand it's capabilities with Python plug-ins. On the other hand GIMP does have thousands of features that you'd no longer will need to create for your stand-alone app. (think on layer support, color filters, image rotation etc...)
Check around on how to install GIMP with Python support on Windows, then spend some hours learning the app, with some book-like text around preferably so you can find the hidden features.
Ah, ok, finally:
If you want a very simple thing, just for the taste of "i did it" - you can use Pygame: You have to do all the drawing on the window, including text - but have straighter access to pixels, colors, mouse clicks and coordinates than with GTK+ or Qt, in a sense it would be a lot less of overhead for you to learn in terms of API's and internal working.

You could try PyGame but, seriously, you couldn't find a freeware graphics editor for Windows??!!
EDIT: In the past I've used Aha-Soft's IconXP for pixel work, but it costs USD 30 and doesn't offer all of the Pixen features that I guess you'll want.

How to make PowerBuilder UI testing application?

I'm not familiar with PowerBuilder but I have a task to create Automatic UI Test Application for PB. We've decided to do it in Python with pywinauto and iaccesible libraries. The problem is that some UI elements like newly added lists record can not be accesed from it (even inspect32 can't get it).
Any ideas how to reach this elements and make them testable?

I'm experimenting with code for a tool for automating PowerBuilder-based GUIs as well. From what I can see, your best bet would be to use the PowerBuilder Native Interface (PBNI), and call PowerScript code from within your NVO.
If you like, feel free to send me an email (see my profile for my email address), I'd be interested in exchanging ideas about how to do this.

I didn't use PowerBuilder for a while but I guess that the problem that you are trying to solve is similar to the one I am trying to address for people making projects with SCADA systems like Wonderware Intouch.
The problem with such an application is that there is no API to get or set the value of a control. So a pywinauto approach can't work.
I've made a small tool to simulate the user events and to get the results from a screencapture. I am usig PIL and pytesser ORM for the analysis of the screen captures. It is not the easiest way but it works OK.
The tool is open-source and free of charge and can be downloaded from my website (Sorry in french). You just need an account but it's free as well. Just ask.
If you can read french, here is one article about testing Intouch-based applications
Sorry for the self promotion, but I was facing a similar problem with no solution so I've written my own. Anyway, that's free and open-source...

I've seen in AutomatedQa support that they a recipe recommending using msaa and setting some properties on the controls. I do not know if it works.

If you are testing DataWindows (the class is pbdwxxx, e.g. pbdw110) you will have to use a combination of clicking at specific coordinates and sending Tab keys to get to the control you want. Of course you can also send up and down arrow keys to move among rows. The easiest thing to do is to start with a normal control like an SLE and tab into the DataWindow. The problem is that the DataWindow is essentially just an image. There is no control for a given field until you move the focus there by clicking or tabbing. I've also found that the DataWindow's iAccessible interface is a bit strange. If you ask the DataWindow for the object with focus, you don't get the right answer. If you enumerate through all of the children you can find the one that has focus. If you can modify the source I also advise that you set AccessibleName for your DataWindow controls, otherwise you probably won't be able to identify the controls except by position (by DataWindow controls I mean the ones inside the DataWindow, not the DataWindow itself). If it's an MDI application, you may also find it useful to locate the MicroHelp window (class fnhelpxxx, e.g. fnhelp110, find from the main application window) to help determine your current context.
Edited to add:
Sikuli looks very promising for testing PowerBuilder. It works by recognizing objects on the screen from a saved fragment of screenshot. That is, you take a screenshot of the part of the screen you want it to find.