NameError: global name 'CV_GUI_NORMAL' is not defined - python

I'm coding using Python and OpenCV on Ubuntu 14.04. When I click on the right button of the mouse, the associated mouse event cv2.EVENT_RBUTTONDOWN does not work and I rather get context menu ("actions"). Is there a way to disable the context menu popup?
A user gave me a hint and I am sure the solution is somewhere there. He asked me to add CV_GUI_NORMAL as shown on here.
So I run: cv2.namedWindow("Window",CV_GUI_NORMAL) but I got this error:
NameError: global name 'CV_GUI_NORMAL' is not defined
When I try cv2.CV_GUI_NORMAL as on the below user's comment instead, I get this error:
AttributeError: 'module' object has no attribute 'CV_GUI_NORMAL'
Note that similar question was asked here but I do not want to change OpenCV code.
How to fix this ?
.

You can use cv2.WINDOW_GUI_NORMAL as follows:
cv2.namedWindow('desired_name_of_window', flags= cv2.WINDOW_GUI_NORMAL)

Allowed windows values in cv2 are:
WINDOW_AUTOSIZE = 1
WINDOW_FREERATIO = 256
WINDOW_FULLSCREEN = 1
WINDOW_GUI_EXPANDED = 0
WINDOW_GUI_NORMAL = 16
WINDOW_KEEPRATIO = 0
WINDOW_NORMAL = 0
WINDOW_OPENGL = 4096
WND_PROP_ASPECT_RATIO = 2
WND_PROP_AUTOSIZE = 1
WND_PROP_FULLSCREEN = 0
WND_PROP_OPENGL = 3
WND_PROP_VISIBLE = 4

The official documentation says:
Python:
cv.NamedWindow(name, flags=CV_WINDOW_AUTOSIZE) → None
Parameters:
name – Name of the window in the window caption that may be used as a window identifier.
flags –
Flags of the window. The supported flags are:
WINDOW_NORMAL If this is set, the user can resize the window (no constraint).
WINDOW_AUTOSIZE If this is set, the window size is automatically adjusted to fit the displayed image (see imshow() ), and you cannot change the window size manually.
WINDOW_OPENGL If this is set, the window will be created with OpenGL support.
Only some implementations with Qt backend support CV_GUI_NORMAL. It seems you have no choice than to install cv2 with Qt support or use other variables.
In that case you'll be using cv2.CV_WINDOW_NORMAL.
For a starter you could build without Qt support if you do not need it. It seems to do more harm than good in many cases. So it is better set the flag WINDOW_OPENGL: That way you disable the QT support and get the OpenGL one.

Related

Adding image into Pygoocanvas

I have been trying to create a CanvasImage item in python using goocanvas however when I try to use the CanvasImage function it gives me an error.
pb = GdkPixbuf.Pixbuf.new_from_file_at_scale("image2.jpg", 1920, 1080, True)
image = GooCanvas.CanvasImage(pb, 200, 200)
TypeError: GObject.init() takes exactly 0 arguments (3 given)
Am I missing something or am I using a wrong function to create an image on the canvas.
I am referring to this as there is no proper documentation for goocanvas bindings in python: https://developer.gnome.org/goocanvas/stable/GooCanvasImage.html
If Goocanvas is not suitable for python, please suggest a different canvas that I could integrate and use in python.
Thank You
Perhaps it's the call.
This is from the goocanvas github : https://github.com/GNOME/goocanvas/blob/33694b33cc337be86d8c848825a463e52bb1a2c0/bindings/python/demo.py#L190
Also the project's github states that it is no longer supported.
An actively developed and better documented library is PyGObject.
https://pygobject.readthedocs.io/en/latest/index.html
To display images: https://lazka.github.io/pgi-docs/#Gtk-3.0/classes/Image.html#Gtk.Image

Changing Screen Resolution of Computer using python

I'm creating a python program that is supposed to streamline the process of setting up a computer. I want this python program to change the screen resolution of the computer and scaling of it. I'm not sure what the best approach is however, or how to approach it.
I've tried using an example pywin32 program, but it only outputted an array of resolution sizes
I had a look how to change screen resolution using C++ and then translated it to Python:
import win32api
import win32con
import pywintypes
devmode = pywintypes.DEVMODEType()
devmode.PelsWidth = 1366
devmode.PelsHeight = 768
devmode.Fields = win32con.DM_PELSWIDTH | win32con.DM_PELSHEIGHT
win32api.ChangeDisplaySettings(devmode, 0)
We needed a DEVMODE object to pass to the ChangeDisplaySettings function. The pywintypes module which is also part of pywin32 has a function to create objects of type DEVMODE.
We then set the PelsWidth and PelsHeight fields and also the Fields field to tell the API which field's values we want to use.
To change back to the previous resolution, simply call:
win32api.ChangeDisplaySettings(None, 0)
Thanks for asking the question. I've learned something.

Python: Tkinter: How to change the windows border color?

Every result I've gotten from searching this question up has to do with changing the border color for Tkinter widget's WITHIN the main app window, or changing the background color and stuff.
What I'm looking to do is actually change the windows border color itself. Which I have marked in this picture here
I read some stuff concerning 'Styles' but it didn't seem to be what I was looking for.
Can anyone help point me to a tutorial for changing this, or explain how it can be done?
Or if there is a question that asked exactly the same question I was asking that is answered point me to it.
As I see you are using windows.
This color is set by the theme you are currently using. It is the same for every window.
So I cross out the possibility of only using the Tkinter module for this.
Tkinter is responsible for what is in the window but the window manager decides about the border. For example in Ubuntu the window would look totally different.
I guess, you would need some windows specific calls for that.
You can remove the border with root.overrideredirect(1) if I remember correctly.
PS: put "windows" into the tags of this question.
Hi I was looking for this answer too, found it after like 80 minutes searching, Only work, to activate DWMWA_USE_IMMERSIVE_DARK_MODE
found it here: Can I change the title bar in Tkinter?
I didnt found dwmwindowattribute in dwmwindowattribute that affect Top bar color sadly :(.
For border colour:
It should be possible to call DWMWA_BORDER_COLOR, but honestly I dont know how, there is some article calling it in C++ here:
change-the-color-of-the-title-bar-caption-of-a-win32-application
Tried this but doesnt work:
set_window_attribute(hwnd, 22, '0x000000FF', 4)
Here is working code for pure black top:
import tkinter as tk
import ctypes as ct
def dark_title_bar(window):
"""
MORE INFO:
https://learn.microsoft.com/en-us/windows/win32/api/dwmapi/ne-dwmapi-dwmwindowattribute
"""
window.update()
set_window_attribute = ct.windll.dwmapi.DwmSetWindowAttribute
get_parent = ct.windll.user32.GetParent
hwnd = get_parent(window.winfo_id())
value = 2
value = ct.c_int(value)
set_window_attribute(hwnd, 20, ct.byref(value),
4)
root = tk.Tk()
root.title("Crystaly Ball")
root.geometry("1400x900")
root.configure(background="#222246")
dark_title_bar(root)
root.mainloop()

How to make python window run as "Always On Top"?

I am running a little program in python that launches a small window that needs to stay on top of all the other windows. I believe this is OS specific, how is it done in GNU-Linux with GNOME?
[Update - Solution for Windows]
Lovely, I think I got it working. I am using Python 2.5.4 with Pygame 1.9.1 in Eclipse on Vista 64-bit. Thus, this is for windows systems. The SetWindowPos function is documented Here. I will refer to this in my explanation.
Imports:
from ctypes import windll
Then I set up a variable that calls the "SetWindowPos" in user32:
SetWindowPos = windll.user32.SetWindowPos
Now, let's say I just made a window:
screen = pygame.display.set_mode((100,100), pygame.NOFRAME)
The next line is the key. This sets the window to be on top of other windows.
SetWindowPos(pygame.display.get_wm_info()['window'], -1, x, y, 0, 0, 0x0001)
Basically, You supply the hWnd(Window Handle) with the window ID returned from a call to display.get_wm_info(). Now the function can edit the window you just initialized.
The -1 is our hWndInsertAfter.
The MSDN site says:
A window can be made a topmost window either by setting the hWndInsertAfter parameter to HWND_TOPMOST and ensuring that the SWP_NOZORDER flag is not set, or by setting a window's position in the Z order so that it is above any existing topmost windows. When a non-topmost window is made topmost, its owned windows are also made topmost. Its owners, however, are not changed.
So, the -1 makes sure the window is above any other existing topmost windows, but this may not work in all cases. Maybe a -2 beats a -1? It currently works for me. :)
The x and y specify the new coordinates for the window being set. I wanted the window to stay at its current position when the SetWindowPos function was called on it. Alas, I couldn't find a way to easily pass the current window (x,y) position into the function. I was able to find a work around, but assume I shouldn't introduce a new topic into this question.
The 0, 0, are supposed to specify the new width and height of the window, in pixels. Well, that functionality is already in your pygame.display.set_mode() function, so I left them at 0. The 0x0001 ignores these parameters.
0x0001 corresponds to SWP_NOSIZE and is my only uFlag. A list of all the available uFlags are on the provided documentation page. Some of their Hex representations are as follows:
SWP_NOSIZE = 0x0001
SWP_NOMOVE = 0x0002
SWP_NOZORDER = 0x0004
SWP_NOREDRAW = 0x0008
SWP_NOACTIVATE = 0x0010
SWP_FRAMECHANGED = 0x0020
SWP_SHOWWINDOW = 0x0040
SWP_HIDEWINDOW = 0x0080
SWP_NOCOPYBITS = 0x0100
SWP_NOOWNERZORDER = 0x0200
SWP_NOSENDCHANGING = 0x0400
That should be it! Hope it works for you!
Credit to John Popplewell at john#johnnypops.demon.co.uk for his help.
The question is more like which windowing toolkit are you using ? PyGTK and similar educated googling gave me this:
gtk.Window.set_keep_above
As mentioned previously it is upto the window manager to respect this setting or not.
Edited to include SDL specific stuff
Pygame uses SDL to do display work and apprently does not play nice with Windowing toolkits. SDL Window can be put on top is discussed here.
I really don't know much Python at all, but Googling "pygtk always on top" gave me this:
http://www.mail-archive.com/pygtk#daa.com.au/msg01370.html
The solution posted there was:
transient.set_transient_for(main_window)
You might also want to search things like "x11 always on top". The underlying concept seems to be that you're giving the window manager a "hint" that it should keep the window above the others. The window manager, however, has free reign and can do whatever it wants.
I've also seen the concept of layers when using window managers like Fluxbox, so maybe there's a way to change the layer on which the window appears.
I was trying to figure out a similar issue and found this solution using the Pmw module
http://www.java2s.com/Code/Python/GUI-Pmw/Showglobalmodaldialog.htm

Stock Icons not shown on buttons

self.button = gtk.Button(stock=gtk.STOCK_DELETE)
Only Shows:
Delete
The Python equivalent for setting the property without having to change any system config files is:
settings = gtk.settings_get_default()
settings.props.gtk_button_images = True
This should follow a call to window.show() and, obviously, precede the gtk.main() loop.
This is a recent change in GTK - the developers wanted icons not to appear on buttons. On Linux, this can be changed by editing the gconf key
/desktop/gnome/interface/buttons_have_icons
On windows, I think (I haven't actually tried this) that you need to set a value in your gtkrc file (for me it's in C:\Program Files\Gtk+\etc\gtkrc) and use a theme that supports icons (I think the default one doesn't).
You can also add gtk-button-images = 1 to your ~/.gtkrc-2.0 file after setting the theme which may over ride the option from gconf.
EDIT in answer to your comment:
Just like this answer, but in Python: In Gtk, how do I make a Button with just a stock icon?
For python, it's just
image = gtk.Image()
# (from http://www.pygtk.org/docs/pygtk/gtk-stock-items.html)
image.set_from_stock(gtk.STOCK_**)
button = gtk.Button()
button.set_image(image)
button.set_label("")
I had to do this to get it to work from Python without changing my config file. When I called set_image(), no image was being displayed.
image = gtk.Image()
image.set_from_stock(gtk.STOCK_**, gtk.ICON_SIZE_BUTTON)
button = gtk.Button()
button.add(image)
button.show()
If you work with pygobject, the new syntax is:
image.set_from_stock(gtk.STOCK_**, Gtk.IconSize.BUTTON)
I had the same issue in GTKmm on Windows. The "MS-Windows" theme disables images on stock buttons and the theme has priority over settings in gtkrc (so putting gtk-button-images = true in gtkrc didn't help). What I did is to modify the GTK settings runtime, and the images appeared as expected. :) Here's the code in C++:
Glib::RefPtr<Gtk::Settings> settings = Gtk::Settings::get_default();
/* force using icons on stock buttons: */
settings->property_gtk_button_images() = true;
It should be placed after the first window is constructed.
in Gtk3 gtk.STOCK method has been deprecated from v3.10.
Deprecated since version 3.10: Use Gtk.Button.new_with_label ()
instead.
In the case it doesn't help since it points to the custom label solution (new_with_label) If you want to use STOCK stuff you still can do so with new methods Gtk.Button.new_from_icon_name(icon_name, size) and Gtk.Button.new_with_mnemonic(label) which will create new buttons with stock icon and label respectively.
Example new button with a "stock" icon:
button = Gtk.Button.new_from_icon_name ("edit-paste", Gtk.IconSize.SMALL_TOOLBAR)
Example new button with a "stock" label:
button = Gtk.Button.new_with_mnemonic("_Open")
NOTE: on serious code creating a constant variable instead of using the string straight is a better option :)
References:
Gtk.Button
static new_with_mnemonic(label)
new_from_icon_name(icon_name, size)
Freedesktops Naming Convention
You can show explicitly the button image, justly, Gtk+ developers do not recommend doing this because it's overrides the Gtk+ user configuration.
So...
button.get_image().show()

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