845973 - Remove win32api dependency from mouse_and_screen_resolution.py

Status: RESOLVED FIXED

(Release Engineering :: General, defect)

Description

[Armen [:armenzg]]

Attachment: Remove win32api dependency from mouse_and_screen_resolution.py

I have been able to query but not call the actual function to change the resolution.
> function 'ChangeDisplaySettings' not found

Any ideas? Thanks!

Comment 1

[William Lachance (:wlach)]

Comment on attachment 719145 [details] [diff] [review]
Remove win32api dependency from mouse_and_screen_resolution.py

To answer your question, it looks like ChangeDisplaySettings is not defined as part of the user32 namespace, you have to call it ChangeDisplaySettingsA.

Here's an example of using it:

https://github.com/ravenscroftj/SPE/blob/master/sm/__init__.py#L50

And here's API documentation for the function:

http://msdn.microsoft.com/en-us/library/windows/desktop/dd183411%28v=vs.85%29.aspx

One quick comment on your patch as it stands:

>diff --git a/scripts/support/mouse_and_screen_resolution.py b/scripts/support/mouse_and_screen_resolution.py
>+from ctypes import *

I think it would be clearer if you just wrote "from ctypes import windll" here. As it is it's ambiguous where windll (which we're using later in the function) is coming from.

Comment 2

[Armen [:armenzg]]

Attachment: Remove win32api dependency from mouse_and_screen_resolution.py - attempt 2

I saw the screen resolution change but then it returns back to the original after the python script ends.

C:\Users\cltbld\Desktop>C:\mozilla-build\python27\python.exe mouse_and_screen_re
solution.py --configuration-url http://hg.mozilla.org/mozilla-central/raw-file/d
efault/testing/machine-configuration.json
Screen resolution (current): (1600, 1200)
Changing the screen resolution...
Screen resolution (new): (1024, 768)

C:\Users\cltbld\Desktop>C:\mozilla-build\python27\python.exe mouse_and_screen_re
solution.py --configuration-url http://hg.mozilla.org/mozilla-central/raw-file/d
efault/testing/machine-configuration.json
Screen resolution (current): (1600, 1200)
Changing the screen resolution...
0
Screen resolution (new): (1024, 768)

Comment 3

[William Lachance (:wlach)]

Comment on attachment 719666 [details] [diff] [review]
Remove win32api dependency from mouse_and_screen_resolution.py - attempt 2

>+    result = windll.user32.ChangeDisplaySettingsA(DevModeData, CDS_FULLSCREEN)

I think you want to pass "0" here instead of CDS_FULLSCREEN. Using CDS_FULLSCREEN makes things temporary, or at least the documentation suggests it does:

http://msdn.microsoft.com/en-us/library/windows/desktop/dd183411%28v=vs.85%29.aspx

Comment 4

[Armen [:armenzg]]

Attachment: Remove win32api dependency from mouse_and_screen_resolution.py - attempt 2

And there was joy!

Comment 5

[William Lachance (:wlach)]

Comment on attachment 719974 [details] [diff] [review]
Remove win32api dependency from mouse_and_screen_resolution.py - attempt 2

Looks pretty reasonable except an unnecessary global. r+ without it.

>+class POINT(Structure):
>+    _fields_ = [("x", c_ulong), ("y", c_ulong)]
> 
> def queryMousePosition():
>-    pos = win32api.GetCursorPos()
>-    return {"x": pos[0], "y": pos[1]}
>+    global pt

Why is this a global? Don't really see any reason why it needs to be. Can't you just remove this line?

>+    pt = POINT()
>+    windll.user32.GetCursorPos(byref(pt))
>+    return pt.x, pt.y

Comment 6

[Armen [:armenzg]]

(In reply to William Lachance (:wlach) from comment #5)
> Comment on attachment 719974 [details] [diff] [review]
> Remove win32api dependency from mouse_and_screen_resolution.py - attempt 2
> 
> Looks pretty reasonable except an unnecessary global. r+ without it.
> 
> >+class POINT(Structure):
> >+    _fields_ = [("x", c_ulong), ("y", c_ulong)]
> > 
> > def queryMousePosition():
> >-    pos = win32api.GetCursorPos()
> >-    return {"x": pos[0], "y": pos[1]}
> >+    global pt
> 
> Why is this a global? Don't really see any reason why it needs to be. Can't
> you just remove this line?
> 
> >+    pt = POINT()
> >+    windll.user32.GetCursorPos(byref(pt))
> >+    return pt.x, pt.y

I'm testing it again without global. Maybe it was leftover from my development.

Comment 7

[Armen [:armenzg]]

Comment on attachment 719974 [details] [diff] [review]
Remove win32api dependency from mouse_and_screen_resolution.py - attempt 2

I removed the global line:
http://hg.mozilla.org/build/tools/rev/0766c91b8536