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[MNT]: findSystemFonts - Use system API instead to look into folder #24001
Description
Summary
Currently, findSystemFonts look at all the file in the specified folders for macos and windows.
This is not a very good method, because a font in a "Font folder" does not necessarily need to be picked up.
A very good example of that is in this issue: #22859
This is why I propose to use CoreText (for mac) and DirectWrite (for Windows).
These are API provided by Apple and Microsoft.
Proposed fix
CoreText - For MAC
In this example, I use this library: https://pypi.org/project/pyobjc-framework-CoreText/
import CoreText
fontURLs = CoreText.CTFontManagerCopyAvailableFontURLs()
fontPath = set()
for i in range(CoreText.CFArrayGetCount(fontURLs)):
url = CoreText.CFArrayGetValueAtIndex(fontURLs, i)
fontPath.add(str(url.path()))DirectWrite - For Windows
I don't know much C/C++, so I can't give an good example.
On recent Windows build, it is pretty simple to get the font path with DirectWrite, but since matplotlib seems to support Windows 7, we would maybe need to use the "complex" solution.
But, here is how I understand it (I have no proof that it works):
Logic for to support only Windows 10:
- GetSystemFontCollection
- GetFontSet
- For loop with GetFontCount
Here is an "pseudo-code" of how I see it.
font_collection = GetSystemFontCollection()
font_set = font_collection.GetFontSet()
for i in range(font_set.GetFontCount()):
font_face_reference = font_set.GetFontFaceReference(i)
font_file = font_face_reference.GetFontFile()
reference_key, reference_key_size = font_file.GetReferenceKey()
path = GetFilePathFromKey(reference_key, reference_key_size)Logic for Windows Vista to this day:
- GetSystemFontCollection
- Do a for loop with GetFontFamilyCount
- GetFontFamily
- GetMatchingFonts - The param weight, stretch, style can be anything. These param seems to only change the order or the return list.
- Do a for loop with GetFontCount
font_collection = GetSystemFontCollection()
for i in range(font_collection.GetFontFamilyCount()):
font_family = font_collection.GetFontFamily(i)
matching_fonts = GetMatchingFonts(ANY_WEIGHT, ANY_STRETCH, ANY_STYLE)
for j in range(matching_fonts.GetFontCount()):
font = matching_fonts.GetFont(j)
font_face = font.CreateFontFace()
for file in font_face.GetFiles():
reference_key, reference_key_size = font_file.GetReferenceKey()
path = GetFilePathFromKey(reference_key, reference_key_size)I have try to see if the GDI api could help us to get the path of the fonts, but from what I can see, it is not an available feature: https://learn.microsoft.com/en-us/windows/win32/gdi/font-and-text-functions
FontConfig (Bonus) - For Linux
Currently, matplotlib parse the result from subprocess.
It would be an good idea to directly use FontConfig. See this answer from stackoverflow to know how to do it: https://stackoverflow.com/a/14634033
I did not found any FontConfig bindings library that are still maintained, so it would need to be implemented with Cython.
Activity
ashb commented on Oct 26, 2022
So I've been working on the Windows part of this (it turns out it was slightly more complex than the functions you highlighted, but that gave me the pointers I needed):
In [1]: __import__('windows_fonts').FontCollection() Out[1]: <windows_fonts.FontCollection at 0x29a415bdb90> In [2]: for f in _1: ...: print(repr(f)) ...: <FontFamily name="Iosevka Term"> <FontFamily name="Cascadia Code"> <FontFamily name="Cascadia Mono"> <FontFamily name="Arial"> <FontFamily name="Bahnschrift"> <FontFamily name="Calibri"> <FontFamily name="Cambria"> <FontFamily name="Cambria Math"> <FontFamily name="Candara"> <FontFamily name="Comic Sans MS"> <FontFamily name="Consolas"> <FontFamily name="Constantia"> <FontFamily name="Corbel"> <FontFamily name="Courier New"> <FontFamily name="Ebrima"> <FontFamily name="Franklin Gothic"> <FontFamily name="Gabriola"> ... <FontFamily name="Marlett"> In [3]: list(f) Out[3]: [<FontVariant family=<FontFamily name="Marlett">, style=Style.NORMAL weight=Weight.MEDIUM>, <FontVariant family=<FontFamily name="Marlett">, style=Style.OBLIQUE weight=Weight.MEDIUM>, <FontVariant family=<FontFamily name="Marlett">, style=Style.NORMAL weight=Weight.BOLD>, <FontVariant family=<FontFamily name="Marlett">, style=Style.OBLIQUE weight=Weight.BOLD>] In [4]: list(map(lambda f: f.filename, f)) Out[4]: ['C:\\WINDOWS\\FONTS\\MARLETT.TTF', 'C:\\WINDOWS\\FONTS\\MARLETT.TTF', 'C:\\WINDOWS\\FONTS\\MARLETT.TTF', 'C:\\WINDOWS\\FONTS\\MARLETT.TTF'](I'm planning to release this as a stand-alone python module as I actually need it for a separate project)
moi15moi commented on Oct 26, 2022
I am sorry. I thought it was the right logic.
I hope i was in the right direction, so you did not waste too much time on that part.
By curiosity, which method have you used?
OR
ashb commented on Oct 27, 2022
@moi15moi You had the right functions, but the issue was that GetFilePathFromKey needs to be called on an instance of IDWriteLocalFontFileLoader, and unlike most other COM objects where you can just do CoCreateInstance to get one, the only way I've found (from searching) is to get an instance of this is to load a local font file, then ask for it's loader.
And I think I've used the Vista+ approach.
moi15moi commented on Oct 27, 2022
Ok, then, i think you could have called GetLoader from the object you have with GetFiles
Here is the updated version
Logic for Windows Vista to this day:
Here is the pseudo-code
Edit: GetLoader return an instance of IDWriteFontFileLoader. It doesn't return of instance of IDWriteLocalFontFileLoader.
Sorry, i missread that.
But, i just found this: https://social.msdn.microsoft.com/Forums/vstudio/en-US/8f57b186-9cf6-417a-8923-092b406d94ea/obtain-filename-from-directwrite-font?forum=windowsuidevelopment
ashb commented on Oct 27, 2022
Yup, that's what I used to get it working :)
ashb commented on Oct 31, 2022
First alpha release available at https://pypi.org/project/windows-fonts/0.1.0a1/ pip install --pre windows-fonts
kostyafarber commented on Nov 8, 2022
Hey is anybody working on the mac portion of this? If not I'd like to have a crack.
greglucas commented on Nov 9, 2022
@kostyafarber, it doesn't look like anyone is working on the mac side of this and in general we have very few people looking into the objective c portion of the code, so I would say go for it! You can also find other mac issues with this label: GUI: MacOSX
kostyafarber commented on Nov 10, 2022
For the windows version would we need to write up the code in c++ and write a Python binding and use it in font_manager.py?
For the Mac version are we happy to explore using https://pypi.org/project/pyobjc-framework-CoreText/ or would we prefer to use a binding as well?
tacaswell commented on Nov 16, 2022
I would much rather have bindings in Matplotlib than pick up a dependency for this. If it is so complex that we need a dependency rather than just implementing it, than I think that continuing to search the directories is fine.
moi15moi commented on Apr 28, 2023
I decided to do a repos to show you how I implemented it: https://github.com/moi15moi/FindSystemFontsFilename
I haven't open an PR here since font_manager can search for .afm file which cannot be done with DirectWrite and CoreText (it may be possible with FontConfig, but I haven't check)
github-actions commented on Jun 15, 2026
This issue has been marked "inactive" because it has been 365 days since the last comment. If this issue is still present in recent Matplotlib releases, or the feature request is still wanted, please leave a comment and this label will be removed. If there are no updates in another 30 days, this issue will be automatically closed, but you are free to re-open or create a new issue if needed. We value issue reports, and this procedure is meant to help us resurface and prioritize issues that have not been addressed yet, not make them disappear. Thanks for your help!
QuLogic commented on Jul 16, 2026
Windows uses the registry since #24655, and macOS will use CoreText once #31977 is in.