Allow default ImageDraw font to be set

Tests/test_imagedraw.py

@@ -1314,6 +1314,23 @@ def test_stroke_multiline():
     assert_image_similar_tofile(im, "Tests/images/imagedraw_stroke_multiline.png", 3.3)
 
 
+def test_setting_default_font():
+    # Arrange
+    im = Image.new("RGB", (100, 250))
+    draw = ImageDraw.Draw(im)
+    font = ImageFont.truetype("Tests/fonts/FreeMono.ttf", 120)
+
+    # Act
+    ImageDraw.ImageDraw.font = font
+
+    # Assert
+    try:
+        assert draw.getfont() == font
+    finally:
+        ImageDraw.ImageDraw.font = None
+        assert isinstance(draw.getfont(), ImageFont.ImageFont)
+
+
 def test_same_color_outline():
     # Prepare shape
     x0, y0 = 5, 5

docs/reference/ImageDraw.rst

@@ -64,7 +64,7 @@ Fonts
 
 PIL can use bitmap fonts or OpenType/TrueType fonts.
 
-Bitmap fonts are stored in PIL’s own format, where each font typically consists
+Bitmap fonts are stored in PIL's own format, where each font typically consists
 of two files, one named .pil and the other usually named .pbm. The former
 contains font metrics, the latter raster data.
 
@@ -146,6 +146,11 @@ Methods
 
     Get the current default font.
 
+    To set the default font for all future ImageDraw instances::
+
+        from PIL import ImageDraw, ImageFont
+        ImageDraw.ImageDraw.font = ImageFont.truetype("Tests/fonts/FreeMono.ttf")
+
     :returns: An image font.
 
 .. py:method:: ImageDraw.arc(xy, start, end, fill=None, width=0)

docs/releasenotes/9.3.0.rst

@@ -26,6 +26,16 @@ TODO
 API Additions
 =============
 
+Allow default ImageDraw font to be set
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Rather than specifying a font when calling text-related ImageDraw methods, or
+setting a font on each ImageDraw instance, the default font can now be set for
+all future ImageDraw operations::
+
+    from PIL import ImageDraw, ImageFont
+    ImageDraw.ImageDraw.font = ImageFont.truetype("Tests/fonts/FreeMono.ttf")
+
 Saving multiple MPO frames
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 

src/PIL/ImageDraw.py

@@ -46,6 +46,8 @@
 
 
 class ImageDraw:
+    font = None
+
     def __init__(self, im, mode=None):
         """
         Create a drawing instance.
@@ -86,12 +88,16 @@ def __init__(self, im, mode=None):
         else:
             self.fontmode = "L"  # aliasing is okay for other modes
         self.fill = 0
-        self.font = None
 
     def getfont(self):
         """
         Get the current default font.
 
+        To set the default font for all future ImageDraw instances::
+
+            from PIL import ImageDraw, ImageFont
+            ImageDraw.ImageDraw.font = ImageFont.truetype("Tests/fonts/FreeMono.ttf")
+
         :returns: An image font."""
         if not self.font:
             # FIXME: should add a font repository