Merge pull request #1399 from freakboy3742/cocoa-fonts

Initial implementation of Cocoa and iOS font loading.

android/tests_backend/fonts.py

@@ -59,6 +59,7 @@ def reflect_font_methods():
 
 class FontMixin:
  supports_custom_fonts = True
+ supports_custom_variable_fonts = True
 
  def assert_font_options(self, weight=NORMAL, style=NORMAL, variant=NORMAL):
  assert (BOLD if self.typeface.isBold() else NORMAL) == weight

changes/1837.feature.rst

@@ -1 +1 @@
-Support for custom font loading was added to the GTK backend.
+Support for custom font loading was added to the GTK, Cocoa and iOS backends.

cocoa/setup.py

@@ -6,6 +6,7 @@
 setup(
  version=version,
  install_requires=[
+ "fonttools >= 4.42.1, < 5.0.0",
  "rubicon-objc >= 0.4.5rc1, < 0.5.0",
  f"toga-core == {version}",
  ],

cocoa/src/toga_cocoa/fonts.py

@@ -1,5 +1,7 @@
 from pathlib import Path
 
+from fontTools.ttLib import TTFont
+
 from toga.fonts import (
  _REGISTERED_FONT_CACHE,
  BOLD,
@@ -14,46 +16,80 @@
  SMALL_CAPS,
  SYSTEM,
  SYSTEM_DEFAULT_FONT_SIZE,
- SYSTEM_DEFAULT_FONTS,
 )
 from toga_cocoa.libs import (
+ NSURL,
  NSFont,
  NSFontManager,
  NSFontMask,
 )
+from toga_cocoa.libs.core_text import core_text, kCTFontManagerScopeProcess
 
 _FONT_CACHE = {}
+_CUSTOM_FONT_NAMES = {}
 
 
 class Font:
  def __init__(self, interface):
  self.interface = interface
  try:
- font = _FONT_CACHE[self.interface]
+ attributed_font = _FONT_CACHE[self.interface]
  except KeyError:
+ font_family = self.interface.family
  font_key = self.interface._registered_font_key(
- self.interface.family,
+ family=font_family,
  weight=self.interface.weight,
  style=self.interface.style,
  variant=self.interface.variant,
  )
+
  try:
- font_path = _REGISTERED_FONT_CACHE[font_key]
+ # Built in fonts have known names; no need to interrogate a file.
+ custom_font_name = {
+ SYSTEM: None, # No font name required
+ MESSAGE: None, # No font name required
+ SERIF: "Times-Roman",
+ SANS_SERIF: "Helvetica",
+ CURSIVE: "Apple Chancery",
+ FANTASY: "Papyrus",
+ MONOSPACE: "Courier New",
+ }[font_family]
  except KeyError:
- # Not a pre-registered font
- if self.interface.family not in SYSTEM_DEFAULT_FONTS:
+ try:
+ font_path = _REGISTERED_FONT_CACHE[font_key]
+ except KeyError:
+ # The requested font has not been registered
  print(
  f"Unknown font '{self.interface}'; "
  "using system font as a fallback"
  )
- else:
- if Path(font_path).is_file():
- # TODO: Load font file
- self.interface.factory.not_implemented("Custom font loading")
- # if corrupted font file:
- # raise ValueError(f"Unable to load font file {font_path}")
+ font_family = SYSTEM
+ custom_font_name = None
  else:
- raise ValueError(f"Font file {font_path} could not be found")
+ # We have a path for a font file.
+ try:
+ # A font *file* an only be registered once under Cocoa.
+ custom_font_name = _CUSTOM_FONT_NAMES[font_path]
+ except KeyError:
+ if Path(font_path).is_file():
+ font_url = NSURL.fileURLWithPath(font_path)
+ success = core_text.CTFontManagerRegisterFontsForURL(
+ font_url, kCTFontManagerScopeProcess, None
+ )
+ if success:
+ ttfont = TTFont(font_path)
+ custom_font_name = ttfont["name"].getBestFullName()
+ # Preserve the Postscript font name contained in the
+ # font file.
+ _CUSTOM_FONT_NAMES[font_path] = custom_font_name
+ else:
+ raise ValueError(
+ f"Unable to load font file {font_path}"
+ )
+ else:
+ raise ValueError(
+ f"Font file {font_path} could not be found"
+ )
 
  if self.interface.size == SYSTEM_DEFAULT_FONT_SIZE:
  font_size = NSFont.systemFontSize
@@ -63,28 +99,13 @@ def __init__(self, interface):
  # (https://developer.apple.com/library/archive/documentation/GraphicsAnimation/Conceptual/HighResolutionOSX/Explained/Explained.html).
  font_size = self.interface.size * 96 / 72
 
- if self.interface.family == SYSTEM:
+ # Construct the NSFont
+ if font_family == SYSTEM:
  font = NSFont.systemFontOfSize(font_size)
- elif self.interface.family == MESSAGE:
+ elif font_family == MESSAGE:
  font = NSFont.messageFontOfSize(font_size)
  else:
- family = {
- SERIF: "Times-Roman",
- SANS_SERIF: "Helvetica",
- CURSIVE: "Apple Chancery",
- FANTASY: "Papyrus",
- MONOSPACE: "Courier New",
- }.get(self.interface.family, self.interface.family)
-
- font = NSFont.fontWithName(family, size=font_size)
-
- if font is None:
- print(
- "Unable to load font: {}pt {}".format(
- self.interface.size, family
- )
- )
- font = NSFont.systemFontOfSize(font_size)
+ font = NSFont.fontWithName(custom_font_name, size=font_size)
 
  # Convert the base font definition into a font with all the desired traits.
  attributes_mask = 0
@@ -97,12 +118,12 @@ def __init__(self, interface):
  attributes_mask |= NSFontMask.SmallCaps.value
 
  if attributes_mask:
- # If there is no font with the requested traits, this returns the original
- # font unchanged.
- font = NSFontManager.sharedFontManager.convertFont(
+ attributed_font = NSFontManager.sharedFontManager.convertFont(
  font, toHaveTrait=attributes_mask
  )
+ else:
+ attributed_font = font
 
- _FONT_CACHE[self.interface] = font.retain()
+ _FONT_CACHE[self.interface] = attributed_font.retain()
 
- self.native = font
+ self.native = attributed_font

cocoa/src/toga_cocoa/libs/core_text.py

@@ -1,106 +1,23 @@
 ##########################################################################
 # System/Library/Frameworks/CoreText.framework
 ##########################################################################
-from ctypes import POINTER, c_bool, c_double, c_uint32, c_void_p, cdll, util
-
-from rubicon.objc import CFIndex, CGFloat, CGGlyph, CGRect, CGSize, UniChar
+from ctypes import c_bool, c_uint32, c_void_p, cdll, util
 
 ######################################################################
 core_text = cdll.LoadLibrary(util.find_library("CoreText"))
 ######################################################################
 
-######################################################################
-# CTFontDescriptor.h
-
-CTFontOrientation = c_uint32
-
-######################################################################
-# CTFontTraits.h
-
-CTFontSymbolicTraits = c_uint32
-
 ######################################################################
 # CTFont.h
-core_text.CTFontGetBoundingRectsForGlyphs.restype = CGRect
-core_text.CTFontGetBoundingRectsForGlyphs.argtypes = [
- c_void_p,
- CTFontOrientation,
- POINTER(CGGlyph),
- POINTER(CGRect),
- CFIndex,
-]
-
-core_text.CTFontGetAdvancesForGlyphs.restype = c_double
-core_text.CTFontGetAdvancesForGlyphs.argtypes = [
- c_void_p,
- CTFontOrientation,
- POINTER(CGGlyph),
- POINTER(CGSize),
- CFIndex,
-]
-
-core_text.CTFontGetAscent.restype = CGFloat
-core_text.CTFontGetAscent.argtypes = [c_void_p]
-
-core_text.CTFontGetDescent.restype = CGFloat
-core_text.CTFontGetDescent.argtypes = [c_void_p]
-
-core_text.CTFontGetSymbolicTraits.restype = CTFontSymbolicTraits
-core_text.CTFontGetSymbolicTraits.argtypes = [c_void_p]
-
-core_text.CTFontGetGlyphsForCharacters.restype = c_bool
-core_text.CTFontGetGlyphsForCharacters.argtypes = [
- c_void_p,
- POINTER(UniChar),
- POINTER(CGGlyph),
- CFIndex,
-]
-
-core_text.CTFontCreateWithGraphicsFont.restype = c_void_p
-core_text.CTFontCreateWithGraphicsFont.argtypes = [
- c_void_p,
- CGFloat,
- c_void_p,
- c_void_p,
-]
-
-core_text.CTFontCopyFamilyName.restype = c_void_p
-core_text.CTFontCopyFamilyName.argtypes = [c_void_p]
-
-core_text.CTFontCopyFullName.restype = c_void_p
-core_text.CTFontCopyFullName.argtypes = [c_void_p]
-
-core_text.CTFontCreateWithFontDescriptor.restype = c_void_p
-core_text.CTFontCreateWithFontDescriptor.argtypes = [c_void_p, CGFloat, c_void_p]
-
-core_text.CTFontDescriptorCreateWithAttributes.restype = c_void_p
-core_text.CTFontDescriptorCreateWithAttributes.argtypes = [c_void_p]
-
-######################################################################
-# CTFontDescriptor.h
-
-kCTFontFamilyNameAttribute = c_void_p.in_dll(core_text, "kCTFontFamilyNameAttribute")
-kCTFontTraitsAttribute = c_void_p.in_dll(core_text, "kCTFontTraitsAttribute")
-
-######################################################################
-# CTFontTraits.h
-
-kCTFontSymbolicTrait = c_void_p.in_dll(core_text, "kCTFontSymbolicTrait")
-kCTFontWeightTrait = c_void_p.in_dll(core_text, "kCTFontWeightTrait")
-
-kCTFontItalicTrait = 1 << 0
-kCTFontBoldTrait = 1 << 1
-
-######################################################################
-# CTLine.h
-
-core_text.CTLineCreateWithAttributedString.restype = c_void_p
-core_text.CTLineCreateWithAttributedString.argtypes = [c_void_p]
 
-core_text.CTLineDraw.restype = None
-core_text.CTLineDraw.argtypes = [c_void_p, c_void_p]
+core_text.CTFontManagerRegisterFontsForURL.restype = c_bool
+core_text.CTFontManagerRegisterFontsForURL.argtypes = [c_void_p, c_uint32, c_void_p]
 
 ######################################################################
-# CTStringAttributes.h
+# CTFontManagerScope.h
 
-kCTFontAttributeName = c_void_p.in_dll(core_text, "kCTFontAttributeName")
+kCTFontManagerScopeNone = 0
+kCTFontManagerScopeProcess = 1
+kCTFontManagerScopePersistent = 2
+kCTFontManagerScopeSession = 3
+kCTFontManagerScopeUser = 2

cocoa/tests_backend/fonts.py

@@ -17,7 +17,8 @@
 
 
 class FontMixin:
- supports_custom_fonts = False
+ supports_custom_fonts = True
+ supports_custom_variable_fonts = False
 
  def assert_font_options(self, weight=NORMAL, style=NORMAL, variant=NORMAL):
  # Cocoa's FANTASY (Papyrus) and CURSIVE (Apple Chancery) system
@@ -52,11 +53,18 @@ def assert_font_size(self, expected):
 
  def assert_font_family(self, expected):
  assert str(self.font.familyName) == {
+ # System and Message fonts use internal names
+ SYSTEM: ".AppleSystemUIFont",
+ MESSAGE: ".AppleSystemUIFont",
+ # Known fonts use pre-registered names
  CURSIVE: "Apple Chancery",
  FANTASY: "Papyrus",
  MONOSPACE: "Courier New",
  SANS_SERIF: "Helvetica",
  SERIF: "Times",
- SYSTEM: ".AppleSystemUIFont",
- MESSAGE: ".AppleSystemUIFont",
+ # Most other fonts we can just use the family name;
+ # however, the Font Awesome font has a different
+ # internal Postscript name, which *doesn't* include
+ # the "solid" weight component.
+ "Font Awesome 5 Free Solid": "Font Awesome 5 Free",
  }.get(expected, expected)

docs/reference/api/resources/fonts.rst

@@ -71,7 +71,9 @@ properties to the ones used for widget styling::
 Notes
 -----
 
-* macOS and iOS do not currently support registering user fonts.
+* iOS and macOS do not support the use of variant font files (that is, fonts that
+ contain the details of multiple weights/variants in a single file). Variant font
+ files can be registered; however, only the "normal" variant will be used.
 
 * Android and Windows do not support the oblique font style. If an oblique font is
  specified, Toga will attempt to use an italic style of the same font.

docs/reference/data/widgets_by_platform.csv

@@ -28,7 +28,7 @@ ScrollContainer,Layout Widget,:class:`~toga.ScrollContainer`,A container that ca
 SplitContainer,Layout Widget,:class:`~toga.SplitContainer`,A container that divides an area into two panels with a movable border,|y|,|y|,|y|,,,,
 OptionContainer,Layout Widget,:class:`~toga.OptionContainer`,A container that can display multiple labeled tabs of content,|y|,|y|,|y|,,,,
 App Paths,Resource,:class:`~toga.paths.Paths`,A mechanism for obtaining platform-appropriate filesystem locations for an application.,|y|,|y|,|y|,|y|,|y|,,|b|
-Font,Resource,:class:`~toga.Font`,A text font,|b|,|y|,|y|,|b|,|y|,,
+Font,Resource,:class:`~toga.Font`,A text font,|y|,|y|,|y|,|y|,|y|,,
 Command,Resource,:class:`~toga.Command`,Command,|b|,|b|,|b|,,|b|,,
 Group,Resource,:class:`~toga.Group`,Command group,|b|,|b|,|b|,|b|,|b|,,
 Icon,Resource,:class:`~toga.Icon`,"A small, square image, used to provide easily identifiable visual context to a widget.",|y|,|y|,|y|,|y|,|y|,,|b|

gtk/tests_backend/fonts.py

@@ -11,6 +11,7 @@
 
 class FontMixin:
  supports_custom_fonts = True
+ supports_custom_variable_fonts = True
 
  def assert_font_family(self, expected):
  assert self.font.get_family().split(",")[0] == expected

iOS/setup.py

@@ -6,6 +6,7 @@
 setup(
  version=version,
  install_requires=[
+ "fonttools >= 4.42.1, < 5.0.0",
  "rubicon-objc >= 0.4.5rc1, < 0.5.0",
  f"toga-core == {version}",
  ],