Fix GetFontWeightFromNSFont()
GetFontWeightFromNSFont() uses a table of CoreText float values to
look up corresponding Font::Weight values. The testing of the
float values was broken; fix it.
Bug: 1112998
Change-Id: Ia3346c2964e3c74cb855b701227a662aa281de8d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2337734
Reviewed-by: Elly Fong-Jones <[email protected]>
Commit-Queue: Avi Drissman <[email protected]>
Cr-Commit-Position: refs/heads/master@{#795061}
diff --git a/ui/gfx/platform_font_mac.mm b/ui/gfx/platform_font_mac.mm
index be3ac0b0..7ade2d4 100644
--- a/ui/gfx/platform_font_mac.mm
+++ b/ui/gfx/platform_font_mac.mm
@@ -91,31 +91,53 @@
DCHECK(font);
// Map CoreText weights in a manner similar to ct_weight_to_fontstyle() from
- // SkFontHost_mac.cpp, but adjust for MEDIUM so that the San Francisco's
- // custom MEDIUM weight can be picked out. San Francisco has weights:
- // [0.23, 0.23, 0.3, 0.4, 0.56, 0.62, 0.62, ...] (no thin weights).
- // See PlatformFontMacTest.FontWeightAPIConsistency for details.
- // Note that the table Skia uses is also determined by experiment.
+ // SkFontHost_mac.cpp, but adjusted for the weights actually used by the
+ // system fonts. See PlatformFontMacTest.FontWeightAPIConsistency for details.
+ // Use ranges for paranoia.
constexpr struct {
- CGFloat ct_weight;
+ // A range of CoreText weights.
+ CGFloat weight_lower;
+ CGFloat weight_upper;
Font::Weight gfx_weight;
} weight_map[] = {
- // Missing: Apple "ultralight".
- {-0.70, Font::Weight::THIN},
- {-0.50, Font::Weight::EXTRA_LIGHT},
- {-0.23, Font::Weight::LIGHT},
- {0.00, Font::Weight::NORMAL},
- {0.23, Font::Weight::MEDIUM}, // Note: adjusted from 0.20 vs Skia.
- // Missing: Apple "demibold".
- {0.30, Font::Weight::SEMIBOLD},
- {0.40, Font::Weight::BOLD},
- {0.60, Font::Weight::EXTRA_BOLD},
- // Missing: Apple "heavyface".
- // Values will be capped to BLACK (this entry is here for consistency).
- {0.80, Font::Weight::BLACK},
- // Missing: Apple "ultrablack".
- // Missing: Apple "extrablack".
+ // NSFontWeight constants introduced in 10.11:
+ // NSFontWeightUltraLight: -0.80
+ // NSFontWeightThin: -0.60
+ // NSFontWeightLight: -0.40
+ // NSFontWeightRegular: 0.0
+ // NSFontWeightMedium: 0.23
+ // NSFontWeightSemibold: 0.30
+ // NSFontWeightBold: 0.40
+ // NSFontWeightHeavy: 0.56
+ // NSFontWeightBlack: 0.62
+ //
+ // Actual system font weights:
+ // 10.10:
+ // .HelveticaNeueDeskInterface-Regular: 0.0
+ // .HelveticaNeueDeskInterface-MediumP4: 0.23
+ // .HelveticaNeueDeskInterface-Bold: 0.4
+ // .HelveticaNeueDeskInterface-Heavy: 0.62
+ // 10.11-:
+ // .AppleSystemUIFontUltraLight: -0.80 (10.12-)
+ // .AppleSystemUIFontLight: -0.40 (10.12-)
+ // .AppleSystemUIFont: 0 (10.11-)
+ // .AppleSystemUIFontMedium: 0.23 (10.12-)
+ // .AppleSystemUIFontDemi: 0.30 (10.12-)
+ // .AppleSystemUIFontBold: 0.40 (10.11)
+ // .AppleSystemUIFontEmphasized: 0.40 (10.12-)
+ // .AppleSystemUIFontHeavy: 0.56 (10.11-)
+ // .AppleSystemUIFontBlack: 0.62 (10.11-)
+ {-1000, -0.70, Font::Weight::THIN}, // NSFontWeightUltraLight
+ {-0.70, -0.45, Font::Weight::EXTRA_LIGHT}, // NSFontWeightThin
+ {-0.45, -0.10, Font::Weight::LIGHT}, // NSFontWeightLight
+ {-0.10, 0.10, Font::Weight::NORMAL}, // NSFontWeightRegular
+ {0.10, 0.27, Font::Weight::MEDIUM}, // NSFontWeightMedium
+ {0.27, 0.35, Font::Weight::SEMIBOLD}, // NSFontWeightSemibold
+ {0.35, 0.50, Font::Weight::BOLD}, // NSFontWeightBold
+ {0.50, 0.60, Font::Weight::EXTRA_BOLD}, // NSFontWeightHeavy
+ {0.60, 1000, Font::Weight::BLACK}, // NSFontWeightBlack
};
+
base::ScopedCFTypeRef<CFDictionaryRef> traits(
CTFontCopyTraits(base::mac::NSToCFCast(font)));
DCHECK(traits);
@@ -125,20 +147,18 @@
if (!cf_weight)
return Font::Weight::NORMAL;
- // Documentation is vague about what sized floating point type should be used.
- // However, numeric_limits::epsilon() for 64-bit types is too small to match
- // the above table, so use 32-bit float. Do not check for the success of
- // CFNumberGetValue(). CFNumberGetValue() returns false for *any* loss of
- // value, and a float is used here deliberately to coarsen the accuracy.
- // There's no guarantee that any particular value for the kCTFontWeightTrait
- // will be able to be accurately represented with a float.
- float weight_value;
- CFNumberGetValue(cf_weight, kCFNumberFloatType, &weight_value);
+ // The value of kCTFontWeightTrait empirically is a kCFNumberFloat64Type
+ // (double) on all tested versions of macOS. However, that doesn't really
+ // matter as only the first two decimal digits need to be tested. Do not check
+ // for the success of CFNumberGetValue() as it returns false for any loss of
+ // value and all that is needed here is two digits of accuracy.
+ CGFloat weight;
+ CFNumberGetValue(cf_weight, kCFNumberCGFloatType, &weight);
for (const auto& item : weight_map) {
- if (weight_value - item.ct_weight <= std::numeric_limits<float>::epsilon())
+ if (item.weight_lower <= weight && weight <= item.weight_upper)
return item.gfx_weight;
}
- return Font::Weight::BLACK;
+ return Font::Weight::INVALID;
}
// Returns an autoreleased NSFont created with the passed-in specifications.
