[Typography] Add warning about custom fonts and Dynamic Type (#1224)

material-components · Feb 27, 2017 · 9bea221 · 9bea221
1 parent 3f2968b
commit 9bea221
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/components/Typography/src/UIFont+MaterialTypography.m b/components/Typography/src/UIFont+MaterialTypography.m
@@ -13,11 +13,19 @@
 
 #import "UIFont+MaterialTypography.h"
 
+#import "MDCTypography.h"
 #import "UIFontDescriptor+MaterialTypography.h"
 
 @implementation UIFont (MaterialTypography)
 
 + (UIFont *)mdc_preferredFontForMaterialTextStyle:(MDCFontTextStyle)style {
+  // Due to the way iOS handles missing glyphs in fonts, we do not support using a custom font
+  // loader with Dynamic Type.
+  id<MDCTypographyFontLoading>fontLoader = [MDCTypography fontLoader];
+  if (![fontLoader isKindOfClass:[MDCSystemFontLoader class]]) {
+    NSLog(@"MaterialTypography : Custom font loaders are not compatible with Dynamic Type.");
+  }
+
   UIFontDescriptor *fontDescriptor =
       [UIFontDescriptor mdc_preferredFontDescriptorForMaterialTextStyle:style];