Implemented validation of font family set for fallback Cocoanetics#661

zen4ever · Nov 15, 2013 · fb129b6 · fb129b6
1 parent 0a85f7a
commit fb129b6
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Showing 3 changed files with 40 additions and 2 deletions.
diff --git a/Core/Source/DTCoreTextConstants.h b/Core/Source/DTCoreTextConstants.h
@@ -79,6 +79,9 @@ extern NSString * const DTListPrefixField;
 // iOS 6 compatibility
 extern BOOL ___useiOS6Attributes;
 
+// exceptions
+extern NSString * const DTCoreTextFontDescriptorException;
+
 // macros
 
 #define IS_WHITESPACE(_c) (_c == ' ' || _c == '\t' || _c == 0xA || _c == 0xB || _c == 0xC || _c == 0xD || _c == 0x85)

diff --git a/Core/Source/DTCoreTextConstants.m b/Core/Source/DTCoreTextConstants.m
@@ -50,4 +50,10 @@
 
 // iOS 6 compatibility
 
-BOOL ___useiOS6Attributes = NO; // this gets set globally by DTHTMLAttributedStringBuilder
+BOOL ___useiOS6Attributes = NO; // this gets set globally by DTHTMLAttributedStringBuilder
+
+
+// exceptions
+
+NSString * const DTCoreTextFontDescriptorException = @"DTCoreTextFontDescriptorException";
+
diff --git a/Core/Source/DTCoreTextFontDescriptor.m b/Core/Source/DTCoreTextFontDescriptor.m
@@ -9,6 +9,7 @@
 #import "DTCoreTextFontDescriptor.h"
 #import "DTCoreTextFontCollection.h"
 #import "DTCompatibility.h"
+#import "DTCoreTextConstants.h"
 
 static NSCache *_fontCache = nil;
 static NSMutableDictionary *_fontOverrides = nil;
@@ -152,8 +153,36 @@ + (void)_createDictionaryOfAllAvailableFontOverrideNamesWithCompletion:(void(^)(
 
 + (void)setFallbackFontFamily:(NSString *)fontFamily
 {
-	NSParameterAssert(fontFamily);
+	if (!fontFamily)
+	{
+		[NSException raise:DTCoreTextFontDescriptorException format:@"Fallback Font Family cannot be nil"];
+	}
+
+	// make sure that only valid font families can be registered
+	NSDictionary *attributes = [NSDictionary dictionaryWithObject:fontFamily forKey:(id)kCTFontFamilyNameAttribute];
+	CTFontDescriptorRef fontDesc = CTFontDescriptorCreateWithAttributes((__bridge CFDictionaryRef)(attributes));
+	CTFontRef font = CTFontCreateWithFontDescriptor(fontDesc, 12, NULL);
+
+	BOOL isValid = NO;
+
+	if (font)
+	{
+		NSString *usedFontFamily = CFBridgingRelease(CTFontCopyFamilyName(font));
+
+		if ([usedFontFamily isEqualToString:fontFamily])
+		{
+			isValid = YES;
+		}
+
+		CFRelease(fontDesc);
+		CFRelease(font);
+	}
 
+	if (!isValid)
+	{
+		[NSException raise:DTCoreTextFontDescriptorException format:@"Fallback Font Family '%@' not registered on the system", fontFamily];
+	}
+
 	_fallbackFontFamily = [fontFamily copy];
 }