1 files changed, 51 insertions, 0 deletions
diff --git a/Framework/MASDictionaryTransformer.m b/Framework/MASDictionaryTransformer.m
new file mode 100644
index 0000000..9e4c82b
--- /dev/null
+++ b/Framework/MASDictionaryTransformer.m
@@ -0,0 +1,51 @@
+#import "MASDictionaryTransformer.h"
+#import "MASShortcut.h"
+
+NSString *const MASDictionaryTransformerName = @"MASDictionaryTransformer";
+
+static NSString *const MASKeyCodeKey = @"keyCode";
+static NSString *const MASModifierFlagsKey = @"modifierFlags";
+
+@implementation MASDictionaryTransformer
+
++ (BOOL) allowsReverseTransformation
+{
+    return YES;
+}
+
+// Storing nil values as an empty dictionary lets us differ between
+// “not available, use default value” and “explicitly set to none”.
+// See http://stackoverflow.com/questions/5540760 for details.
+- (NSDictionary*) reverseTransformedValue: (MASShortcut*) shortcut
+{
+    if (shortcut == nil) {
+        return [NSDictionary dictionary];
+    } else {
+        return @{
+            MASKeyCodeKey: @([shortcut keyCode]),
+            MASModifierFlagsKey: @([shortcut modifierFlags])
+        };
+    }
+}
+
+- (MASShortcut*) transformedValue: (NSDictionary*) dictionary
+{
+    // We have to be defensive here as the value may come from user defaults.
+    if (![dictionary isKindOfClass:[NSDictionary class]]) {
+        return nil;
+    }
+
+    id keyCodeBox = [dictionary objectForKey:MASKeyCodeKey];
+    id modifierFlagsBox = [dictionary objectForKey:MASModifierFlagsKey];
+
+    SEL integerValue = @selector(integerValue);
+    if (![keyCodeBox respondsToSelector:integerValue] || ![modifierFlagsBox respondsToSelector:integerValue]) {
+        return nil;
+    }
+
+    return [MASShortcut
+        shortcutWithKeyCode:[keyCodeBox integerValue]
+        modifierFlags:[modifierFlagsBox integerValue]];
+}
+
+@end