Added a custom transformer to store shortcuts as dictionaries.

The MASDictionaryTransformer class is used to save shortcuts to
user defaults (and load them back) using a simple dictionary. The
value stored in the user defaults looks like this:

$ defaults read com.shpakovski.mac.Demo
{
    MASDemoShortcut =     {
        keyCode = 15;
        modifierFlags = 1048576;
    };
    …
}

This storage format has got the distinct advantage of being compatible
with the format used by Shortcut Recorder. In order to use it, you
have to set proper binding options for MASShortcutBinder and the
recorder control (MASShortcutView).

5 files changed, 82 insertions, 1 deletions

diff --git a/Framework/MASDictionaryTransformer.h b/Framework/MASDictionaryTransformer.h
new file mode 100644
index 0000000..94c5bc9
--- /dev/null
+++ b/Framework/MASDictionaryTransformer.h
@@ -0,0 +1,2 @@
+@interface MASDictionaryTransformer : NSValueTransformer
+@end
diff --git a/Framework/MASDictionaryTransformer.m b/Framework/MASDictionaryTransformer.m
new file mode 100644
index 0000000..f0d9b2e
--- /dev/null
+++ b/Framework/MASDictionaryTransformer.m
@@ -0,0 +1,42 @@
+#import "MASDictionaryTransformer.h"
+#import "MASShortcut.h"
+
+static NSString *const MASKeyCodeKey = @"keyCode";
+static NSString *const MASModifierFlagsKey = @"modifierFlags";
+
+@implementation MASDictionaryTransformer
+
++ (BOOL) allowsReverseTransformation
+{
+    return YES;
+}
+
+- (NSDictionary*) reverseTransformedValue: (MASShortcut*) shortcut
+{
+    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
diff --git a/Framework/MASDictionaryTransformerTests.m b/Framework/MASDictionaryTransformerTests.m
new file mode 100644
index 0000000..78dfa25
--- /dev/null
+++ b/Framework/MASDictionaryTransformerTests.m
@@ -0,0 +1,25 @@
+#import "Shortcut.h"
+
+@interface MASDictionaryTransformerTests : XCTestCase
+@end
+
+@implementation MASDictionaryTransformerTests
+
+- (void) testErrorHandling
+{
+    MASDictionaryTransformer *transformer = [MASDictionaryTransformer new];
+    XCTAssertNil([transformer transformedValue:nil],
+        @"Decoding a shortcut from a nil dictionary returns nil.");
+    XCTAssertNil([transformer transformedValue:(id)@"foo"],
+        @"Decoding a shortcut from a invalid-type dictionary returns nil.");
+    XCTAssertNil([transformer transformedValue:@{}],
+        @"Decoding a shortcut from an empty dictionary returns nil.");
+    XCTAssertNil([transformer transformedValue:@{@"keyCode":@"foo"}],
+        @"Decoding a shortcut from a wrong-typed dictionary returns nil.");
+    XCTAssertNil([transformer transformedValue:@{@"keyCode":@1}],
+        @"Decoding a shortcut from an incomplete dictionary returns nil.");
+    XCTAssertNil([transformer transformedValue:@{@"modifierFlags":@1}],
+        @"Decoding a shortcut from an incomplete dictionary returns nil.");
+}
+
+@end
diff --git a/Framework/MASShortcutBinderTests.m b/Framework/MASShortcutBinderTests.m
index 9259e9d..199eb2f 100644
--- a/Framework/MASShortcutBinderTests.m
+++ b/Framework/MASShortcutBinderTests.m
@@ -1,4 +1,4 @@
-#import "MASShortcutBinder.h"
+#import "Shortcut.h"
 
 static NSString *const SampleDefaultsKey = @"sampleShortcut";
 
@@ -77,4 +77,15 @@ static NSString *const SampleDefaultsKey = @"sampleShortcut";
         @"Bind after unbinding.");
 }
 
+- (void) testTransformerDeserialization
+{
+    MASShortcut *shortcut = [MASShortcut shortcutWithKeyCode:5 modifierFlags:1048576];
+    NSDictionary *storedShortcut = @{@"keyCode": @5, @"modifierFlags": @1048576};
+    [_defaults setObject:storedShortcut forKey:SampleDefaultsKey];
+    [_binder setBindingOptions:@{NSValueTransformerBindingOption:[MASDictionaryTransformer new]}];
+    [_binder bindShortcutWithDefaultsKey:SampleDefaultsKey toAction:^{}];
+    XCTAssertTrue([_monitor isShortcutRegistered:shortcut],
+        @"Deserialize shortcut from user defaults using a custom transformer.");
+}
+
 @end
diff --git a/Framework/Shortcut.h b/Framework/Shortcut.h
index dce07a5..df33f17 100644
--- a/Framework/Shortcut.h
+++ b/Framework/Shortcut.h
@@ -2,4 +2,5 @@
 #import "MASShortcutValidator.h"
 #import "MASShortcutMonitor.h"
 #import "MASShortcutBinder.h"
+#import "MASDictionaryTransformer.h"
 #import "MASShortcutView.h"