Added pretty pring value transformer

MacPass/MPPrettyPasswordTransformer.m

@@ -0,0 +1,41 @@
+//
+//  MPPrettyPasswordTransformer.m
+//  MacPass
+//
+//  Created by Michael Starke on 01.12.17.
+//  Copyright © 2017 HicknHack Software GmbH. All rights reserved.
+//
+
+#import "MPPrettyPasswordTransformer.h"
+#import "NSString+MPPrettyPasswordDisplay.h"
+
+NSString *const MPPrettyPasswordTransformerName = @"com.hicknhack.macpass.MPPrettyPasswordTransformerName";
+
+@implementation MPPrettyPasswordTransformer
+
++ (Class)transformedValueClass {
+  return NSAttributedString.class;
+}
+
++ (BOOL)allowsReverseTransformation {
+  return YES;
+}
+
++ (void)registerTransformer {
+ MPPrettyPasswordTransformer *transformer = [[MPPrettyPasswordTransformer alloc] init];
+  [NSValueTransformer setValueTransformer:transformer
+                                  forName:MPPrettyPasswordTransformerName];
+}
+
+- (id)transformedValue:(id)value {
+  if([value isKindOfClass:NSString.class]) {
+    return ((NSString *)value).passwordPrettified;
+  }
+  if([value isKindOfClass:NSAttributedString.class]) {
+    return ((NSAttributedString *)value).string;
+  }
+  return nil;
+}
+
+
+@end