More imporvements on the Plugin System

Signed-off-by: michael starke <michael.starke@hicknhack-software.com>

MacPass/MPPluginHost.m

@@ -0,0 +1,52 @@
+//
+//  MPPluginHost.m
+//  MacPass
+//
+//  Created by Michael Starke on 13/11/15.
+//  Copyright © 2015 HicknHack Software GmbH. All rights reserved.
+//
+
+#import "MPPluginHost.h"
+#import "MPDocument.h"
+
+@implementation MPPluginHost
+
+static MPPluginHost *_instance;
+
++ (instancetype)sharedHost {
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    _instance = [[MPPluginHost alloc] _init];
+  });
+  return _instance;
+}
+
+- (instancetype)init {
+  return _instance;
+}
+
+- (instancetype)_init {
+  self = [super init];
+  if(self) {
+  }
+  return self;
+}
+
+- (NSArray *)filteredEntriesUsingBlock:(NodeMatchBlock)matchBlock {
+  NSArray *currentDocuments = [[NSDocumentController sharedDocumentController] documents];
+  NSMutableArray *entries = [[NSMutableArray alloc] initWithCapacity:200];
+  for(MPDocument *document in currentDocuments) {
+    if(document.tree) {
+      [entries addObjectsFromArray:document.tree.allEntries];
+    }
+  }
+  NSPredicate *predicate = [NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *bindings) { return matchBlock(evaluatedObject); }];
+  return [[NSArray alloc] initWithArray:[entries filteredArrayUsingPredicate:predicate] copyItems:YES];
+}
+
+- (NSArray *)filteredGroupsUsingBlock:(NodeMatchBlock)matchBlock {
+  NSAssert(NO, @"Not implemented");
+  return nil;
+}
+
+@end