[iOS Clean] Wired up ContextMenuCommands.

ios/clean/chrome/browser/ui/context_menu/context_menu_view_controller.mm

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/clean/chrome/browser/ui/context_menu/context_menu_view_controller.h"
 
+#include "base/logging.h"
+#import "ios/clean/chrome/browser/ui/context_menu/context_menu_context.h"
+
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 // Typedef the block parameter for UIAlertAction for readability.
 typedef void (^AlertActionHandler)(UIAlertAction*);
+// Sends |commands| to |dispatcher| using |context| as the menu context.
+void DispatchContextMenuCommands(const std::vector<SEL>& commands,
+                                 id dispatcher,
+                                 ContextMenuContext* context) {
+  DCHECK(dispatcher);
+  DCHECK(context);
+  for (SEL command : commands) {
+    IMP command_imp = [dispatcher methodForSelector:command];
+    DCHECK(command_imp);
+    command_imp(dispatcher, command, context);
+  }
+}
 }
 
 @interface ContextMenuViewController ()
-// Object to which command messages will be sent.
-@property(nonatomic, weak) id dispatcher;
+// The dispatcher passed on initialization.
+@property(nonatomic, readonly, weak) id<ContextMenuCommands> dispatcher;
+// The context passed on initialization.
+@property(nonatomic, strong) ContextMenuContext* context;
+
+// Creates an UIAlertAction for |item| using |style| to manage the action's
+// appearance.
+- (UIAlertAction*)alertActionForItem:(ContextMenuItem*)item
+                               style:(UIAlertActionStyle)style;
+
 @end
 
 @implementation ContextMenuViewController
 @synthesize dispatcher = _dispatcher;
+@synthesize context = _context;
 
-- (instancetype)initWithDispatcher:(id)dispatcher {
+- (instancetype)initWithDispatcher:(id<ContextMenuCommands>)dispatcher {
   self =
       [[self class] alertControllerWithTitle:nil
                                      message:nil
                               preferredStyle:UIAlertControllerStyleActionSheet];
   if (self) {
+    DCHECK(dispatcher);
     _dispatcher = dispatcher;
   }
   return self;
 }
 
 #pragma mark - ContextMenuConsumer
 
+- (void)setContextMenuContext:(ContextMenuContext*)context {
+  DCHECK(context);
+  self.context = context;
+}
+
 - (void)setContextMenuTitle:(NSString*)title {
   self.title = title;
 }
 
-- (void)setContextMenuItems:(NSArray<ContextMenuItem*>*)items {
+- (void)setContextMenuItems:(NSArray<ContextMenuItem*>*)items
+                 cancelItem:(ContextMenuItem*)cancelItem {
+  // Add an alert action for each item in |items|, then add |cancelItem|.
   for (ContextMenuItem* item in items) {
-    // Create a block that sends the invocation passed in with the item's
-    // configuration to the dispatcher.
-    AlertActionHandler handler = ^(UIAlertAction* action) {
-      [item.command invokeWithTarget:self.dispatcher];
-    };
-    [self addAction:[UIAlertAction actionWithTitle:item.title
-                                             style:UIAlertActionStyleDefault
-                                           handler:handler]];
+    [self addAction:[self alertActionForItem:item
+                                       style:UIAlertActionStyleDefault]];
   }
+  [self addAction:[self alertActionForItem:cancelItem
+                                     style:UIAlertActionStyleCancel]];
+}
 
-  // Always add a cancel action.
-  [self addAction:[UIAlertAction actionWithTitle:@"Cancel"
-                                           style:UIAlertActionStyleCancel
-                                         handler:nil]];
+#pragma mark -
+
+- (UIAlertAction*)alertActionForItem:(ContextMenuItem*)item
+                               style:(UIAlertActionStyle)style {
+  DCHECK(item);
+  // Create a block that dispatches |item|'s ContextMenuCommands.
+  AlertActionHandler handler = ^(UIAlertAction* action) {
+    DispatchContextMenuCommands(item.commands, self.dispatcher, self.context);
+  };
+  return [UIAlertAction actionWithTitle:item.title style:style handler:handler];
 }
 
 @end