[iOS Clean] Added dialogs UI support.

ios/clean/chrome/browser/ui/dialogs/dialog_mediator.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/dialogs/dialog_mediator.h"
+
+#include "base/logging.h"
+#import "ios/clean/chrome/browser/ui/commands/dialog_commands.h"
+#import "ios/clean/chrome/browser/ui/dialogs/dialog_button_item.h"
+#import "ios/clean/chrome/browser/ui/dialogs/dialog_consumer.h"
+#import "ios/clean/chrome/browser/ui/dialogs/dialog_mediator+internal.h"
+#import "ios/shared/chrome/browser/ui/commands/command_dispatcher.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@interface DialogMediator ()
+
+// Redefine as readwrite.
+@property(nonatomic, readonly, strong) CommandDispatcher* dispatcher;
+
+@end
+
+@implementation DialogMediator
+
+@synthesize dispatcher = _dispatcher;
+
+- (instancetype)initWithDispatcher:(CommandDispatcher*)dispatcher {
+  DCHECK(dispatcher);
+  if ((self = [super init])) {
+    _dispatcher = dispatcher;
+  }
+  return self;
+}
+
+#pragma mark - Public
+
+- (void)updateConsumer:(id<DialogConsumer>)consumer {
+  [consumer setDialogTitle:[self dialogTitle]];

[marq (ping after 24h), 2017/06/14 10:52:15]

Usually the mediator is created or handed a pointer to the consumer that it
keeps, often at init time.

[kkhorimoto, 2017/06/23 06:24:18]

I was going to do that, but ran into style guide violations.  If we were to
update the consumer in |-init|, it makes most sense for this to happen in the
DialogMediator superclass, not the subclasses.  However, the subclasses have not
been initialized yet, so these getters are not available in the superclass's
initializer.

+  [consumer setDialogMessage:[self dialogMessage]];
+  [consumer setDialogButtonItems:[self buttonItems]];
+  [consumer setDialogTextFieldItems:[self textFieldItems]];
+}
+
+- (void)dialogWillStart {
+  [self.dispatcher startDispatchingToTarget:self

[marq (ping after 24h), 2017/06/14 10:52:15]

Starting/stopping dispatch based on coordinator start/stop should be done in the
coordinator -- it's fine for a coordinator to arrange dispatch to objects other
than itself.

This means that this class should just publicly conform to <DialogCommands>
instead of taking the dispatcher on init.

[kkhorimoto, 2017/06/23 06:24:18]

Done.

+                                forProtocol:@protocol(DialogDismissalCommands)];
+}
+
+- (void)dialogWillStop {
+  [self.dispatcher stopDispatchingToTarget:self];
+}
+
+@end
+
+@implementation DialogMediator (Internal)
+
+- (NSString*)dialogTitle {
+  // Implemented by subclasses.
+  return nil;
+}
+
+- (NSString*)dialogMessage {
+  // Implemented by subclasses.
+  return nil;
+}
+
+- (NSArray<DialogButtonItem*>*)buttonItems {
+  // Implemented by subclasses.
+  return nil;
+}
+
+- (NSArray<DialogTextFieldItem*>*)textFieldItems {
+  // Implemented by subclasses.
+  return nil;
+}
+
+#pragma mark - DialogDismissalCommands
+
+- (void)dismissDialogWithButtonTag:(id)buttonTag
+                  userInputStrings:(NSArray<NSString*>*)inputStrings {
+  // Implemented by subclasses.
+}
+
+@end