[clean] Use CommandDispatcher to show/close Settings.

ios/clean/chrome/browser/ui/tab_grid/tab_grid_coordinator.mm

 // Copyright 2016 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/tab_grid/tab_grid_coordinator.h"
 
 #include <memory>
 
 #include "base/strings/sys_string_conversions.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #import "ios/clean/chrome/browser/ui/commands/settings_commands.h"
 #import "ios/clean/chrome/browser/ui/commands/tab_commands.h"
 #import "ios/clean/chrome/browser/ui/commands/tab_grid_commands.h"
 #import "ios/clean/chrome/browser/ui/settings/settings_coordinator.h"
 #import "ios/clean/chrome/browser/ui/tab/tab_coordinator.h"
 #import "ios/clean/chrome/browser/ui/tab_grid/tab_grid_mediator.h"
 #import "ios/clean/chrome/browser/ui/tab_grid/tab_grid_view_controller.h"
 #import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 #import "ios/shared/chrome/browser/tabs/web_state_list.h"
 #import "ios/shared/chrome/browser/ui/browser_list/browser.h"
+#import "ios/shared/chrome/browser/ui/commands/command_dispatcher.h"
 #import "ios/shared/chrome/browser/ui/coordinators/browser_coordinator+internal.h"
 #import "ios/web/public/navigation_manager.h"
 #include "ios/web/public/web_state/web_state.h"
 #import "net/base/mac/url_conversions.h"
 #include "ui/base/page_transition_types.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
@@ skipping 85 matching lines @@
   // This object should only ever have at most one child.
   DCHECK_LE(self.children.count, 1UL);
   BrowserCoordinator* child = [self.children anyObject];
   [child stop];
   [self removeChildCoordinator:child];
 }
 
 #pragma mark - SettingsCommands
 
 - (void)showSettings {
+  CommandDispatcher* dispatcher = self.browser->dispatcher();
+  [dispatcher startDispatchingToTarget:self
+                           forSelector:@selector(closeSettings)];
   SettingsCoordinator* settingsCoordinator = [[SettingsCoordinator alloc] init];
-  settingsCoordinator.settingsCommandHandler = self;
   [self addOverlayCoordinator:settingsCoordinator];
   self.settingsCoordinator = settingsCoordinator;
   [settingsCoordinator start];
 }
 
 - (void)closeSettings {
+  CommandDispatcher* dispatcher = self.browser->dispatcher();
+  [dispatcher stopDispatchingToTarget:self];

[lpromero, 2017/03/29 17:48:46]

This will be problematic if this controller starts listening for other
selectors. This is a stopAll method. Should I add a fine-grained
stopDispatchingToTarget:forSelector:?

[marq (ping after 24h), 2017/03/30 07:53:33]

Yes, or maybe (also?) -stopDispatchingToTarget:forProtocol:

[lpromero, 2017/03/30 11:45:26]

Done for the individual method. I don't pass the target as it's not used (or
maybe we could DCHECK?).
I'd rather add this in a CL adding startDispatchingToTarget:forProtocol:.

   [self.settingsCoordinator stop];
   [self.settingsCoordinator.parentCoordinator
       removeChildCoordinator:self.settingsCoordinator];
   // self.settingsCoordinator should be presumed to be nil after this point.
 }
 
 #pragma mark - URLOpening
 
 - (void)openURL:(NSURL*)URL {
   if (self.webStateList.active_index() == WebStateList::kInvalidIndex) {
     return;
   }
   [self.overlayCoordinator stop];
   [self removeOverlayCoordinator];
   web::WebState* activeWebState = self.webStateList.GetActiveWebState();
   web::NavigationManager::WebLoadParams params(net::GURLWithNSURL(URL));
   params.transition_type = ui::PAGE_TRANSITION_LINK;
   activeWebState->GetNavigationManager()->LoadURLWithParams(params);
   if (!self.children.count) {
     [self showTabAtIndex:self.webStateList.active_index()];
   }
 }
 
 @end