Upstream Chrome on iOS source code [9/11].

ios/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.
+
+// ======                        New Architecture                         =====
+// =         This code is only used in the new iOS Chrome architecture.       =
+// ============================================================================
+
+#import "ios/chrome/browser/ui/tab_grid/tab_grid_coordinator.h"
+
+#include <memory>
+
+#include "base/strings/sys_string_conversions.h"
+#import "ios/chrome/browser/browser_coordinator+internal.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#import "ios/chrome/browser/ui/settings/settings_coordinator.h"
+#import "ios/chrome/browser/ui/tab/tab_coordinator.h"
+#import "ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.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
+
+@interface TabGridCoordinator ()<TabGridDataSource,
+                                 TabGridActionDelegate,
+                                 SettingsActionDelegate>
+@property(nonatomic, strong) TabGridViewController* viewController;
+@property(nonatomic, weak) SettingsCoordinator* settingsCoordinator;
+@end
+
+@implementation TabGridCoordinator {
+  std::unique_ptr<web::WebState> _placeholderWebState;
+}
+
+@synthesize viewController = _viewController;
+@synthesize settingsCoordinator = _settingsCoordinator;
+
+#pragma mark - BrowserCoordinator
+
+- (void)start {
+  self.viewController = [[TabGridViewController alloc] init];
+  self.viewController.dataSource = self;
+  self.viewController.actionDelegate = self;
+
+  // |rootViewController| is nullable, so this is by design a no-op if it hasn't
+  // been set. This may be true in a unit test, or if this coordinator is being
+  // used as a root coordinator.
+  [self.rootViewController presentViewController:self.viewController
+                                        animated:YES
+                                      completion:nil];
+}
+
+#pragma mark - TabGridDataSource
+
+- (NSUInteger)numberOfTabsInTabGrid {
+  return 1;
+}
+
+- (NSString*)titleAtIndex:(NSInteger)index {
+  // Placeholder implementation: ignore |index| and return the placeholder
+  // web state, lazily creating it if needed.
+  if (!_placeholderWebState.get()) {
+    web::WebState::CreateParams webStateCreateParams(self.browserState);
+    _placeholderWebState = web::WebState::Create(webStateCreateParams);
+    _placeholderWebState->SetWebUsageEnabled(true);
+  }
+  GURL url = _placeholderWebState.get()->GetVisibleURL();
+  NSString* urlText = @"<New Tab>";
+  if (!url.is_valid()) {
+    urlText = base::SysUTF8ToNSString(url.spec());
+  }
+  return urlText;
+}
+
+#pragma mark - TabGridActionDelegate
+
+- (void)showTabAtIndexPath:(NSIndexPath*)indexPath {
+  DCHECK(_placeholderWebState);
+
+  TabCoordinator* tabCoordinator = [[TabCoordinator alloc] init];
+  tabCoordinator.webState = _placeholderWebState.get();
+  tabCoordinator.presentationKey = indexPath;
+  [self addChildCoordinator:tabCoordinator];
+  [tabCoordinator start];
+}
+
+- (void)showTabGrid {
+  // 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 - TabGridActionDelegate
+
+- (void)showSettings {
+  SettingsCoordinator* settingsCoordinator = [[SettingsCoordinator alloc] init];
+  settingsCoordinator.actionDelegate = self;
+  [self addOverlayCoordinator:settingsCoordinator];
+  self.settingsCoordinator = settingsCoordinator;
+  [settingsCoordinator start];
+}
+
+#pragma mark - SettingsActionDelegate
+
+- (void)closeSettings {
+  [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 {
+  [self.overlayCoordinator stop];
+  [self removeOverlayCoordinator];
+  web::NavigationManager::WebLoadParams params(net::GURLWithNSURL(URL));
+  params.transition_type = ui::PAGE_TRANSITION_LINK;
+  _placeholderWebState->GetNavigationManager()->LoadURLWithParams(params);
+  if (!self.children.count) {
+    // Placeholder — since there's only one tab in the grid, just open
+    // the tab at index path (0,0).
+    [self showTabAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:0]];
+  }
+}
+
+@end