[ios] Add tab grid to view controller and showcase

Bug: 804496, 804497
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I05b6627c4eb9ab6ae33e337631b7f1e70466730c
Reviewed-on: https://chromium-review.googlesource.com/924650
Commit-Queue: edchin <edchin@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537485}

ios/chrome/browser/ui/tab_grid/grid_view_controller.h

@@ -11,6 +11,8 @@
 
 // A view controller that contains a grid of items.
 @interface GridViewController : UIViewController<GridConsumer>
+// The gridView is accessible to manage the content inset behavior.
+@property(nonatomic, readonly) UIScrollView* gridView;
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_TAB_GRID_GRID_VIEW_CONTROLLER_H_

ios/chrome/browser/ui/tab_grid/grid_view_controller.mm

@@ -55,6 +55,12 @@ NSString* const kCellIdentifier = @"GridCellIdentifier";
   self.view = collectionView;
 }
 
+#pragma mark - Public
+
+- (UIScrollView*)gridView {
+  return self.collectionView;
+}
+
 #pragma mark - UICollectionViewDataSource
 
 - (NSInteger)collectionView:(UICollectionView*)collectionView
@@ -78,9 +84,7 @@ NSString* const kCellIdentifier = @"GridCellIdentifier";
   self.items = [items mutableCopy];
   self.selectedIndex = selectedIndex;
   if ([self isViewLoaded]) {
-    [self.collectionView
-        reloadItemsAtIndexPaths:[self.collectionView
-                                        indexPathsForVisibleItems]];
+    [self.collectionView reloadData];
   }
 }
 

ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.h

@@ -7,9 +7,13 @@
 
 #import <UIKit/UIKit.h>
 
+#import "ios/chrome/browser/ui/tab_grid/grid_consumer.h"
+
 // View controller representing a tab switcher. The tab switcher has an
 // incognito tab grid, regular tab grid, and remote tabs.
 @interface TabGridViewController : UIViewController
+@property(nonatomic, readonly) id<GridConsumer> regularTabsConsumer;
+@property(nonatomic, readonly) id<GridConsumer> incognitoTabsConsumer;
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_TAB_GRID_TAB_GRID_VIEW_CONTROLLER_H_

ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm

@@ -4,6 +4,7 @@
 
 #import "ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.h"
 
+#import "ios/chrome/browser/ui/tab_grid/grid_view_controller.h"
 #import "ios/chrome/browser/ui/tab_grid/tab_grid_bottom_toolbar.h"
 #import "ios/chrome/browser/ui/tab_grid/tab_grid_top_toolbar.h"
 
@@ -11,13 +12,63 @@
 #error "This file requires ARC support."
 #endif
 
+@interface TabGridViewController ()
+@property(nonatomic, weak) GridViewController* regularTabsViewController;
+@property(nonatomic, weak) GridViewController* incognitoTabsViewController;
+@end
+
 @implementation TabGridViewController
+@synthesize regularTabsViewController = _regularTabsViewController;
+@synthesize incognitoTabsViewController = _incognitoTabsViewController;
 
 #pragma mark - UIViewController
 
 - (void)viewDidLoad {
   [super viewDidLoad];
+  [self setupRegularTabsViewController];
+  [self setupToolbars];
+}
+
+- (UIStatusBarStyle)preferredStatusBarStyle {
+  return UIStatusBarStyleLightContent;
+}
+
+#pragma mark - Public
+
+- (id<GridConsumer>)regularTabsConsumer {
+  return self.regularTabsViewController;
+}
 
+- (id<GridConsumer>)incognitoTabsConsumer {
+  return self.incognitoTabsViewController;
+}
+
+#pragma mark - Private
+
+// Adds the regular tabs GridViewController as a contained view controller, and
+// sets constraints.
+- (void)setupRegularTabsViewController {
+  GridViewController* viewController = [[GridViewController alloc] init];
+  viewController.view.translatesAutoresizingMaskIntoConstraints = NO;
+  [self addChildViewController:viewController];
+  [self.view addSubview:viewController.view];
+  [viewController didMoveToParentViewController:self];
+  self.regularTabsViewController = viewController;
+
+  NSArray* constraints = @[
+    [viewController.view.topAnchor constraintEqualToAnchor:self.view.topAnchor],
+    [viewController.view.bottomAnchor
+        constraintEqualToAnchor:self.view.bottomAnchor],
+    [viewController.view.leadingAnchor
+        constraintEqualToAnchor:self.view.leadingAnchor],
+    [viewController.view.trailingAnchor
+        constraintEqualToAnchor:self.view.trailingAnchor],
+  ];
+  [NSLayoutConstraint activateConstraints:constraints];
+}
+
+// Adds the top and bottom toolbars and sets constraints.
+- (void)setupToolbars {
   UIView* topToolbar = [[TabGridTopToolbar alloc] init];
   topToolbar.translatesAutoresizingMaskIntoConstraints = NO;
 
@@ -63,10 +114,12 @@
     ]];
   }
   [NSLayoutConstraint activateConstraints:constraints];
-}
 
-- (UIStatusBarStyle)preferredStatusBarStyle {
-  return UIStatusBarStyleLightContent;
+  // The content inset of the tab grids must be modified so that the toolbars do
+  // not obscure the tabs.
+  self.regularTabsViewController.gridView.contentInset =
+      UIEdgeInsetsMake(topToolbar.intrinsicContentSize.height, 0,
+                       bottomToolbar.intrinsicContentSize.height, 0);
 }
 
 @end

ios/showcase/tab_grid/sc_tab_grid_coordinator.mm

@@ -4,13 +4,14 @@
 
 #import "ios/showcase/tab_grid/sc_tab_grid_coordinator.h"
 
+#import "ios/chrome/browser/ui/tab_grid/grid_item.h"
 #import "ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-@interface SCTabGridCoordinator ()
+@interface SCTabGridCoordinator ()<UINavigationControllerDelegate>
 @property(nonatomic, strong) TabGridViewController* viewController;
 @end
 
@@ -20,9 +21,29 @@
 
 - (void)start {
   self.viewController = [[TabGridViewController alloc] init];
-  self.viewController.title = @"Tab Grid";
-  [self.baseViewController setHidesBarsOnSwipe:YES];
+  self.viewController.title = @"Full TabGrid UI";
+  self.baseViewController.delegate = self;
+  self.baseViewController.hidesBarsOnSwipe = YES;
   [self.baseViewController pushViewController:self.viewController animated:YES];
 }
 
+#pragma mark - UINavigationControllerDelegate
+
+// This delegate method is used as a way to have a completion handler after
+// pushing onto a navigation controller.
+- (void)navigationController:(UINavigationController*)navigationController
+       didShowViewController:(UIViewController*)viewController
+                    animated:(BOOL)animated {
+  if (viewController != self.viewController)
+    return;
+
+  NSMutableArray* items = [[NSMutableArray alloc] init];
+  for (int i = 0; i < 10; i++) {
+    GridItem* item = [[GridItem alloc] init];
+    item.title = @"The New York Times - Breaking News";
+    [items addObject:item];
+  }
+  [self.viewController.regularTabsConsumer populateItems:items selectedIndex:0];
+}
+
 @end