[ios clean] Add placeholder for NTP bookmarks, chrome home and open tabs.

ios/clean/chrome/browser/ui/ntp/ntp_view_controller.mm

Index: ios/clean/chrome/browser/ui/ntp/ntp_view_controller.mm
diff --git a/ios/clean/chrome/browser/ui/ntp/ntp_view_controller.mm b/ios/clean/chrome/browser/ui/ntp/ntp_view_controller.mm
new file mode 100644
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+++ b/ios/clean/chrome/browser/ui/ntp/ntp_view_controller.mm
@@ -0,0 +1,194 @@
+// 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/ntp/ntp_view_controller.h"
+
+#import "base/ios/crb_protocol_observers.h"
+#include "components/strings/grit/components_strings.h"
+#import "ios/chrome/browser/ui/ntp/new_tab_page_bar.h"
+#import "ios/chrome/browser/ui/ntp/new_tab_page_bar_item.h"
+#import "ios/chrome/browser/ui/ntp/new_tab_page_controller.h"
+#import "ios/chrome/browser/ui/ntp/new_tab_page_view.h"
+#import "ios/chrome/browser/ui/rtl_geometry.h"
+#include "ios/chrome/browser/ui/ui_util.h"
+#include "ios/chrome/grit/ios_strings.h"
+#import "ios/clean/chrome/browser/ui/commands/ntp_commands.h"
+#include "ui/base/l10n/l10n_util.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@interface NTPViewController ()<UIScrollViewDelegate, NewTabPageBarDelegate>
+@property(nonatomic, strong) NewTabPageView* NTPView;
+@property(nonatomic, strong) NSArray* tabBarItems;
+@end
+
+@implementation NTPViewController
+
+@synthesize bookmarksViewController = _bookmarksViewController;
+@synthesize dispatcher = _dispatcher;
+@synthesize homeViewController = _homeViewController;
+@synthesize NTPView = _NTPView;
+@synthesize recentTabsViewController = _recentTabsViewController;
+@synthesize tabBarItems = _tabBarItems;
+
+#pragma mark - UIViewController
+
+- (void)viewDidLoad {
+  [super viewDidLoad];
+  self.title = l10n_util::GetNSString(IDS_NEW_TAB_TITLE);
+  self.view.backgroundColor = [UIColor whiteColor];
+
+  UIScrollView* scrollView = [[UIScrollView alloc] initWithFrame:CGRectZero];
+  [scrollView setAutoresizingMask:(UIViewAutoresizingFlexibleWidth |
+                                   UIViewAutoresizingFlexibleHeight)];
+  scrollView.pagingEnabled = YES;
+  scrollView.showsHorizontalScrollIndicator = NO;
+  scrollView.showsVerticalScrollIndicator = NO;
+  scrollView.contentMode = UIViewContentModeScaleAspectFit;
+  scrollView.bounces = YES;
+  scrollView.scrollsToTop = NO;
+  scrollView.delegate = self;
+
+  NewTabPageBar* tabBar = [[NewTabPageBar alloc] initWithFrame:CGRectZero];
+  tabBar.delegate = self;
+  self.NTPView = [[NewTabPageView alloc] initWithFrame:CGRectZero
+                                         andScrollView:scrollView
+                                             andTabBar:tabBar];
+  self.NTPView.translatesAutoresizingMaskIntoConstraints = NO;
+  [self.view addSubview:self.NTPView];
+
+  [NSLayoutConstraint activateConstraints:@[
+    [self.NTPView.topAnchor constraintEqualToAnchor:self.view.topAnchor],
+    [self.NTPView.leadingAnchor
+        constraintEqualToAnchor:self.view.leadingAnchor],
+    [self.NTPView.bottomAnchor constraintEqualToAnchor:self.view.bottomAnchor],
+    [self.NTPView.trailingAnchor
+        constraintEqualToAnchor:self.view.trailingAnchor],
+  ]];
+
+  DCHECK(self.tabBarItems);
+  self.NTPView.tabBar.items = self.tabBarItems;
+}
+
+- (void)viewDidLayoutSubviews {
+  [super viewDidLayoutSubviews];
+
+  if (!self.homeViewController) {
+    // Make sure scrollView is properly set up.
+    [self.NTPView layoutIfNeeded];
+    // PLACEHOLDER: This should come from the mediator.
+    if (IsIPadIdiom()) {
+      CGRect itemFrame = [self.NTPView panelFrameForItemAtIndex:1];
+      CGPoint point = CGPointMake(CGRectGetMinX(itemFrame), 0);
+      [self.NTPView.scrollView setContentOffset:point animated:NO];
+    } else {
+      [self.dispatcher showNTPHomePanel];
+    }
+  }
+}
+
+- (void)setHomeViewController:(UIViewController*)controller {
+  _homeViewController = controller;
+  if (IsIPadIdiom()) {
+    controller.view.frame = [self.NTPView panelFrameForItemAtIndex:1];
+  } else {
+    controller.view.frame = [self.NTPView panelFrameForItemAtIndex:0];
+  }
+  NewTabPageBarItem* item = self.NTPView.tabBar.items[1];
+  item.view = controller.view;
+  [self addControllerToScrollView:controller];
+}
+
+- (void)setBookmarksViewController:(UIViewController*)controller {
+  _bookmarksViewController = controller;
+  controller.view.frame = [self.NTPView panelFrameForItemAtIndex:0];
+  NewTabPageBarItem* item = self.NTPView.tabBar.items[0];
+  item.view = controller.view;
+  [self addControllerToScrollView:controller];
+}
+
+- (void)setRecentTabsViewController:(UIViewController*)controller {
+  _recentTabsViewController = controller;
+  controller.view.frame = [self.NTPView panelFrameForItemAtIndex:2];
+  NewTabPageBarItem* item = self.NTPView.tabBar.items[2];
+  item.view = controller.view;
+  [self addControllerToScrollView:_recentTabsViewController];
+}
+
+#pragma mark - Private
+
+// Add the view controller to vc hierarchy and add the view to the scrollview.
+- (void)addControllerToScrollView:(UIViewController*)controller {
+  [self addChildViewController:controller];
+  [self.NTPView.scrollView addSubview:controller.view];
+  [controller didMoveToParentViewController:self];
+}
+
+#pragma mark - NTPConsumer
+
+- (void)setBarItems:(NSArray*)items {
+  self.tabBarItems = items;
+}
+
+#pragma mark - UIScrollViewDelegate
+
+// TODO(crbug.com/709086) Move UIScrollViewDelegate to shared object.
+- (void)scrollViewDidScroll:(UIScrollView*)scrollView {
+  // Position is used to track the exact X position of the scroll view, whereas
+  // index is rounded to the panel that is most visible.
+  CGFloat panelWidth =
+      scrollView.contentSize.width / self.NTPView.tabBar.items.count;
+  LayoutOffset position =
+      LeadingContentOffsetForScrollView(scrollView) / panelWidth;
+  NSUInteger index = round(position);
+
+  // |scrollView| can be out of range when the frame changes.
+  if (index >= self.NTPView.tabBar.items.count)
+    return;
+
+  NewTabPageBarItem* item = self.NTPView.tabBar.items[index];
+  if (item.identifier == NewTabPage::kBookmarksPanel &&
+      !self.bookmarksViewController)
+    [self.dispatcher showNTPBookmarksPanel];
+  else if (item.identifier == NewTabPage::kMostVisitedPanel &&
+           !self.homeViewController)
+    [self.dispatcher showNTPHomePanel];
+  else if (item.identifier == NewTabPage::kOpenTabsPanel &&
+           !self.recentTabsViewController)
+    [self.dispatcher showNTPRecentTabsPanel];
+
+  // If index changed, follow same path as if a tab bar item was pressed.  When
+  // |index| == |position|, the panel is completely in view.
+  if (index == position && self.NTPView.tabBar.selectedIndex != index) {
+    NewTabPageBarItem* item = [self.NTPView.tabBar.items objectAtIndex:index];
+    DCHECK(item);
+    self.NTPView.tabBar.selectedIndex = index;
+  }
+  [self.NTPView.tabBar updateColorsForScrollView:scrollView];
+
+  self.NTPView.tabBar.overlayPercentage =
+      scrollView.contentOffset.x / scrollView.contentSize.width;
+}
+
+#pragma mark - NewTabPageBarDelegate
+
+- (void)newTabBarItemDidChange:(NewTabPageBarItem*)selectedItem
+                   changePanel:(BOOL)changePanel {
+  if (IsIPadIdiom()) {
+    NSUInteger index = [self.NTPView.tabBar.items indexOfObject:selectedItem];
+    CGRect itemFrame = [self.NTPView panelFrameForItemAtIndex:index];
+    CGPoint point = CGPointMake(CGRectGetMinX(itemFrame), 0);
+    [self.NTPView.scrollView setContentOffset:point animated:YES];
+  } else {
+    if (selectedItem.identifier == NewTabPage::kBookmarksPanel) {
+      [self.dispatcher showNTPBookmarksPanel];
+    } else if (selectedItem.identifier == NewTabPage::kOpenTabsPanel) {
+      [self.dispatcher showNTPRecentTabsPanel];
+    }
+  }
+}
+
+@end