Upstream Chrome on iOS source code [6/11].

ios/chrome/browser/ui/ntp/recent_tabs/views/panel_bar_view.mm

+// Copyright 2014 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.
+
+#include "ios/chrome/browser/ui/ntp/recent_tabs/views/panel_bar_view.h"
+
+#import "ios/chrome/browser/ui/ntp/recent_tabs/views/views_utils.h"
+#include "ios/chrome/browser/ui/rtl_geometry.h"
+#include "ios/chrome/browser/ui/ui_util.h"
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
+#include "ios/chrome/grit/ios_strings.h"
+#import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
+#import "ios/third_party/material_roboto_font_loader_ios/src/src/MaterialRobotoFontLoader.h"
+#include "ui/base/l10n/l10n_util_mac.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+
+const int kBackgroundColor = 0xf2f2f2;
+const CGFloat kFontSize = 20;
+
+}  // namespace
+
+@interface PanelBarView () {
+  UIButton* _closeButton;
+  NSLayoutConstraint* _statusBarSpacerConstraint;
+}
+// Whether the panel view extends throughout the whole screen. For example,
+// when presented fullscreen, the panel bar extends to the borders of the app
+// and the function returns YES.
+// When presented modally as on iPad and iPhone 6 Plus landscape, it returns NO.
+- (BOOL)coversFullAppWidth;
+@end
+
+@implementation PanelBarView
+
+- (instancetype)init {
+  self = [super initWithFrame:CGRectZero];
+  if (self) {
+    [self setBackgroundColor:UIColorFromRGB(kBackgroundColor)];
+    // Create and add the bar's title.
+    UILabel* title = [[UILabel alloc] initWithFrame:CGRectZero];
+    [title setTranslatesAutoresizingMaskIntoConstraints:NO];
+    [title setFont:[[MDFRobotoFontLoader sharedInstance]
+                       mediumFontOfSize:kFontSize]];
+    [title setTextColor:recent_tabs::GetTextColorGray()];
+    [title setTextAlignment:NSTextAlignmentNatural];
+    [title setText:l10n_util::GetNSString(IDS_IOS_NEW_TAB_RECENT_TABS)];
+    [title setBackgroundColor:UIColorFromRGB(kBackgroundColor)];
+    [self addSubview:title];
+
+    // Create and add the bar's close button.
+    _closeButton = [[UIButton alloc] initWithFrame:CGRectZero];
+    [_closeButton setTranslatesAutoresizingMaskIntoConstraints:NO];
+    [_closeButton
+        setTitle:l10n_util::GetNSString(IDS_IOS_NAVIGATION_BAR_DONE_BUTTON)
+                     .uppercaseString
+        forState:UIControlStateNormal];
+    [_closeButton setTitleColor:recent_tabs::GetTextColorGray()
+                       forState:UIControlStateNormal];
+    [[_closeButton titleLabel] setFont:[MDCTypography buttonFont]];
+    [_closeButton setAccessibilityIdentifier:@"Exit"];
+    [self addSubview:_closeButton];
+
+    // Create and add the view that adds vertical padding that matches the
+    // status bar's height.
+    UIView* statusBarSpacer = [[UIView alloc] initWithFrame:CGRectZero];
+    [statusBarSpacer setTranslatesAutoresizingMaskIntoConstraints:NO];
+    [self addSubview:statusBarSpacer];
+
+    // Add the constraints on all the subviews.
+    NSDictionary* viewsDictionary = @{
+      @"title" : title,
+      @"closeButton" : _closeButton,
+      @"statusBar" : statusBarSpacer,
+    };
+    NSArray* constraints = @[
+      @"V:|-0-[statusBar]-14-[closeButton]-13-|",
+      @"H:|-16-[title]-(>=0)-[closeButton]-16-|",
+    ];
+    ApplyVisualConstraintsWithOptions(constraints, viewsDictionary,
+                                      LayoutOptionForRTLSupport(), self);
+    AddSameCenterYConstraint(self, title, _closeButton);
+    _statusBarSpacerConstraint =
+        [NSLayoutConstraint constraintWithItem:statusBarSpacer
+                                     attribute:NSLayoutAttributeHeight
+                                     relatedBy:NSLayoutRelationEqual
+                                        toItem:nil
+                                     attribute:NSLayoutAttributeNotAnAttribute
+                                    multiplier:1
+                                      constant:0];
+    [self addConstraint:_statusBarSpacerConstraint];
+  }
+  return self;
+}
+
+- (void)updateConstraints {
+  UIInterfaceOrientation orientation =
+      [[UIApplication sharedApplication] statusBarOrientation];
+  // On Plus phones in landscape, the modal is not fullscreen. The panel bar
+  // doesn't need to take the status bar into account.
+  BOOL takeStatusBarIntoAccount = [self coversFullAppWidth] ||
+                                  UIInterfaceOrientationIsPortrait(orientation);
+  if (takeStatusBarIntoAccount) {
+    CGFloat statusBarHeight = StatusBarHeight();
+    [_statusBarSpacerConstraint setConstant:statusBarHeight];
+  } else {
+    [_statusBarSpacerConstraint setConstant:0];
+  }
+  [super updateConstraints];
+}
+
+- (void)setCloseTarget:(id)target action:(SEL)action {
+  [_closeButton addTarget:target
+                   action:action
+         forControlEvents:UIControlEventTouchUpInside];
+}
+
+- (void)layoutSubviews {
+  [self setNeedsUpdateConstraints];
+  [super layoutSubviews];
+}
+
+- (BOOL)coversFullAppWidth {
+  return self.traitCollection.horizontalSizeClass ==
+         self.window.traitCollection.horizontalSizeClass;
+}
+
+@end