[ios clean] Toolbar displays total number of tabs.

ios/clean/chrome/browser/ui/toolbar/toolbar_view_controller.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/toolbar/toolbar_view_controller.h"
 
 #import "base/mac/foundation_util.h"
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
 #import "ios/clean/chrome/browser/ui/actions/tab_strip_actions.h"
 #import "ios/clean/chrome/browser/ui/commands/navigation_commands.h"
 #import "ios/clean/chrome/browser/ui/commands/tab_grid_commands.h"
 #import "ios/clean/chrome/browser/ui/commands/tools_menu_commands.h"
 #import "ios/clean/chrome/browser/ui/toolbar/toolbar_button+factory.h"
 #import "ios/clean/chrome/browser/ui/toolbar/toolbar_component_options.h"
 #import "ios/clean/chrome/browser/ui/toolbar/toolbar_constants.h"
 #import "ios/third_party/material_components_ios/src/components/ProgressView/src/MaterialProgressView.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ skipping 35 matching lines @@
     [self setUpToolbarButtons];
     [self setUpLocationBarContainer];
     [self setUpProgressBar];
   }
   return self;
 }
 
 #pragma mark - View lifecyle
 
 - (void)viewDidLoad {
-  self.view.backgroundColor =
-      [UIColor colorWithWhite:kToolbarBackgroundBrightness alpha:1.0];
+  self.view.backgroundColor = UIColorFromRGB(kToolbarBackgroundColor);
   [self addChildViewController:self.locationBarViewController
                      toSubview:self.locationBarContainer];
   [self setUpToolbarStackView];
   [self.view addSubview:self.stackView];
   [self.view addSubview:self.progressBar];
   [self setConstraints];
 }
 
 #pragma mark - View Setup
 
@@ skipping 80 matching lines @@
   self.tabSwitchStripButton = [ToolbarButton tabSwitcherStripToolbarButton];
   self.tabSwitchStripButton.visibilityMask =
       ToolbarComponentVisibilityCompactWidth |
       ToolbarComponentVisibilityRegularWidth;
   [buttonConstraints
       addObject:[self.tabSwitchStripButton.widthAnchor
                     constraintEqualToConstant:kToolbarButtonWidth]];
   [self.tabSwitchStripButton addTarget:nil
                                 action:@selector(showTabStrip:)
                       forControlEvents:UIControlEventTouchUpInside];
+  [self.tabSwitchStripButton
+      setTitleColor:UIColorFromRGB(kToolbarButtonTitleNormalColor)
+           forState:UIControlStateNormal];
+  [self.tabSwitchStripButton
+      setTitleColor:UIColorFromRGB(kToolbarButtonTitleHighlightedColor)
+           forState:UIControlStateHighlighted];
 
   // Tab switcher Grid button.
   self.tabSwitchGridButton = [ToolbarButton tabSwitcherGridToolbarButton];
   self.tabSwitchGridButton.visibilityMask =
       ToolbarComponentVisibilityCompactWidth |
       ToolbarComponentVisibilityRegularWidth;
   [buttonConstraints
       addObject:[self.tabSwitchGridButton.widthAnchor
                     constraintEqualToConstant:kToolbarButtonWidth]];
   [self.tabSwitchGridButton addTarget:self
@@ skipping 35 matching lines @@
   // Stop button.
   self.stopButton = [ToolbarButton stopToolbarButton];
   self.stopButton.visibilityMask = ToolbarComponentVisibilityRegularWidth;
   [buttonConstraints
       addObject:[self.stopButton.widthAnchor
                     constraintEqualToConstant:kToolbarButtonWidth]];
   [self.stopButton addTarget:self
                       action:@selector(stop:)
             forControlEvents:UIControlEventTouchUpInside];
 
-  // // Set the buttons constraints priority to UILayoutPriorityDefaultHigh so
+  // Set the button constraint priority to UILayoutPriorityDefaultHigh so
   // these are not broken when being hidden by the StackView.
   [self activateConstraints:buttonConstraints
                withPriority:UILayoutPriorityDefaultHigh];
 }
 
 - (void)setUpLocationBarContainer {
   UIView* locationBarContainer = [[UIView alloc] initWithFrame:CGRectZero];
   locationBarContainer.translatesAutoresizingMaskIntoConstraints = NO;
   locationBarContainer.backgroundColor = [UIColor whiteColor];
   locationBarContainer.layer.borderWidth = kLocationBarBorderWidth;
   locationBarContainer.layer.borderColor =
-      [UIColor colorWithWhite:kLocationBarBorderColorBrightness alpha:1.0]
-          .CGColor;
+      UIColorFromRGB(kLocationBarBorderColor).CGColor;
   locationBarContainer.layer.shadowRadius = kLocationBarShadowRadius;
   locationBarContainer.layer.shadowOpacity = kLocationBarShadowOpacity;
   locationBarContainer.layer.shadowOffset = CGSizeMake(0.0f, 0.5f);
 
   [locationBarContainer
       setContentHuggingPriority:UILayoutPriorityDefaultLow
                         forAxis:UILayoutConstraintAxisHorizontal];
   self.locationBarContainer = locationBarContainer;
 }
 
@@ skipping 78 matching lines @@
 - (void)setLoadingProgress:(double)progress {
   [self.progressBar setProgress:progress animated:YES completion:nil];
 }
 
 - (void)setTabStripVisible:(BOOL)visible {
   self.tabSwitchStripButton.hiddenInCurrentState = visible;
   self.tabSwitchGridButton.hiddenInCurrentState = !visible;
   [self updateAllButtonsVisibility];
 }
 
+- (void)setTabCount:(int)tabCount {
+  // Return if tabSwitchStripButton wasn't initialized.
+  if (!self.tabSwitchStripButton)
+    return;
+
+  // Update the text shown in the |self.tabSwitchStripButton|. Note that the
+  // button's title may be empty or contain an easter egg, but the accessibility
+  // value will always be equal to |tabCount|.
+  NSString* tabStripButtonValue = [NSString stringWithFormat:@"%d", tabCount];
+  NSString* tabStripButtonTitle;
+  if (tabCount <= 0) {
+    tabStripButtonTitle = @"";
+  } else if (tabCount > kShowTabStripButtonMaxTabCount) {
+    tabStripButtonTitle = @":)";

[marq (ping after 24h), 2017/05/31 09:47:26]

Just for clarity, I'd add a comment here to the effect of: "As an easter egg,
show a smiley face instead of the count if the user has more than 99 tabs open".

[sczs, 2017/05/31 23:19:07]

Done.

+    [[self.tabSwitchStripButton titleLabel]
+        setFont:[UIFont boldSystemFontOfSize:kFontSizeFewerThanTenTabs]];
+  } else {
+    tabStripButtonTitle = tabStripButtonValue;
+    if (tabCount < 10) {
+      [[self.tabSwitchStripButton titleLabel]
+          setFont:[UIFont boldSystemFontOfSize:kFontSizeFewerThanTenTabs]];
+    } else {
+      [[self.tabSwitchStripButton titleLabel]
+          setFont:[UIFont boldSystemFontOfSize:kFontSizeTenTabsOrMore]];
+    }
+  }
+
+  [self.tabSwitchStripButton setTitle:tabStripButtonTitle
+                             forState:UIControlStateNormal];
+  [self.tabSwitchStripButton setAccessibilityValue:tabStripButtonValue];
+}
+
 #pragma mark - ZoomTransitionDelegate
 
 - (CGRect)rectForZoomWithKey:(NSObject*)key inView:(UIView*)view {
   return [view convertRect:self.toolsMenuButton.bounds
                   fromView:self.toolsMenuButton];
 }
 
 #pragma mark - Private Methods
 
 - (void)showToolsMenu:(id)sender {
@@ skipping 43 matching lines @@
 // Sets the priority for an array of constraints and activates them.
 - (void)activateConstraints:(NSArray*)constraintsArray
                withPriority:(UILayoutPriority)priority {
   for (NSLayoutConstraint* constraint in constraintsArray) {
     constraint.priority = priority;
   }
   [NSLayoutConstraint activateConstraints:constraintsArray];
 }
 
 @end