[iOS] Support dark mode on content suggestions/NTP

This does not change the color on the placeholder background + icon
for when a suggestion has no image because that will be removed before
dark mode is finished.

Bug: 976641
Change-Id: I0bf0e26e7ce087917c38017d15a85c0a2ecbf6b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1706431
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#678266}

ios/chrome/browser/ui/content_suggestions/BUILD.gn

@@ -135,6 +135,7 @@ source_set("content_suggestions_ui") {
     "//ios/chrome/browser/ui/toolbar/public",
     "//ios/chrome/browser/ui/toolbar/resources:tab_toolbar_shadow_color",
     "//ios/chrome/browser/ui/util:util",
+    "//ios/chrome/common/colors",
     "//ios/chrome/common/favicon",
     "//ios/chrome/common/ui_util",
     "//ios/web/common",

ios/chrome/browser/ui/content_suggestions/cells/BUILD.gn

@@ -63,6 +63,7 @@ source_set("cells_ui") {
     "//ios/chrome/browser/ui/ntp_tile_views:constants",
     "//ios/chrome/browser/ui/util",
     "//ios/chrome/common",
+    "//ios/chrome/common/colors",
     "//ios/chrome/common/favicon",
     "//ios/chrome/common/ui_util",
     "//ui/base",

ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_articles_header_item.mm

@@ -5,6 +5,8 @@
 #import "ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_articles_header_item.h"
 
 #import "ios/chrome/browser/ui/util/uikit_ui_util.h"
+#import "ios/chrome/common/colors/UIColor+cr_semantic_colors.h"
+#import "ios/chrome/common/colors/semantic_color_names.h"
 #import "ios/chrome/common/ui_util/constraints_ui_util.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -16,8 +18,6 @@
 namespace {
 // Leading and trailing margin for label and button.
 const CGFloat kTextMargin = 13;
-// Color for label text.
-const int kLabelColorRGB = 0x6D6D72;
 }
 
 #pragma mark - ContentSuggestionsArticlesHeaderItem
@@ -90,11 +90,12 @@ const int kLabelColorRGB = 0x6D6D72;
     _label = [[UILabel alloc] init];
     _label.translatesAutoresizingMaskIntoConstraints = NO;
     _label.font = [UIFont preferredFontForTextStyle:UIFontTextStyleFootnote];
-    _label.textColor = UIColorFromRGB(kLabelColorRGB, 1.0);
+    _label.textColor = UIColor.cr_secondaryLabelColor;
     _label.adjustsFontForContentSizeCategory = YES;
     _label.adjustsFontSizeToFitWidth = YES;
 
     _button = [UIButton buttonWithType:UIButtonTypeSystem];
+    _button.tintColor = [UIColor colorNamed:kTintColor];
     _button.translatesAutoresizingMaskIntoConstraints = NO;
     _button.titleLabel.font =
         [UIFont preferredFontForTextStyle:UIFontTextStyleFootnote];

ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_cell.mm

@@ -8,6 +8,7 @@
 #import "ios/chrome/browser/ui/util/i18n_string.h"
 #include "ios/chrome/browser/ui/util/ui_util.h"
 #import "ios/chrome/browser/ui/util/uikit_ui_util.h"
+#import "ios/chrome/common/colors/UIColor+cr_semantic_colors.h"
 #import "ios/chrome/common/favicon/favicon_view.h"
 #import "ios/chrome/common/ui_util/constraints_ui_util.h"
 #import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
@@ -113,8 +114,7 @@ const CGFloat kAnimationDuration = 0.3;
     [[self class] configureTitleLabel:_titleLabel];
     _additionalInformationLabel.font = [[self class] additionalInformationFont];
     _faviconView.font = [[MDCTypography fontLoader] mediumFontOfSize:10];
-    _additionalInformationLabel.textColor =
-        [UIColor colorWithWhite:0 alpha:0.54];
+    _additionalInformationLabel.textColor = UIColor.cr_secondaryLabelColor;
 
     [self applyConstraints];
   }
@@ -374,7 +374,7 @@ const CGFloat kAnimationDuration = 0.3;
 
 // Configures the |titleLabel|.
 + (void)configureTitleLabel:(UILabel*)titleLabel {
-  titleLabel.textColor = [UIColor colorWithWhite:0 alpha:0.8];
+  titleLabel.textColor = UIColor.cr_labelColor;
   UIFontDescriptor* descriptor = [[UIFontDescriptor
       preferredFontDescriptorWithTextStyle:UIFontTextStyleSubheadline]
       fontDescriptorWithSymbolicTraits:UIFontDescriptorTraitBold];

ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_footer_item.mm

@@ -6,6 +6,7 @@
 
 #import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
 #include "ios/chrome/browser/ui/util/ui_util.h"
+#import "ios/chrome/common/colors/semantic_color_names.h"
 #import "ios/chrome/common/ui_util/constraints_ui_util.h"
 #import "ios/third_party/material_components_ios/src/components/ActivityIndicator/src/MaterialActivityIndicator.h"
 
@@ -84,9 +85,10 @@ const CGFloat kButtonPadding = 16;
   self = [super initWithFrame:frame];
   if (self) {
     _activityIndicator = [[MDCActivityIndicator alloc] init];
-    _activityIndicator.cycleColors = @[ [[MDCPalette cr_bluePalette] tint500] ];
+    _activityIndicator.cycleColors = @[ [UIColor colorNamed:kTintColor] ];
     _activityIndicator.translatesAutoresizingMaskIntoConstraints = NO;
     _button = [UIButton buttonWithType:UIButtonTypeSystem];
+    _button.tintColor = [UIColor colorNamed:kTintColor];
     _button.translatesAutoresizingMaskIntoConstraints = NO;
     _button.titleLabel.font =
         [UIFont preferredFontForTextStyle:UIFontTextStyleFootnote];

ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm

@@ -27,6 +27,7 @@
 #import "ios/chrome/browser/ui/toolbar/public/toolbar_utils.h"
 #import "ios/chrome/browser/ui/ui_feature_flags.h"
 #import "ios/chrome/browser/ui/util/uikit_ui_util.h"
+#import "ios/chrome/common/colors/UIColor+cr_semantic_colors.h"
 #import "ios/chrome/common/ui_util/constraints_ui_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -469,8 +470,17 @@ NSString* const kContentSuggestionsMostVisitedAccessibilityIdentifierPrefix =
     cellBackgroundColorAtIndexPath:(nonnull NSIndexPath*)indexPath {
   if ([self.collectionUpdater
           shouldUseCustomStyleForSection:indexPath.section]) {
-    return [UIColor clearColor];
+    return UIColor.clearColor;
   }
+  // MDCCollectionView doesn't support dynamic colors, so they have to be
+  // resolved now.
+  // TODO(crbug.com/984928): Clean up once dynamic color support is added.
+#if defined(__IPHONE_13_0) && (__IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_13_0)
+  if (@available(iOS 13, *)) {
+    return [ntp_home::kNTPBackgroundColor()
+        resolvedColorWithTraitCollection:self.traitCollection];
+  }
+#endif
   return ntp_home::kNTPBackgroundColor();
 }
 

ios/chrome/browser/ui/ntp_tile_views/BUILD.gn

@@ -23,6 +23,7 @@ source_set("ntp_tile_views") {
     "resources:ntp_recent_icon",
     "//base",
     "//ios/chrome/browser/ui/util",
+    "//ios/chrome/common/colors",
     "//ios/chrome/common/favicon",
     "//ios/chrome/common/ui_util",
     "//ios/third_party/material_components_ios",

ios/chrome/browser/ui/ntp_tile_views/ntp_tile_view.mm

@@ -5,6 +5,7 @@
 #import "ios/chrome/browser/ui/ntp_tile_views/ntp_tile_view.h"
 
 #import "ios/chrome/browser/ui/util/dynamic_type_util.h"
+#import "ios/chrome/common/colors/UIColor+cr_semantic_colors.h"
 #import "ios/chrome/common/ui_util/constraints_ui_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -16,7 +17,6 @@ namespace {
 const NSInteger kLabelNumLines = 2;
 const CGFloat kSpaceIconTitle = 10;
 const CGFloat kIconSize = 56;
-const CGFloat kTitleAlpha = 0.54;
 const CGFloat kPreferredMaxWidth = 73;
 
 }  // namespace
@@ -27,7 +27,7 @@ const CGFloat kPreferredMaxWidth = 73;
   self = [super initWithFrame:frame];
   if (self) {
     _titleLabel = [[UILabel alloc] init];
-    _titleLabel.textColor = [UIColor colorWithWhite:0 alpha:kTitleAlpha];
+    _titleLabel.textColor = UIColor.cr_secondaryLabelColor;
     _titleLabel.font = [self titleLabelFont];
     _titleLabel.textAlignment = NSTextAlignmentCenter;
     _titleLabel.preferredMaxLayoutWidth = kPreferredMaxWidth;