Upstream Chrome on iOS source code [7/11].

ios/chrome/browser/ui/settings/cells/account_signin_item.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/chrome/browser/ui/settings/cells/account_signin_item.h"
+
+#include "ios/chrome/grit/ios_chromium_strings.h"
+#include "ios/chrome/grit/ios_strings.h"
+#import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
+#import "ios/third_party/material_roboto_font_loader_ios/src/src/MaterialRobotoFontLoader.h"
+#include "ui/base/l10n/l10n_util.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+// Padding used on the leading and trailing edges of the cell.
+const CGFloat kHorizontalPadding = 16;
+
+// Padding used between the image and text.
+const CGFloat kHorizontalPaddingBetweenImageAndText = 10;
+
+// Image fixed horizontal size.
+const CGFloat kHorizontalImageFixedSize = 40;
+}
+
+@implementation AccountSignInItem
+
+@synthesize image = _image;
+
+- (instancetype)initWithType:(NSInteger)type {
+  self = [super initWithType:type];
+  if (self) {
+    self.cellClass = [AccountSignInCell class];
+    self.accessibilityTraits |= UIAccessibilityTraitButton;
+  }
+  return self;
+}
+
+#pragma mark - CollectionViewItem
+
+- (void)configureCell:(AccountSignInCell*)cell {
+  [super configureCell:cell];
+  cell.textLabel.text =
+      l10n_util::GetNSString(IDS_IOS_SIGN_IN_TO_CHROME_SETTING_TITLE);
+  cell.detailTextLabel.text =
+      l10n_util::GetNSString(IDS_IOS_SIGN_IN_TO_CHROME_SETTING_SUBTITLE);
+  cell.imageView.image = self.image;
+}
+
+@end
+
+@implementation AccountSignInCell
+
+@synthesize textLabel = _textLabel;
+@synthesize detailTextLabel = _detailTextLabel;
+@synthesize imageView = _imageView;
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  self = [super initWithFrame:frame];
+  if (self) {
+    self.isAccessibilityElement = YES;
+    [self addSubviews];
+    [self setDefaultViewStyling];
+    [self setViewConstraints];
+  }
+  return self;
+}
+
+// Create and add subviews.
+- (void)addSubviews {
+  UIView* contentView = self.contentView;
+  contentView.clipsToBounds = YES;
+
+  _imageView = [[UIImageView alloc] init];
+  _imageView.translatesAutoresizingMaskIntoConstraints = NO;
+  [contentView addSubview:_imageView];
+
+  _textLabel = [[UILabel alloc] init];
+  _textLabel.translatesAutoresizingMaskIntoConstraints = NO;
+  [contentView addSubview:_textLabel];
+
+  _detailTextLabel = [[UILabel alloc] init];
+  _detailTextLabel.translatesAutoresizingMaskIntoConstraints = NO;
+  [_detailTextLabel setNumberOfLines:3];
+  [contentView addSubview:_detailTextLabel];
+}
+
+- (void)setDefaultViewStyling {
+  _imageView.contentMode = UIViewContentModeCenter;
+  _imageView.layer.masksToBounds = YES;
+  _imageView.contentMode = UIViewContentModeScaleAspectFit;
+  _textLabel.font = [[MDFRobotoFontLoader sharedInstance] mediumFontOfSize:14];
+  _textLabel.textColor = [[MDCPalette greyPalette] tint900];
+  _detailTextLabel.font =
+      [[MDFRobotoFontLoader sharedInstance] regularFontOfSize:14];
+  _detailTextLabel.textColor = [[MDCPalette greyPalette] tint500];
+}
+
+- (void)setViewConstraints {
+  UIView* contentView = self.contentView;
+
+  // This view is used to center the two leading textLabels.
+  UIView* verticalCenteringView = [[UIView alloc] init];
+  verticalCenteringView.translatesAutoresizingMaskIntoConstraints = NO;
+  [contentView addSubview:verticalCenteringView];
+
+  [NSLayoutConstraint activateConstraints:@[
+    // Set leading anchors.
+    [_imageView.leadingAnchor constraintEqualToAnchor:contentView.leadingAnchor
+                                             constant:kHorizontalPadding],
+    [_detailTextLabel.leadingAnchor
+        constraintEqualToAnchor:_textLabel.leadingAnchor],
+    [_textLabel.leadingAnchor
+        constraintEqualToAnchor:_imageView.trailingAnchor
+                       constant:kHorizontalPaddingBetweenImageAndText],
+
+    // Fix image widths.
+    [_imageView.widthAnchor
+        constraintEqualToConstant:kHorizontalImageFixedSize],
+
+    // Set vertical anchors. This approach assumes the cell height is set by
+    // the view controller. Contents are pinned to centerY, rather than pushing
+    // against the top/bottom boundaries.
+    [_imageView.centerYAnchor
+        constraintEqualToAnchor:contentView.centerYAnchor],
+    [_textLabel.topAnchor
+        constraintEqualToAnchor:verticalCenteringView.topAnchor],
+    [_textLabel.bottomAnchor
+        constraintEqualToAnchor:_detailTextLabel.topAnchor],
+    [_detailTextLabel.bottomAnchor
+        constraintEqualToAnchor:verticalCenteringView.bottomAnchor],
+    [verticalCenteringView.centerYAnchor
+        constraintEqualToAnchor:contentView.centerYAnchor],
+    // Set trailing anchors.
+    [_detailTextLabel.trailingAnchor
+        constraintEqualToAnchor:contentView.trailingAnchor
+                       constant:-kHorizontalPadding],
+    [_textLabel.trailingAnchor
+        constraintLessThanOrEqualToAnchor:contentView.trailingAnchor
+                                 constant:-kHorizontalPadding],
+  ]];
+
+  // This is needed so the image doesn't get pushed out if both text and detail
+  // are long.
+  [_textLabel
+      setContentCompressionResistancePriority:UILayoutPriorityDefaultLow
+                                      forAxis:UILayoutConstraintAxisHorizontal];
+  [_detailTextLabel
+      setContentCompressionResistancePriority:UILayoutPriorityDefaultLow
+                                      forAxis:UILayoutConstraintAxisHorizontal];
+}
+
+#pragma mark - UICollectionReusableView
+
+- (void)prepareForReuse {
+  [super prepareForReuse];
+  _imageView.image = nil;
+  self.textLabel.text = nil;
+  self.detailTextLabel.text = nil;
+}
+
+#pragma mark - NSObject(Accessibility)
+
+- (NSString*)accessibilityLabel {
+  return l10n_util::GetNSString(IDS_IOS_SIGN_IN_TO_CHROME_SETTING_TITLE);
+}
+
+- (NSString*)accessibilityValue {
+  return [NSString stringWithFormat:@"%@, %@", self.textLabel.text,
+                                    self.detailTextLabel.text];
+}
+
+@end