Add a footer item for the Content Suggestions

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

+// 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/chrome/browser/ui/content_suggestions/content_suggestions_footer_item.h"
+
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+const CGFloat kMinimalCellHeight = 44;
+}
+
+#pragma mark - ContentSuggestionsFooterItem
+
+@interface ContentSuggestionsFooterItem ()
+
+@property(nonatomic, copy) NSString* title;
+@property(nonatomic, copy) ProceduralBlock block;
+
+@end
+
+@implementation ContentSuggestionsFooterItem
+
+@synthesize title = _title;
+@synthesize block = _block;
+@synthesize suggestionIdentifier = _suggestionIdentifier;
+
+- (instancetype)initWithType:(NSInteger)type
+                       title:(NSString*)title
+                       block:(ProceduralBlock)block {
+  self = [super initWithType:type];
+  if (self) {
+    self.cellClass = [ContentSuggestionsFooterCell class];
+    _title = [title copy];
+    _block = [block copy];
+  }
+  return self;
+}
+
+- (void)configureCell:(ContentSuggestionsFooterCell*)cell {
+  [super configureCell:cell];
+  [cell.button setTitle:self.title forState:UIControlStateNormal];
+  [cell.button addTarget:self
+                  action:@selector(executeBlock)
+        forControlEvents:UIControlEventTouchUpInside];
+}
+
+#pragma mark - Private
+
+// Executes the |_block| if not nil.
+- (void)executeBlock {
+  if (self.block) {
+    self.block();
+  }
+}
+
+@end
+
+#pragma mark - ContentSuggestionsFooterCell
+
+@implementation ContentSuggestionsFooterCell
+
+@synthesize button = _button;
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  self = [super initWithFrame:frame];
+  if (self) {
+    _button = [UIButton buttonWithType:UIButtonTypeSystem];
+    _button.translatesAutoresizingMaskIntoConstraints = NO;
+    [self.contentView addSubview:_button];
+    [_button.heightAnchor
+        constraintGreaterThanOrEqualToConstant:kMinimalCellHeight]
+        .active = YES;
+    AddSameSizeConstraint(self.contentView, _button);
+  }
+  return self;
+}
+
+- (void)prepareForReuse {
+  [self.button removeTarget:nil
+                     action:NULL
+           forControlEvents:UIControlEventAllEvents];
+}
+
+@end