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

ios/chrome/browser/ui/reading_list/reading_list_side_swipe_provider.mm

Index: ios/chrome/browser/ui/reading_list/reading_list_side_swipe_provider.mm
diff --git a/ios/chrome/browser/ui/reading_list/reading_list_side_swipe_provider.mm b/ios/chrome/browser/ui/reading_list/reading_list_side_swipe_provider.mm
new file mode 100644
index 0000000000000000000000000000000000000000..f3273a75499fee2ec29948d71d74026ce1b2a949
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+++ b/ios/chrome/browser/ui/reading_list/reading_list_side_swipe_provider.mm
@@ -0,0 +1,73 @@
+// 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/reading_list/reading_list_side_swipe_provider.h"
+
+#include "base/logging.h"
+#include "components/reading_list/ios/reading_list_entry.h"
+#include "components/reading_list/ios/reading_list_model.h"
+#include "ios/chrome/browser/reading_list/reading_list_entry_loading_util.h"
+#include "ios/web/public/web_state/web_state.h"
+#include "url/gurl.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+class ReadingListObserverBridge;
+
+@interface ReadingListSideSwipeProvider () {
+  // Keep a reference to detach before deallocing.
+  ReadingListModel* _readingListModel;  // weak
+}
+
+@end
+
+@implementation ReadingListSideSwipeProvider
+- (instancetype)initWithReadingList:(ReadingListModel*)readingListModel {
+  if (self = [super init]) {
+    _readingListModel = readingListModel;
+  }
+  return self;
+}
+
+- (BOOL)canGoBack {
+  return NO;
+}
+
+- (void)goBack:(web::WebState*)webState {
+  NOTREACHED();
+}
+
+- (BOOL)canGoForward {
+  return _readingListModel->unread_size() > 0;
+}
+
+- (UIImage*)paneIcon {
+  return [UIImage imageNamed:@"reading_list_side_swipe"];
+}
+
+- (BOOL)rotateForwardIcon {
+  return NO;
+}
+
+- (void)goForward:(web::WebState*)webState {
+  if (!webState || _readingListModel->unread_size() == 0) {
+    return;
+  }
+  int64_t updatetime = 0;
+  const ReadingListEntry* first_entry = nullptr;
+  for (const auto& url : _readingListModel->Keys()) {
+    const ReadingListEntry* entry = _readingListModel->GetEntryByURL(url);
+    if (!entry->IsRead() && entry->UpdateTime() > updatetime) {
+      updatetime = entry->UpdateTime();
+      first_entry = entry;
+    }
+  }
+  DCHECK_GT(updatetime, 0);
+  DCHECK_NE(first_entry, nullptr);
+  reading_list::LoadReadingListEntry(*first_entry, _readingListModel, webState);
+}
+
+@end