Upstream Chrome on iOS source code [9/11].

ios/chrome/browser/ui/tab_switcher/tab_switcher_header_view.h

+// Copyright 2015 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_TAB_SWITCHER_TAB_SWITCHER_HEADER_VIEW_H_
+#define IOS_CHROME_BROWSER_UI_TAB_SWITCHER_TAB_SWITCHER_HEADER_VIEW_H_
+
+#import <UIKit/UIKit.h>
+
+#include "base/ios/block_types.h"
+
+@class SessionCellData;
+@class TabSwitcherHeaderView;
+
+@protocol TabSwitcherHeaderViewDelegate<NSObject>
+
+- (void)tabSwitcherHeaderViewDismiss:(TabSwitcherHeaderView*)view;
+- (void)tabSwitcherHeaderViewDidSelectSessionAtIndex:(NSInteger)index;
+// Called to get the currently selected panel index. Returns NSNotFound when no
+// panel is selected.
+- (NSInteger)tabSwitcherHeaderViewSelectedPanelIndex;
+
+@end
+
+@protocol TabSwitcherHeaderViewDataSource<NSObject>
+
+- (NSInteger)tabSwitcherHeaderViewSessionCount;
+- (SessionCellData*)sessionCellDataAtIndex:(NSUInteger)index;
+
+@end
+
+@interface TabSwitcherHeaderView : UIView
+
+@property(nonatomic, assign) id<TabSwitcherHeaderViewDelegate> delegate;
+@property(nonatomic, assign) id<TabSwitcherHeaderViewDataSource> dataSource;
+@property(nonatomic, readonly) UIView* dismissButton;
+
+// Selects the item at the specified index.
+// The delegate is not called.
+- (void)selectItemAtIndex:(NSInteger)index;
+
+// Reload the collection view.
+- (void)reloadData;
+
+// Performs an update on the header view using the passed block.
+- (void)performUpdate:(void (^)(TabSwitcherHeaderView* headerView))updateBlock;
+
+// Performs an update on the header view using the passed block, the completion
+// handler block is called at the end of the update animations.
+- (void)performUpdate:(void (^)(TabSwitcherHeaderView* headerView))updateBlock
+           completion:(ProceduralBlock)completion;
+
+// Updates methods can only be called inside an update block passed to the
+// - (void)performUpdate: method.
+// Update methods takes arrays of NSNumbers.
+- (void)insertSessionsAtIndexes:(NSArray*)indexes;
+- (void)removeSessionsAtIndexes:(NSArray*)indexes;
+
+// Returns the accessibility title of the panel at index |index|.
+- (NSString*)panelTitleAtIndex:(NSInteger)index;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_TAB_SWITCHER_TAB_SWITCHER_HEADER_VIEW_H_