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Tweaks/FLEX/Toolbar/FLEXExplorerToolbarItem.h

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+//
+//  FLEXExplorerToolbarItem.h
+//  Flipboard
+//
+//  Created by Ryan Olson on 4/4/14.
+//  Copyright (c) 2020 FLEX Team. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FLEXExplorerToolbarItem : UIButton
+
++ (instancetype)itemWithTitle:(NSString *)title image:(UIImage *)image;
+
+/// @param backupItem a toolbar item to use in place of this item when it becomes disabled.
+/// Items without a sibling item exhibit expected behavior when they become disabled, and are greyed out.
++ (instancetype)itemWithTitle:(NSString *)title image:(UIImage *)image sibling:(nullable FLEXExplorerToolbarItem *)backupItem;
+
+/// If a toolbar item has a sibling, the item will replace itself with its
+/// sibling when it becomes disabled, and vice versa when it becomes enabled again.
+@property (nonatomic, readonly) FLEXExplorerToolbarItem *sibling;
+
+/// When a toolbar item has a sibling and it becomes disabled, the sibling is the view
+/// that should be added to or removed from a new or existing toolbar. This property
+/// alleviates the programmer from determining whether to use \c item or \c item.sibling
+/// or \c item.sibling.sibling and so on. Yes, sibling items can also have siblings so
+/// that each item which becomes disabled may present another item in its place, creating
+/// a "stack" of toolbar items. This behavior is useful for making buttons which occupy
+/// the same space under different states.
+///
+/// With this in mind, you should never access a stored toolbar item's view properties
+/// such as \c frame or \c superview directly; you should access them on \c currentItem.
+/// If you are trying to modify the frame of an item, and the item itself is not currently
+/// displayed but instead its sibling is being displayed, then your changes could be ignored.
+///
+/// @return the result of the item's sibling's \c currentItem,
+/// if this item has a sibling and this item is disabled, otherwise this item.
+@property (nonatomic, readonly) FLEXExplorerToolbarItem *currentItem;
+
+@end
+
+NS_ASSUME_NONNULL_END