1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#import <Cocoa/Cocoa.h>
6
7#include "base/mac/scoped_nsobject.h"
8#import "chrome/browser/ui/cocoa/bookmarks/bookmark_button.h"
9
10// Hover state machine.  Encapsulates the hover state for
11// BookmarkBarFolderController.
12// A strict call order is implied with these calls.  It is ONLY valid to make
13// the following state transitions:
14// From:            To:               Via:
15// closed           opening           scheduleOpen...:
16// opening          closed            cancelPendingOpen...: or
17//                  open              scheduleOpen...: completes.
18// open             closing           scheduleClose...:
19// closing          open              cancelPendingClose...: or
20//                  closed            scheduleClose...: completes.
21//
22@interface BookmarkBarFolderHoverState : NSObject {
23 @private
24  // Enumeration of the valid states that the |hoverButton_| member can be in.
25  // Because the opening and closing of hover views can be done asyncronously
26  // there are periods where the hover state is in transtion between open and
27  // closed.  During those times of transition the opening or closing operation
28  // can be cancelled.  We serialize the opening and closing of the
29  // |hoverButton_| using this state information.  This serialization is to
30  // avoid race conditions where one hover button is being opened while another
31  // is closing.
32  enum HoverState {
33    kHoverStateClosed = 0,
34    kHoverStateOpening = 1,
35    kHoverStateOpen = 2,
36    kHoverStateClosing = 3
37  };
38
39  // Like normal menus, hovering over a folder button causes it to
40  // open.  This variable is set when a hover is initiated (but has
41  // not necessarily fired yet).
42  base::scoped_nsobject<BookmarkButton> hoverButton_;
43
44  // We model hover state as a state machine with specific allowable
45  // transitions.  |hoverState_| is the state of this machine at any
46  // given time.
47  HoverState hoverState_;
48}
49
50// Designated initializer.
51- (id)init;
52
53// The BookmarkBarFolderHoverState decides when it is appropriate to hide
54// and show the button that the BookmarkBarFolderController drags over.
55- (NSDragOperation)draggingEnteredButton:(BookmarkButton*)button;
56
57// The BookmarkBarFolderHoverState decides the fate of the hover button
58// when the BookmarkBarFolderController's view is exited.
59- (void)draggingExited;
60
61@end
62
63// Exposing these for unit testing purposes.  They are used privately in the
64// implementation as well.
65@interface BookmarkBarFolderHoverState(PrivateAPI)
66// State change APIs.
67- (void)scheduleCloseBookmarkFolderOnHoverButton;
68- (void)cancelPendingCloseBookmarkFolderOnHoverButton;
69- (void)scheduleOpenBookmarkFolderOnHoverButton:(BookmarkButton*)hoverButton;
70- (void)cancelPendingOpenBookmarkFolderOnHoverButton;
71@end
72
73// Exposing these for unit testing purposes.  They are used only in tests.
74@interface BookmarkBarFolderHoverState(TestingAPI)
75// Accessors and setters for button and hover state.
76- (BookmarkButton*)hoverButton;
77- (HoverState)hoverState;
78@end
79