1// Copyright 2014 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#ifndef CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_OVERSCROLL_ANIMATOR_MAC_H_
6#define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_OVERSCROLL_ANIMATOR_MAC_H_
7
8#import <Cocoa/Cocoa.h>
9
10namespace content {
11class WebContentsImpl;
12
13// The direction of the overscroll animations. Backwards means that the user
14// wants to navigate backwards in the navigation history. The opposite applies
15// to forwards.
16enum OverscrollAnimatorDirection {
17  OVERSCROLL_ANIMATOR_DIRECTION_BACKWARDS,
18  OVERSCROLL_ANIMATOR_DIRECTION_FORWARDS,
19};
20}  // namespace content
21
22// NSViews that intend to manage the animation associated with an overscroll
23// must implement this protocol.
24@protocol WebContentsOverscrollAnimator
25// Some implementations require the WebContentsView to supply a snapshot of a
26// previous navigation state. This method determines whether the snapshot passed
27// to the overscroll animator is expected to be non-nil.
28- (BOOL)needsNavigationSnapshot;
29
30// Begin an overscroll animation. The method -needsNavigationSnapshot determines
31// whether |snapshot| can be nil.
32- (void)beginOverscrollInDirection:
33            (content::OverscrollAnimatorDirection)direction
34                navigationSnapshot:(NSImage*)snapshot;
35
36// Due to the nature of some of the overscroll animations, implementators of
37// this protocol must have control over the layout of the RenderWidgetHost's
38// NativeView. When there is no overscroll animation in progress, the
39// implementor must guarantee that the frame of the RenderWidgetHost's
40// NativeView in screen coordinates is the same as its own frame in screen
41// coordinates.
42// Due to the odd ownership cycles of the RenderWidgetHost's NativeView, it is
43// important that its presence in the NSView hierarchy is the only strong
44// reference, and that when it gets removed from the NSView hierarchy, it will
45// be dealloc'ed shortly thereafter.
46- (void)addRenderWidgetHostNativeView:(NSView*)view;
47
48// During an overscroll animation, |progress| ranges from 0 to 2, and indicates
49// how close the overscroll is to completing. If the overscroll ends with
50// |progress| >= 1, then the overscroll is considered completed.
51- (void)updateOverscrollProgress:(CGFloat)progress;
52
53// Animate the finish of the overscroll and perform a navigation. The navigation
54// may not happen synchronously, but is guaranteed to eventually occur.
55- (void)completeOverscroll:(content::WebContentsImpl*)webContents;
56
57// Animate the cancellation of the overscroll.
58- (void)cancelOverscroll;
59@end
60
61#endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_OVERSCROLL_ANIMATOR_MAC_H_
62