blob: 66f9ad4b45ab601a55424d3bd37892992250d7b7 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
// Copyright 2013 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 CC_INPUT_LAYER_SCROLL_OFFSET_DELEGATE_H_
#define CC_INPUT_LAYER_SCROLL_OFFSET_DELEGATE_H_
#include "base/basictypes.h"
#include "ui/gfx/size_f.h"
#include "ui/gfx/vector2d_f.h"
namespace cc {
// The LayerScrollOffsetDelegate allows for the embedder to take ownership of
// the scroll offset of the root layer.
//
// The LayerScrollOffsetDelegate is only used on the impl thread.
class LayerScrollOffsetDelegate {
public:
// This is called by the compositor to notify the delegate what is the upper
// total scroll offset bound.
virtual void SetMaxScrollOffset(gfx::Vector2dF max_scroll_offset) = 0;
// This is called by the compositor when the scroll offset of the layer would
// have otherwise changed.
virtual void SetTotalScrollOffset(gfx::Vector2dF new_value) = 0;
// This is called by the compositor to query the current scroll offset of the
// layer.
// There is no requirement that the return values of this method are
// stable in time (two subsequent calls may yield different results).
// The return value is not required to be related to the values passed in to
// the SetTotalScrollOffset method in any way however it is required to be no
// more than the value passed to the most recent SetMaxScrollOffset call.
virtual gfx::Vector2dF GetTotalScrollOffset() = 0;
// This is called by the compositor to notify the delegate what is the current
// page scale factor is.
virtual void SetPageScaleFactor(float page_scale_factor) = 0;
// This is called by the compositor to notify the delegate what is the layer's
// scrollable size is.
virtual void SetScrollableSize(gfx::SizeF scrollable_size) = 0;
protected:
LayerScrollOffsetDelegate() {}
virtual ~LayerScrollOffsetDelegate() {}
private:
DISALLOW_COPY_AND_ASSIGN(LayerScrollOffsetDelegate);
};
} // namespace cc
#endif // CC_INPUT_LAYER_SCROLL_OFFSET_DELEGATE_H_
|
