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
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
// Copyright 2017 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 COMPONENTS_EXO_DATA_SOURCE_H_
#define COMPONENTS_EXO_DATA_SOURCE_H_
#include <string>
#include "base/callback.h"
#include "base/containers/flat_set.h"
#include "base/macros.h"
#include "base/observer_list.h"
namespace exo {
class DataSourceDelegate;
class DataSourceObserver;
enum class DndAction;
// Object representing transferred data offered by a client.
class DataSource {
public:
explicit DataSource(DataSourceDelegate* delegate);
~DataSource();
void AddObserver(DataSourceObserver* observer);
void RemoveObserver(DataSourceObserver* observer);
// Notifies to DataSource that the client offers new mime type.
void Offer(const std::string& mime_type);
// Notifies the possible drag and drop actions selected by the data source to
// DataSource.
void SetActions(const base::flat_set<DndAction>& dnd_actions);
// Notifies the data source is cancelled. e.g. Replaced with another data
// source.
void Cancelled();
// Search the set of offered MIME types for the most preferred of each of the
// following categories: text/plain*, text/rtf, text/html*, image/*. If any
// usable MIME types in a given category are available, the corresponding
// |*_reader| input callback will be called with the best one and the
// corresponding data. For any category that has no available MIME types,
// |failure_callback| is run. |failure_callback| may therefore be run as many
// as four times.
using ReadDataCallback =
base::OnceCallback<void(const std::string&, const std::vector<uint8_t>&)>;
void GetDataForPreferredMimeTypes(ReadDataCallback text_reader,
ReadDataCallback rtf_reader,
ReadDataCallback html_reader,
ReadDataCallback image_reader,
base::RepeatingClosure failure_callback);
void ReadDataForTesting(const std::string& mime_type,
ReadDataCallback callback);
private:
// Reads data from the source. Then |callback| is invoked with read data. If
// Cancelled() is invoked or DataSource is destroyed before completion,
// |callback| is never called, and |failure_callback| is run instead.
void ReadData(const std::string& mime_type,
ReadDataCallback callback,
base::OnceClosure failure_callback);
void OnDataRead(ReadDataCallback callback,
const std::string& mime_type,
const std::vector<uint8_t>&);
DataSourceDelegate* const delegate_;
base::ObserverList<DataSourceObserver>::Unchecked observers_;
// Mime types which has been offered.
std::set<std::string> mime_types_;
bool cancelled_;
base::WeakPtrFactory<DataSource> read_data_weak_ptr_factory_;
DISALLOW_COPY_AND_ASSIGN(DataSource);
};
class ScopedDataSource {
public:
ScopedDataSource(DataSource* data_source, DataSourceObserver* observer);
~ScopedDataSource();
DataSource* get() { return data_source_; }
private:
DataSource* const data_source_;
DataSourceObserver* const observer_;
DISALLOW_COPY_AND_ASSIGN(ScopedDataSource);
};
} // namespace exo
#endif // COMPONENTS_EXO_DATA_SOURCE_H_
|
