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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_ACCESSIBILITY_AX_SELECTION_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_ACCESSIBILITY_AX_SELECTION_H_
#include <stdint.h>
#include <optional>
#include <ostream>
#include "base/dcheck_is_on.h"
#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/editing/forward.h"
#include "third_party/blink/renderer/core/html/forms/text_control_element.h"
#include "third_party/blink/renderer/modules/accessibility/ax_object_cache_impl.h"
#include "third_party/blink/renderer/modules/accessibility/ax_position.h"
#include "third_party/blink/renderer/modules/modules_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace blink {
// If the |AXSelection| is defined by endpoints that are present in the
// accessibility tree but not in the DOM tree, determines whether setting the
// selection will shrink or extend the |AXSelection| to encompass endpoints that
// are in the DOM.
// Conversely, if a DOM selection is converted to an |AXSelection| via the
// |FromSelection| method, but the endpoints of the DOM selection are not
// present in the accessibility tree, e.g. they are aria-hidden, determines
// whether the conversion will shrink or extend the DOM selection to encompass
// endpoints that are in the accessibility tree.
enum class AXSelectionBehavior { kShrinkToValidRange, kExtendToValidRange };
class MODULES_EXPORT AXSelection final {
DISALLOW_NEW();
public:
class Builder;
static void ClearCurrentSelection(Document&);
// These constructors will use the default AXObjectCache for the
// document unless a different one is passed in.
static AXSelection FromCurrentSelection(
const Document&,
const AXObjectCacheImpl& ax_object_cache,
const AXSelectionBehavior = AXSelectionBehavior::kExtendToValidRange);
static AXSelection FromCurrentSelection(
const TextControlElement&,
const AXObjectCacheImpl& ax_object_cache);
static AXSelection FromSelection(
const SelectionInDOMTree&,
const AXObjectCacheImpl& ax_object_cache,
const AXSelectionBehavior = AXSelectionBehavior::kExtendToValidRange);
AXSelection(const AXSelection&) = default;
AXSelection& operator=(const AXSelection&) = default;
~AXSelection() = default;
const AXPosition Anchor() const { return anchor_; }
const AXPosition Focus() const { return focus_; }
// The selection is invalid if either the anchor or the focus position is
// invalid, or if the positions are in two separate documents.
bool IsValid() const;
operator bool() const { return IsValid(); }
const SelectionInDOMTree AsSelection(
const AXSelectionBehavior =
AXSelectionBehavior::kExtendToValidRange) const;
// Tries to set the DOM selection to this. Returns |false| if the selection
// has been cancelled via the "selectionstart" event or if the selection could
// not be set for any other reason.
bool Select(
const AXSelectionBehavior = AXSelectionBehavior::kExtendToValidRange);
// Returns a string representation of this object.
String ToString() const;
private:
// Holds the endpoints of a selection that affects the value of a text
// control, i.e. that is inside its shadow tree.
struct TextControlSelection final {
TextControlSelection(int start,
int end,
TextFieldSelectionDirection direction)
: start(start), end(end), direction(direction) {}
TextControlSelection()
: start(-1), end(-1), direction(kSelectionHasNoDirection) {}
int start;
int end;
TextFieldSelectionDirection direction;
};
AXSelection();
// If a layout is pending, update the style and layout along with the DOM
// tree and style versions of the AXSelection and associated AXPositions.
void UpdateSelectionIfNecessary();
// Determines whether this selection is targeted to the contents of a text
// field, and returns the start and end text offsets, as well as its
// direction. |start| should always be less than equal to |end|.
std::optional<TextControlSelection> AsTextControlSelection() const;
// The |AXPosition| where the selection starts.
AXPosition anchor_;
// The |AXPosition| where the selection ends.
AXPosition focus_;
#if DCHECK_IS_ON()
// TODO(accessibility): Use layout tree version in place of DOM and style
// versions.
uint64_t dom_tree_version_;
uint64_t style_version_;
#endif
friend class Builder;
};
class MODULES_EXPORT AXSelection::Builder final {
STACK_ALLOCATED();
public:
Builder(const AXObjectCacheImpl& ax_object_cache)
: ax_object_cache_(ax_object_cache) {}
~Builder() = default;
Builder& SetAnchor(const AXPosition&);
Builder& SetAnchor(const Position&);
Builder& SetFocus(const AXPosition&);
Builder& SetFocus(const Position&);
Builder& SetSelection(const SelectionInDOMTree&);
const AXSelection Build();
private:
AXSelection selection_;
const AXObjectCacheImpl& ax_object_cache_;
};
MODULES_EXPORT bool operator==(const AXSelection&, const AXSelection&);
MODULES_EXPORT bool operator!=(const AXSelection&, const AXSelection&);
MODULES_EXPORT std::ostream& operator<<(std::ostream&, const AXSelection&);
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_MODULES_ACCESSIBILITY_AX_SELECTION_H_
|
