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keyboard_key_channel_handler.cc
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1 // Copyright 2013 The Flutter 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 #include "flutter/shell/platform/windows/keyboard_key_channel_handler.h"
6
7 #include <windows.h>
8
9 #include "flutter/fml/logging.h"
10 #include "flutter/shell/platform/common/json_message_codec.h"
11 #include "flutter/shell/platform/windows/keyboard_utils.h"
12
13 namespace flutter {
14
15 namespace {
16
17 static constexpr char kChannelName[] = "flutter/keyevent";
18
19 static constexpr char kKeyCodeKey[] = "keyCode";
20 static constexpr char kScanCodeKey[] = "scanCode";
21 static constexpr char kCharacterCodePointKey[] = "characterCodePoint";
22 static constexpr char kModifiersKey[] = "modifiers";
23 static constexpr char kKeyMapKey[] = "keymap";
24 static constexpr char kTypeKey[] = "type";
25 static constexpr char kHandledKey[] = "handled";
26
27 static constexpr char kWindowsKeyMap[] = "windows";
28 static constexpr char kKeyUp[] = "keyup";
29 static constexpr char kKeyDown[] = "keydown";
30
31 // The maximum number of pending events to keep before
32 // emitting a warning on the console about unhandled events.
33 static constexpr int kMaxPendingEvents = 1000;
34
35 // The bit for a scancode indicating the key is extended.
36 //
37 // Win32 defines some keys to be "extended", such as ShiftRight, which shares
38 // the same scancode as its non-extended counterpart, such as ShiftLeft. In
39 // Chromium's scancode table, from which Flutter's physical key list is
40 // derived, these keys are marked with this bit. See
41 // https://chromium.googlesource.com/codesearch/chromium/src/+/refs/heads/main/ui/events/keycodes/dom/dom_code_data.inc
42 static constexpr int kScancodeExtended = 0xe000;
43
44 // Re-definition of the modifiers for compatibility with the Flutter framework.
45 // These have to be in sync with the framework's RawKeyEventDataWindows
46 // modifiers definition.
47 // https://github.com/flutter/flutter/blob/19ff596979e407c484a32f4071420fca4f4c885f/packages/flutter/lib/src/services/raw_keyboard_windows.dart#L203
48 static constexpr int kShift = 1 << 0;
49 static constexpr int kShiftLeft = 1 << 1;
50 static constexpr int kShiftRight = 1 << 2;
51 static constexpr int kControl = 1 << 3;
52 static constexpr int kControlLeft = 1 << 4;
53 static constexpr int kControlRight = 1 << 5;
54 static constexpr int kAlt = 1 << 6;
55 static constexpr int kAltLeft = 1 << 7;
56 static constexpr int kAltRight = 1 << 8;
57 static constexpr int kWinLeft = 1 << 9;
58 static constexpr int kWinRight = 1 << 10;
59 static constexpr int kCapsLock = 1 << 11;
60 static constexpr int kNumLock = 1 << 12;
61 static constexpr int kScrollLock = 1 << 13;
62
63 /// Calls GetKeyState() an all modifier keys and packs the result in an int,
64 /// with the re-defined values declared above for compatibility with the Flutter
65 /// framework.
66 int GetModsForKeyState() {
67 int mods = 0;
68
69 if (GetKeyState(VK_SHIFT) < 0)
70 mods |= kShift;
71 if (GetKeyState(VK_LSHIFT) < 0)
72 mods |= kShiftLeft;
73 if (GetKeyState(VK_RSHIFT) < 0)
74 mods |= kShiftRight;
75 if (GetKeyState(VK_CONTROL) < 0)
76 mods |= kControl;
77 if (GetKeyState(VK_LCONTROL) < 0)
78 mods |= kControlLeft;
79 if (GetKeyState(VK_RCONTROL) < 0)
80 mods |= kControlRight;
81 if (GetKeyState(VK_MENU) < 0)
82 mods |= kAlt;
83 if (GetKeyState(VK_LMENU) < 0)
84 mods |= kAltLeft;
85 if (GetKeyState(VK_RMENU) < 0)
86 mods |= kAltRight;
87 if (GetKeyState(VK_LWIN) < 0)
88 mods |= kWinLeft;
89 if (GetKeyState(VK_RWIN) < 0)
90 mods |= kWinRight;
91 if (GetKeyState(VK_CAPITAL) < 0)
92 mods |= kCapsLock;
93 if (GetKeyState(VK_NUMLOCK) < 0)
94 mods |= kNumLock;
95 if (GetKeyState(VK_SCROLL) < 0)
96 mods |= kScrollLock;
97 return mods;
98 }
99
100 } // namespace
101
102 KeyboardKeyChannelHandler::KeyboardKeyChannelHandler(
103 flutter::BinaryMessenger* messenger)
104 : channel_(
105 std::make_unique<flutter::BasicMessageChannel<rapidjson::Document>>(
106 messenger,
107 kChannelName,
108 &flutter::JsonMessageCodec::GetInstance())) {}
109
110 KeyboardKeyChannelHandler::~KeyboardKeyChannelHandler() = default;
111
112 void KeyboardKeyChannelHandler::SyncModifiersIfNeeded(int modifiers_state) {
113 // Do nothing.
114 }
115
116 std::map<uint64_t, uint64_t> KeyboardKeyChannelHandler::GetPressedState() {
117 // Returns an empty state because it will never be called.
118 // KeyboardKeyEmbedderHandler is the only KeyboardKeyHandlerDelegate to handle
119 // GetPressedState() calls.
120 std::map<uint64_t, uint64_t> empty_state;
121 return empty_state;
122 }
123
124 void KeyboardKeyChannelHandler::KeyboardHook(
125 int key,
126 int scancode,
127 int action,
128 char32_t character,
129 bool extended,
130 bool was_down,
131 std::function<void(bool)> callback) {
132 // TODO: Translate to a cross-platform key code system rather than passing
133 // the native key code.
134 rapidjson::Document event(rapidjson::kObjectType);
135 auto& allocator = event.GetAllocator();
136 event.AddMember(kKeyCodeKey, key, allocator);
137 event.AddMember(kScanCodeKey, scancode | (extended ? kScancodeExtended : 0),
138 allocator);
139 event.AddMember(kCharacterCodePointKey, UndeadChar(character), allocator);
140 event.AddMember(kKeyMapKey, kWindowsKeyMap, allocator);
141 event.AddMember(kModifiersKey, GetModsForKeyState(), allocator);
142
143 switch (action) {
144 case WM_SYSKEYDOWN:
145 case WM_KEYDOWN:
146 event.AddMember(kTypeKey, kKeyDown, allocator);
147 break;
148 case WM_SYSKEYUP:
149 case WM_KEYUP:
150 event.AddMember(kTypeKey, kKeyUp, allocator);
151 break;
152 default:
153 FML_LOG(WARNING) << "Unknown key event action: " << action;
154 callback(false);
155 return;
156 }
157 channel_->Send(event, [callback = std::move(callback)](const uint8_t* reply,
158 size_t reply_size) {
159 auto decoded = flutter::JsonMessageCodec::GetInstance().DecodeMessage(
160 reply, reply_size);
161 bool handled = decoded ? (*decoded)[kHandledKey].GetBool() : false;
162 callback(handled);
163 });
164 }
165
166 } // namespace flutter
flutter::BasicMessageChannel
Definition: basic_message_channel.h:56
flutter::BinaryMessenger
Definition: binary_messenger.h:29
flutter::JsonMessageCodec
Definition: json_message_codec.h:16
flutter::JsonMessageCodec::GetInstance
static const JsonMessageCodec & GetInstance()
Definition: json_message_codec.cc:17
flutter::KeyboardKeyChannelHandler::~KeyboardKeyChannelHandler
~KeyboardKeyChannelHandler()
flutter::KeyboardKeyChannelHandler::KeyboardHook
void KeyboardHook(int key, int scancode, int action, char32_t character, bool extended, bool was_down, std::function< void(bool)> callback)
Definition: keyboard_key_channel_handler.cc:124
flutter::KeyboardKeyChannelHandler::SyncModifiersIfNeeded
void SyncModifiersIfNeeded(int modifiers_state)
Definition: keyboard_key_channel_handler.cc:112
flutter::KeyboardKeyChannelHandler::KeyboardKeyChannelHandler
KeyboardKeyChannelHandler(flutter::BinaryMessenger *messenger)
Definition: keyboard_key_channel_handler.cc:102
flutter::KeyboardKeyChannelHandler::GetPressedState
std::map< uint64_t, uint64_t > GetPressedState()
Definition: keyboard_key_channel_handler.cc:116
flutter::MessageCodec::DecodeMessage
std::unique_ptr< T > DecodeMessage(const uint8_t *binary_message, const size_t message_size) const
Definition: message_codec.h:29
kChannelName
static constexpr char kChannelName[]
Definition: cursor_handler.cc:12
callback
FlutterDesktopBinaryReply callback
Definition: flutter_windows_view_unittests.cc:52
json_message_codec.h
keyboard_key_channel_handler.h
extended
bool extended
Definition: keyboard_key_handler_unittests.cc:118
key
int key
Definition: keyboard_key_handler_unittests.cc:114
character
char32_t character
Definition: keyboard_key_handler_unittests.cc:117
action
int action
Definition: keyboard_key_handler_unittests.cc:116
scancode
int scancode
Definition: keyboard_key_handler_unittests.cc:115
was_down
bool was_down
Definition: keyboard_key_handler_unittests.cc:119
keyboard_utils.h
flutter
Definition: accessibility_bridge_windows.cc:11
flutter::kShift
constexpr int kShift
Definition: keyboard_utils.h:14
flutter::kControl
constexpr int kControl
Definition: keyboard_utils.h:15
flutter::UndeadChar
uint32_t UndeadChar(uint32_t ch)
Definition: keyboard_utils.h:34