🎨 Optimize hotkey service

internal/common/hotkey/hotkey_windows.go

@@ -0,0 +1,224 @@
+// Copyright 2021 The golang.design Initiative Authors.
+// All rights reserved. Use of this source code is governed
+// by a MIT license that can be found in the LICENSE file.
+//
+// Written by Changkun Ou <changkun.de>
+
+//go:build windows
+
+package hotkey
+
+import (
+	"errors"
+	"runtime"
+	"sync"
+	"sync/atomic"
+	"time"
+	"voidraft/internal/common/hotkey/internal/win"
+)
+
+type platformHotkey struct {
+	mu         sync.Mutex
+	hotkeyId   uint64
+	registered bool
+	funcs      chan func()
+	canceled   chan struct{}
+}
+
+var hotkeyId uint64 // atomic
+
+// register registers a system hotkey. It returns an error if
+// the registration is failed. This could be that the hotkey is
+// conflict with other hotkeys.
+func (hk *Hotkey) register() error {
+	hk.mu.Lock()
+	if hk.registered {
+		hk.mu.Unlock()
+		return errors.New("hotkey already registered")
+	}
+
+	mod := uint8(0)
+	for _, m := range hk.mods {
+		mod = mod | uint8(m)
+	}
+
+	hk.hotkeyId = atomic.AddUint64(&hotkeyId, 1)
+	hk.funcs = make(chan func())
+	hk.canceled = make(chan struct{})
+	go hk.handle()
+
+	var (
+		ok   bool
+		err  error
+		done = make(chan struct{})
+	)
+	hk.funcs <- func() {
+		ok, err = win.RegisterHotKey(0, uintptr(hk.hotkeyId), uintptr(mod), uintptr(hk.key))
+		done <- struct{}{}
+	}
+	<-done
+	if !ok {
+		close(hk.canceled)
+		hk.mu.Unlock()
+		return err
+	}
+	hk.registered = true
+	hk.mu.Unlock()
+	return nil
+}
+
+// unregister deregisteres a system hotkey.
+func (hk *Hotkey) unregister() error {
+	hk.mu.Lock()
+	defer hk.mu.Unlock()
+	if !hk.registered {
+		return errors.New("hotkey is not registered")
+	}
+
+	done := make(chan struct{})
+	hk.funcs <- func() {
+		win.UnregisterHotKey(0, uintptr(hk.hotkeyId))
+		done <- struct{}{}
+		close(hk.canceled)
+	}
+	<-done
+
+	<-hk.canceled
+	hk.registered = false
+	return nil
+}
+
+const (
+	// wmHotkey represents hotkey message
+	wmHotkey uint32 = 0x0312
+	wmQuit   uint32 = 0x0012
+)
+
+// handle handles the hotkey event loop.
+func (hk *Hotkey) handle() {
+	// We could optimize this. So far each hotkey is served in an
+	// individual thread. If we have too many hotkeys, then a program
+	// have to create too many threads to serve them.
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	isKeyDown := false
+	tk := time.NewTicker(time.Second / 100)
+	for range tk.C {
+		msg := win.MSG{}
+		if !win.PeekMessage(&msg, 0, 0, 0) {
+			select {
+			case f := <-hk.funcs:
+				f()
+			case <-hk.canceled:
+				return
+			default:
+				// If the latest status is KeyDown, and AsyncKeyState is 0, consider key is up.
+				if win.GetAsyncKeyState(int(hk.key)) == 0 && isKeyDown {
+					hk.keyupIn <- Event{}
+					isKeyDown = false
+				}
+			}
+			continue
+		}
+		if !win.GetMessage(&msg, 0, 0, 0) {
+			return
+		}
+
+		switch msg.Message {
+		case wmHotkey:
+			hk.keydownIn <- Event{}
+			isKeyDown = true
+		case wmQuit:
+			return
+		}
+	}
+}
+
+// Modifier represents a modifier.
+// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-registerhotkey
+type Modifier uint8
+
+// All kinds of Modifiers
+const (
+	ModAlt   Modifier = 0x1
+	ModCtrl  Modifier = 0x2
+	ModShift Modifier = 0x4
+	ModWin   Modifier = 0x8
+)
+
+// Key represents a key.
+// https://docs.microsoft.com/en-us/windows/win32/inputdev/virtual-key-codes
+type Key uint16
+
+// All kinds of Keys
+const (
+	KeySpace Key = 0x20
+	Key0     Key = 0x30
+	Key1     Key = 0x31
+	Key2     Key = 0x32
+	Key3     Key = 0x33
+	Key4     Key = 0x34
+	Key5     Key = 0x35
+	Key6     Key = 0x36
+	Key7     Key = 0x37
+	Key8     Key = 0x38
+	Key9     Key = 0x39
+	KeyA     Key = 0x41
+	KeyB     Key = 0x42
+	KeyC     Key = 0x43
+	KeyD     Key = 0x44
+	KeyE     Key = 0x45
+	KeyF     Key = 0x46
+	KeyG     Key = 0x47
+	KeyH     Key = 0x48
+	KeyI     Key = 0x49
+	KeyJ     Key = 0x4A
+	KeyK     Key = 0x4B
+	KeyL     Key = 0x4C
+	KeyM     Key = 0x4D
+	KeyN     Key = 0x4E
+	KeyO     Key = 0x4F
+	KeyP     Key = 0x50
+	KeyQ     Key = 0x51
+	KeyR     Key = 0x52
+	KeyS     Key = 0x53
+	KeyT     Key = 0x54
+	KeyU     Key = 0x55
+	KeyV     Key = 0x56
+	KeyW     Key = 0x57
+	KeyX     Key = 0x58
+	KeyY     Key = 0x59
+	KeyZ     Key = 0x5A
+
+	KeyReturn Key = 0x0D
+	KeyEscape Key = 0x1B
+	KeyDelete Key = 0x2E
+	KeyTab    Key = 0x09
+
+	KeyLeft  Key = 0x25
+	KeyRight Key = 0x27
+	KeyUp    Key = 0x26
+	KeyDown  Key = 0x28
+
+	KeyF1  Key = 0x70
+	KeyF2  Key = 0x71
+	KeyF3  Key = 0x72
+	KeyF4  Key = 0x73
+	KeyF5  Key = 0x74
+	KeyF6  Key = 0x75
+	KeyF7  Key = 0x76
+	KeyF8  Key = 0x77
+	KeyF9  Key = 0x78
+	KeyF10 Key = 0x79
+	KeyF11 Key = 0x7A
+	KeyF12 Key = 0x7B
+	KeyF13 Key = 0x7C
+	KeyF14 Key = 0x7D
+	KeyF15 Key = 0x7E
+	KeyF16 Key = 0x7F
+	KeyF17 Key = 0x80
+	KeyF18 Key = 0x81
+	KeyF19 Key = 0x82
+	KeyF20 Key = 0x83
+)