🎨 Optimize hotkey service

internal/common/hotkey/hotkey_darwin.go

@@ -0,0 +1,176 @@
+// 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 darwin
+
+package hotkey
+
+/*
+#cgo CFLAGS: -x objective-c
+#cgo LDFLAGS: -framework Cocoa -framework Carbon
+#include <stdint.h>
+#import <Cocoa/Cocoa.h>
+#import <Carbon/Carbon.h>
+
+extern void keydownCallback(uintptr_t handle);
+extern void keyupCallback(uintptr_t handle);
+int registerHotKey(int mod, int key, uintptr_t handle, EventHotKeyRef* ref);
+int unregisterHotKey(EventHotKeyRef ref);
+*/
+import "C"
+import (
+	"errors"
+	"runtime/cgo"
+	"sync"
+)
+
+// Hotkey is a combination of modifiers and key to trigger an event
+type platformHotkey struct {
+	mu         sync.Mutex
+	registered bool
+	hkref      C.EventHotKeyRef
+}
+
+func (hk *Hotkey) register() error {
+	hk.mu.Lock()
+	defer hk.mu.Unlock()
+	if hk.registered {
+		return errors.New("hotkey already registered")
+	}
+
+	// Note: we use handle number as hotkey id in the C side.
+	// A cgo handle could ran out of space, but since in hotkey purpose
+	// we won't have that much number of hotkeys. So this should be fine.
+
+	h := cgo.NewHandle(hk)
+	var mod Modifier
+	for _, m := range hk.mods {
+		mod += m
+	}
+
+	ret := C.registerHotKey(C.int(mod), C.int(hk.key), C.uintptr_t(h), &hk.hkref)
+	if ret == C.int(-1) {
+		return errors.New("failed to register the hotkey")
+	}
+
+	hk.registered = true
+	return nil
+}
+
+func (hk *Hotkey) unregister() error {
+	hk.mu.Lock()
+	defer hk.mu.Unlock()
+	if !hk.registered {
+		return errors.New("hotkey is not registered")
+	}
+
+	ret := C.unregisterHotKey(hk.hkref)
+	if ret == C.int(-1) {
+		return errors.New("failed to unregister the current hotkey")
+	}
+	hk.registered = false
+	return nil
+}
+
+//export keydownCallback
+func keydownCallback(h uintptr) {
+	hk := cgo.Handle(h).Value().(*Hotkey)
+	hk.keydownIn <- Event{}
+}
+
+//export keyupCallback
+func keyupCallback(h uintptr) {
+	hk := cgo.Handle(h).Value().(*Hotkey)
+	hk.keyupIn <- Event{}
+}
+
+// Modifier represents a modifier.
+// See: /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/Headers/Events.h
+type Modifier uint32
+
+// All kinds of Modifiers
+const (
+	ModCtrl   Modifier = 0x1000
+	ModShift  Modifier = 0x200
+	ModOption Modifier = 0x800
+	ModCmd    Modifier = 0x100
+)
+
+// Key represents a key.
+// See: /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/Headers/Events.h
+type Key uint8
+
+// All kinds of keys
+const (
+	KeySpace Key = 49
+	Key1     Key = 18
+	Key2     Key = 19
+	Key3     Key = 20
+	Key4     Key = 21
+	Key5     Key = 23
+	Key6     Key = 22
+	Key7     Key = 26
+	Key8     Key = 28
+	Key9     Key = 25
+	Key0     Key = 29
+	KeyA     Key = 0
+	KeyB     Key = 11
+	KeyC     Key = 8
+	KeyD     Key = 2
+	KeyE     Key = 14
+	KeyF     Key = 3
+	KeyG     Key = 5
+	KeyH     Key = 4
+	KeyI     Key = 34
+	KeyJ     Key = 38
+	KeyK     Key = 40
+	KeyL     Key = 37
+	KeyM     Key = 46
+	KeyN     Key = 45
+	KeyO     Key = 31
+	KeyP     Key = 35
+	KeyQ     Key = 12
+	KeyR     Key = 15
+	KeyS     Key = 1
+	KeyT     Key = 17
+	KeyU     Key = 32
+	KeyV     Key = 9
+	KeyW     Key = 13
+	KeyX     Key = 7
+	KeyY     Key = 16
+	KeyZ     Key = 6
+
+	KeyReturn Key = 0x24
+	KeyEscape Key = 0x35
+	KeyDelete Key = 0x33
+	KeyTab    Key = 0x30
+
+	KeyLeft  Key = 0x7B
+	KeyRight Key = 0x7C
+	KeyUp    Key = 0x7E
+	KeyDown  Key = 0x7D
+
+	KeyF1  Key = 0x7A
+	KeyF2  Key = 0x78
+	KeyF3  Key = 0x63
+	KeyF4  Key = 0x76
+	KeyF5  Key = 0x60
+	KeyF6  Key = 0x61
+	KeyF7  Key = 0x62
+	KeyF8  Key = 0x64
+	KeyF9  Key = 0x65
+	KeyF10 Key = 0x6D
+	KeyF11 Key = 0x67
+	KeyF12 Key = 0x6F
+	KeyF13 Key = 0x69
+	KeyF14 Key = 0x6B
+	KeyF15 Key = 0x71
+	KeyF16 Key = 0x6A
+	KeyF17 Key = 0x40
+	KeyF18 Key = 0x4F
+	KeyF19 Key = 0x50
+	KeyF20 Key = 0x5A
+)