all: support keyup event (darwin)

Fixes #9

README.md

@@ -13,10 +13,51 @@ import "golang.design/x/hotkey"
 
 ## API Usage
 
-Package hotkey provides the primary facility to register a system-level global hotkey shortcut to notify an application if a user triggers the desired hotkey. A hotkey must be a combination of modifiers and a single key.
+Package hotkey provides the basic facility to register a system-level
+global hotkey shortcut so that an application can be notified if a user
+triggers the desired hotkey. A hotkey must be a combination of modifiers
+and a single key.
 
-Note a platform-specific detail on `macOS` due to the OS restriction (other platforms do not have this restriction): hotkey events must be handled on the "main thread". Therefore, to use this package properly, one must call the `(*Hotkey).Register` method on the main thread, and an OS app main event loop must be established. One can use  the provided `golang.design/x/hotkey/mainthread` for self-contained applications. For applications based on other GUI frameworks, one has to use their provided ability to run the `(*Hotkey).Register` on the main thread. See the [examples](./examples) folder for more examples.
+```go
+func main() { mainthread.Init(fn) } // not necessary when use in Fyne, Ebiten or Gio.
+func fn() {
+    hk := hotkey.New([]hotkey.Modifier{hotkey.ModCtrl, hotkey.ModShift}, hotkey.KeyS)
+    err := hk.Register()
+    if err != nil {
+        return
+    }
+    fmt.Printf("hotkey: %v is registered\n", hk)
+    <-hk.Keydown()
+    fmt.Printf("hotkey: %v is down\n", hk)
+    <-hk.Keyup()
+    fmt.Printf("hotkey: %v is up\n", hk)
+    hk.Unregister()
+    fmt.Printf("hotkey: %v is unregistered\n", hk)
+}
+```
+
+Note platform specific details:
+
+- On macOS, due to the OS restriction (other
+  platforms does not have this restriction), hotkey events must be handled
+  on the "main thread". Therefore, in order to use this package properly,
+  one must start an OS main event loop on the main thread, For self-contained
+  applications, using [golang.design/x/hotkey/mainthread](https://pkg.go.dev/golang.design/x/hotkey/mainthread) is possible.
+  For applications based on other GUI frameworks, such as fyne, ebiten, or Gio.
+  This is not necessary. See the "[./examples](./examples)" folder for more examples.
+- On Linux (X11), when AutoRepeat is enabled in the X server, the Keyup
+  is triggered automatically and continuously as Keydown continues.
+
+## Examples
 
+| Description | Folder |
+|:------------|:------:|
+| A minimum example | [minimum](./examples/minimum/main.go) |
+| Register multiple hotkeys | [multiple](./examples/multiple/main.go) |
+| A example to use in GLFW | [glfw](./examples/glfw/main.go) |
+| A example to use in Fyne | [fyne](./examples/fyne/main.go) |
+| A example to use in Ebiten | [ebiten](./examples/ebiten/main.go) |
+| A example to use in Gio | [gio](./examples/gio/main.go) |
 ## Who is using this package?
 
 The main purpose of building this package is to support the

examples/ebiten/main.go

@@ -39,8 +39,7 @@ func reghk() {
 	// Register a desired hotkey.
 	hk := hotkey.New([]hotkey.Modifier{hotkey.ModCtrl, hotkey.ModShift}, hotkey.KeyS)
 
-	var err error
-	if ebiten.RunOnMainThread(func() { err = hk.Register() }); err != nil {
+	if err := hk.Register(); err != nil {
 		log.Println("failed to register hotkey: %v", err)
 		return
 	}

examples/fyne/main.go

@@ -0,0 +1,34 @@
+// Copyright 2022 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.
+
+package main
+
+import (
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/app"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/widget"
+	"golang.design/x/hotkey"
+)
+
+func main() {
+	w := app.New().NewWindow("golang.design/x/hotkey")
+	label := widget.NewLabel("Hello golang.design!")
+	button := widget.NewButton("Hi!", func() { label.SetText("Welcome :)") })
+	w.SetContent(container.NewVBox(label, button))
+
+	go func() {
+		// Register a desired hotkey.
+		hk := hotkey.New([]hotkey.Modifier{hotkey.ModCtrl, hotkey.ModShift}, hotkey.KeyS)
+		if err := hk.Register(); err != nil {
+			panic("hotkey registration failed")
+		}
+		// Start listen hotkey event whenever it is ready.
+		for range hk.Keydown() {
+			button.Tapped(&fyne.PointEvent{})
+		}
+	}()
+
+	w.ShowAndRun()
+}

examples/gio/main.go

@@ -0,0 +1,43 @@
+// Copyright 2022 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.
+
+package main
+
+import (
+	"os"
+
+	"gioui.org/app"
+	"gioui.org/unit"
+	"golang.design/x/hotkey"
+)
+
+func main() {
+	go fn()
+	app.Main()
+}
+
+func fn() {
+	w := app.NewWindow(app.Title("golang.design/x/hotkey"), app.Size(unit.Dp(200), unit.Dp(200)))
+
+	go reghk()
+
+	for range w.Events() {
+	}
+}
+
+func reghk() {
+	// Register a desired hotkey.
+	hk := hotkey.New([]hotkey.Modifier{hotkey.ModCtrl, hotkey.ModShift}, hotkey.KeyS)
+	if err := hk.Register(); err != nil {
+		panic("hotkey registration failed")
+	}
+
+	// Unregister the hotkey when keydown event is triggered
+	for range hk.Keydown() {
+		hk.Unregister()
+	}
+
+	// Exist the app.
+	os.Exit(0)
+}

examples/glfw/main.go

@@ -0,0 +1,47 @@
+// Copyright 2022 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.
+
+package main
+
+import (
+	"fmt"
+	"runtime"
+
+	"github.com/go-gl/glfw/v3.3/glfw"
+	"golang.design/x/hotkey"
+)
+
+func init() {
+	runtime.LockOSThread()
+}
+
+func main() {
+	err := glfw.Init()
+	if err != nil {
+		panic(err)
+	}
+	defer glfw.Terminate()
+	window, err := glfw.CreateWindow(640, 480, "golang.design/x/hotkey", nil, nil)
+	if err != nil {
+		panic(err)
+	}
+
+	go func() {
+		// Register a desired hotkey.
+		hk := hotkey.New([]hotkey.Modifier{hotkey.ModCtrl, hotkey.ModShift}, hotkey.KeyS)
+		if err := hk.Register(); err != nil {
+			panic("hotkey registration failed")
+		}
+		// Start listen hotkey event whenever it is ready.
+		for range hk.Keydown() {
+			fmt.Println("keydown!")
+		}
+	}()
+
+	window.MakeContextCurrent()
+	for !window.ShouldClose() {
+		window.SwapBuffers()
+		glfw.PollEvents()
+	}
+}

examples/go.mod

@@ -3,19 +3,37 @@ module golang.design/x/hotkey/examples
 go 1.17
 
 require (
+	fyne.io/fyne/v2 v2.1.2
+	gioui.org v0.0.0-20220104172405-7751d737403e
+	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20211213063430-748e38ca8aec
 	github.com/hajimehoshi/ebiten/v2 v2.3.0-alpha.4.0.20220103082943-8418c4a65551
 	golang.design/x/hotkey v0.2.1
 )
 
 require (
-	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20211213063430-748e38ca8aec // indirect
+	gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2 // indirect
+	gioui.org/shader v1.0.6 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/fredbi/uri v0.0.0-20181227131451-3dcfdacbaaf3 // indirect
+	github.com/fsnotify/fsnotify v1.4.9 // indirect
+	github.com/go-gl/gl v0.0.0-20210813123233-e4099ee2221f // indirect
+	github.com/godbus/dbus/v5 v5.0.4 // indirect
+	github.com/goki/freetype v0.0.0-20181231101311-fa8a33aabaff // indirect
 	github.com/jezek/xgb v0.0.0-20210312150743-0e0f116e1240 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/srwiley/oksvg v0.0.0-20200311192757-870daf9aa564 // indirect
+	github.com/srwiley/rasterx v0.0.0-20200120212402-85cb7272f5e9 // indirect
+	github.com/stretchr/testify v1.7.0 // indirect
+	github.com/yuin/goldmark v1.4.0 // indirect
 	golang.design/x/mainthread v0.3.0 // indirect
-	golang.org/x/exp v0.0.0-20190731235908-ec7cb31e5a56 // indirect
+	golang.org/x/exp v0.0.0-20210722180016-6781d3edade3 // indirect
 	golang.org/x/image v0.0.0-20210628002857-a66eb6448b8d // indirect
 	golang.org/x/mobile v0.0.0-20210902104108-5d9a33257ab5 // indirect
+	golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d // indirect
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
 	golang.org/x/sys v0.0.0-20210917161153-d61c044b1678 // indirect
+	golang.org/x/text v0.3.6 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
 )
 
 replace golang.design/x/hotkey => ../