Switch player to MPRIS interface

This commit is contained in:
Arsen Musayelyan 2021-11-24 16:31:18 -08:00
parent ec1548ec0f
commit d9823bf0c8
4 changed files with 265 additions and 113 deletions

5
go.mod
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@ -2,4 +2,7 @@ module go.arsenm.dev/infinitime
go 1.16
require github.com/muka/go-bluetooth v0.0.0-20211122080231-b99792bbe62a
require (
github.com/godbus/dbus/v5 v5.0.3
github.com/muka/go-bluetooth v0.0.0-20211122080231-b99792bbe62a
)

37
internal/utils/dbus.go Normal file
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@ -0,0 +1,37 @@
package utils
import "github.com/godbus/dbus/v5"
func NewSystemBusConn() (*dbus.Conn, error) {
// Connect to dbus session bus
conn, err := dbus.SystemBusPrivate()
if err != nil {
return nil, err
}
err = conn.Auth(nil)
if err != nil {
return nil, err
}
err = conn.Hello()
if err != nil {
return nil, err
}
return conn, nil
}
func NewSessionBusConn() (*dbus.Conn, error) {
// Connect to dbus session bus
conn, err := dbus.SessionBusPrivate()
if err != nil {
return nil, err
}
err = conn.Auth(nil)
if err != nil {
return nil, err
}
err = conn.Hello()
if err != nil {
return nil, err
}
return conn, nil
}

224
pkg/player/player.go Normal file
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@ -0,0 +1,224 @@
package player
import (
"strings"
"github.com/godbus/dbus/v5"
"go.arsenm.dev/infinitime/internal/utils"
)
var (
method, monitor *dbus.Conn
monitorCh chan *dbus.Message
)
// Init makes required connections to DBis and
// initializes change monitoring channel
func Init() error {
// Connect to session bus for monitoring
monitorConn, err := utils.NewSessionBusConn()
if err != nil {
return err
}
// Add match rule for PropertiesChanged on media player
monitorConn.AddMatchSignal(
dbus.WithMatchObjectPath("/org/mpris/MediaPlayer2"),
dbus.WithMatchInterface("org.freedesktop.DBus.Properties"),
dbus.WithMatchMember("PropertiesChanged"),
)
monitorCh = make(chan *dbus.Message)
monitorConn.Eavesdrop(monitorCh)
// Connect to session bus for method calls
methodConn, err := utils.NewSessionBusConn()
if err != nil {
return err
}
method, monitor = methodConn, monitorConn
return nil
}
// Exit closes all connections and channels
func Exit() {
close(monitorCh)
method.Close()
monitor.Close()
}
// Play uses MPRIS to play media
func Play() error {
player, err := getPlayerObj()
if err != nil {
return err
}
if player != nil {
call := player.Call("org.mpris.MediaPlayer2.Player.Play", 0)
if call.Err != nil {
return call.Err
}
}
return nil
}
// Pause uses MPRIS to pause media
func Pause() error {
player, err := getPlayerObj()
if err != nil {
return err
}
if player != nil {
call := player.Call("org.mpris.MediaPlayer2.Player.Pause", 0)
if call.Err != nil {
return call.Err
}
}
return nil
}
// Next uses MPRIS to skip to next media
func Next() error {
player, err := getPlayerObj()
if err != nil {
return err
}
if player != nil {
call := player.Call("org.mpris.MediaPlayer2.Player.Next", 0)
if call.Err != nil {
return call.Err
}
}
return nil
}
// Prev uses MPRIS to skip to previous media
func Prev() error {
player, err := getPlayerObj()
if err != nil {
return err
}
if player != nil {
call := player.Call("org.mpris.MediaPlayer2.Player.Previous", 0)
if call.Err != nil {
return call.Err
}
}
return nil
}
type ChangeType int
const (
ChangeTypeTitle ChangeType = iota
ChangeTypeArtist
ChangeTypeAlbum
ChangeTypeStatus
)
func (ct ChangeType) String() string {
switch ct {
case ChangeTypeTitle:
return "Title"
case ChangeTypeAlbum:
return "Album"
case ChangeTypeArtist:
return "Artist"
case ChangeTypeStatus:
return "Status"
}
return ""
}
// OnChange runs cb when a value changes
func OnChange(cb func(ChangeType, string)) {
go func() {
// For every message on channel
for msg := range monitorCh {
// Parse PropertiesChanged
iface, changed, ok := parsePropertiesChanged(msg)
if !ok || iface != "org.mpris.MediaPlayer2.Player" {
continue
}
// For every property changed
for name, val := range changed {
// If metadata changed
if name == "Metadata" {
// Get fields
fields := val.Value().(map[string]dbus.Variant)
// For every field
for name, val := range fields {
// Handle each field appropriately
if strings.HasSuffix(name, "title") {
title := val.Value().(string)
if title == "" {
title = "Unknown " + ChangeTypeTitle.String()
}
cb(ChangeTypeTitle, title)
} else if strings.HasSuffix(name, "album") {
album := val.Value().(string)
if album == "" {
album = "Unknown " + ChangeTypeAlbum.String()
}
cb(ChangeTypeAlbum, album)
} else if strings.HasSuffix(name, "artist") {
artists := val.Value().([]string)
artistStr := strings.Join(artists, ", ")
if artistStr == "" {
artistStr = "Unknown " + ChangeTypeArtist.String()
}
cb(ChangeTypeArtist, artistStr)
}
}
} else if name == "PlaybackStatus" {
// Handle status change
cb(ChangeTypeStatus, val.Value().(string))
}
}
}
}()
}
// getPlayerNames gets all DBus MPRIS player bus names
func getPlayerNames(conn *dbus.Conn) ([]string, error) {
var names []string
err := conn.BusObject().Call("org.freedesktop.DBus.ListNames", 0).Store(&names)
if err != nil {
return nil, err
}
var players []string
for _, name := range names {
if strings.HasPrefix(name, "org.mpris.MediaPlayer2") {
players = append(players, name)
}
}
return players, nil
}
// GetPlayerObj gets the object corresponding to the first
// bus name found in DBus
func getPlayerObj() (dbus.BusObject, error) {
players, err := getPlayerNames(method)
if err != nil {
return nil, err
}
if len(players) == 0 {
return nil, nil
}
return method.Object(players[0], "/org/mpris/MediaPlayer2"), nil
}
// parsePropertiesChanged parses a DBus PropertiesChanged signal
func parsePropertiesChanged(msg *dbus.Message) (iface string, changed map[string]dbus.Variant, ok bool) {
if len(msg.Body) != 3 {
return "", nil, false
}
iface, ok = msg.Body[0].(string)
if !ok {
return
}
changed, ok = msg.Body[1].(map[string]dbus.Variant)
if !ok {
return
}
return
}

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@ -1,112 +0,0 @@
package player
import (
"bufio"
"io"
"os/exec"
"strings"
)
// Play uses playerctl to play media
func Play() error {
return exec.Command("playerctl", "play").Run()
}
// Pause uses playerctl to pause media
func Pause() error {
return exec.Command("playerctl", "pause").Run()
}
// Next uses playerctl to skip to next media
func Next() error {
return exec.Command("playerctl", "next").Run()
}
// Prev uses playerctl to skip to previous media
func Prev() error {
return exec.Command("playerctl", "previous").Run()
}
// Metadata uses playerctl to detect music metadata changes
func Metadata(key string, onChange func(string)) error {
// Execute playerctl command with key and follow flag
cmd := exec.Command("playerctl", "metadata", key, "-F")
// Get stdout pipe
stdout, err := cmd.StdoutPipe()
if err != nil {
return err
}
go func() {
for {
// Read line from command stdout
line, _, err := bufio.NewReader(stdout).ReadLine()
if err == io.EOF {
continue
}
// Convert line to string
data := string(line)
// If key unknown, return suitable default
if data == "No player could handle this command" || data == "" {
data = "Unknown " + strings.Title(key)
}
// Run the onChange callback
onChange(data)
}
}()
// Start command asynchronously
err = cmd.Start()
if err != nil {
return err
}
return nil
}
func Status(onChange func(bool)) error {
// Execute playerctl status with follow flag
cmd := exec.Command("playerctl", "status", "-F")
// Get stdout pipe
stdout, err := cmd.StdoutPipe()
if err != nil {
return err
}
go func() {
for {
// Read line from command stdout
line, _, err := bufio.NewReader(stdout).ReadLine()
if err == io.EOF {
continue
}
// Convert line to string
data := string(line)
// Run the onChange callback
onChange(data == "Playing")
}
}()
// Start command asynchronously
err = cmd.Start()
if err != nil {
return err
}
return nil
}
func CurrentMetadata(key string) (string, error) {
out, err := exec.Command("playerctl", "metadata", key).Output()
if err != nil {
return "", err
}
data := string(out)
if data == "No player could handle this command" || data == "" {
data = "Unknown " + strings.Title(key)
}
return data, nil
}
func CurrentStatus() (bool, error) {
out, err := exec.Command("playerctl", "status").Output()
if err != nil {
return false, err
}
data := string(out)
return data == "Playing", nil
}