Refactor

 -  Delete `mpd` directory.

 -  Allow updating multiple items from the same "data source", e.g. for
    displaying time in two different formats without having to read the
    time twice.

I'm still not satisfied with how the code looks, and I want to think of
better names for some types, but this works for now.

README.md

@@ -2,36 +2,8 @@
 
 My custom status for i3bar.
 
-There's no configuration files, everything is decided at compile time.
-
-I don't even use this anymore, but I also don't want to archive it just
-yet.
-
-## Compile-time requirements
-
-*  Go compiler. See the `go.mod' file to know which version I was using
-   last time I updated this repository.
-
-## Runtime requirements
-
-*  A running instance of MPD. Take a look at the `cmd/dsts' package to
-   know which port number is expected.
-
-## What is being displayed
-
-*  Current date and time in the same format as Skyrim.
-*  Song currently playing in MPD.
-
-## How it works
-
-Each `component' is a function receiving a channel as its only argument.
-Each time a status is sent to that channel, a refresh is triggered.
-
-The main program coordinates all those updates, and sends new messages
-when necessary.
-
-This allows components to each have their own `refresh rate', instead of
-using a single global refresh rate for everything.
+There's runtime no configuration files. The whole point of this, is to
+have a single executable that just works.
 
 ## License
 

cmd/dsts/main.go

@@ -4,78 +4,83 @@
 package main
 
 import (
+	"context"
 	"encoding/json"
+	"errors"
 	"os"
-	"sync"
+	"sync/atomic"
 
 	"github.com/c032/dsts"
-	"github.com/c032/dsts/mpd"
-	"github.com/c032/dsts/tamrieltime"
+	dststime "github.com/c032/dsts/time"
 )
 
-const (
-	// mpdAddr is the address where MPD is listening in.
-	mpdAddr = ":6600"
+func main() {
+	ctx := context.Background()
 
-	// mpdStatusMaxWidth is the maximum width, in characters, allowed for the
-	// MPD status.
-	mpdStatusMaxWidth = 80
-)
+	timeSource := &dststime.Source{}
+
+	sources := []dsts.Source{
+		timeSource,
+	}
 
-func main() {
 	// Active providers, in the same order that they will be displayed in the
 	// i3bar.
 	//
 	// Providers with a lower index will be displayed somewhere to the left of
 	// providers with a higher index.
-	providers := []dsts.Provider{
-		dsts.Wrap(
-			mpd.Dial(mpdAddr),
-			mpdStatusMaxWidth,
-		),
-		tamrieltime.TamrielTime,
+	mutableStatusItems := []*atomic.Pointer[dsts.I3Status]{
+		&timeSource.StatusUnix,
+		&timeSource.StatusDateTime,
 	}
 
-	enc := json.NewEncoder(os.Stdout)
-
-	os.Stdout.Write([]byte(`{"version":1}[[]`))
-
 	// tick is only used to notify when the status line must be updated.
 	tick := make(chan struct{})
 
-	// mu prevents multiple goroutines from modifying `i3sts` at the same time.
-	mu := sync.RWMutex{}
+	for _, source := range sources {
+		_ = source.OnUpdate(func() {
+			tick <- struct{}{}
+		})
+	}
 
-	// i3sts is what will be serialized as JSON and printed to standard output.
-	i3sts := make([]dsts.I3Status, len(providers))
+	enc := json.NewEncoder(os.Stdout)
 
-	// Run each provider on their own goroutine, coordinate updates to the
-	// i3status line, and trigger a refresh when necessary.
-	for i, p := range providers {
-		ch := make(chan dsts.I3Status)
+	os.Stdout.Write([]byte(`{"version":1}[[]`))
 
-		// Run the provider, usually forever.
-		go p(ch)
+	// visibleStatusItems is what will be serialized as JSON and printed to
+	// standard output.
+	visibleStatusItems := make([]dsts.I3Status, len(mutableStatusItems))
 
-		// For each update from the provider, update the current status and
-		// trigger a refresh.
-		go func(i int, p dsts.Provider) {
-			for status := range ch {
-				mu.Lock()
-				i3sts[i] = status
-				mu.Unlock()
+	// Wait for a refresh to trigger, and update the status line.
+	for range tick {
+		for i, itemPtr := range mutableStatusItems {
+			if itemPtr == nil {
+				continue
+			}
 
-				tick <- struct{}{}
+			v := itemPtr.Load()
+			if v == nil {
+				continue
 			}
-		}(i, p)
-	}
 
-	// Wait for a refresh to trigger, and update the status line.
-	for range tick {
+			visibleStatusItems[i] = *v
+		}
+
 		os.Stdout.Write([]byte{','})
 
-		mu.RLock()
-		_ = enc.Encode(i3sts)
-		mu.RUnlock()
+		_ = enc.Encode(visibleStatusItems)
+	}
+
+	<-ctx.Done()
+
+	err := ctx.Err()
+	if err != nil {
+		if !errors.Is(err, context.Canceled) {
+			os.Exit(1)
+		}
+
+		cause := context.Cause(ctx)
+		if cause != nil && cause != err {
+			os.Exit(1)
+		}
 	}
 }

color.go

@@ -0,0 +1,36 @@
+package dsts
+
+import (
+	"errors"
+)
+
+var ErrInvalidColor = errors.New("invalid color")
+
+const (
+	DefaultStatusColor      = "#999999"
+	DefaultStatusColorError = "#e20024"
+)
+
+func isNumber(c rune) bool {
+	return c >= '0' && c <= '9'
+}
+
+func IsValidColor(color string) bool {
+	if len(color) != len("#000") && len(color) != len("#000000") {
+		return false
+	}
+	if color[0] != '#' {
+		return false
+	}
+
+	for i, c := range color {
+		if i == 0 {
+			continue
+		}
+		if !isNumber(c) {
+			return false
+		}
+	}
+
+	return true
+}