Initial rough cut UI

cmd/ui/ui.go

@@ -1,50 +1,58 @@
 package main
 
 import (
-	bh1750 "github.com/d2r2/go-bh1750"
-	i2c "github.com/d2r2/go-i2c"
-	logger "github.com/d2r2/go-logger"
-	"time"
-)
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"os/signal"
+	"syscall"
 
-var lg = logger.NewPackageLogger("main",
-	logger.ErrorLevel,
+	"github.com/gdamore/tcell"
+	"github.com/rivo/tview"
 )
 
 func main() {
-	defer logger.FinalizeLogger()
+	// fim placeholder so we can operate on it when a signal is received
+	var fim *exec.Cmd = nil
 
-	logger.ChangePackageLogLevel("i2c", logger.ErrorLevel)
-	logger.ChangePackageLogLevel("bh1750", logger.ErrorLevel)
+	// Setup signal listening
+	sigs := make(chan os.Signal)
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+	defer func() { close(sigs) }()
 
-	// Create new connection to I2C to bh1750
-	i2c, err := i2c.NewI2C(0x23, 1)
-	if err != nil {
-		lg.Fatal(err)
-	}
+	// Goroutine to handle os signals (nuke fim so we can get to config ui)
+	go func() {
+		for sig := range sigs {
+			fmt.Println(sig)
+			if fim != nil { // Just in case someone lays on ctrl-c or similar during startup
+				if err := fim.Process.Kill(); err != nil {
+					log.Fatal("failed to kill process: ", err)
+				}
+			}
+		}
+	}()
 
-	// Free I2C connection on exit
-	defer i2c.Close()
-
-	// Setup sensor
-	sensor := bh1750.NewBH1750()
-
-	// Reset sensor prior to use
-	err = sensor.Reset(i2c)
-	if err != nil {
-		lg.Fatal(err)
-	}
-
-	// Read sensor value over time
+	// Forever run slideshow / show ui as the main program executed on a PiFrame
 	for {
-		resolution := bh1750.HighResolution
-		lux, err := sensor.MeasureAmbientLight(i2c, resolution)
-		if err != nil {
-			lg.Fatal(err)
+		// Run slideshow
+		fim = exec.Command("/usr/local/bin/fim-slideshow.sh")
+		if err := fim.Run(); err != nil {
+			// Unwrap the error a bit so we can find out if a signal killed fim or something else
+			// An exit code of -1 means the program didn't exit in time or was terminated by a signal (per the docs)
+			if exitError, ok := err.(*exec.ExitError); ok && exitError.ExitCode() != -1 {
+				log.Fatalf("Error : ", err)
+			}
 		}
 
-		println("Illuminance:", lux, "lx")
-
-		time.Sleep(500 * time.Millisecond)
+		// Run config UI when slideshow stops
+		app := tview.NewApplication()
+		frame := tview.NewFrame(tview.NewBox().SetBackgroundColor(tcell.ColorBlack)).
+			SetBorders(2, 2, 2, 2, 4, 4).
+			AddText("PiFrame", true, tview.AlignCenter, tcell.ColorWhite).
+			AddText("Configuration Utility", true, tview.AlignCenter, tcell.ColorRed)
+		if err := app.SetRoot(frame, true).EnableMouse(true).Run(); err != nil {
+			log.Fatal(err)
+		}
 	}
 }