cleaning up, early http server draft

http/http.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"net/http"
+	"log"
+)
+
+type imageTransform struct {
+	image.Image
+	TransformFunc func(image.Image) image.Image
+}
+
+func (t imageTransform) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	
+}
+
+func indexHTML(w http.ResponseWriter, r *http.Request) {
+	f, err := os.Open("index.html")
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		log.Fatalln("error opening file:", err)
+		return
+	}
+	_, err := io.Copy(w, f)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		log.Println("copy error:", err)
+		return
+	}	
+}
+
+func main() {
+	http.HandleFunc("/", indexHTML)
+	http.Handle("POST /upload", imageTransform)
+
+	err := http.ListenAndServe(":8080", nil) 
+	if err != nil {
+		log.Panicln(err)
+	}
+}

http/index.html

@@ -0,0 +1,4 @@
+<form action="/upload" method="POST" enctype="multipart/form-data">
+    <input type="file" name="image" accept="image/*" required>
+    <button type="submit">Upload Image</button>
+</form>

util/hex.go

@@ -0,0 +1,32 @@
+package imageutils
+
+import (
+	"fmt"
+	"image/color"
+	"errors"
+)
+
+var ParseHexColorErr = errors.New("invalid length, must be 7 or 4")
+
+func ParseHexColor(s string) (c color.RGBA, err error) {
+	c.A = 0xff
+	switch len(s) {
+	case 7:
+		_, err = fmt.Sscanf(s, "#%02x%02x%02x", &c.R, &c.G, &c.B)
+	case 4:
+		_, err = fmt.Sscanf(s, "#%1x%1x%1x", &c.R, &c.G, &c.B)
+		// Double the hex digits:
+		c.R *= 17
+		c.G *= 17
+		c.B *= 17
+	default:
+		err = ParseHexColorErr
+
+	}
+	return
+}
+
+func ColorToHex(c color.Color) string {
+	r, g, b, _ := color.NRGBAModel.Convert(c).RGBA()
+	return fmt.Sprintf("#%02x%02x%02x", byte(r), byte(g), byte(b))
+}

util/hex_test.go

@@ -0,0 +1,47 @@
+package imageutils
+
+import (
+	"fmt"
+	"image/png"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// Returns path of first occured file
+// with png extension in user's home directory.
+func firstPNG(root string) (filename string,
+	err error) {
+	var fn filepath.WalkFunc = func(path string,
+		info os.FileInfo,
+		fileErr error) error {
+		if fileErr != nil {
+			return fileErr
+		}
+		if !info.IsDir() &&
+			filepath.Ext(path) == ".png" {
+			filename = path
+			return nil
+		}
+		return nil
+	}
+	err = filepath.Walk(root, fn)
+	return
+}
+
+func TestColorToHex(t *testing.T) {
+	root := os.Getenv("HOME")
+	path, err := firstPNG(root)
+	if err != nil {
+		t.Fatal(err)
+	}
+	f, err := os.Open(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	img, err := png.Decode(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+	fmt.Println(ColorToHex(img.At(0, 0)))
+}