// Checkerboard is the handler for /checkerboard
// build a 6x6 checkerboard with alternate black and white colors.
func Checkerboard(w http.ResponseWriter, r *http.Request) {
size := extract.Size(r)
theme := extract.Theme(r)
colorMap := colors.MapOfColorThemes()
var c1, c2 color.RGBA
if val, ok := colorMap[theme]; ok {
c1 = val[0]
c2 = val[1]
} else {
c1 = colorMap["base"][0]
c2 = colorMap["base"][1]
}
if f := extract.Format(r); f == format.JPEG {
m := image.NewRGBA(image.Rect(0, 0, size, size))
squares.Grid(m, c1, c2)
var img image.Image = m
write.ImageJPEG(w, &img)
} else if f == format.SVG {
write.ImageSVG(w)
squares.GridSVG(w, c1, c2, size)
}
}
// Square handler for /squares/:key
// builds a 6 by 6 grid with alternate colors based the key passed in the url.
func Square(w http.ResponseWriter, r *http.Request) {
var err error
var key string
if key, err = route.Context.Get(r, "key"); err != nil {
log.Println("Unable to get 'key' value: ", err)
key = ""
}
theme := extract.Theme(r)
h := md5.New()
io.WriteString(h, key)
key = fmt.Sprintf("%x", h.Sum(nil)[:])
e := `"` + theme + key + `"`
w.Header().Set("Etag", e)
w.Header().Set("Cache-Control", "max-age=2592000") // 30 days
if match := r.Header.Get("If-None-Match"); match != "" {
if strings.Contains(match, e) {
w.WriteHeader(http.StatusNotModified)
return
}
}
colors := extract.Colors(r)
size := extract.Size(r)
if f := extract.Format(r); f == format.JPEG {
m := image.NewRGBA(image.Rect(0, 0, size, size))
squares.Image(m, key, colors)
var img image.Image = m
write.ImageJPEG(w, &img)
} else if f == format.SVG {
write.ImageSVG(w)
squares.SVG(w, key, colors, size)
}
}
