Allow disabling of attribution rendering

Signed-off-by: Knut Ahlers <knut@ahlers.me>

Gopkg.lock

@@ -2,10 +2,10 @@
 
 
 [[projects]]
-  branch = "master"
+  branch = "allow-disable-of-attribution-rendering"
   name = "github.com/Luzifer/go-staticmaps"
   packages = ["."]
-  revision = "5f69ec7945b506b1d33edd717e84e479818e2365"
+  revision = "d701c2c232ad9cbcac3e48e2c34e98544191c2fe"
 
 [[projects]]
   name = "github.com/Luzifer/go_helpers"
@@ -166,6 +166,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "7c8497a8311887c02aced01ebdf91a73dc82b48920f8f9ebd5ad643204043ce2"
+  inputs-digest = "bc8b02eb09921c3dcef7328c41ec92c8442d151672053769293e0c476f4a2188"
   solver-name = "gps-cdcl"
   solver-version = 1

Gopkg.toml

@@ -26,7 +26,7 @@
 
 
 [[constraint]]
-  branch = "master"
+  branch = "allow-disable-of-attribution-rendering"
   name = "github.com/Luzifer/go-staticmaps"
 
 [[constraint]]

cache.go

@@ -9,14 +9,14 @@ import (
 	"github.com/golang/geo/s2"
 )
 
-type cacheFunction func(center s2.LatLng, zoom int, marker []marker, x, y int) (io.ReadCloser, error)
+type cacheFunction func(center s2.LatLng, zoom int, marker []marker, x, y int, disableAttribution bool) (io.ReadCloser, error)
 
-func cacheKeyHelper(center s2.LatLng, zoom int, marker []marker, x, y int) string {
+func cacheKeyHelper(center s2.LatLng, zoom int, marker []marker, x, y int, disableAttribution bool) string {
 	markerString := []string{}
 	for _, m := range marker {
 		markerString = append(markerString, m.String())
 	}
-	hashString := fmt.Sprintf("%s|%d|%s|%dx%d", center.String(), zoom, strings.Join(markerString, "+"), x, y)
+	hashString := fmt.Sprintf("%s|%d|%s|%dx%d|%v", center.String(), zoom, strings.Join(markerString, "+"), x, y, disableAttribution)
 
 	return fmt.Sprintf("%x", sha256.Sum256([]byte(hashString)))
 }

cache_filesystem.go

@@ -11,8 +11,8 @@ import (
 	"github.com/golang/geo/s2"
 )
 
-func filesystemCache(center s2.LatLng, zoom int, marker []marker, x, y int) (io.ReadCloser, error) {
+func filesystemCache(center s2.LatLng, zoom int, marker []marker, x, y int, disableAttribution bool) (io.ReadCloser, error) {
-	cacheKey := cacheKeyHelper(center, zoom, marker, x, y)
+	cacheKey := cacheKeyHelper(center, zoom, marker, x, y, disableAttribution)
 	cacheFileName := path.Join(cfg.CacheDir, cacheKey[0:2], cacheKey+".png")
 
 	if info, err := os.Stat(cacheFileName); err == nil && info.ModTime().Add(cfg.ForceCache).After(time.Now()) {
@@ -20,7 +20,7 @@ func filesystemCache(center s2.LatLng, zoom int, marker []marker, x, y int) (io.
 	}
 
 	// No cache hit, generate a new map
-	mapReader, err := generateMap(center, zoom, marker, x, y)
+	mapReader, err := generateMap(center, zoom, marker, x, y, disableAttribution)
 	if err != nil {
 		return nil, err
 	}

main.go

@@ -65,12 +65,13 @@ func main() {
 
 func handleMapRequest(res http.ResponseWriter, r *http.Request) {
 	var (
-		center    *s2.LatLng
+		center             *s2.LatLng
-		err       error
+		disableAttribution bool = r.URL.Query().Get("no-attribution") == "true"
-		mapReader io.ReadCloser
+		err                error
-		markers   []marker
+		mapReader          io.ReadCloser
-		x, y      int
+		markers            []marker
-		zoom      int
+		x, y               int
+		zoom               int
 	)
 
 	if center, err = parseCoordinate(r.URL.Query().Get("center")); err != nil {
@@ -93,7 +94,7 @@ func handleMapRequest(res http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if mapReader, err = cacheFunc(*center, zoom, markers, x, y); err != nil {
+	if mapReader, err = cacheFunc(*center, zoom, markers, x, y, disableAttribution); err != nil {
 		log.Errorf("Map render failed: %s (Request: %s)", err, r.URL.String())
 		http.Error(res, fmt.Sprintf("I experienced difficulties rendering your map: %s", err), http.StatusInternalServerError)
 		return

map.go

@@ -43,7 +43,7 @@ func (m marker) String() string {
 	return fmt.Sprintf("%s|%.0f|%d,%d,%d,%d", m.pos.String(), m.size, r, g, b, a)
 }
 
-func generateMap(center s2.LatLng, zoom int, marker []marker, x, y int) (io.Reader, error) {
+func generateMap(center s2.LatLng, zoom int, marker []marker, x, y int, disableAttribution bool) (io.Reader, error) {
 	ctx := staticMap.NewContext()
 	ctx.SetUserAgent(fmt.Sprintf("Mozilla/5.0+(compatible; staticmap/%s; https://github.com/Luzifer/staticmap)", version))
 
@@ -51,6 +51,10 @@ func generateMap(center s2.LatLng, zoom int, marker []marker, x, y int) (io.Read
 	ctx.SetCenter(center)
 	ctx.SetZoom(zoom)
 
+	if disableAttribution {
+		ctx.ForceNoAttribution()
+	}
+
 	if marker != nil {
 		for _, m := range marker {
 			ctx.AddMarker(staticMap.NewMarker(m.pos, m.color, float64(m.size)))

vendor/github.com/Luzifer/go-staticmaps/context.go

@@ -42,6 +42,8 @@ type Context struct {
 
 	userAgent    string
 	tileProvider *TileProvider
+
+	forceNoAttribution bool
 }
 
 // NewContext creates a new instance of Context
@@ -147,6 +149,14 @@ func (m *Context) ClearOverlays() {
 	m.overlays = nil
 }
 
+// ForceNoAttribution disables attribution rendering
+//
+// Pay attention you might be violating the terms of usage for the
+// selected map provider - only use the function if you are aware of this!
+func (m *Context) ForceNoAttribution() {
+	m.forceNoAttribution = true
+}
+
 func (m *Context) determineBounds() s2.Rect {
 	r := s2.EmptyRect()
 	for _, marker := range m.markers {
@@ -381,7 +391,7 @@ func (m *Context) Render() (image.Image, error) {
 		draw.Src)
 
 	// draw attribution
-	if m.tileProvider.Attribution == "" {
+	if m.tileProvider.Attribution == "" || m.forceNoAttribution {
 		return croppedImg, nil
 	}
 	_, textHeight := gc.MeasureString(m.tileProvider.Attribution)