support StreetView Images API

maps.go

@@ -85,3 +85,7 @@ func encodeLocations(ls []Location) string {
 	}
 	return strings.Join(s, "|")
 }
+
+func Float64(f float64) *float64 {
+	return &f
+}

maps_test.go

@@ -75,3 +75,17 @@ func TestStaticMap(t *testing.T) {
 		t.Errorf("unexpected error: %v", err)
 	}
 }
+
+func TestStreetView(t *testing.T) {
+	c := NewClient("")
+	s := Size{600, 300}
+	opts := &StreetViewOpts{
+		Location: &LatLng{46.414382, 10.013988},
+		Heading:  Float64(151.78),
+		Pitch:    -0.76,
+	}
+	t.Logf("%s", baseURL+streetview(s, opts))
+	if _, err := c.StreetView(s, opts); err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+}

streetview.go

@@ -0,0 +1,55 @@
+package maps
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+)
+
+func (c Client) StreetView(s Size, opts *StreetViewOpts) (io.ReadCloser, error) {
+	resp, err := c.do(baseURL + streetview(s, opts))
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, HTTPError{resp}
+	}
+	return resp.Body, nil
+}
+
+func streetview(s Size, opts *StreetViewOpts) string {
+	p := url.Values{}
+	p.Set("size", s.String())
+	opts.update(p)
+	return "streetview?" + p.Encode()
+}
+
+type StreetViewOpts struct {
+	Location Location
+	Pano     string   // panoramio ID
+	Heading  *float64 // 0-360
+	FOV      *float64 // 0-120, 90 default
+	Pitch    float64  // -90 to +90
+}
+
+func (s *StreetViewOpts) update(p url.Values) {
+	if s == nil {
+		return
+	}
+	if s.Location != nil {
+		p.Set("location", s.Location.Location())
+	}
+	if s.Pano != "" {
+		p.Set("pano", s.Pano)
+	}
+	if s.Heading != nil {
+		p.Set("heading", fmt.Sprintf("%f", *s.Heading))
+	}
+	if s.FOV != nil {
+		p.Set("fov", fmt.Sprintf("%f", *s.FOV))
+	}
+	if s.Pitch != 0 {
+		p.Set("pitch", fmt.Sprintf("%f", s.Pitch))
+	}
+}