func (m *Map) RenderToMemoryUTFGrid(lname string, key string, res uint) (string, error) {
l := &Layer{}
n := int(C.mapnik_map_layer_count(m.m))
for i := 0; i < n; i++ {
ml := C.mapnik_map_get_layer(m.m, C.size_t(i))
defer C.free(unsafe.Pointer(ml))
if C.GoString(C.mapnik_layer_name(ml)) == lname {
l.l = ml
break
}
}
if l.l == nil {
return "", fmt.Errorf("no such layer %s", lname)
}
cs := C.CString(key)
defer C.free(unsafe.Pointer(cs))
g := C.mapnik_map_render_to_grid(m.m, l.l, cs)
if g == nil {
return "", m.lastError()
}
defer C.mapnik_grid_free(g)
json := C.mapnik_grid_to_json(g, C.uint(res))
if json == nil {
return "", m.lastError()
}
defer C.free(unsafe.Pointer(json))
return C.GoString(json), nil
}
func (m *Map) printLayerStatus() {
n := C.mapnik_map_layer_count(m.m)
for i := 0; i < int(n); i++ {
fmt.Println(
C.GoString(C.mapnik_map_layer_name(m.m, C.size_t(i))),
C.mapnik_map_layer_is_active(m.m, C.size_t(i)),
)
}
}
func (m *Map) currentLayerStatus() []bool {
n := C.mapnik_map_layer_count(m.m)
active := make([]bool, n)
for i := 0; i < int(n); i++ {
if C.mapnik_map_layer_is_active(m.m, C.size_t(i)) == 1 {
active[i] = true
}
}
return active
}
func (m *Map) SetActiveLayer(lname string) {
n := int(C.mapnik_map_layer_count(m.m))
for i := 0; i < n; i++ {
l := C.mapnik_map_get_layer(m.m, C.size_t(i))
defer C.free(unsafe.Pointer(l))
if C.GoString(C.mapnik_layer_name(l)) == lname {
C.mapnik_layer_set_active(l, 1)
} else {
C.mapnik_layer_set_active(l, 0)
}
}
}
// SelectLayers enables/disables single layers. LayerSelector or SelectorFunc gets called for each layer.
func (m *Map) SelectLayers(selector LayerSelector) {
m.storeLayerStatus()
n := C.mapnik_map_layer_count(m.m)
for i := 0; i < int(n); i++ {
layerName := C.GoString(C.mapnik_map_layer_name(m.m, C.size_t(i)))
switch selector.Select(layerName) {
case Include:
C.mapnik_map_layer_set_active(m.m, C.size_t(i), 1)
case Exclude:
C.mapnik_map_layer_set_active(m.m, C.size_t(i), 0)
case Default:
}
}
}
func (m *Map) resetLayerStatus() {
if len(m.layerStatus) == 0 {
return // not stored
}
n := C.mapnik_map_layer_count(m.m)
if int(n) > len(m.layerStatus) {
// should not happen
return
}
for i := 0; i < int(n); i++ {
if m.layerStatus[i] {
C.mapnik_map_layer_set_active(m.m, C.size_t(i), 1)
} else {
C.mapnik_map_layer_set_active(m.m, C.size_t(i), 0)
}
}
m.layerStatus = nil
}