Golang mapnik_map_layer_set_active Examples

Example #1

File: mapnik.go Project: fawick/go-mapnik-1

// 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:
		}
	}
}

Example #2

File: mapnik.go Project: fawick/go-mapnik-1

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
}