[core] Group Map LatLngBounds, min and max zoom methods

Group bounds, minimum and maximum zoom related methods together using
the new BoundOptions.

v2: Document that getBounds() initializes all optional fields.
  - Add test for getBounds() on a map with default values.

1 files changed, 30 insertions, 0 deletions

diff --git a/include/mbgl/map/bound_options.hpp b/include/mbgl/map/bound_options.hpp
new file mode 100644
index 0000000000..69d353a301
--- /dev/null
+++ b/include/mbgl/map/bound_options.hpp
@@ -0,0 +1,30 @@
+#pragma once
+
+#include <mbgl/util/geo.hpp>
+#include <mbgl/util/optional.hpp>
+
+namespace mbgl {
+
+/**
+ * @brief Holds options to limit what parts of a map are visible. All fields are
+ * optional.
+ */
+struct BoundOptions {
+    /// Sets the latitude and longitude bounds to which the camera center are constrained
+    BoundOptions& withLatLngBounds(LatLngBounds b) { bounds = b; return *this; }
+    /// Sets the minimum zoom level
+    BoundOptions& withMinZoom(double z) { minZoom = z; return *this; }
+    /// Sets the maximum zoom level
+    BoundOptions& withMaxZoom(double z) { maxZoom = z; return *this; }
+
+    /// Constrain the center of the camera to be within these bounds.
+    optional<LatLngBounds> bounds;
+
+    /// Maximum zoom level allowed.
+    optional<double> maxZoom;
+
+    /// Minimum zoom level allowed.
+    optional<double> minZoom;
+};
+
+}  // namespace mbgl