layer: document intentions of layer structure

[staging/windowmanager.git] / src / layers.hpp

diff --git a/src/layers.hpp b/src/layers.hpp
index 7b35c63..a3cb2a9 100644 (file)
--- a/src/layers.hpp
+++ b/src/layers.hpp
@@ -5,21 +5,31 @@
 #ifndef TMCAGLWM_LAYERS_H
 #define TMCAGLWM_LAYERS_H
 
-#include <algorithm>
-#include <experimental/optional>
 #include <json.hpp>
 #include <set>
 #include <string>
 
 #include "result.hpp"
+#include "wayland.hpp"
 
 namespace wm {
 
 struct surface_id_to_layer {
+   // Min and max surface ID mapped to this layer
    int id_min = -1;
    int id_max = -1;
+   // A more or less descriptive name?
    std::string name = "";
+   // The actual layer ID
    int layer_id = -1;
+   // The rectangular region surfaces are allowed to draw on
+   // this layer, note however, width and hieght of the rect
+   // can be negative, in which case they specify that
+   // the actual value is computed using MAX + 1 - w
+   // That is; allow us to specify dimensions dependent on
+   // e.g. screen dimension, w/o knowing the actual screen size.
+   genivi::rect rect;
+   // XXX perhaps a zorder is needed here?
 
    explicit surface_id_to_layer(nlohmann::json const &j);
 
@@ -28,26 +38,19 @@ struct surface_id_to_layer {
    }
 };
 
-inline bool operator<(struct surface_id_to_layer const &a, int b) {
-   return a.id_max < b;
-}
-
+// Actually, we shouldn't need a struct here ... but let's just keep it at that
+// for now, to contain its mapping type and the _single_ useful method.
 struct surface_id_to_layer_map {
-   typedef std::set<struct surface_id_to_layer> map_type;
-
-   map_type mapping;
-
-   std::experimental::optional<int> get_layer_for_surface(int surface_id) {
-      auto i = std::lower_bound(std::cbegin(this->mapping),
-                                std::cend(this->mapping), surface_id);
+   typedef std::set<struct surface_id_to_layer> surface_to_layer_map_type;
+   typedef std::vector<unsigned int> layers_type;
 
-      if (i != this->mapping.end()) {
-         if (i->id_min <= surface_id) {
-            return std::experimental::optional<int>(i->layer_id);
-         }
-      }
+   surface_to_layer_map_type mapping;
+   layers_type layers;
 
-      return std::experimental::nullopt;
+   optional<int> get_layer_for_surface(int surface_id);
+   optional<genivi::rect> get_rect_for_surface(int surface_id);
+   layers_type::size_type get_layers_count() const {
+      return this->layers.size();
    }
 };