App/layers: deactivate surfaces on layers above.

* When activating a surface on layer x, all surfaces on all layers above
  this will be deactivated.
* Remove main_surface special case (we get the same result by putting
  the main_surface on the bottom layer).
* Track LayoutState per layer, make can_split() accept this layer-local
  LayoutState for its decision.
* Sort layers on load according to their ID. That is, do not make use
  Of the layer's z-order attribute, also there is no need to.

Signed-off-by: Marcus Fritzsch <marcus_fritzsch@mentor.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/src/layers.hpp b/src/layers.hpp
index ee32054..ada7344 100644
--- a/src/layers.hpp
+++ b/src/layers.hpp
@@ -23,6 +23,7 @@
 #include <set>
 #include <string>
 
+#include "layout.hpp"
 #include "result.hpp"
 #include "wayland.hpp"
 
@@ -57,6 +58,8 @@ struct layer {
    std::string role;
    // XXX perhaps a zorder is needed here?
    std::vector<struct split_layout> layouts;
+   // XXX need to change the way we store these things...
+   mutable struct LayoutState state;
 
    explicit layer(nlohmann::json const &j);
 
@@ -88,6 +91,13 @@ struct layer_map {
 
    optional<int> get_layer_id(int surface_id);
    optional<int> get_layer_id(std::string const &role);
+   optional<struct LayoutState*> get_layout_state(int surface_id) {
+      int layer_id = *this->get_layer_id(surface_id);
+      auto i = std::find_if(
+              std::begin(this->mapping), std::end(this->mapping),
+              [layer_id](struct layer const &l) { return layer_id == l.layer_id; });
+      return i == this->mapping.end() ? nullopt : optional<struct LayoutState *>(&i->state);
+   }
    optional<struct layer> get_layer(int layer_id) {
       auto i = std::find_if(
          std::cbegin(this->mapping), std::cend(this->mapping),