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>

4 files changed, 85 insertions, 60 deletions

diff --git a/src/app.cpp b/src/app.cpp
index 7673ba9..c0cb100 100644
--- a/src/app.cpp
+++ b/src/app.cpp
@@ -332,10 +332,6 @@ void App::surface_set_layout_split(uint32_t surface_id, uint32_t sub_surface_id)
    int w = rect.w;
    int h = rect.h;
 
-   this->state.main = surface_id;
-   this->state.sub = sub_surface_id;
-   this->state.s = LayoutState::Split;
-
    // less-than-0 values refer to MAX + 1 - $VALUE
    // e.g. MAX is either screen width or height
    if (w < 0) {
@@ -390,67 +386,83 @@ char const *App::activate_surface(char const *drawing_name) {
       return "Surface does not exist in controller!";
    }
 
-   if (this->state.main == *surface_id || this->state.sub == *surface_id) {
-      return "Surface already active";
-   }
+   auto layer_id = *this->layers.get_layer_id(*surface_id);
+   struct LayoutState &state = **this->layers.get_layout_state(*surface_id);
 
-   // Special case main_surface
-   if (*surface_id == this->layers.main_surface) {
-      for (auto const &s: this->controller->surfaces) {
-         if (s.second->id != *surface_id) {
-            this->deactivate(s.second->id);
-         }
+   logdebug("state @ %p = { %d, %d, %d }", &state, state.main, state.sub, state.s);
+
+   // disable layers that are above our current layer
+   for (auto const &l : this->layers.mapping) {
+      if (l.layer_id <= layer_id) {
+         continue;
+      }
+
+      bool flush = false;
+      if (l.state.main != -1) {
+         this->deactivate(l.state.main);
+         l.state.main = -1;
+         flush = true;
+      }
+
+      if (l.state.sub != -1) {
+         this->deactivate(l.state.sub);
+         l.state.sub = -1;
+         flush = true;
+      }
+
+      l.state.s = LayoutState::Single;
+
+      if (flush) {
+         this->controller->commit_changes();
+         this->display->flush();
       }
-      this->activate(*surface_id);
-      this->state.main = this->state.sub = -1;
-      this->state.s = LayoutState::Single;
-      // commit changes
-      this->controller->commit_changes();
-      this->display->flush();
-      return nullptr;
+   }
+
+   if (state.main == *surface_id || state.sub == *surface_id) {
+      return "Surface already active";
    }
 
    // This should involve a policy check, but as we do not (yet) have
    // such a thing, we will just switch to this surface.
    // XXX: input focus missing!!1
 
-   if (this->state.main == -1) {
+   if (state.main == -1) {
       this->emit_syncdraw(drawing_name);
 
       this->surface_set_layout_full(*surface_id);
       this->activate(*surface_id);
-      this->state.main = *surface_id;
-      this->state.sub = -1;
-      this->state.s = LayoutState::Single;
+      state.main = *surface_id;
+      state.sub = -1;
+      state.s = LayoutState::Single;
 
       this->emit_flushdraw(drawing_name);
    } else {
-      bool can_split = this->can_split(*surface_id);
+      bool can_split = this->can_split(state, *surface_id);
 
-      if (this->state.sub == -1) {
+      if (state.sub == -1) {
          if (can_split) {
-            if (this->state.main != *surface_id) {
+            if (state.main != *surface_id) {
                this->emit_syncdraw(drawing_name);
-               this->emit_syncdraw(this->lookup_name(this->state.main)->c_str());
+               this->emit_syncdraw(this->lookup_name(state.main)->c_str());
 
-               this->surface_set_layout_split(this->state.main, *surface_id);
+               this->surface_set_layout_split(state.main, *surface_id);
                this->activate(*surface_id);
-               this->state.sub = *surface_id;
+               state.sub = *surface_id;
 
                // Should wait for EndDraw event...
                this->emit_flushdraw(drawing_name);
-               this->emit_flushdraw(this->lookup_name(this->state.main)->c_str());
+               this->emit_flushdraw(this->lookup_name(state.main)->c_str());
             }
          } else {
             this->emit_syncdraw(drawing_name);
 
             this->surface_set_layout_full(*surface_id);
-            this->deactivate(this->state.main);
+            this->deactivate(state.main);
             this->activate(*surface_id);
-            this->deactivate(this->state.sub);
-            this->state.main = *surface_id;
-            this->state.sub = -1;
-            this->state.s = LayoutState::Single;
+            this->deactivate(state.sub);
+            state.main = *surface_id;
+            state.sub = -1;
+            state.s = LayoutState::Single;
 
             this->emit_flushdraw(drawing_name);
          }
@@ -477,7 +489,9 @@ char const *App::deactivate_surface(char const *drawing_name) {
       return "Cannot deactivate main_surface";
    }
 
-   if (this->state.main == -1) {
+   struct LayoutState &state = **this->layers.get_layout_state(*surface_id);
+
+   if (state.main == -1) {
       return "No surface active";
    }
 
@@ -486,31 +500,33 @@ char const *App::deactivate_surface(char const *drawing_name) {
       return nullptr;
    }
 
-   if (this->state.main == *surface_id) {
-      if (this->state.sub != -1) {
-         this->emit_syncdraw(this->lookup_name(this->state.sub)->c_str());
+   logdebug("state @ %p = { %d, %d, %d }", &state, state.main, state.sub, state.s);
+
+   if (state.main == *surface_id) {
+      if (state.sub != -1) {
+         this->emit_syncdraw(this->lookup_name(state.sub)->c_str());
 
          this->deactivate(*surface_id);
-         this->surface_set_layout_full(this->state.sub);
-         this->state.main = this->state.sub;
-         this->state.sub = -1;
-         this->state.s = LayoutState::Single;
+         this->surface_set_layout_full(state.sub);
+         state.main = state.sub;
+         state.sub = -1;
+         state.s = LayoutState::Single;
 
-         this->emit_flushdraw(this->lookup_name(this->state.sub)->c_str());
+         this->emit_flushdraw(this->lookup_name(state.sub)->c_str());
       } else {
          this->deactivate(*surface_id);
-         this->state.main = -1;
+         state.main = -1;
       }
-   }else if (this->state.sub == *surface_id) {
-      this->emit_syncdraw(this->lookup_name(this->state.main)->c_str());
+   }else if (state.sub == *surface_id) {
+      this->emit_syncdraw(this->lookup_name(state.main)->c_str());
 
       this->deactivate(*surface_id);
       this->deactivate(*surface_id);
-      this->surface_set_layout_full(this->state.main);
-      this->state.sub = -1;
-      this->state.s = LayoutState::Single;
+      this->surface_set_layout_full(state.main);
+      state.sub = -1;
+      state.s = LayoutState::Single;
 
-      this->emit_flushdraw(this->lookup_name(this->state.main)->c_str());
+      this->emit_flushdraw(this->lookup_name(state.main)->c_str());
    } else {
       return "Surface is not active";
    }
@@ -621,11 +637,11 @@ void App::deactivate(int id) {
    }
 }
 
-bool App::can_split(int new_id) {
-   if (this->state.main != -1 && this->state.main != new_id) {
+bool App::can_split(struct LayoutState const &state, int new_id) {
+   if (state.main != -1 && state.main != new_id) {
       auto new_id_layer = this->layers.get_layer_id(new_id).value();
       auto current_id_layer =
-         this->layers.get_layer_id(this->state.main).value();
+         this->layers.get_layer_id(state.main).value();
 
       // surfaces are on separate layers, don't bother.
       if (new_id_layer != current_id_layer) {
@@ -634,7 +650,7 @@ bool App::can_split(int new_id) {
 
       std::string const &new_id_str = this->lookup_name(new_id).value();
       std::string const &cur_id_str =
-         this->lookup_name(this->state.main).value();
+         this->lookup_name(state.main).value();
 
       auto const &layer = this->layers.get_layer(new_id_layer);
 
diff --git a/src/app.hpp b/src/app.hpp
index 297b6af..2e5478b 100644
--- a/src/app.hpp
+++ b/src/app.hpp
@@ -127,8 +127,6 @@ struct App {
       return this->id_alloc.lookup(id);
    }
 
-   struct LayoutState state;
-
    // Set by AFB API when wayland events need to be dispatched
    std::atomic<bool> pending_events;
    void set_pending_events() {
@@ -180,7 +178,7 @@ struct App {
    void activate(int id);
    void deactivate(int id);
 
-   bool can_split(int new_id);
+   bool can_split(struct LayoutState const &state, int new_id);
 };
 
 }  // namespace wm
diff --git a/src/layers.cpp b/src/layers.cpp
index d0a769a..a0665b7 100644
--- a/src/layers.cpp
+++ b/src/layers.cpp
@@ -87,7 +87,8 @@ struct result<struct layer_map> to_layer_map(nlohmann::json const &j) {
             return unsigned(k.layer_id);
          });
 
-      // XXX need to sort layers?
+      std::sort(stl.layers.begin(), stl.layers.end());
+
       for (auto i : stl.mapping) {
          if (i.name.empty()) {
             return Err<struct layer_map>("Found mapping w/o name");
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),