app/api: add demo_activate_surface() api_binding

* Added "main_surface" entry to layers.json.
* This surface is never made invisible by activate_surface().

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

1 files changed, 5 insertions, 0 deletions

diff --git a/src/layers.cpp b/src/layers.cpp
index b5ce2ed..6eae48a 100644
--- a/src/layers.cpp
+++ b/src/layers.cpp
@@ -71,6 +71,11 @@ struct result<struct layer_map> to_layer_map(nlohmann::json const &j) {
          }
       }
 
+      auto msi = j.find("main_surface");
+      if (msi != j.end()) {
+         stl.main_surface = get<int>((*msi)["surface_id"]);
+      }
+
       // Check lookup
       auto jtests = j.value("tests", json());