session-manager: implement configurable server-side decoration

Author: thdaemon

scripts/snap-wrapper.sh

@@ -47,6 +47,10 @@ if [ "$(snapctl get touch-emulation.enable)" = false ]; then
 	export ANBOX_ENABLE_TOUCH_EMULATION=false
 fi
 
+if [ "$(snapctl get server-side-decoration.enable)" = true ]; then
+	export ANBOX_FORCE_SERVER_SIDE_DECORATION=true
+fi
+
 # Use custom Anbox binary for debugging purposes if available
 ANBOX="$SNAP"/usr/bin/anbox
 if [ -e "$SNAP_COMMON"/anbox.debug ]; then

src/anbox/cmds/session_manager.cpp

@@ -115,6 +115,9 @@ anbox::cmds::SessionManager::SessionManager()
   flag(cli::make_flag(cli::Name{"no-touch-emulation"},
                       cli::Description{"Disable touch emulation applied on mouse inputs"},
                       no_touch_emulation_));
+  flag(cli::make_flag(cli::Name{"server-side-decoration"},
+                      cli::Description{"Prefer to use server-side decoration instead of client-side decoration"},
+                      server_side_decoration_));
 
   action([this](const cli::Command::Context &) {
     auto trap = core::posix::trap_signals_for_process(
@@ -161,10 +164,15 @@ anbox::cmds::SessionManager::SessionManager()
     if (should_enable_touch_emulation == "false" || no_touch_emulation_)
       no_touch_emulation_ = true;
 
+    const auto should_force_server_side_decoration = utils::get_env_value("ANBOX_FORCE_SERVER_SIDE_DECORATION", "false");
+    if (should_force_server_side_decoration == "true")
+      server_side_decoration_ = true;
+
     platform::Configuration platform_config;
     platform_config.single_window = single_window_;
     platform_config.no_touch_emulation = no_touch_emulation_;
     platform_config.display_frame = display_frame;
+    platform_config.server_side_decoration = server_side_decoration_;
 
     auto platform = platform::create(utils::get_env_value("ANBOX_PLATFORM", "sdl"),
                                      input_manager,
@@ -259,6 +267,9 @@ anbox::cmds::SessionManager::SessionManager()
     // See https://github.com/anbox/anbox/issues/780 for further details.
     container_configuration.extra_properties.push_back("ro.boot.fake_battery=1");
 
+    if (server_side_decoration_)
+        container_configuration.extra_properties.push_back("ro.anbox.no_decorations=1");
+
     if (!standalone_) {
       container_configuration.bind_mounts = {
         {qemu_pipe_connector->socket_file(), "/dev/qemu_pipe"},

src/anbox/cmds/session_manager.h

@@ -51,6 +51,7 @@ class SessionManager : public cli::CommandWithFlagsAndAction {
   bool use_system_dbus_ = false;
   bool use_software_rendering_ = false;
   bool no_touch_emulation_ = false;
+  bool server_side_decoration_ = false;
 };
 }  // namespace cmds
 }  // namespace anbox

src/anbox/platform/base_platform.h

@@ -64,6 +64,7 @@ struct Configuration {
   graphics::Rect display_frame = graphics::Rect::Invalid;
   bool single_window = false;
   bool no_touch_emulation = false;
+  bool server_side_decoration = false;
 };
 
 std::shared_ptr<BasePlatform> create(const std::string &name,

src/anbox/platform/sdl/platform.cpp

@@ -418,7 +418,8 @@ std::shared_ptr<wm::Window> Platform::create_window(
   }
 
   auto id = next_window_id();
-  auto w = std::make_shared<Window>(renderer_, id, task, shared_from_this(), frame, title, !window_size_immutable_);
+  auto w = std::make_shared<Window>(renderer_, id, task, shared_from_this(), frame, title,
+		  !window_size_immutable_, !config_.server_side_decoration);
   focused_sdl_window_id_ = w->window_id();
   windows_.insert({id, w});
   return w;

src/anbox/platform/sdl/window.cpp

@@ -46,7 +46,8 @@ Window::Window(const std::shared_ptr<Renderer> &renderer,
                const std::shared_ptr<Observer> &observer,
                const graphics::Rect &frame,
                const std::string &title,
-               bool resizable)
+               bool resizable,
+               bool borderless)
     : wm::Window(renderer, task, frame, title),
       id_(id),
       observer_(observer),
@@ -59,7 +60,9 @@ Window::Window(const std::shared_ptr<Renderer> &renderer,
   // initializing GL here will cause a surface to be created and the
   // renderer will attempt to create one too which will not work as
   // only a single surface per EGLNativeWindowType is supported.
-  std::uint32_t flags = SDL_WINDOW_BORDERLESS;
+  std::uint32_t flags = 0;
+  if (borderless)
+    flags |= SDL_WINDOW_BORDERLESS;
   if (resizable)
     flags |= SDL_WINDOW_RESIZABLE;
 
@@ -72,7 +75,10 @@ Window::Window(const std::shared_ptr<Renderer> &renderer,
     BOOST_THROW_EXCEPTION(std::runtime_error(message));
   }
 
-  if (utils::get_env_value("ANBOX_NO_SDL_WINDOW_HIT_TEST", "false") == "false")
+  // If we create a window with border (server-side decoration), We
+  // should not set hit test handler beacuse we don't need to simulate
+  // the behavior of the title bar and resize area.
+  if (borderless && utils::get_env_value("ANBOX_NO_SDL_WINDOW_HIT_TEST", "false") == "false")
     if (SDL_SetWindowHitTest(window_, &Window::on_window_hit, this) < 0)
       BOOST_THROW_EXCEPTION(std::runtime_error("Failed to register for window hit test"));
 

src/anbox/platform/sdl/window.h

@@ -52,7 +52,8 @@ class Window : public std::enable_shared_from_this<Window>, public wm::Window {
          const std::shared_ptr<Observer> &observer,
          const graphics::Rect &frame,
          const std::string &title,
-         bool resizable);
+         bool resizable,
+         bool borderless);
   ~Window();
 
   void process_event(const SDL_Event &event);