GHOST/Wayland: support window activation

Calling render (for example) with an existing window open now activates
the window on Wayland. Tested to work on GNOME & KDE.

Use the xdg-activation protocol which typically brings the
window to the foreground.

Partially resolves #102985.

intern/ghost/CMakeLists.txt

@@ -398,6 +398,10 @@ elseif(WITH_GHOST_X11 OR WITH_GHOST_WAYLAND)
     generate_protocol_bindings(
       "${WAYLAND_PROTOCOLS_DIR}/unstable/xdg-output/xdg-output-unstable-v1.xml"
     )
+    # `xdg-activation`.
+    generate_protocol_bindings(
+      "${WAYLAND_PROTOCOLS_DIR}/staging/xdg-activation/xdg-activation-v1.xml"
+    )
     # Pointer-constraints.
     generate_protocol_bindings(
       "${WAYLAND_PROTOCOLS_DIR}/unstable/pointer-constraints/pointer-constraints-unstable-v1.xml"

intern/ghost/intern/GHOST_SystemWayland.cpp

@@ -59,6 +59,7 @@
 #include <primary-selection-unstable-v1-client-protocol.h>
 #include <relative-pointer-unstable-v1-client-protocol.h>
 #include <tablet-unstable-v2-client-protocol.h>
+#include <xdg-activation-v1-client-protocol.h>
 #include <xdg-output-unstable-v1-client-protocol.h>
 
 /* Decorations `xdg_decor`. */
@@ -934,6 +935,7 @@ struct GWL_Display {
   struct zwp_tablet_manager_v2 *wp_tablet_manager = nullptr;
   struct zwp_relative_pointer_manager_v1 *wp_relative_pointer_manager = nullptr;
   struct zwp_primary_selection_device_manager_v1 *wp_primary_selection_device_manager = nullptr;
+  struct xdg_activation_v1 *xdg_activation_manager = nullptr;
 
   struct zwp_pointer_constraints_v1 *wp_pointer_constraints = nullptr;
   struct zwp_pointer_gestures_v1 *wp_pointer_gestures = nullptr;
@@ -5161,6 +5163,24 @@ static void gwl_registry_wp_pointer_gestures_remove(GWL_Display *display,
   *value_p = nullptr;
 }
 
+/* #GWL_Display.xdg_activation */
+
+static void gwl_registry_xdg_activation_add(GWL_Display *display,
+                                            const GWL_RegisteryAdd_Params *params)
+{
+  display->xdg_activation_manager = static_cast<xdg_activation_v1 *>(
+      wl_registry_bind(display->wl_registry, params->name, &xdg_activation_v1_interface, 1));
+  gwl_registry_entry_add(display, params, nullptr);
+}
+static void gwl_registry_xdg_activation_remove(GWL_Display *display,
+                                               void * /*user_data*/,
+                                               const bool /*on_exit*/)
+{
+  struct xdg_activation_v1 **value_p = &display->xdg_activation_manager;
+  xdg_activation_v1_destroy(*value_p);
+  *value_p = nullptr;
+}
+
 /* #GWL_Display.wp_primary_selection_device_manager */
 
 static void gwl_registry_wp_primary_selection_device_manager_add(
@@ -5264,6 +5284,12 @@ static const GWL_RegistryHandler gwl_registry_handlers[] = {
         nullptr,
         gwl_registry_wp_pointer_gestures_remove,
     },
+    {
+        &xdg_activation_v1_interface.name,
+        gwl_registry_xdg_activation_add,
+        nullptr,
+        gwl_registry_xdg_activation_remove,
+    },
     /* Display outputs. */
     {
         &wl_output_interface.name,
@@ -6823,6 +6849,11 @@ struct zwp_primary_selection_device_manager_v1 *GHOST_SystemWayland::wp_primary_
   return display_->wp_primary_selection_device_manager;
 }
 
+struct xdg_activation_v1 *GHOST_SystemWayland::xdg_activation_manager()
+{
+  return display_->xdg_activation_manager;
+}
+
 struct zwp_pointer_gestures_v1 *GHOST_SystemWayland::wp_pointer_gestures()
 {
   return display_->wp_pointer_gestures;
@@ -6934,6 +6965,16 @@ void GHOST_SystemWayland::seat_active_set(const struct GWL_Seat *seat)
   gwl_display_seat_active_set(display_, seat);
 }
 
+struct wl_seat *GHOST_SystemWayland::wl_seat_active_get_with_input_serial(uint32_t &serial)
+{
+  GWL_Seat *seat = gwl_display_seat_active_get(display_);
+  if (seat) {
+    serial = seat->data_source_serial;
+    return seat->wl_seat;
+  }
+  return nullptr;
+}
+
 bool GHOST_SystemWayland::window_surface_unref(const wl_surface *wl_surface)
 {
   bool changed = false;

intern/ghost/intern/GHOST_SystemWayland.h

@@ -179,6 +179,7 @@ class GHOST_SystemWayland : public GHOST_System {
   struct wl_display *wl_display();
   struct wl_compositor *wl_compositor();
   struct zwp_primary_selection_device_manager_v1 *wp_primary_selection_manager();
+  struct xdg_activation_v1 *xdg_activation_manager();
   struct zwp_pointer_gestures_v1 *wp_pointer_gestures();
 
 #ifdef WITH_GHOST_WAYLAND_LIBDECOR
@@ -205,6 +206,8 @@ class GHOST_SystemWayland : public GHOST_System {
   /** Set this seat to be active. */
   void seat_active_set(const struct GWL_Seat *seat);
 
+  struct wl_seat *wl_seat_active_get_with_input_serial(uint32_t &serial);
+
   /**
    * Clear all references to this output.
    *

intern/ghost/intern/GHOST_WindowWayland.cpp

@@ -35,6 +35,7 @@
 #endif
 
 /* Generated by `wayland-scanner`. */
+#include <xdg-activation-v1-client-protocol.h>
 #include <xdg-decoration-unstable-v1-client-protocol.h>
 #include <xdg-shell-client-protocol.h>
 
@@ -43,6 +44,8 @@
 /* Logging, use `ghost.wl.*` prefix. */
 #include "CLG_log.h"
 
+static const struct xdg_activation_token_v1_listener *xdg_activation_listener_get();
+
 static constexpr size_t base_dpi = 96;
 
 #ifdef WITH_GHOST_WAYLAND_LIBDECOR
@@ -111,6 +114,9 @@ struct GWL_Window {
    */
   wl_fixed_t scale_fractional = 0;
 
+  /** A temporary token used for the window to be notified of of it's activation. */
+  struct xdg_activation_token_v1 *xdg_activation_token = nullptr;
+
 #ifdef WITH_GHOST_WAYLAND_LIBDECOR
   WGL_LibDecor_Window *libdecor = nullptr;
 #endif
@@ -281,6 +287,61 @@ static bool gwl_window_state_set(GWL_Window *win, const GHOST_TWindowState state
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name Internal #GWL_Window Activation
+ * \{ */
+
+/**
+ * Unlike #GHOST_WindowWayland::activate which responds to WAYLAND having set the window active.
+ * This function makes a request to WAYLAND for the window to become active.
+ *
+ * \note The request may be ignored and may not work on all compositors.
+ */
+static void gwl_window_activate(GWL_Window *win)
+{
+  GHOST_SystemWayland *system = win->ghost_system;
+  struct xdg_activation_v1 *activation_manager = system->xdg_activation_manager();
+  if (UNLIKELY(activation_manager == nullptr)) {
+    return;
+  }
+
+  if (win->xdg_activation_token) {
+    /* We're about to overwrite this with a new request. */
+    xdg_activation_token_v1_destroy(win->xdg_activation_token);
+  }
+  win->xdg_activation_token = xdg_activation_v1_get_activation_token(activation_manager);
+
+  xdg_activation_token_v1_add_listener(
+      win->xdg_activation_token, xdg_activation_listener_get(), win);
+
+  xdg_activation_token_v1_set_app_id(win->xdg_activation_token, GHOST_SystemWayland::xdg_app_id());
+
+  /* The serial of the input device requesting activation. */
+  {
+    uint32_t serial = 0;
+    struct wl_seat *seat = system->wl_seat_active_get_with_input_serial(serial);
+    if (seat) {
+      xdg_activation_token_v1_set_serial(win->xdg_activation_token, serial, seat);
+    }
+  }
+
+  /* The surface of the window requesting activation. */
+  {
+    GHOST_WindowWayland *ghost_window_active = static_cast<GHOST_WindowWayland *>(
+        system->getWindowManager()->getActiveWindow());
+    if (ghost_window_active) {
+      struct wl_surface *surface = ghost_window_active->wl_surface();
+      if (surface) {
+        xdg_activation_token_v1_set_surface(win->xdg_activation_token, surface);
+      }
+    }
+  }
+
+  xdg_activation_token_v1_commit(win->xdg_activation_token);
+}
+
+/** \} */
+
 /* -------------------------------------------------------------------- */
 /** \name Internal #GWL_Window Pending Actions
  * \{ */
@@ -521,6 +582,39 @@ static const xdg_toplevel_listener xdg_toplevel_listener = {
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name Listener (XDG Activation), #xdg_activation_v1_interface
+ *
+ * Used by #gwl_window_activate.
+ * \{ */
+
+static void xdg_activation_handle_done(void *data,
+                                       struct xdg_activation_token_v1 *xdg_activation_token_v1,
+                                       const char *token)
+{
+  GWL_Window *win = static_cast<GWL_Window *>(data);
+  if (xdg_activation_token_v1 != win->xdg_activation_token) {
+    return;
+  }
+
+  GHOST_SystemWayland *system = win->ghost_system;
+  struct xdg_activation_v1 *activation_manager = system->xdg_activation_manager();
+  xdg_activation_v1_activate(activation_manager, token, win->wl_surface);
+  xdg_activation_token_v1_destroy(win->xdg_activation_token);
+  win->xdg_activation_token = nullptr;
+}
+
+static const struct xdg_activation_token_v1_listener xdg_activation_listener = {
+    /*done*/ xdg_activation_handle_done,
+};
+
+static const struct xdg_activation_token_v1_listener *xdg_activation_listener_get()
+{
+  return &xdg_activation_listener;
+}
+
+/** \} */
+
 /* -------------------------------------------------------------------- */
 /** \name Listener (LibDecor Frame), #libdecor_frame_interface
  * \{ */
@@ -1060,6 +1154,11 @@ GHOST_WindowWayland::~GHOST_WindowWayland()
 
   wl_egl_window_destroy(window_->egl_window);
 
+  if (window_->xdg_activation_token) {
+    xdg_activation_token_v1_destroy(window_->xdg_activation_token);
+    window_->xdg_activation_token = nullptr;
+  }
+
 #ifdef WITH_GHOST_WAYLAND_LIBDECOR
   if (use_libdecor) {
     gwl_libdecor_window_destroy(window_->libdecor);
@@ -1123,8 +1222,16 @@ GHOST_TSuccess GHOST_WindowWayland::invalidate()
   return GHOST_kSuccess;
 }
 
-GHOST_TSuccess GHOST_WindowWayland::setOrder(GHOST_TWindowOrder /*order*/)
+GHOST_TSuccess GHOST_WindowWayland::setOrder(GHOST_TWindowOrder order)
 {
+  /* NOTE(@ideasman42): only activation is supported (on X11 & Cocoa for e.g.)
+   * both activation and raising is performed. Since WAYLAND only supports activation,
+   * do that as the compositor will likely raise the window as well.
+   * Although it's not ideal that raising does something but lowering a window is ignored. */
+  if (order == GHOST_kWindowOrderTop) {
+    gwl_window_activate(window_);
+  }
+
   return GHOST_kSuccess;
 }