[client] wayland: set the application icon

client/displayservers/Wayland/CMakeLists.txt

@@ -16,6 +16,7 @@ add_library(displayserver_Wayland STATIC
   colormgmt.c
   cursor.c
   gl.c
+  icon.c
   idle.c
   input.c
   output.c
@@ -33,6 +34,7 @@ add_subdirectory(desktops)
 target_link_libraries(displayserver_Wayland
   PkgConfig::DISPLAYSERVER_Wayland
   lg_common
+  lg_resources
   wayland_protocol
   wayland_desktops
 )

client/displayservers/Wayland/desktops/libdecor/libdecor.c

@@ -142,6 +142,11 @@ static bool libdecor_shellInit(
   libdecor_frame_set_title(state.libdecorFrame, title);
   libdecor_frame_map(state.libdecorFrame);
 
+  // Get the xdg_toplevel for icon setting
+  struct xdg_surface * xdgSurface = libdecor_frame_get_xdg_surface(state.libdecorFrame);
+  if (xdgSurface)
+    wlWm.xdgToplevel = xdg_surface_get_toplevel(xdgSurface);
+
   if (fullscreen)
     libdecor_frame_set_fullscreen(state.libdecorFrame, NULL);
 

client/displayservers/Wayland/desktops/xdg/xdg.c

@@ -149,6 +149,7 @@ bool xdg_shellInit(struct wl_display * display, struct wl_surface * surface,
   xdg_toplevel_add_listener(state.toplevel, &xdgToplevelListener, NULL);
   xdg_toplevel_set_title(state.toplevel, title);
   xdg_toplevel_set_app_id(state.toplevel, appId);
+  wlWm.xdgToplevel = state.toplevel;
 
   if (fullscreen)
     xdg_toplevel_set_fullscreen(state.toplevel, NULL);

client/displayservers/Wayland/icon.c

@@ -0,0 +1,136 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#define _GNU_SOURCE
+#include "wayland.h"
+
+#include <stdbool.h>
+#include <string.h>
+
+#include <errno.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <wayland-client.h>
+
+#include "common/debug.h"
+#include "resources/icondata.h"
+
+// icondata is defined as an array of unsigned long, but on 64-bit platforms
+// unsigned long is 8 bytes while the actual data is 32-bit ARGB packed in
+// unsigned long values (the top 32 bits are zero). The first two values are
+// width and height (both 64), followed by pixel rows.
+// We need to convert this to a uint32_t buffer for wl_shm (ARGB8888).
+//
+// Note: sizeof(icondata) / sizeof(icondata[0]) gives the total array length,
+// which includes the 2 header values + 64*64 = 4096 pixel values = 4098 total.
+
+#define ICON_SIZE 64
+// header: width and height, then pixel data
+#define ICON_HEADER_WORDS 2
+#define ICON_PIXEL_WORDS (ICON_SIZE * ICON_SIZE)
+#define ICON_TOTAL_WORDS (ICON_HEADER_WORDS + ICON_PIXEL_WORDS)
+
+static uint32_t g_iconPixels[ICON_SIZE * ICON_SIZE];
+
+bool waylandIconInit(void)
+{
+  if (!wlWm.iconManager || !wlWm.xdgToplevel || !wlWm.shm)
+    return true; // not an error, just no support
+
+  for (size_t i = 0; i < ICON_TOTAL_WORDS; ++i)
+  {
+    if (i >= icondataSize / sizeof(icondata[0]))
+    {
+      DEBUG_ERROR("Icon data array is smaller than expected");
+      return true;
+    }
+    uint32_t val = (uint32_t)icondata[i];
+    // First two words are width/height, skip them
+    if (i >= ICON_HEADER_WORDS)
+      g_iconPixels[i - ICON_HEADER_WORDS] = val;
+  }
+
+  // Create shared memory buffer for the icon
+  size_t dataSize = sizeof(g_iconPixels);
+  int fd = memfd_create("lg-icon", 0);
+  if (fd < 0)
+  {
+    DEBUG_ERROR("Failed to create icon shared memory: %d", errno);
+    return true; // not fatal
+  }
+
+  struct wl_buffer * buffer = NULL;
+  struct xdg_toplevel_icon_v1 * icon = NULL;
+
+  if (ftruncate(fd, (off_t)dataSize) < 0)
+  {
+    DEBUG_ERROR("Failed to ftruncate icon shared memory: %d", errno);
+    goto fail;
+  }
+
+  void * shm_data = mmap(NULL, dataSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+  if (shm_data == MAP_FAILED)
+  {
+    DEBUG_ERROR("Failed to mmap icon shared memory: %d", errno);
+    goto fail;
+  }
+
+  memcpy(shm_data, g_iconPixels, dataSize);
+  munmap(shm_data, dataSize);
+
+  struct wl_shm_pool * pool = wl_shm_create_pool(wlWm.shm, fd, (int32_t)dataSize);
+  buffer = wl_shm_pool_create_buffer(pool, 0, ICON_SIZE, ICON_SIZE,
+      ICON_SIZE * 4, WL_SHM_FORMAT_ARGB8888);
+  wl_shm_pool_destroy(pool);
+
+  if (!buffer)
+  {
+    DEBUG_ERROR("Failed to create wl_buffer for icon");
+    goto fail;
+  }
+
+  icon = xdg_toplevel_icon_manager_v1_create_icon(wlWm.iconManager);
+  if (!icon)
+  {
+    DEBUG_ERROR("Failed to create icon object");
+    goto fail;
+  }
+
+  xdg_toplevel_icon_v1_add_buffer(icon, buffer, 1);
+  xdg_toplevel_icon_manager_v1_set_icon(wlWm.iconManager,
+      (struct xdg_toplevel *)wlWm.xdgToplevel, icon);
+
+  // After set_icon, the icon object is immutable. We can destroy it;
+  // the compositor retains its data.
+  xdg_toplevel_icon_v1_destroy(icon);
+  wl_buffer_destroy(buffer);
+
+  close(fd);
+  return true;
+
+fail:
+  if (icon)
+    xdg_toplevel_icon_v1_destroy(icon);
+  if (buffer)
+    wl_buffer_destroy(buffer);
+  close(fd);
+
+  return true; // not fatal
+}

client/displayservers/Wayland/protocol/CMakeLists.txt

@@ -69,6 +69,9 @@ wayland_generate(
 wayland_generate(
   "${WAYLAND_PROTOCOLS_BASE}/staging/color-management/color-management-v1.xml"
   "${CMAKE_BINARY_DIR}/wayland/wayland-color-management-v1-client-protocol")
+wayland_generate(
+  "${WAYLAND_PROTOCOLS_BASE}/staging/xdg-toplevel-icon/xdg-toplevel-icon-v1.xml"
+  "${CMAKE_BINARY_DIR}/wayland/wayland-xdg-toplevel-icon-v1-client-protocol")
 
 target_link_libraries(wayland_protocol
   PkgConfig::WAYLAND

client/displayservers/Wayland/registry.c

@@ -77,6 +77,9 @@ static void registryGlobalHandler(void * data, struct wl_registry * registry,
   else if (!strcmp(interface, wp_color_manager_v1_interface.name))
     wlWm.colorManager = wl_registry_bind(wlWm.registry, name,
         &wp_color_manager_v1_interface, 1);
+  else if (!strcmp(interface, xdg_toplevel_icon_manager_v1_interface.name))
+    wlWm.iconManager = wl_registry_bind(wlWm.registry, name,
+        &xdg_toplevel_icon_manager_v1_interface, 1);
   else if (wlWm.desktop->registryGlobalHandler(
         data, registry, name, interface, version))
     return;

client/displayservers/Wayland/wayland.c

@@ -170,6 +170,8 @@ static bool waylandInit(const LG_DSInitParams params)
   if (!waylandEGLInit(params.w, params.h))
     return false;
 
+  waylandIconInit();
+
 #ifdef ENABLE_OPENGL
   if (params.opengl && !waylandOpenGLInit())
     return false;

client/displayservers/Wayland/wayland.h

@@ -50,6 +50,7 @@
 #include "wayland-fractional-scale-v1-client-protocol.h"
 #include "wayland-content-type-v1-client-protocol.h"
 #include "wayland-color-management-v1-client-protocol.h"
+#include "wayland-xdg-toplevel-icon-v1-client-protocol.h"
 
 #include "scale.h"
 
@@ -205,6 +206,12 @@ struct WaylandDSState
   bool cmHasPerceptualIntent;
   bool cmCanDoHDR;       // true if compositor supports features needed for HDR
 
+  // toplevel icon manager
+  struct xdg_toplevel_icon_manager_v1 * iconManager;
+
+  // set by the active desktop backend during shellInit
+  void * xdgToplevel;
+
   // Pending HDR format to apply (set by frame thread, applied in swap buffers).
   // pendingHDRApply and pendingHDRClear are accessed from multiple threads
   // without a lock, so they must be atomic.
@@ -370,3 +377,6 @@ bool waylandWaitFrame(void);
 void waylandSkipFrame(void);
 void waylandStopWaitFrame(void);
 void waylandNeedsResize(void);
+
+// icon module
+bool waylandIconInit(void);

client/displayservers/X11/x11.c

@@ -617,7 +617,7 @@ static bool x11Init(const LG_DSInitParams params)
     32,
     PropModeReplace,
     (unsigned char *)icondata,
-    sizeof(icondata) / sizeof(icondata[0])
+    icondataSize / sizeof(icondata[0])
   );
 
   /* create the blank cursor */