From f8e6fca745f27adc8f40f022d415b4ac7cbc375e Mon Sep 17 00:00:00 2001
From: JakobDev <jakobdev@gmx.de>
Date: Wed, 12 Feb 2025 19:24:19 +0100
Subject: [PATCH] Wayland: Implement glfwSetWindowIcon

---
 deps/wayland/xdg-toplevel-icon-v1.xml | 205 ++++++++++++++++++++++++++
 include/GLFW/glfw3.h                  |   6 +-
 src/CMakeLists.txt                    |   1 +
 src/wl_init.c                         |  14 ++
 src/wl_platform.h                     |   1 +
 src/wl_window.c                       |  52 ++++++-
 6 files changed, 274 insertions(+), 5 deletions(-)
 create mode 100644 deps/wayland/xdg-toplevel-icon-v1.xml

diff --git a/deps/wayland/xdg-toplevel-icon-v1.xml b/deps/wayland/xdg-toplevel-icon-v1.xml
new file mode 100644
index 0000000000..fc409fef7c
--- /dev/null
+++ b/deps/wayland/xdg-toplevel-icon-v1.xml
@@ -0,0 +1,205 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="xdg_toplevel_icon_v1">
+
+  <copyright>
+    Copyright © 2023-2024 Matthias Klumpp
+    Copyright ©      2024 David Edmundson
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice (including the next
+    paragraph) shall be included in all copies or substantial portions of the
+    Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+  </copyright>
+
+  <description summary="protocol to assign icons to toplevels">
+    This protocol allows clients to set icons for their toplevel surfaces
+    either via the XDG icon stock (using an icon name), or from pixel data.
+
+    A toplevel icon represents the individual toplevel (unlike the application
+    or launcher icon, which represents the application as a whole), and may be
+    shown in window switchers, window overviews and taskbars that list
+    individual windows.
+
+    This document adheres to RFC 2119 when using words like "must",
+    "should", "may", etc.
+
+    Warning! The protocol described in this file is currently in the testing
+    phase. Backward compatible changes may be added together with the
+    corresponding interface version bump. Backward incompatible changes can
+    only be done by creating a new major version of the extension.
+  </description>
+
+  <interface name="xdg_toplevel_icon_manager_v1" version="1">
+    <description summary="interface to manage toplevel icons">
+      This interface allows clients to create toplevel window icons and set
+      them on toplevel windows to be displayed to the user.
+    </description>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the toplevel icon manager">
+        Destroy the toplevel icon manager.
+        This does not destroy objects created with the manager.
+      </description>
+    </request>
+
+    <request name="create_icon">
+      <description summary="create a new icon instance">
+        Creates a new icon object. This icon can then be attached to a
+        xdg_toplevel via the 'set_icon' request.
+      </description>
+      <arg name="id" type="new_id" interface="xdg_toplevel_icon_v1"/>
+    </request>
+
+    <request name="set_icon">
+      <description summary="set an icon on a toplevel window">
+        This request assigns the icon 'icon' to 'toplevel', or clears the
+        toplevel icon if 'icon' was null.
+        This state is double-buffered and is applied on the next
+        wl_surface.commit of the toplevel.
+
+        After making this call, the xdg_toplevel_icon_v1 provided as 'icon'
+        can be destroyed by the client without 'toplevel' losing its icon.
+        The xdg_toplevel_icon_v1 is immutable from this point, and any
+        future attempts to change it must raise the
+        'xdg_toplevel_icon_v1.immutable' protocol error.
+
+        The compositor must set the toplevel icon from either the pixel data
+        the icon provides, or by loading a stock icon using the icon name.
+        See the description of 'xdg_toplevel_icon_v1' for details.
+
+        If 'icon' is set to null, the icon of the respective toplevel is reset
+        to its default icon (usually the icon of the application, derived from
+        its desktop-entry file, or a placeholder icon).
+        If this request is passed an icon with no pixel buffers or icon name
+        assigned, the icon must be reset just like if 'icon' was null.
+      </description>
+      <arg name="toplevel" type="object" interface="xdg_toplevel" summary="the toplevel to act on"/>
+      <arg name="icon" type="object" interface="xdg_toplevel_icon_v1" allow-null="true"/>
+    </request>
+
+    <event name="icon_size">
+      <description summary="describes a supported &amp; preferred icon size">
+        This event indicates an icon size the compositor prefers to be
+        available if the client has scalable icons and can render to any size.
+
+        When the 'xdg_toplevel_icon_manager_v1' object is created, the
+        compositor may send one or more 'icon_size' events to describe the list
+        of preferred icon sizes. If the compositor has no size preference, it
+        may not send any 'icon_size' event, and it is up to the client to
+        decide a suitable icon size.
+
+        A sequence of 'icon_size' events must be finished with a 'done' event.
+        If the compositor has no size preferences, it must still send the
+        'done' event, without any preceding 'icon_size' events.
+      </description>
+      <arg name="size" type="int"
+	   summary="the edge size of the square icon in surface-local coordinates, e.g. 64"/>
+    </event>
+
+    <event name="done">
+      <description summary="all information has been sent">
+        This event is sent after all 'icon_size' events have been sent.
+      </description>
+    </event>
+  </interface>
+
+  <interface name="xdg_toplevel_icon_v1" version="1">
+    <description summary="a toplevel window icon">
+      This interface defines a toplevel icon.
+      An icon can have a name, and multiple buffers.
+      In order to be applied, the icon must have either a name, or at least
+      one buffer assigned. Applying an empty icon (with no buffer or name) to
+      a toplevel should reset its icon to the default icon.
+
+      It is up to compositor policy whether to prefer using a buffer or loading
+      an icon via its name. See 'set_name' and 'add_buffer' for details.
+    </description>
+
+    <enum name="error">
+      <entry name="invalid_buffer"
+             summary="the provided buffer does not satisfy requirements"
+	     value="1"/>
+      <entry name="immutable"
+             summary="the icon has already been assigned to a toplevel and must not be changed"
+	     value="2"/>
+      <entry name="no_buffer"
+             summary="the provided buffer has been destroyed before the toplevel icon"
+             value="3"/>
+    </enum>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the icon object">
+        Destroys the 'xdg_toplevel_icon_v1' object.
+        The icon must still remain set on every toplevel it was assigned to,
+        until the toplevel icon is reset explicitly.
+      </description>
+    </request>
+
+    <request name="set_name">
+      <description summary="set an icon name">
+        This request assigns an icon name to this icon.
+        Any previously set name is overridden.
+
+        The compositor must resolve 'icon_name' according to the lookup rules
+        described in the XDG icon theme specification[1] using the
+        environment's current icon theme.
+
+        If the compositor does not support icon names or cannot resolve
+        'icon_name' according to the XDG icon theme specification it must
+        fall back to using pixel buffer data instead.
+
+        If this request is made after the icon has been assigned to a toplevel
+        via 'set_icon', a 'immutable' error must be raised.
+
+        [1]: https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html
+      </description>
+      <arg name="icon_name" type="string"/>
+    </request>
+
+    <request name="add_buffer">
+      <description summary="add icon data from a pixel buffer">
+        This request adds pixel data supplied as wl_buffer to the icon.
+
+        The client should add pixel data for all icon sizes and scales that
+        it can provide, or which are explicitly requested by the compositor
+        via 'icon_size' events on xdg_toplevel_icon_manager_v1.
+
+        The wl_buffer supplying pixel data as 'buffer' must be backed by wl_shm
+        and must be a square (width and height being equal).
+        If any of these buffer requirements are not fulfilled, a 'invalid_buffer'
+        error must be raised.
+
+        If this icon instance already has a buffer of the same size and scale
+        from a previous 'add_buffer' request, data from the last request
+        overrides the preexisting pixel data.
+
+        The wl_buffer must be kept alive for as long as the xdg_toplevel_icon
+        it is associated with is not destroyed, otherwise a 'no_buffer' error
+        is raised. The buffer contents must not be modified after it was
+        assigned to the icon. As a result, the region of the wl_shm_pool's
+        backing storage used for the wl_buffer must not be modified after this
+        request is sent. The wl_buffer.release event is unused.
+
+        If this request is made after the icon has been assigned to a toplevel
+        via 'set_icon', a 'immutable' error must be raised.
+      </description>
+      <arg name="buffer" type="object" interface="wl_buffer"/>
+      <arg name="scale" type="int"
+	   summary="the scaling factor of the icon, e.g. 1"/>
+    </request>
+  </interface>
+</protocol>
diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
index 79b0628849..1dd1cda85a 100644
--- a/include/GLFW/glfw3.h
+++ b/include/GLFW/glfw3.h
@@ -3399,9 +3399,9 @@ GLFWAPI void glfwSetWindowTitle(GLFWwindow* window, const char* title);
  *
  *  [bundle-guide]: https://developer.apple.com/library/mac/documentation/CoreFoundation/Conceptual/CFBundles/
  *
- *  @remark @wayland There is no existing protocol to change an icon, the
- *  window will thus inherit the one defined in the application's desktop file.
- *  This function will emit @ref GLFW_FEATURE_UNAVAILABLE.
+ *  @remark @wayland This only works on compositors implementing the XDG toplevel icon protocol.
+ *  This function will emit @ref GLFW_FEATURE_UNAVAILABLE if this protocol is not available.
+ *  The icon must be square. Otherwise @ref GLFW_INVALID_VALUE will be emited.
  *
  *  @thread_safety This function must only be called from the main thread.
  *
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1a085b2b6a..8118e45ed6 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -105,6 +105,7 @@ if (GLFW_BUILD_WAYLAND)
     generate_wayland_protocol("fractional-scale-v1.xml")
     generate_wayland_protocol("xdg-activation-v1.xml")
     generate_wayland_protocol("xdg-decoration-unstable-v1.xml")
+    generate_wayland_protocol("xdg-toplevel-icon-v1.xml")
 endif()
 
 if (WIN32 AND GLFW_BUILD_SHARED_LIBRARY)
diff --git a/src/wl_init.c b/src/wl_init.c
index ef9e450360..0ff46c1891 100644
--- a/src/wl_init.c
+++ b/src/wl_init.c
@@ -49,6 +49,7 @@
 #include "fractional-scale-v1-client-protocol.h"
 #include "xdg-activation-v1-client-protocol.h"
 #include "idle-inhibit-unstable-v1-client-protocol.h"
+#include "xdg-toplevel-icon-v1-client-protocol.h"
 
 // NOTE: Versions of wayland-scanner prior to 1.17.91 named every global array of
 //       wl_interface pointers 'types', making it impossible to combine several unmodified
@@ -91,6 +92,10 @@
 #include "idle-inhibit-unstable-v1-client-protocol-code.h"
 #undef types
 
+#define types _glfw_toplevel_icon_types
+#include "xdg-toplevel-icon-v1-client-protocol-code.h"
+#undef types
+
 static void wmBaseHandlePing(void* userData,
                              struct xdg_wm_base* wmBase,
                              uint32_t serial)
@@ -208,6 +213,13 @@ static void registryHandleGlobal(void* userData,
                              &wp_fractional_scale_manager_v1_interface,
                              1);
     }
+    else if (strcmp(interface, xdg_toplevel_icon_manager_v1_interface.name) == 0)
+    {
+        _glfw.wl.toplevelIconManager =
+            wl_registry_bind(registry, name,
+                             &xdg_toplevel_icon_manager_v1_interface,
+                             1);
+    }
 }
 
 static void registryHandleGlobalRemove(void* userData,
@@ -988,6 +1000,8 @@ void _glfwTerminateWayland(void)
         xdg_activation_v1_destroy(_glfw.wl.activationManager);
     if (_glfw.wl.fractionalScaleManager)
         wp_fractional_scale_manager_v1_destroy(_glfw.wl.fractionalScaleManager);
+    if (_glfw.wl.toplevelIconManager)
+        xdg_toplevel_icon_manager_v1_destroy(_glfw.wl.toplevelIconManager);
     if (_glfw.wl.registry)
         wl_registry_destroy(_glfw.wl.registry);
     if (_glfw.wl.display)
diff --git a/src/wl_platform.h b/src/wl_platform.h
index afa6f50af5..86116e086d 100644
--- a/src/wl_platform.h
+++ b/src/wl_platform.h
@@ -438,6 +438,7 @@ typedef struct _GLFWlibraryWayland
     struct zwp_idle_inhibit_manager_v1*     idleInhibitManager;
     struct xdg_activation_v1*               activationManager;
     struct wp_fractional_scale_manager_v1*  fractionalScaleManager;
+    struct xdg_toplevel_icon_manager_v1*    toplevelIconManager;
 
     _GLFWofferWayland*          offers;
     unsigned int                offerCount;
diff --git a/src/wl_window.c b/src/wl_window.c
index 72c1a40260..0fa20bb2bb 100644
--- a/src/wl_window.c
+++ b/src/wl_window.c
@@ -51,6 +51,7 @@
 #include "xdg-activation-v1-client-protocol.h"
 #include "idle-inhibit-unstable-v1-client-protocol.h"
 #include "fractional-scale-v1-client-protocol.h"
+#include "xdg-toplevel-icon-v1-client-protocol.h"
 
 #define GLFW_BORDER_SIZE    4
 #define GLFW_CAPTION_HEIGHT 24
@@ -2227,8 +2228,55 @@ void _glfwSetWindowTitleWayland(_GLFWwindow* window, const char* title)
 void _glfwSetWindowIconWayland(_GLFWwindow* window,
                                int count, const GLFWimage* images)
 {
-    _glfwInputError(GLFW_FEATURE_UNAVAILABLE,
-                    "Wayland: The platform does not support setting the window icon");
+    if (!_glfw.wl.toplevelIconManager)
+    {
+        _glfwInputError(GLFW_FEATURE_UNAVAILABLE,
+                        "Wayland: The platform does not support setting the window icon");
+        return;
+    }
+
+    if (!count)
+    {
+        if (window->wl.libdecor.frame)
+            xdg_toplevel_icon_manager_v1_set_icon(_glfw.wl.toplevelIconManager,
+                                                libdecor_frame_get_xdg_toplevel(window->wl.libdecor.frame),
+                                                NULL);
+        else if (window->wl.xdg.toplevel)
+            xdg_toplevel_icon_manager_v1_set_icon(_glfw.wl.toplevelIconManager, window->wl.xdg.toplevel, NULL);
+        return;
+    }
+
+    for (int i = 0;  i < count;  i++)
+    {
+        if (images[i].width != images[i].height)
+        {
+            _glfwInputError(GLFW_INVALID_VALUE,
+                            "Wayland: The icon must be a square");
+            return;
+        }
+    }
+
+    struct xdg_toplevel_icon_v1 *icon = xdg_toplevel_icon_manager_v1_create_icon(_glfw.wl.toplevelIconManager);
+    struct wl_buffer *bufferArr[count];
+
+    for (int i = 0;  i < count;  i++)
+    {
+        bufferArr[i] = createShmBuffer(&images[i]);
+        xdg_toplevel_icon_v1_add_buffer(icon, bufferArr[i], 1);
+    }
+
+    if (window->wl.libdecor.frame)
+        xdg_toplevel_icon_manager_v1_set_icon(_glfw.wl.toplevelIconManager,
+                                                libdecor_frame_get_xdg_toplevel(window->wl.libdecor.frame),
+                                                icon);
+    else if (window->wl.xdg.toplevel)
+        xdg_toplevel_icon_manager_v1_set_icon(_glfw.wl.toplevelIconManager, window->wl.xdg.toplevel, icon);
+    xdg_toplevel_icon_v1_destroy(icon);
+
+    for (int i = 0;  i < count;  i++)
+    {
+        wl_buffer_destroy(bufferArr[i]);
+    }
 }
 
 void _glfwGetWindowPosWayland(_GLFWwindow* window, int* xpos, int* ypos)
