cube: Port Wayland impl from wl-shell to xdg-shell

This change ports vkcube in both C and C++ versions to use the stable
xdg-shell protocol for Wayland compositors. The original wl-shell
protocol has been deprecated and is being removed from major compositor
libraries; wlroots has already dropped support.

New cmake modules have been added to look for Wayland-Protocols
(containing XML descriptions of all common protocols) and
`wayland-scanner`, the tool used to convert the XML files to a usable C
interface.

The change also adds support for the xdg-decoration protocol, which for
some compositors is provided and needed to let them know that they
should draw a titlebar, borders with resize controls, and other standard
features.

Change-Id: I39bedda93a7c5d0aeeb59c68023552723b413567

1 files changed, 90 insertions, 17 deletions

diff --git a/cube/cube.cpp b/cube/cube.cpp
index e5b2782b..9ff103c5 100644
--- a/cube/cube.cpp
+++ b/cube/cube.cpp
@@ -22,6 +22,8 @@
 #include <X11/Xutil.h>
 #elif defined(VK_USE_PLATFORM_WAYLAND_KHR)
 #include <linux/input.h>
+#include "xdg-shell-client-header.h"
+#include "xdg-decoration-client-header.h"
 #endif
 
 #include <cassert>
@@ -286,8 +288,12 @@ struct Demo {
     wl_registry *registry;
     wl_compositor *compositor;
     wl_surface *window;
-    wl_shell *shell;
-    wl_shell_surface *shell_surface;
+    xdg_wm_base *wm_base;
+    zxdg_decoration_manager_v1 *xdg_decoration_mgr;
+    zxdg_toplevel_decoration_v1 *toplevel_decoration;
+    xdg_surface *window_surface;
+    bool xdg_surface_has_been_configured;
+    xdg_toplevel *window_toplevel;
     wl_seat *seat;
     wl_pointer *pointer;
     wl_keyboard *keyboard;
@@ -420,7 +426,7 @@ static void pointer_handle_button(void *data, struct wl_pointer *wl_pointer, uin
                                   uint32_t state) {
     Demo *demo = (Demo *)data;
     if (button == BTN_LEFT && state == WL_POINTER_BUTTON_STATE_PRESSED) {
-        wl_shell_surface_move(demo->shell_surface, demo->seat, serial);
+        xdg_toplevel_move(demo->window_toplevel, demo->seat, serial);
     }
 }
 
@@ -488,16 +494,24 @@ static const wl_seat_listener seat_listener = {
     seat_handle_capabilities,
 };
 
+static void wm_base_ping(void *data, xdg_wm_base *xdg_wm_base, uint32_t serial) { xdg_wm_base_pong(xdg_wm_base, serial); }
+
+static const struct xdg_wm_base_listener wm_base_listener = {wm_base_ping};
+
 static void registry_handle_global(void *data, wl_registry *registry, uint32_t id, const char *interface, uint32_t version) {
     Demo *demo = (Demo *)data;
     // pickup wayland objects when they appear
-    if (strcmp(interface, "wl_compositor") == 0) {
+    if (strcmp(interface, wl_compositor_interface.name) == 0) {
         demo->compositor = (wl_compositor *)wl_registry_bind(registry, id, &wl_compositor_interface, 1);
-    } else if (strcmp(interface, "wl_shell") == 0) {
-        demo->shell = (wl_shell *)wl_registry_bind(registry, id, &wl_shell_interface, 1);
-    } else if (strcmp(interface, "wl_seat") == 0) {
+    } else if (strcmp(interface, xdg_wm_base_interface.name) == 0) {
+        demo->wm_base = (xdg_wm_base *)wl_registry_bind(registry, id, &xdg_wm_base_interface, 1);
+        xdg_wm_base_add_listener(demo->wm_base, &wm_base_listener, nullptr);
+    } else if (strcmp(interface, wl_seat_interface.name) == 0) {
         demo->seat = (wl_seat *)wl_registry_bind(registry, id, &wl_seat_interface, 1);
         wl_seat_add_listener(demo->seat, &seat_listener, demo);
+    } else if (strcmp(interface, zxdg_decoration_manager_v1_interface.name) == 0) {
+        demo->xdg_decoration_mgr =
+            (zxdg_decoration_manager_v1 *)wl_registry_bind(registry, id, &zxdg_decoration_manager_v1_interface, 1);
     }
 }
 
@@ -527,8 +541,12 @@ Demo::Demo()
       registry{nullptr},
       compositor{nullptr},
       window{nullptr},
-      shell{nullptr},
-      shell_surface{nullptr},
+      wm_base{nullptr},
+      xdg_decoration_mgr{nullptr},
+      toplevel_decoration{nullptr},
+      window_surface{nullptr},
+      xdg_surface_has_been_configured{false},
+      window_toplevel{nullptr},
       seat{nullptr},
       pointer{nullptr},
       keyboard{nullptr},
@@ -676,9 +694,14 @@ void Demo::cleanup() {
     wl_keyboard_destroy(keyboard);
     wl_pointer_destroy(pointer);
     wl_seat_destroy(seat);
-    wl_shell_surface_destroy(shell_surface);
+    xdg_toplevel_destroy(window_toplevel);
+    xdg_surface_destroy(window_surface);
     wl_surface_destroy(window);
-    wl_shell_destroy(shell);
+    xdg_wm_base_destroy(wm_base);
+    if (xdg_decoration_mgr) {
+        zxdg_toplevel_decoration_v1_destroy(toplevel_decoration);
+        zxdg_decoration_manager_v1_destroy(xdg_decoration_mgr);
+    }
     wl_compositor_destroy(compositor);
     wl_registry_destroy(registry);
     wl_display_disconnect(display);
@@ -2808,7 +2831,45 @@ void Demo::run() {
     }
 }
 
+static void handle_surface_configure(void *data, xdg_surface *xdg_surface, uint32_t serial) {
+    Demo *demo = (Demo *)data;
+    xdg_surface_ack_configure(xdg_surface, serial);
+    if (demo->xdg_surface_has_been_configured) {
+        demo->resize();
+    }
+    demo->xdg_surface_has_been_configured = true;
+}
+
+static const xdg_surface_listener surface_listener = {handle_surface_configure};
+
+static void handle_toplevel_configure(void *data, xdg_toplevel *xdg_toplevel, int32_t width, int32_t height,
+                                      struct wl_array *states) {
+    Demo *demo = (Demo *)data;
+    /* zero values imply the program may choose its own size, so in that case
+     * stay with the existing value (which on startup is the default) */
+    if (width > 0) {
+        demo->width = width;
+    }
+    if (height > 0) {
+        demo->height = height;
+    }
+    // This will be followed by a surface configure
+}
+
+static void handle_toplevel_close(void *data, xdg_toplevel *xdg_toplevel) {
+    Demo *demo = (Demo *)data;
+    demo->quit = true;
+}
+
+static const xdg_toplevel_listener toplevel_listener = {handle_toplevel_configure, handle_toplevel_close};
+
 void Demo::create_window() {
+    if (!wm_base) {
+        printf("Compositor did not provide the standard protocol xdg-wm-base\n");
+        fflush(stdout);
+        exit(1);
+    }
+
     window = wl_compositor_create_surface(compositor);
     if (!window) {
         printf("Can not create wayland_surface from compositor!\n");
@@ -2816,16 +2877,28 @@ void Demo::create_window() {
         exit(1);
     }
 
-    shell_surface = wl_shell_get_shell_surface(shell, window);
-    if (!shell_surface) {
-        printf("Can not get shell_surface from wayland_surface!\n");
+    window_surface = xdg_wm_base_get_xdg_surface(wm_base, window);
+    if (!window_surface) {
+        printf("Can not get xdg_surface from wayland_surface!\n");
+        fflush(stdout);
+        exit(1);
+    }
+    window_toplevel = xdg_surface_get_toplevel(window_surface);
+    if (!window_toplevel) {
+        printf("Can not allocate xdg_toplevel for xdg_surface!\n");
         fflush(stdout);
         exit(1);
     }
+    xdg_surface_add_listener(window_surface, &surface_listener, this);
+    xdg_toplevel_add_listener(window_toplevel, &toplevel_listener, this);
+    xdg_toplevel_set_title(window_toplevel, APP_SHORT_NAME);
+    if (xdg_decoration_mgr) {
+        // if supported, let the compositor render titlebars for us
+        toplevel_decoration = zxdg_decoration_manager_v1_get_toplevel_decoration(xdg_decoration_mgr, window_toplevel);
+        zxdg_toplevel_decoration_v1_set_mode(toplevel_decoration, ZXDG_TOPLEVEL_DECORATION_V1_MODE_SERVER_SIDE);
+    }
 
-    wl_shell_surface_add_listener(shell_surface, &shell_surface_listener, this);
-    wl_shell_surface_set_toplevel(shell_surface);
-    wl_shell_surface_set_title(shell_surface, APP_SHORT_NAME);
+    wl_surface_commit(window);
 }
 #elif defined(VK_USE_PLATFORM_DIRECTFB_EXT)