input: set hotkeys in compositor if running under (X)Wayland

As Wayland has no other possibility to globally listen for hotkey
events than via the compositor, set the hotkeys there. This is not
device-specific anymore of course.

Currently supports GNOME, more hopefully to follow.

re #27

src/gromit-mpx.c

@@ -1352,7 +1352,7 @@ int main (int argc, char **argv)
   /* Main application */
   setup_main_app (data, app_parse_args (argc, argv, data));
   gtk_main ();
-  release_grab(data, NULL); /* ungrab all */
+  shutdown_input_devices(data);
   write_keyfile(data); // save keyfile config
   g_free (data);
   return 0;

src/input.c

@@ -13,6 +13,8 @@
 #include <gdk/gdkwayland.h>
 #endif
 
+#define WAYLAND_HOTKEY_PREFIX "gromit-mpx-wayland-hotkey"
+
 #include "input.h"
 
 
@@ -57,7 +59,142 @@ static gboolean get_are_some_grabbed(GromitData *data)
     return some_grabbed;
 }
 
+static void remove_hotkeys_from_compositor(GromitData *data) {
+    char *xdg_current_desktop = getenv("XDG_CURRENT_DESKTOP");
+    if (xdg_current_desktop && strcmp(xdg_current_desktop, "GNOME") == 0) {
+	/*
+	  Get all custom key bindings and save back the ones that are not from us.
+	*/
+	if(data->debug)
+	    g_print("DEBUG: Detected GNOME under Wayland, removing our hotkeys from compositor\n");
+
+	GPtrArray *other_key_bindings_mutable_array = g_ptr_array_new();
+
+	GSettings *settings = g_settings_new("org.gnome.settings-daemon.plugins.media-keys");
+
+	gchar **key_bindings_array = g_settings_get_strv(settings, "custom-keybindings");
+	gchar **binding;
+	for (binding = key_bindings_array; *binding; binding++) {
+	    GSettings *settings = g_settings_new_with_path("org.gnome.settings-daemon.plugins.media-keys.custom-keybinding",
+							   *binding);
+	    gchar *name = g_settings_get_string(settings, "name");
+
+            if (!g_str_has_prefix(name, WAYLAND_HOTKEY_PREFIX)) {
+		g_ptr_array_add(other_key_bindings_mutable_array, strdup(*binding));
+            } else {
+		if (data->debug)
+		    g_print("DEBUG:   removing %s with name '%s'\n", *binding, name);
+            }
+
+            g_free(name);
+	    g_object_unref(settings);
+	}
+
+	g_ptr_array_add(other_key_bindings_mutable_array, NULL);
+	gchar **other_key_bindings_array = (gchar **)g_ptr_array_free(other_key_bindings_mutable_array, FALSE);
+	g_settings_set_strv(settings, "custom-keybindings", (const gchar**)other_key_bindings_array);
+
+	g_strfreev(other_key_bindings_array);
+	g_strfreev(key_bindings_array);
+	g_object_unref(settings);
+    }
+}
+
+static void add_hotkeys_to_compositor(GromitData *data) {
+    char *xdg_current_desktop = getenv("XDG_CURRENT_DESKTOP");
+    if (xdg_current_desktop && strcmp(xdg_current_desktop, "GNOME") == 0) {
+
+	if(data->debug)
+	    g_print("DEBUG: Detected GNOME under Wayland, adding our hotkeys to compositor\n");
+
+	/*
+	  Get highest custom keybinding index, collecting keybindings on the way.
+	*/
+	guint binding_index = 0;
+	GPtrArray *new_key_bindings_mutable_array = g_ptr_array_new();
+
+	GSettings *settings = g_settings_new("org.gnome.settings-daemon.plugins.media-keys");
+
+	gchar **old_key_bindings_array = g_settings_get_strv(settings, "custom-keybindings");
+	gchar **binding;
+	for (binding = old_key_bindings_array; *binding; binding++) {
+	    /* store existing bindings in mutable array */
+	    g_ptr_array_add(new_key_bindings_mutable_array, strdup(*binding));
+
+	    /* get the path components */
+	    gchar **components = g_strsplit (*binding, "/", 0);
+	    /* get the last component. -2 because g_strv_length() counts the trailing NULL as well */
+	    gchar *custom_numbered = components[g_strv_length(components)-2];
+	    guint custom_index = g_ascii_strtoull (custom_numbered+6, NULL, 10);
+	    if(custom_index >= binding_index)
+		binding_index = custom_index + 1;
 
+	    g_strfreev(components);
+	}
+
+	/*
+	  add our keybindings
+	 */
+	gchar *modifier_hotkey_option[18];
+	modifier_hotkey_option[0] = "";
+	modifier_hotkey_option[1] = data->hot_keyval;
+	modifier_hotkey_option[2] = "--toggle";
+	modifier_hotkey_option[3] = "<Shift>";
+	modifier_hotkey_option[4] = data->hot_keyval;
+	modifier_hotkey_option[5] = "--clear";
+	modifier_hotkey_option[6] = "<Ctrl>";
+	modifier_hotkey_option[7] = data->hot_keyval;
+	modifier_hotkey_option[8] = "--visibility";
+	modifier_hotkey_option[9] = "<Alt>";
+	modifier_hotkey_option[10] = data->hot_keyval;
+	modifier_hotkey_option[11] = "--quit";
+	modifier_hotkey_option[12] = "";
+	modifier_hotkey_option[13] = data->undo_keyval;
+	modifier_hotkey_option[14] = "--undo";
+	modifier_hotkey_option[15] = "<Shift>";
+	modifier_hotkey_option[16] = data->undo_keyval;
+	modifier_hotkey_option[17] = "--redo";
+
+	for(int i = 0; i < 18; i+=3) {
+	    gchar *new_binding = g_malloc(128);
+	    snprintf(new_binding,
+		     128,
+		     "/org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/custom%d/",
+		     binding_index++);
+	    g_ptr_array_add(new_key_bindings_mutable_array, new_binding);
+
+	    GSettings *settings = g_settings_new_with_path("org.gnome.settings-daemon.plugins.media-keys.custom-keybinding",
+							   new_binding);
+	    gchar name[64];
+	    snprintf(name, 64, "%s %s", WAYLAND_HOTKEY_PREFIX, modifier_hotkey_option[i+2]);
+	    g_settings_set_string(settings, "name", name);
+
+	    gchar command[64];
+	    if(getenv("FLATPAK_ID"))
+		snprintf(command, 64, "%s %s", "flatpak run net.christianbeier.Gromit-MPX", modifier_hotkey_option[i+2]);
+	    else
+		snprintf(command, 64, "%s %s", "gromit-mpx", modifier_hotkey_option[i+2]);
+	    g_settings_set_string(settings, "command", command);
+
+	    gchar binding[64];
+	    snprintf(binding, 64, "%s%s", modifier_hotkey_option[i], modifier_hotkey_option[i+1]);
+	    g_settings_set_string(settings, "binding", binding);
+
+	    g_object_unref(settings);
+	}
+
+	/*
+	  Convert the mutable bindings array into a static array and apply this to the setting.
+	 */
+	g_ptr_array_add(new_key_bindings_mutable_array, NULL);
+	gchar **new_key_bindings_array = (gchar **)g_ptr_array_free(new_key_bindings_mutable_array, FALSE);
+	g_settings_set_strv(settings, "custom-keybindings", (const gchar**)new_key_bindings_array);
+
+        g_strfreev(new_key_bindings_array);
+        g_strfreev(old_key_bindings_array);
+	g_object_unref(settings);
+    }
+}
 
 void setup_input_devices (GromitData *data)
 {
@@ -195,8 +332,18 @@ void setup_input_devices (GromitData *data)
 			  }
 		  }
 	  } // GDK_IS_X11_DISPLAY()
-
-	  g_hash_table_insert(data->devdatatable, device, devdata);
+
+	  /*
+	    When running under XWayland, hotkey grabbing does not work and we
+	    have to register shortcuts with the compositor.
+	   */
+	  char *xdg_session_type = getenv("XDG_SESSION_TYPE");
+	  if (xdg_session_type && strcmp(xdg_session_type, "wayland") == 0) {
+	      remove_hotkeys_from_compositor(data);
+	      add_hotkeys_to_compositor(data);
+          }
+
+          g_hash_table_insert(data->devdatatable, device, devdata);
           g_printerr ("Enabled Device %d: \"%s\", (Type: %d)\n", 
 		      i++, gdk_device_get_name(device), gdk_device_get_source(device));
         }
@@ -205,7 +352,13 @@ void setup_input_devices (GromitData *data)
   g_printerr ("Now %d enabled devices.\n", g_hash_table_size(data->devdatatable));
 }
 
-
+void shutdown_input_devices(GromitData *data)
+{
+    release_grab(data, NULL); /* ungrab all */
+    char *xdg_session_type = getenv("XDG_SESSION_TYPE");
+    if (xdg_session_type && strcmp(xdg_session_type, "wayland") == 0)
+	remove_hotkeys_from_compositor(data);
+}
 
 void release_grab (GromitData *data, 
 		   GdkDevice *dev)

src/input.h

@@ -6,6 +6,7 @@
 #include "gromit-mpx.h"
 
 void setup_input_devices (GromitData *data);
+void shutdown_input_devices (GromitData *data);
 void release_grab (GromitData *data, GdkDevice *dev);
 void acquire_grab (GromitData *data, GdkDevice *dev);
 void toggle_grab  (GromitData *data, GdkDevice *dev);