linux-pipewire: Explicitly enumerate cursor modes

The ScreenCast portal defines 3 cursor modes [1]:

 * Hidden: no visible cursor (value: 1)
 * Embedded: cursor is drawn in the frames (value: 2)
 * Metadata: cursor is sent as stream metadata (value: 4)

The values are power-of-two due to be used as flags.

Explicitly listing these values in an enum improves legibility
of the code, so do that instead of hardcoding 1, 2, and 4.

[1] https://github.com/flatpak/xdg-desktop-portal/blob/main/data/org.freedesktop.portal.ScreenCast.xml#L302-L316

plugins/linux-pipewire/pipewire.c

@@ -1228,15 +1228,19 @@ static void select_source(obs_pipewire_data *obs_pw)
 
 	available_cursor_modes = portal_get_available_cursor_modes();
 
-	if (available_cursor_modes & 4)
-		g_variant_builder_add(&builder, "{sv}", "cursor_mode",
-				      g_variant_new_uint32(4));
-	else if ((available_cursor_modes & 2) && obs_pw->cursor.visible)
-		g_variant_builder_add(&builder, "{sv}", "cursor_mode",
-				      g_variant_new_uint32(2));
+	if (available_cursor_modes & PORTAL_CURSOR_MODE_METADATA)
+		g_variant_builder_add(
+			&builder, "{sv}", "cursor_mode",
+			g_variant_new_uint32(PORTAL_CURSOR_MODE_METADATA));
+	else if ((available_cursor_modes & PORTAL_CURSOR_MODE_EMBEDDED) &&
+		 obs_pw->cursor.visible)
+		g_variant_builder_add(
+			&builder, "{sv}", "cursor_mode",
+			g_variant_new_uint32(PORTAL_CURSOR_MODE_EMBEDDED));
 	else
-		g_variant_builder_add(&builder, "{sv}", "cursor_mode",
-				      g_variant_new_uint32(1));
+		g_variant_builder_add(
+			&builder, "{sv}", "cursor_mode",
+			g_variant_new_uint32(PORTAL_CURSOR_MODE_HIDDEN));
 
 	if (portal_get_screencast_version() >= 4) {
 		g_variant_builder_add(&builder, "{sv}", "persist_mode",

plugins/linux-pipewire/portal.h

@@ -23,6 +23,12 @@
 #include <stdint.h>
 #include <gio/gio.h>
 
+enum portal_cursor_mode {
+	PORTAL_CURSOR_MODE_HIDDEN = 1 << 0,
+	PORTAL_CURSOR_MODE_EMBEDDED = 1 << 1,
+	PORTAL_CURSOR_MODE_METADATA = 1 << 2,
+};
+
 uint32_t portal_get_available_capture_types(void);
 uint32_t portal_get_available_cursor_modes(void);
 uint32_t portal_get_screencast_version(void);