backend/x11: Hide cursor with Xfixes

backend/x11/backend.c

@@ -12,6 +12,7 @@
 #include <X11/Xlib-xcb.h>
 #include <wayland-server.h>
 #include <xcb/xcb.h>
+#include <xcb/xfixes.h>
 #include <xcb/xinput.h>
 
 #include <wlr/backend/interface.h>
@@ -106,15 +107,6 @@ static bool backend_start(struct wlr_backend *backend) {
 	struct wlr_x11_backend *x11 = get_x11_backend_from_backend(backend);
 	x11->started = true;
 
-	// create a blank cursor
-	xcb_pixmap_t pix = xcb_generate_id(x11->xcb);
-	xcb_create_pixmap(x11->xcb, 1, pix, x11->screen->root, 1, 1);
-
-	x11->cursor = xcb_generate_id(x11->xcb);
-	xcb_create_cursor(x11->xcb, x11->cursor, pix, pix, 0, 0, 0, 0, 0, 0,
-		0, 0);
-	xcb_free_pixmap(x11->xcb, pix);
-
 	wlr_signal_emit_safe(&x11->backend.events.new_input, &x11->keyboard_dev);
 
 	for (size_t i = 0; i < x11->requested_outputs; ++i) {
@@ -148,9 +140,6 @@ static void backend_destroy(struct wlr_backend *backend) {
 	wlr_renderer_destroy(x11->renderer);
 	wlr_egl_finish(&x11->egl);
 
-	if (x11->cursor) {
-		xcb_free_cursor(x11->xcb, x11->cursor);
-	}
 	if (x11->xlib_conn) {
 		XCloseDisplay(x11->xlib_conn);
 	}
@@ -233,8 +222,27 @@ struct wlr_backend *wlr_x11_backend_create(struct wl_display *display,
 		}
 	}
 
-	const xcb_query_extension_reply_t *ext =
+	const xcb_query_extension_reply_t *ext;
-		xcb_get_extension_data(x11->xcb, &xcb_input_id);
+
+	ext = xcb_get_extension_data(x11->xcb, &xcb_xfixes_id);
+	if (!ext || !ext->present) {
+		wlr_log(WLR_ERROR, "X11 does not support Xfixes extension");
+		goto error_display;
+	}
+
+	xcb_xfixes_query_version_cookie_t fixes_cookie =
+		xcb_xfixes_query_version(x11->xcb, 4, 0);
+	xcb_xfixes_query_version_reply_t *fixes_reply =
+		xcb_xfixes_query_version_reply(x11->xcb, fixes_cookie, NULL);
+
+	if (!fixes_reply || fixes_reply->major_version < 4) {
+		wlr_log(WLR_ERROR, "X11 does not support required Xfixes version");
+		free(fixes_reply);
+		goto error_display;
+	}
+	free(fixes_reply);
+
+	ext = xcb_get_extension_data(x11->xcb, &xcb_input_id);
 	if (!ext || !ext->present) {
 		wlr_log(WLR_ERROR, "X11 does not support Xinput extension");
 		goto error_display;

backend/x11/input_device.c

@@ -9,6 +9,7 @@
 #endif
 
 #include <xcb/xcb.h>
+#include <xcb/xfixes.h>
 #include <xcb/xinput.h>
 
 #include <wlr/interfaces/wlr_input_device.h>
@@ -164,6 +165,36 @@ void handle_x11_xinput_event(struct wlr_x11_backend *x11,
 		x11->time = ev->time;
 		break;
 	}
+	case XCB_INPUT_ENTER: {
+		xcb_input_enter_event_t *ev = (xcb_input_enter_event_t *)event;
+
+		output = get_x11_output_from_window_id(x11, ev->event);
+		if (!output) {
+			return;
+		}
+
+		if (!output->cursor_hidden) {
+			xcb_xfixes_hide_cursor(x11->xcb, output->win);
+			xcb_flush(x11->xcb);
+			output->cursor_hidden = true;
+		}
+		break;
+	}
+	case XCB_INPUT_LEAVE: {
+		xcb_input_leave_event_t *ev = (xcb_input_leave_event_t *)event;
+
+		output = get_x11_output_from_window_id(x11, ev->event);
+		if (!output) {
+			return;
+		}
+
+		if (output->cursor_hidden) {
+			xcb_xfixes_show_cursor(x11->xcb, output->win);
+			xcb_flush(x11->xcb);
+			output->cursor_hidden = false;
+		}
+		break;
+	}
 	}
 }
 

backend/x11/meson.build

@@ -3,6 +3,7 @@ x11_required = [
 	'x11-xcb',
 	'xcb',
 	'xcb-xinput',
+	'xcb-xfixes',
 ]
 
 foreach lib : x11_required

backend/x11/output.c

@@ -168,7 +168,9 @@ struct wlr_output *wlr_x11_output_create(struct wlr_backend *backend) {
 			XCB_INPUT_XI_EVENT_MASK_KEY_RELEASE |
 			XCB_INPUT_XI_EVENT_MASK_BUTTON_PRESS |
 			XCB_INPUT_XI_EVENT_MASK_BUTTON_RELEASE |
-			XCB_INPUT_XI_EVENT_MASK_MOTION,
+			XCB_INPUT_XI_EVENT_MASK_MOTION |
+			XCB_INPUT_XI_EVENT_MASK_ENTER |
+			XCB_INPUT_XI_EVENT_MASK_LEAVE,
 	};
 	xcb_input_xi_select_events(x11->xcb, output->win, 1, &xinput_mask.head);
 
@@ -190,10 +192,6 @@ struct wlr_output *wlr_x11_output_create(struct wlr_backend *backend) {
 			strlen(title), title);
 	}
 
-	uint32_t cursor_values[] = { x11->cursor };
-	xcb_change_window_attributes(x11->xcb, output->win, XCB_CW_CURSOR,
-		cursor_values);
-
 	xcb_map_window(x11->xcb, output->win);
 	xcb_flush(x11->xcb);
 

include/backend/x11.h

@@ -33,6 +33,8 @@ struct wlr_x11_output {
 
 	struct wl_event_source *frame_timer;
 	int frame_delay;
+
+	bool cursor_hidden;
 };
 
 struct wlr_x11_backend {
@@ -64,9 +66,6 @@ struct wlr_x11_backend {
 	// The time we last received an event
 	xcb_timestamp_t time;
 
-	// A blank cursor
-	xcb_cursor_t cursor;
-
 	uint8_t xinput_opcode;
 
 	struct wl_listener display_destroy;