backend/x11: fix cursor position when receiving configure event

backend/x11/input_device.c

@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <wlr/config.h>
 #include <wlr/interfaces/wlr_input_device.h>
 #include <wlr/interfaces/wlr_keyboard.h>
@@ -27,6 +28,34 @@ static uint32_t xcb_button_to_wl(uint32_t button) {
 	}
 }
 
+static void x11_handle_pointer_position(struct wlr_x11_output *output,
+		int16_t x, int16_t y, xcb_timestamp_t time) {
+	struct wlr_x11_backend *x11 = output->x11;
+	struct wlr_output *wlr_output = &output->wlr_output;
+
+	struct wlr_box box = { .x = x, .y = y };
+	wlr_box_transform(&box, wlr_output->transform, wlr_output->width,
+		wlr_output->height, &box);
+	box.x /= wlr_output->scale;
+	box.y /= wlr_output->scale;
+
+	struct wlr_box layout_box;
+	x11_output_layout_get_box(x11, &layout_box);
+
+	double ox = wlr_output->lx / (double)layout_box.width;
+	double oy = wlr_output->ly / (double)layout_box.height;
+
+	struct wlr_event_pointer_motion_absolute wlr_event = {
+		.device = &x11->pointer_dev,
+		.time_msec = time,
+		.x = box.x / (double)layout_box.width + ox,
+		.y = box.y / (double)layout_box.height + oy,
+	};
+	wlr_signal_emit_safe(&x11->pointer.events.motion_absolute, &wlr_event);
+
+	x11->time = time;
+}
+
 bool x11_handle_input_event(struct wlr_x11_backend *x11,
 		xcb_generic_event_t *event) {
 	switch (event->response_type & XCB_EVENT_RESPONSE_TYPE_MASK) {
@@ -91,30 +120,8 @@ bool x11_handle_input_event(struct wlr_x11_backend *x11,
 		if (output == NULL) {
 			return false;
 		}
-		struct wlr_output *wlr_output = &output->wlr_output;
-
-		struct wlr_box box = { .x = ev->event_x, .y = ev->event_y };
-		wlr_box_transform(&box, wlr_output->transform, wlr_output->width,
-			wlr_output->height, &box);
-		box.x /= wlr_output->scale;
-		box.y /= wlr_output->scale;
 
-		struct wlr_box layout_box;
+		x11_handle_pointer_position(output, ev->event_x, ev->event_y, ev->time);
-		x11_output_layout_get_box(x11, &layout_box);
-
-		double ox = wlr_output->lx / (double)layout_box.width;
-		double oy = wlr_output->ly / (double)layout_box.height;
-
-		struct wlr_event_pointer_motion_absolute wlr_event = {
-			.device = &x11->pointer_dev,
-			.time_msec = ev->time,
-			.x = box.x / (double)layout_box.width + ox,
-			.y = box.y / (double)layout_box.height + oy,
-		};
-
-		wlr_signal_emit_safe(&x11->pointer.events.motion_absolute, &wlr_event);
-
-		x11->time = ev->time;
 		return true;
 	}
 	default:
@@ -135,6 +142,23 @@ bool x11_handle_input_event(struct wlr_x11_backend *x11,
 
 const struct wlr_input_device_impl input_device_impl = { 0 };
 
+void x11_update_pointer_position(struct wlr_x11_output *output,
+		xcb_timestamp_t time) {
+	struct wlr_x11_backend *x11 = output->x11;
+
+	xcb_query_pointer_cookie_t cookie =
+		xcb_query_pointer(x11->xcb_conn, output->win);
+	xcb_query_pointer_reply_t *reply =
+		xcb_query_pointer_reply(x11->xcb_conn, cookie, NULL);
+	if (!reply) {
+		return;
+	}
+
+	x11_handle_pointer_position(output, reply->win_x, reply->win_y, time);
+
+	free(reply);
+}
+
 bool wlr_input_device_is_x11(struct wlr_input_device *wlr_dev) {
 	return wlr_dev->impl == &input_device_impl;
 }

backend/x11/output.c

@@ -157,29 +157,11 @@ struct wlr_output *wlr_x11_output_create(struct wlr_backend *backend) {
 
 void x11_output_handle_configure_notify(struct wlr_x11_output *output,
 		xcb_configure_notify_event_t *ev) {
-	struct wlr_x11_backend *x11 = output->x11;
-
 	wlr_output_update_custom_mode(&output->wlr_output, ev->width,
 		ev->height, output->wlr_output.refresh);
 
 	// Move the pointer to its new location
-	xcb_query_pointer_cookie_t cookie =
+	x11_update_pointer_position(output, output->x11->time);
-		xcb_query_pointer(x11->xcb_conn, output->win);
-	xcb_query_pointer_reply_t *pointer =
-		xcb_query_pointer_reply(x11->xcb_conn, cookie, NULL);
-	if (!pointer) {
-		return;
-	}
-
-	struct wlr_event_pointer_motion_absolute abs = {
-		.device = &x11->pointer_dev,
-		.time_msec = x11->time,
-		.x = (double)pointer->root_x / output->wlr_output.width,
-		.y = (double)pointer->root_y / output->wlr_output.height,
-	};
-
-	wlr_signal_emit_safe(&x11->pointer.events.motion_absolute, &abs);
-	free(pointer);
 }
 
 bool wlr_output_is_x11(struct wlr_output *wlr_output) {

include/backend/x11.h

@@ -79,6 +79,8 @@ const struct wlr_input_device_impl input_device_impl;
 
 bool x11_handle_input_event(struct wlr_x11_backend *x11,
 	xcb_generic_event_t *event);
+void x11_update_pointer_position(struct wlr_x11_output *output,
+	xcb_timestamp_t time);
 
 void x11_output_handle_configure_notify(struct wlr_x11_output *output,
 	xcb_configure_notify_event_t *event);