Center xdg shell views

include/rootston/view.h

@@ -1,5 +1,6 @@
 #ifndef _ROOTSTON_VIEW_H
 #define _ROOTSTON_VIEW_H
+
 #include <stdbool.h>
 #include <wlr/types/wlr_box.h>
 #include <wlr/types/wlr_surface.h>
@@ -18,7 +19,9 @@ struct roots_wl_shell_surface {
 
 struct roots_xdg_surface_v6 {
 	struct roots_view *view;
+
 	// TODO: Maybe destroy listener should go in roots_view
+	struct wl_listener commit;
 	struct wl_listener destroy;
 	struct wl_listener ping_timeout;
 	struct wl_listener request_minimize;
@@ -73,5 +76,6 @@ void view_get_input_bounds(struct roots_view *view, struct wlr_box *box);
 void view_activate(struct roots_view *view, bool active);
 void view_resize(struct roots_view *view, uint32_t width, uint32_t height);
 void view_close(struct roots_view *view);
+bool view_center(struct roots_view *view);
 
 #endif

rootston/desktop.c

@@ -83,6 +83,26 @@ void view_close(struct roots_view *view) {
 	}
 }
 
+bool view_center(struct roots_view *view) {
+	struct wlr_box size;
+	view_get_size(view, &size);
+	if (size.width == 0 && size.height == 0) {
+		return false;
+	}
+
+	struct roots_desktop *desktop = view->desktop;
+	struct wlr_cursor *cursor = desktop->server->input->cursor;
+	struct wlr_output *output = wlr_output_layout_output_at(desktop->layout,
+		cursor->x, cursor->y);
+	if (!output) {
+		return false;
+	}
+
+	view->x = (double)(output->width - size.width) / 2;
+	view->y = (double)(output->height - size.height) / 2;
+	return true;
+}
+
 static struct wlr_subsurface *subsurface_at(struct wlr_surface *surface,
 		double sx, double sy, double *sub_x, double *sub_y) {
 	struct wlr_subsurface *subsurface;

rootston/xdg_shell_v6.c

@@ -67,6 +67,17 @@ static void handle_request_resize(struct wl_listener *listener, void *data) {
 	view_begin_resize(input, event->cursor, view, e->edges);
 }
 
+static void handle_commit(struct wl_listener *listener, void *data) {
+	struct roots_xdg_surface_v6 *roots_xdg_surface =
+		wl_container_of(listener, roots_xdg_surface, commit);
+	struct roots_view *view = roots_xdg_surface->view;
+
+	bool centered = view_center(view);
+	if (centered) {
+		wl_list_remove(&listener->link);
+	}
+}
+
 static void handle_destroy(struct wl_listener *listener, void *data) {
 	struct roots_xdg_surface_v6 *roots_xdg_surface =
 		wl_container_of(listener, roots_xdg_surface, destroy);
@@ -98,7 +109,12 @@ void handle_xdg_shell_v6_surface(struct wl_listener *listener, void *data) {
 
 	struct roots_xdg_surface_v6 *roots_surface =
 		calloc(1, sizeof(struct roots_xdg_surface_v6));
-	// TODO: all of the trimmings
+	if (!roots_surface) {
+		return;
+	}
+	wl_list_init(&roots_surface->commit.link);
+	roots_surface->commit.notify = handle_commit;
+	wl_signal_add(&surface->events.commit, &roots_surface->commit);
 	wl_list_init(&roots_surface->destroy.link);
 	roots_surface->destroy.notify = handle_destroy;
 	wl_signal_add(&surface->events.destroy, &roots_surface->destroy);
@@ -115,7 +131,6 @@ void handle_xdg_shell_v6_surface(struct wl_listener *listener, void *data) {
 
 	struct roots_view *view = calloc(1, sizeof(struct roots_view));
 	view->type = ROOTS_XDG_SHELL_V6_VIEW;
-	view->x = view->y = 200;
 	view->xdg_surface_v6 = surface;
 	view->roots_xdg_surface_v6 = roots_surface;
 	view->wlr_surface = surface->surface;