diyac/diyac.c

#define _POSIX_C_SOURCE 200112L
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <getopt.h>
#include <wlr/types/wlr_scene.h>
#include <wlr/util/log.h>
#include <wlr/render/allocator.h>
#include <wlr/types/wlr_compositor.h>
#include <wlr/types/wlr_subcompositor.h>
#include <wlr/types/wlr_data_device.h>
#include <wlr/types/wlr_output_layout.h>
#include <wlr/types/wlr_xcursor_manager.h>

#include "diyac.h"
#include "output.h"
#include "xdg.h"
#include "cursor.h"
#include "seat.h"

void diyac_focus_toplevel(struct diyac_toplevel *toplevel, struct wlr_surface *surface)
{
	/* Note: this function only deals with keyboard focus. */
	if (toplevel == NULL)
	{
		return;
	}
	struct diyac_server *server = toplevel->server;
	struct wlr_seat *seat = server->seat.wlr_seat;
	struct wlr_surface *prev_surface = seat->keyboard_state.focused_surface;
	if (prev_surface == surface)
	{
		/* Don't re-focus an already focused surface. */
		return;
	}
	if (prev_surface)
	{
		/*
		 * Deactivate the previously focused surface. This lets the client know
		 * it no longer has focus and the client will repaint accordingly, e.g.
		 * stop displaying a caret.
		 */
		struct wlr_xdg_toplevel *prev_toplevel =
			wlr_xdg_toplevel_try_from_wlr_surface(prev_surface);
		if (prev_toplevel != NULL)
		{
			wlr_xdg_toplevel_set_activated(prev_toplevel, false);
		}
	}
	struct wlr_keyboard *keyboard = wlr_seat_get_keyboard(seat);
	/* Move the toplevel to the front */
	wlr_scene_node_raise_to_top(&toplevel->scene_tree->node);
	wl_list_remove(&toplevel->link);
	wl_list_insert(&server->toplevels, &toplevel->link);
	/* Activate the new surface */
	wlr_xdg_toplevel_set_activated(toplevel->xdg_toplevel, true);
	/*
	 * Tell the seat to have the keyboard enter this surface. wlroots will keep
	 * track of this and automatically send key events to the appropriate
	 * clients without additional work on your part.
	 */
	if (keyboard != NULL)
	{
		wlr_seat_keyboard_notify_enter(seat, toplevel->xdg_toplevel->base->surface,
									   keyboard->keycodes, keyboard->num_keycodes, &keyboard->modifiers);
	}
}

struct diyac_toplevel *diyac_toplevel_at(
	struct diyac_server *server, double lx, double ly,
	struct wlr_surface **surface, double *sx, double *sy)
{
	/* This returns the topmost node in the scene at the given layout coords.
	 * We only care about surface nodes as we are specifically looking for a
	 * surface in the surface tree of a diyac_toplevel. */
	struct wlr_scene_node *node = wlr_scene_node_at(
		&server->scene->tree.node, lx, ly, sx, sy);
	if (node == NULL || node->type != WLR_SCENE_NODE_BUFFER)
	{
		return NULL;
	}
	struct wlr_scene_buffer *scene_buffer = wlr_scene_buffer_from_node(node);
	struct wlr_scene_surface *scene_surface =
		wlr_scene_surface_try_from_buffer(scene_buffer);
	if (!scene_surface)
	{
		return NULL;
	}

	*surface = scene_surface->surface;
	/* Find the node corresponding to the diyac_toplevel at the root of this
	 * surface tree, it is the only one for which we set the data field. */
	struct wlr_scene_tree *tree = node->parent;
	while (tree != NULL && tree->node.data == NULL)
	{
		tree = tree->node.parent;
	}
	return tree->node.data;
}

int main(int argc, char *argv[])
{
	wlr_log_init(WLR_INFO, NULL);
	char *startup_cmd = NULL;

	int c;
	while ((c = getopt(argc, argv, "s:h")) != -1)
	{
		switch (c)
		{
		case 's':
			startup_cmd = optarg;
			break;
		default:
			printf("Usage: %s [-s startup command]\n", argv[0]);
			return 0;
		}
	}
	if (optind < argc)
	{
		printf("Usage: %s [-s startup command]\n", argv[0]);
		return 0;
	}

	struct diyac_server server = {0};
	/* The Wayland display is managed by libwayland. It handles accepting
	 * clients from the Unix socket, manging Wayland globals, and so on. */
	server.wl_display = wl_display_create();
	/* The backend is a wlroots feature which abstracts the underlying input and
	 * output hardware. The autocreate option will choose the most suitable
	 * backend based on the current environment, such as opening an X11 window
	 * if an X11 server is running. */
	server.backend = wlr_backend_autocreate(server.wl_display, NULL);
	if (server.backend == NULL)
	{
		wlr_log(WLR_ERROR, "failed to create wlr_backend");
		return 1;
	}

	/* Autocreates a renderer, either Pixman, GLES2 or Vulkan for us. The user
	 * can also specify a renderer using the WLR_RENDERER env var.
	 * The renderer is responsible for defining the various pixel formats it
	 * supports for shared memory, this configures that for clients. */
	server.renderer = wlr_renderer_autocreate(server.backend);
	if (server.renderer == NULL)
	{
		wlr_log(WLR_ERROR, "failed to create wlr_renderer");
		return 1;
	}

	wlr_renderer_init_wl_display(server.renderer, server.wl_display);

	/* Autocreates an allocator for us.
	 * The allocator is the bridge between the renderer and the backend. It
	 * handles the buffer creation, allowing wlroots to render onto the
	 * screen */
	server.allocator = wlr_allocator_autocreate(server.backend,
												server.renderer);
	if (server.allocator == NULL)
	{
		wlr_log(WLR_ERROR, "failed to create wlr_allocator");
		return 1;
	}

	/* This creates some hands-off wlroots interfaces. The compositor is
	 * necessary for clients to allocate surfaces, the subcompositor allows to
	 * assign the role of subsurfaces to surfaces and the data device manager
	 * handles the clipboard. Each of these wlroots interfaces has room for you
	 * to dig your fingers in and play with their behavior if you want. Note that
	 * the clients cannot set the selection directly without compositor approval,
	 * see the handling of the request_set_selection event below.*/
	wlr_compositor_create(server.wl_display, 5, server.renderer);
	wlr_subcompositor_create(server.wl_display);
	wlr_data_device_manager_create(server.wl_display);

	/* Creates an output layout, which a wlroots utility for working with an
	 * arrangement of screens in a physical layout. */
	server.output_layout = wlr_output_layout_create();

	/* Configure a listener to be notified when new outputs are available on the
	 * backend. */
	wl_list_init(&server.outputs);
	server.new_output.notify = diyac_server_new_output;
	wl_signal_add(&server.backend->events.new_output, &server.new_output);

	/* Create a scene graph. This is a wlroots abstraction that handles all
	 * rendering and damage tracking. All the compositor author needs to do
	 * is add things that should be rendered to the scene graph at the proper
	 * positions and then call wlr_scene_output_commit() to render a frame if
	 * necessary.
	 */
	server.scene = wlr_scene_create();
	server.scene_layout = wlr_scene_attach_output_layout(server.scene, server.output_layout);

	/* Set up xdg-shell version 3. The xdg-shell is a Wayland protocol which is
	 * used for application windows. For more detail on shells, refer to
	 * https://drewdevault.com/2018/07/29/Wayland-shells.html.
	 */
	wl_list_init(&server.toplevels);
	server.xdg_shell = wlr_xdg_shell_create(server.wl_display, 3);
	server.new_xdg_surface.notify = diyac_new_xdg_surface;
	wl_signal_add(&server.xdg_shell->events.new_surface,
				  &server.new_xdg_surface);

	/**
	 * TODO
	 *

	server.new_layer_surface.notify = server_new_layer_surface;
	wl_signal_add(&server.layer_shell->events.new_surface,
		&server.new_layer_surface);
	*/
	diyac_init_cursor_manager(&server);

	/*
	 * Configures a seat, which is a single "seat" at which a user sits and
	 * operates the computer. This conceptually includes up to one keyboard,
	 * pointer, touch, and drawing tablet device. We also rig up a listener to
	 * let us know when new input devices are available on the backend.
	 */
	wl_list_init(&server.seat.keyboards);
	diyac_init_seat(&server);

	/* Add a Unix socket to the Wayland display. */
	const char *socket = wl_display_add_socket_auto(server.wl_display);
	if (!socket)
	{
		wlr_backend_destroy(server.backend);
		return 1;
	}

	/* Start the backend. This will enumerate outputs and inputs, become the DRM
	 * master, etc */
	if (!wlr_backend_start(server.backend))
	{
		wlr_backend_destroy(server.backend);
		wl_display_destroy(server.wl_display);
		return 1;
	}

	/* Set the WAYLAND_DISPLAY environment variable to our socket and run the
	 * startup command if requested. */
	setenv("WAYLAND_DISPLAY", socket, true);
	if (startup_cmd)
	{
		if (fork() == 0)
		{
			execl("/bin/sh", "/bin/sh", "-c", startup_cmd, (void *)NULL);
		}
	}
	/* Run the Wayland event loop. This does not return until you exit the
	 * compositor. Starting the backend rigged up all of the necessary event
	 * loop configuration to listen to libinput events, DRM events, generate
	 * frame events at the refresh rate, and so on. */
	wlr_log(WLR_INFO, "Running Wayland compositor on WAYLAND_DISPLAY=%s",
			socket);
	wl_display_run(server.wl_display);

	/* Once wl_display_run returns, we destroy all clients then shut down the
	 * server. */
	wl_display_destroy_clients(server.wl_display);
	wlr_scene_node_destroy(&server.scene->tree.node);
	wlr_xcursor_manager_destroy(server.seat.cursor_mgr);
	wlr_output_layout_destroy(server.output_layout);
	wl_display_destroy(server.wl_display);
	return 0;
}