From 88bc4b528ef3e1af3598b513dd5c1572dd09ec23 Mon Sep 17 00:00:00 2001
From: Brian Ashworth <bosrsf04@gmail.com>
Date: Wed, 25 Jul 2018 21:57:19 -0400
Subject: [PATCH] Implements swaynagbar

---
 include/swaynagbar/nagbar.h |  88 +++++++++
 include/swaynagbar/render.h |   6 +
 meson.build                 |   2 +
 swaynagbar/main.c           | 184 ++++++++++++++++++
 swaynagbar/meson.build      |  20 ++
 swaynagbar/nagbar.c         | 364 ++++++++++++++++++++++++++++++++++++
 swaynagbar/render.c         | 152 +++++++++++++++
 swaynagbar/swaynagbar.1.scd |  41 ++++
 8 files changed, 857 insertions(+)
 create mode 100644 include/swaynagbar/nagbar.h
 create mode 100644 include/swaynagbar/render.h
 create mode 100644 swaynagbar/main.c
 create mode 100644 swaynagbar/meson.build
 create mode 100644 swaynagbar/nagbar.c
 create mode 100644 swaynagbar/render.c
 create mode 100644 swaynagbar/swaynagbar.1.scd

diff --git a/include/swaynagbar/nagbar.h b/include/swaynagbar/nagbar.h
new file mode 100644
index 00000000..07a0d51e
--- /dev/null
+++ b/include/swaynagbar/nagbar.h
@@ -0,0 +1,88 @@
+#ifndef _SWAY_NAGBAR_NAGBAR_H
+#define _SWAY_NAGBAR_NAGNAR_H
+#include <stdint.h>
+#include "list.h"
+#include "pool-buffer.h"
+#include "xdg-output-unstable-v1-client-protocol.h"
+
+#define NAGBAR_BAR_BORDER_THICKNESS 2
+#define NAGBAR_MESSAGE_PADDING 8
+#define NAGBAR_BUTTON_BORDER_THICKNESS 3
+#define NAGBAR_BUTTON_GAP 20
+#define NAGBAR_BUTTON_GAP_CLOSE 15
+#define NAGBAR_BUTTON_MARGIN_RIGHT 2
+#define NAGBAR_BUTTON_PADDING 3
+
+enum sway_nagbar_type {
+	NAGBAR_ERROR,
+	NAGBAR_WARNING,
+};
+
+struct sway_nagbar_colors {
+	uint32_t button_background;
+	uint32_t background;
+	uint32_t text;
+	uint32_t border;
+	uint32_t border_bottom;
+};
+
+struct sway_nagbar_pointer {
+	struct wl_pointer *pointer;
+	struct wl_cursor_theme *cursor_theme;
+	struct wl_cursor_image *cursor_image;
+	struct wl_surface *cursor_surface;
+	int x;
+	int y;
+};
+
+struct sway_nagbar_output {
+	char *name;
+	struct wl_output *wl_output;
+	uint32_t wl_name;
+};
+
+struct sway_nagbar_button {
+	char *text;
+	char *action;
+	int x;
+	int y;
+	int width;
+	int height;
+};
+
+struct sway_nagbar {
+	bool run_display;
+	int querying_outputs;
+
+	struct wl_display *display;
+	struct wl_compositor *compositor;
+	struct wl_seat *seat;
+	struct wl_shm *shm;
+	struct sway_nagbar_pointer pointer;
+	struct zxdg_output_manager_v1 *xdg_output_manager;
+	struct sway_nagbar_output output;
+	struct zwlr_layer_shell_v1 *layer_shell;
+	struct zwlr_layer_surface_v1 *layer_surface;
+	struct wl_surface *surface;
+
+	uint32_t width;
+	uint32_t height;
+	int32_t scale;
+	struct pool_buffer buffers[2];
+	struct pool_buffer *current_buffer;
+
+	enum sway_nagbar_type type;
+	struct sway_nagbar_colors colors;
+	uint32_t anchors;
+	char *message;
+	char *font;
+	list_t *buttons;
+};
+
+void nagbar_setup(struct sway_nagbar *nagbar);
+
+void nagbar_run(struct sway_nagbar *nagbar);
+
+void nagbar_destroy(struct sway_nagbar *nagbar);
+
+#endif
diff --git a/include/swaynagbar/render.h b/include/swaynagbar/render.h
new file mode 100644
index 00000000..d9429f7f
--- /dev/null
+++ b/include/swaynagbar/render.h
@@ -0,0 +1,6 @@
+#ifndef _SWAY_NAGBAR_RENDER_H
+#define _SWAY_NAGBAR_RENDER_H
+
+void render_frame(struct sway_nagbar *nagbar);
+
+#endif
diff --git a/meson.build b/meson.build
index 05d334d2..26d36e06 100644
--- a/meson.build
+++ b/meson.build
@@ -82,6 +82,7 @@ if scdoc.found()
 		'swaylock/swaylock.1.scd',
 		'swaymsg/swaymsg.1.scd',
 		'swayidle/swayidle.1.scd',
+		'swaynagbar/swaynagbar.1.scd',
 	]
 	foreach filename : man_files
 		topic = filename.split('.')[-3].split('/')[-1]
@@ -130,6 +131,7 @@ subdir('swaybg')
 subdir('swaybar')
 subdir('swaylock')
 subdir('swayidle')
+subdir('swaynagbar')
 
 config = configuration_data()
 config.set('sysconfdir', join_paths(prefix, sysconfdir))
diff --git a/swaynagbar/main.c b/swaynagbar/main.c
new file mode 100644
index 00000000..f5ed064e
--- /dev/null
+++ b/swaynagbar/main.c
@@ -0,0 +1,184 @@
+#define _XOPEN_SOURCE 500
+#include <getopt.h>
+#include <signal.h>
+#include "log.h"
+#include "list.h"
+#include "swaynagbar/nagbar.h"
+#include "wlr-layer-shell-unstable-v1-client-protocol.h"
+
+static struct sway_nagbar nagbar;
+
+void sig_handler(int signal) {
+	nagbar_destroy(&nagbar);
+	exit(EXIT_FAILURE);
+}
+
+void sway_terminate(int code) {
+	nagbar_destroy(&nagbar);
+	exit(code);
+}
+
+static void set_nagbar_colors() {
+	if (nagbar.type == NAGBAR_ERROR) {
+		nagbar.colors.button_background = 0x680A0AFF;
+		nagbar.colors.background = 0x900000FF;
+		nagbar.colors.text = 0xFFFFFFFF;
+		nagbar.colors.border = 0xD92424FF;
+		nagbar.colors.border_bottom = 0x470909FF;
+	} else if (nagbar.type == NAGBAR_WARNING) {
+		nagbar.colors.button_background = 0xFFC100FF;
+		nagbar.colors.background = 0xFFA800FF;
+		nagbar.colors.text = 0x000000FF;
+		nagbar.colors.border = 0xAB7100FF;
+		nagbar.colors.border_bottom = 0xAB7100FF;
+	}
+}
+
+int main(int argc, char **argv) {
+	int exit_code = EXIT_SUCCESS;
+	bool debug = false;
+
+	memset(&nagbar, 0, sizeof(nagbar));
+	nagbar.anchors = ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP
+		| ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT
+		| ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+	nagbar.type = NAGBAR_ERROR;
+	set_nagbar_colors();
+	nagbar.font = strdup("pango:monospace 8");
+	nagbar.buttons = create_list();
+
+	struct sway_nagbar_button *button_close =
+		calloc(sizeof(struct sway_nagbar_button), 1);
+	button_close->text = strdup("X");
+	button_close->action = NULL;
+	list_add(nagbar.buttons, button_close);
+
+	static struct option long_options[] = {
+		{"button", required_argument, NULL, 'b'},
+		{"debug", no_argument, NULL, 'd'},
+		{"edge", required_argument, NULL, 'e'},
+		{"font", required_argument, NULL, 'f'},
+		{"help", no_argument, NULL, 'h'},
+		{"message", required_argument, NULL, 'm'},
+		{"output", required_argument, NULL, 'o'},
+		{"type", required_argument, NULL, 't'},
+		{"version", no_argument, NULL, 'v'},
+		{0, 0, 0, 0}
+	};
+
+	const char *usage =
+		"Usage: swaynagbar [options...]\n"
+		"\n"
+		"  -b, --button <text> <action>  Create a button with text that "
+			"executes action when pressed. Multiple buttons can be defined.\n"
+		"  -d, --debug                   Enable debugging.\n"
+		"  -e, --edge top|bottom         Set the edge to use.\n"
+		"  -f, --font <font>             Set the font to use.\n"
+		"  -h, --help                    Show help message and quit.\n"
+		"  -m, --message <msg>           Set the message text.\n"
+		"  -o, --output <output>         Set the output to use.\n"
+		"  -t, --type error|warning      Set the message type.\n"
+		"  -v, --version                 Show the version number and quit.\n";
+
+	while (1) {
+		int c = getopt_long(argc, argv, "b:de:f:hm:o:t:v", long_options, NULL);
+		if (c == -1) {
+			break;
+		}
+		switch (c) {
+		case 'b': // Button
+			if (optind >= argc) {
+				fprintf(stderr, "Missing action for button %s", optarg);
+				exit_code = EXIT_FAILURE;
+				goto cleanup;
+			}
+			struct sway_nagbar_button *button;
+			button = calloc(sizeof(struct sway_nagbar_button), 1);
+			button->text = strdup(optarg);
+			button->action = strdup(argv[optind]);
+			optind++;
+			list_add(nagbar.buttons, button);
+			break;
+		case 'd': // Debug
+			debug = true;
+			break;
+		case 'e': // Edge
+			if (strcmp(optarg, "top") == 0) {
+				nagbar.anchors = ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP
+					| ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT
+					| ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+			} else if (strcmp(optarg, "bottom") == 0) {
+				nagbar.anchors = ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM
+					| ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT
+					| ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+			} else {
+				fprintf(stderr, "Invalid edge: %s\n", optarg);
+				exit_code = EXIT_FAILURE;
+				goto cleanup;
+			}
+			break;
+		case 'f': // Font
+			free(nagbar.font);
+			nagbar.font = strdup(optarg);
+			break;
+		case 'm': // Message
+			free(nagbar.message);
+			nagbar.message = strdup(optarg);
+			break;
+		case 'o': // Output
+			free(nagbar.output.name);
+			nagbar.output.name = strdup(optarg);
+			break;
+		case 't': // Type
+			if (strcmp(optarg, "error") == 0) {
+				nagbar.type = NAGBAR_ERROR;
+			} else if (strcmp(optarg, "warning") == 0) {
+				nagbar.type = NAGBAR_WARNING;
+			} else {
+				fprintf(stderr, "Type must be either 'error' or 'warning'");
+				exit_code = EXIT_FAILURE;
+				goto cleanup;
+			}
+			set_nagbar_colors();
+			break;
+		case 'v': // Version
+			fprintf(stdout, "sway version " SWAY_VERSION "\n");
+			exit_code = EXIT_SUCCESS;
+			goto cleanup;
+		default: // Help or unknown flag
+			fprintf(c == 'h' ? stdout : stderr, "%s", usage);
+			exit_code = c == 'h' ? EXIT_SUCCESS : EXIT_FAILURE;
+			goto cleanup;
+		}
+	}
+
+	wlr_log_init(debug ? WLR_DEBUG : WLR_ERROR, NULL);
+
+	if (!nagbar.message) {
+		wlr_log(WLR_ERROR, "No message passed. Please provide --message/-m");
+		exit_code = EXIT_FAILURE;
+		goto cleanup;
+	}
+
+	wlr_log(WLR_DEBUG, "Output: %s", nagbar.output.name);
+	wlr_log(WLR_DEBUG, "Anchors: %d", nagbar.anchors);
+	wlr_log(WLR_DEBUG, "Type: %d", nagbar.type);
+	wlr_log(WLR_DEBUG, "Message: %s", nagbar.message);
+	wlr_log(WLR_DEBUG, "Font: %s", nagbar.font);
+	wlr_log(WLR_DEBUG, "Buttons");
+	for (int i = 0; i < nagbar.buttons->length; i++) {
+		struct sway_nagbar_button *button = nagbar.buttons->items[i];
+		wlr_log(WLR_DEBUG, "\t[%s] `%s`", button->text, button->action);
+	}
+
+	signal(SIGTERM, sig_handler);
+
+	nagbar_setup(&nagbar);
+	nagbar_run(&nagbar);
+	return exit_code;
+
+cleanup:
+	nagbar_destroy(&nagbar);
+	return exit_code;
+}
+
diff --git a/swaynagbar/meson.build b/swaynagbar/meson.build
new file mode 100644
index 00000000..254462f2
--- /dev/null
+++ b/swaynagbar/meson.build
@@ -0,0 +1,20 @@
+executable(
+	'swaynagbar', [
+		'main.c',
+		'nagbar.c',
+		'render.c',
+	],
+	include_directories: [sway_inc],
+	dependencies: [
+		cairo,
+		client_protos,
+		gdk_pixbuf,
+		pango,
+		pangocairo,
+		wayland_client,
+		wayland_cursor,
+		wlroots,
+	],
+	link_with: [lib_sway_common, lib_sway_client],
+	install: true
+)
diff --git a/swaynagbar/nagbar.c b/swaynagbar/nagbar.c
new file mode 100644
index 00000000..22e5aff4
--- /dev/null
+++ b/swaynagbar/nagbar.c
@@ -0,0 +1,364 @@
+#define _XOPEN_SOURCE 500
+#include <assert.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <wayland-client.h>
+#include <wayland-cursor.h>
+#include "log.h"
+#include "list.h"
+#include "swaynagbar/nagbar.h"
+#include "swaynagbar/render.h"
+#include "wlr-layer-shell-unstable-v1-client-protocol.h"
+
+static void nop() {
+	// Intentionally left blank
+}
+
+static bool terminal_execute(char *terminal, char *command) {
+	char fname[] = "/tmp/swaynagbarXXXXXX";
+	FILE *tmp= fdopen(mkstemp(fname), "w");
+	if (!tmp) {
+		wlr_log(WLR_ERROR, "Failed to create temp script");
+		return false;
+	}
+	wlr_log(WLR_DEBUG, "Created temp script: %s", fname);
+	fprintf(tmp, "#!/bin/sh\nrm %s\n%s", fname, command);
+	fclose(tmp);
+	chmod(fname, S_IRUSR | S_IWUSR | S_IXUSR);
+	char cmd[strlen(terminal) + strlen(" -e ") + strlen(fname) + 1];
+	sprintf(cmd, "%s -e %s", terminal, fname);
+	execl("/bin/sh", "/bin/sh", "-c", cmd, NULL);
+	return true;
+}
+
+static void nagbar_button_execute(struct sway_nagbar *nagbar,
+		struct sway_nagbar_button *button) {
+	wlr_log(WLR_DEBUG, "Executing [%s]: %s", button->text, button->action);
+	if (!button->action) {
+		nagbar->run_display = false;
+	} else {
+		if (fork() == 0) {
+			// Child process. Will be used to prevent zombie processes
+			setsid();
+			if (fork() == 0) {
+				// Child of the child. Will be reparented to the init process
+				char *terminal = getenv("TERMINAL");
+				if (terminal && strlen(terminal)) {
+					wlr_log(WLR_DEBUG, "Found $TERMINAL: %s", terminal);
+					if (!terminal_execute(terminal, button->action)) {
+						nagbar_destroy(nagbar);
+						exit(EXIT_FAILURE);
+					}
+				} else {
+					wlr_log(WLR_DEBUG, "$TERMINAL not found. Running directly");
+					execl("/bin/sh", "/bin/sh", "-c", button->action, NULL);
+				}
+			}
+			exit(EXIT_SUCCESS);
+		}
+	}
+	wait(0);
+}
+
+static void layer_surface_configure(void *data,
+		struct zwlr_layer_surface_v1 *surface,
+		uint32_t serial, uint32_t width, uint32_t height) {
+	struct sway_nagbar *nagbar = data;
+	nagbar->width = width;
+	nagbar->height = height;
+	zwlr_layer_surface_v1_ack_configure(surface, serial);
+	render_frame(nagbar);
+}
+
+static void layer_surface_closed(void *data,
+		struct zwlr_layer_surface_v1 *surface) {
+	struct sway_nagbar *nagbar = data;
+	nagbar_destroy(nagbar);
+}
+
+static struct zwlr_layer_surface_v1_listener layer_surface_listener = {
+	.configure = layer_surface_configure,
+	.closed = layer_surface_closed,
+};
+
+static void wl_pointer_enter(void *data, struct wl_pointer *wl_pointer,
+		uint32_t serial, struct wl_surface *surface,
+		wl_fixed_t surface_x, wl_fixed_t surface_y) {
+	struct sway_nagbar *nagbar = data;
+	struct sway_nagbar_pointer *pointer = &nagbar->pointer;
+	wl_surface_set_buffer_scale(pointer->cursor_surface, nagbar->scale);
+	wl_surface_attach(pointer->cursor_surface,
+			wl_cursor_image_get_buffer(pointer->cursor_image), 0, 0);
+	wl_pointer_set_cursor(wl_pointer, serial, pointer->cursor_surface,
+			pointer->cursor_image->hotspot_x / nagbar->scale,
+			pointer->cursor_image->hotspot_y / nagbar->scale);
+	wl_surface_commit(pointer->cursor_surface);
+}
+
+static void wl_pointer_motion(void *data, struct wl_pointer *wl_pointer,
+		uint32_t time, wl_fixed_t surface_x, wl_fixed_t surface_y) {
+	struct sway_nagbar *nagbar = data;
+	nagbar->pointer.x = wl_fixed_to_int(surface_x);
+	nagbar->pointer.y = wl_fixed_to_int(surface_y);
+}
+
+static void wl_pointer_button(void *data, struct wl_pointer *wl_pointer,
+		uint32_t serial, uint32_t time, uint32_t button, uint32_t state) {
+	struct sway_nagbar *nagbar = data;
+
+	if (state != WL_POINTER_BUTTON_STATE_PRESSED) {
+		return;
+	}
+
+	double x = nagbar->pointer.x * nagbar->scale;
+	double y = nagbar->pointer.y * nagbar->scale;
+	for (int i = 0; i < nagbar->buttons->length; i++) {
+		struct sway_nagbar_button *nagbutton = nagbar->buttons->items[i];
+		if (x >= nagbutton->x
+				&& y >= nagbutton->y
+				&& x < nagbutton->x + nagbutton->width
+				&& y < nagbutton->y + nagbutton->height) {
+			nagbar_button_execute(nagbar, nagbutton);
+		}
+	}
+}
+
+static struct wl_pointer_listener pointer_listener = {
+	.enter = wl_pointer_enter,
+	.leave = nop,
+	.motion = wl_pointer_motion,
+	.button = wl_pointer_button,
+	.axis = nop,
+	.frame = nop,
+	.axis_source = nop,
+	.axis_stop = nop,
+	.axis_discrete = nop,
+};
+
+static void seat_handle_capabilities(void *data, struct wl_seat *wl_seat,
+		enum wl_seat_capability caps) {
+	struct sway_nagbar *nagbar = data;
+	if ((caps & WL_SEAT_CAPABILITY_POINTER)) {
+		nagbar->pointer.pointer = wl_seat_get_pointer(wl_seat);
+		wl_pointer_add_listener(nagbar->pointer.pointer, &pointer_listener,
+				nagbar);
+	}
+}
+
+const struct wl_seat_listener seat_listener = {
+	.capabilities = seat_handle_capabilities,
+	.name = nop,
+};
+
+static void output_scale(void *data, struct wl_output *output,
+		int32_t factor) {
+	struct sway_nagbar *nagbar = data;
+	nagbar->scale = factor;
+	render_frame(nagbar);
+}
+
+static struct wl_output_listener output_listener = {
+	.geometry = nop,
+	.mode = nop,
+	.done = nop,
+	.scale = output_scale,
+};
+
+struct output_state {
+	struct wl_output *wl_output;
+	uint32_t wl_name;
+	struct zxdg_output_v1 *xdg_output;
+	struct sway_nagbar *nagbar;
+};
+
+static void xdg_output_handle_name(void *data,
+		struct zxdg_output_v1 *xdg_output, const char *name) {
+	struct output_state *state = data;
+	char *outname = state->nagbar->output.name;
+	wlr_log(WLR_DEBUG, "Checking against output %s for %s", name, outname);
+	if ((!outname && !state->nagbar->output.wl_output)
+			|| (name && outname && strcmp(name, outname) == 0)) {
+		wlr_log(WLR_DEBUG, "Using output %s", name);
+		state->nagbar->output.wl_output = state->wl_output;
+		state->nagbar->output.wl_name = state->wl_name;
+		wl_output_add_listener(state->nagbar->output.wl_output,
+				&output_listener, state->nagbar);
+		wl_display_roundtrip(state->nagbar->display);
+		zxdg_output_v1_destroy(state->xdg_output);
+	} else {
+		zxdg_output_v1_destroy(state->xdg_output);
+		wl_output_destroy(state->wl_output);
+	}
+	state->nagbar->querying_outputs--;
+	free(state);
+}
+
+static struct zxdg_output_v1_listener xdg_output_listener = {
+	.logical_position = nop,
+	.logical_size = nop,
+	.done = nop,
+	.name = xdg_output_handle_name,
+	.description = nop,
+};
+
+static void handle_global(void *data, struct wl_registry *registry,
+		uint32_t name, const char *interface, uint32_t version) {
+	struct sway_nagbar *nagbar = data;
+	if (strcmp(interface, wl_compositor_interface.name) == 0) {
+		nagbar->compositor = wl_registry_bind(registry, name,
+				&wl_compositor_interface, 3);
+	} else if (strcmp(interface, wl_seat_interface.name) == 0) {
+		nagbar->seat = wl_registry_bind(registry, name, &wl_seat_interface, 1);
+		wl_seat_add_listener(nagbar->seat, &seat_listener, nagbar);
+	} else if (strcmp(interface, wl_shm_interface.name) == 0) {
+		nagbar->shm = wl_registry_bind(registry, name, &wl_shm_interface, 1);
+	} else if (strcmp(interface, wl_output_interface.name) == 0) {
+		if (!nagbar->output.wl_output && nagbar->xdg_output_manager) {
+			nagbar->querying_outputs++;
+			struct output_state *state =
+				calloc(1, sizeof(struct output_state));
+			state->nagbar = nagbar;
+			state->wl_output = wl_registry_bind(registry, name,
+					&wl_output_interface, 3);
+			state->wl_name = name;
+			state->xdg_output = zxdg_output_manager_v1_get_xdg_output(
+					nagbar->xdg_output_manager, state->wl_output);
+			zxdg_output_v1_add_listener(state->xdg_output,
+					&xdg_output_listener, state);
+		} else if (!nagbar->output.wl_output && !nagbar->xdg_output_manager) {
+			wlr_log(WLR_ERROR, "Warning: zxdg_output_manager_v1 not supported."
+					" Falling back to first detected output");
+			nagbar->output.wl_output = wl_registry_bind(registry, name,
+					&wl_output_interface, 3);
+			nagbar->output.wl_name = name;
+			wl_output_add_listener(nagbar->output.wl_output,
+					&output_listener, nagbar);
+		}
+	} else if (strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) {
+		nagbar->layer_shell = wl_registry_bind(
+				registry, name, &zwlr_layer_shell_v1_interface, 1);
+	} else if (strcmp(interface, zxdg_output_manager_v1_interface.name) == 0
+			&& version >= ZXDG_OUTPUT_V1_NAME_SINCE_VERSION) {
+		nagbar->xdg_output_manager = wl_registry_bind(registry, name,
+				&zxdg_output_manager_v1_interface,
+				ZXDG_OUTPUT_V1_NAME_SINCE_VERSION);
+	}
+}
+
+static void handle_global_remove(void *data, struct wl_registry *registry,
+		uint32_t name) {
+	struct sway_nagbar *nagbar = data;
+	if (nagbar->output.wl_name == name) {
+		nagbar->run_display = false;
+	}
+}
+
+static const struct wl_registry_listener registry_listener = {
+	.global = handle_global,
+	.global_remove = handle_global_remove,
+};
+
+void nagbar_setup(struct sway_nagbar *nagbar) {
+	nagbar->display = wl_display_connect(NULL);
+	assert(nagbar->display);
+
+	nagbar->scale = 1;
+
+	struct wl_registry *registry = wl_display_get_registry(nagbar->display);
+	wl_registry_add_listener(registry, &registry_listener, nagbar);
+	wl_display_roundtrip(nagbar->display);
+	assert(nagbar->compositor && nagbar->layer_shell && nagbar->shm);
+
+	while (nagbar->querying_outputs > 0) {
+		wl_display_roundtrip(nagbar->display);
+	}
+
+	if (!nagbar->output.wl_output) {
+		if (nagbar->output.name) {
+			wlr_log(WLR_ERROR, "Output '%s' not found", nagbar->output.name);
+		} else {
+			wlr_log(WLR_ERROR, "No outputs detected");
+		}
+		nagbar_destroy(nagbar);
+		exit(EXIT_FAILURE);
+	}
+
+	struct sway_nagbar_pointer *pointer = &nagbar->pointer;
+	int scale = nagbar->scale < 1 ? 1 : nagbar->scale;
+	pointer->cursor_theme = wl_cursor_theme_load(
+			NULL, 24 * scale, nagbar->shm);
+	assert(pointer->cursor_theme);
+	struct wl_cursor *cursor =
+		wl_cursor_theme_get_cursor(pointer->cursor_theme, "left_ptr");
+	assert(cursor);
+	pointer->cursor_image = cursor->images[0];
+	pointer->cursor_surface = wl_compositor_create_surface(nagbar->compositor);
+	assert(pointer->cursor_surface);
+
+	nagbar->surface = wl_compositor_create_surface(nagbar->compositor);
+	assert(nagbar->surface);
+	nagbar->layer_surface = zwlr_layer_shell_v1_get_layer_surface(
+			nagbar->layer_shell, nagbar->surface, nagbar->output.wl_output,
+			ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM, "nagbar");
+	assert(nagbar->layer_surface);
+	zwlr_layer_surface_v1_add_listener(nagbar->layer_surface,
+			&layer_surface_listener, nagbar);
+	zwlr_layer_surface_v1_set_anchor(nagbar->layer_surface, nagbar->anchors);
+
+	wl_registry_destroy(registry);
+}
+
+void nagbar_run(struct sway_nagbar *nagbar) {
+	nagbar->run_display = true;
+	render_frame(nagbar);
+	while (nagbar->run_display && wl_display_dispatch(nagbar->display) != -1) {
+		// This is intentionally left blank
+	}
+}
+
+void nagbar_destroy(struct sway_nagbar *nagbar) {
+	nagbar->run_display = false;
+
+	free(nagbar->message);
+	free(nagbar->font);
+	while (nagbar->buttons->length) {
+		struct sway_nagbar_button *button = nagbar->buttons->items[0];
+		list_del(nagbar->buttons, 0);
+		free(button->text);
+		free(button->action);
+		free(button);
+	}
+	list_free(nagbar->buttons);
+
+	if (nagbar->layer_surface) {
+		zwlr_layer_surface_v1_destroy(nagbar->layer_surface);
+	}
+
+	if (nagbar->surface) {
+		wl_surface_destroy(nagbar->surface);
+	}
+
+	if (nagbar->output.wl_output) {
+		wl_output_destroy(nagbar->output.wl_output);
+	}
+
+	if (&nagbar->buffers[0]) {
+		destroy_buffer(&nagbar->buffers[0]);
+	}
+
+	if (&nagbar->buffers[1]) {
+		destroy_buffer(&nagbar->buffers[1]);
+	}
+
+	if (nagbar->compositor) {
+		wl_compositor_destroy(nagbar->compositor);
+	}
+
+	if (nagbar->shm) {
+		wl_shm_destroy(nagbar->shm);
+	}
+
+	if (nagbar->display) {
+		wl_display_disconnect(nagbar->display);
+	}
+}
diff --git a/swaynagbar/render.c b/swaynagbar/render.c
new file mode 100644
index 00000000..c0f59298
--- /dev/null
+++ b/swaynagbar/render.c
@@ -0,0 +1,152 @@
+#include <stdint.h>
+#include "cairo.h"
+#include "log.h"
+#include "pango.h"
+#include "pool-buffer.h"
+#include "swaynagbar/nagbar.h"
+#include "wlr-layer-shell-unstable-v1-client-protocol.h"
+
+static uint32_t render_message(cairo_t *cairo, struct sway_nagbar *nagbar) {
+	uint32_t height = nagbar->height * nagbar->scale;
+	height -= NAGBAR_BAR_BORDER_THICKNESS * nagbar->scale;
+
+	int text_width, text_height;
+	get_text_size(cairo, nagbar->font, &text_width, &text_height,
+			nagbar->scale, true, "%s", nagbar->message);
+
+	int padding = NAGBAR_MESSAGE_PADDING * nagbar->scale;
+
+	uint32_t ideal_height = text_height + padding * 2;
+	uint32_t ideal_surface_height = ideal_height / nagbar->scale;
+	if (nagbar->height < ideal_surface_height) {
+		return ideal_surface_height;
+	}
+
+	cairo_set_source_u32(cairo, nagbar->colors.text);
+	cairo_move_to(cairo, padding, (int)(height / 2.0 - text_height / 2.0));
+	pango_printf(cairo, nagbar->font, nagbar->scale, true, "%s",
+			nagbar->message);
+
+	return nagbar->height;
+}
+
+static uint32_t render_button(cairo_t *cairo, struct sway_nagbar *nagbar,
+		int button_index, int *x) {
+	uint32_t height = nagbar->height * nagbar->scale;
+	height -= NAGBAR_BAR_BORDER_THICKNESS * nagbar->scale;
+	struct sway_nagbar_button *button = nagbar->buttons->items[button_index];
+
+	int text_width, text_height;
+	get_text_size(cairo, nagbar->font, &text_width, &text_height,
+			nagbar->scale, true, "%s", button->text);
+
+	int border = NAGBAR_BUTTON_BORDER_THICKNESS * nagbar->scale;
+	int padding = NAGBAR_BUTTON_PADDING * nagbar->scale;
+
+	uint32_t ideal_height = text_height + padding * 2 + border * 2;
+	uint32_t ideal_surface_height = ideal_height / nagbar->scale;
+	if (nagbar->height < ideal_surface_height) {
+		return ideal_surface_height;
+	}
+
+	button->x = *x - border - text_width - padding * 2;
+	button->y = (int)(height / 2.0 - text_height / 2.0) - padding;
+	button->width = text_width + padding * 2;
+	button->height = text_height + padding * 2;
+
+	cairo_set_source_u32(cairo, nagbar->colors.border);
+	cairo_rectangle(cairo, button->x - border, button->y - border,
+			button->width + border * 2, button->height + border * 2);
+	cairo_fill(cairo);
+
+	cairo_set_source_u32(cairo, nagbar->colors.button_background);
+	cairo_rectangle(cairo, button->x, button->y,
+			button->width, button->height);
+	cairo_fill(cairo);
+
+	cairo_set_source_u32(cairo, nagbar->colors.text);
+	cairo_move_to(cairo, button->x + padding, button->y + padding);
+	pango_printf(cairo, nagbar->font, nagbar->scale, true, "%s", button->text);
+
+	*x = button->x - border;
+
+	return nagbar->height;
+}
+
+static uint32_t render_to_cairo(cairo_t *cairo, struct sway_nagbar *nagbar) {
+	uint32_t max_height = 0;
+
+	cairo_set_operator(cairo, CAIRO_OPERATOR_SOURCE);
+	cairo_set_source_u32(cairo, nagbar->colors.background);
+	cairo_paint(cairo);
+
+	uint32_t h = render_message(cairo, nagbar);
+	max_height = h > max_height ? h : max_height;
+
+	int x = (nagbar->width - NAGBAR_BUTTON_MARGIN_RIGHT) * nagbar->scale;
+	for (int i = 0; i < nagbar->buttons->length; i++) {
+		h = render_button(cairo, nagbar, i, &x);
+		max_height = h > max_height ? h : max_height;
+		x -= NAGBAR_BUTTON_GAP * nagbar->scale;
+		if (i == 0) {
+			x -= NAGBAR_BUTTON_GAP_CLOSE * nagbar->scale;
+		}
+	}
+
+	int border = NAGBAR_BAR_BORDER_THICKNESS * nagbar->scale;
+	if (max_height > nagbar->height) {
+		max_height += border;
+	}
+	cairo_set_source_u32(cairo, nagbar->colors.border_bottom);
+	cairo_rectangle(cairo, 0, nagbar->height * nagbar->scale - border,
+			nagbar->width * nagbar->scale, border);
+	cairo_fill(cairo);
+
+	return max_height > nagbar->height ? max_height : nagbar->height;
+}
+
+void render_frame(struct sway_nagbar *nagbar) {
+	if (!nagbar->run_display) {
+		return;
+	}
+
+	cairo_surface_t *recorder = cairo_recording_surface_create(
+			CAIRO_CONTENT_COLOR_ALPHA, NULL);
+	cairo_t *cairo = cairo_create(recorder);
+	cairo_save(cairo);
+	cairo_set_operator(cairo, CAIRO_OPERATOR_CLEAR);
+	cairo_paint(cairo);
+	cairo_restore(cairo);
+	uint32_t height = render_to_cairo(cairo, nagbar);
+	if (height != nagbar->height) {
+		zwlr_layer_surface_v1_set_size(nagbar->layer_surface, 0, height);
+		zwlr_layer_surface_v1_set_exclusive_zone(nagbar->layer_surface,
+				height);
+		wl_surface_commit(nagbar->surface);
+		wl_display_roundtrip(nagbar->display);
+	} else {
+		nagbar->current_buffer = get_next_buffer(nagbar->shm,
+				nagbar->buffers,
+				nagbar->width * nagbar->scale,
+				nagbar->height * nagbar->scale);
+		cairo_t *shm = nagbar->current_buffer->cairo;
+
+		cairo_save(shm);
+		cairo_set_operator(shm, CAIRO_OPERATOR_CLEAR);
+		cairo_paint(shm);
+		cairo_restore(shm);
+
+		cairo_set_source_surface(shm, recorder, 0.0, 0.0);
+		cairo_paint(shm);
+
+		wl_surface_set_buffer_scale(nagbar->surface, nagbar->scale);
+		wl_surface_attach(nagbar->surface,
+				nagbar->current_buffer->buffer, 0, 0);
+		wl_surface_damage(nagbar->surface, 0, 0,
+				nagbar->width, nagbar->height);
+		wl_surface_commit(nagbar->surface);
+		wl_display_roundtrip(nagbar->display);
+	}
+	cairo_surface_destroy(recorder);
+	cairo_destroy(cairo);
+}
diff --git a/swaynagbar/swaynagbar.1.scd b/swaynagbar/swaynagbar.1.scd
new file mode 100644
index 00000000..4235e2ea
--- /dev/null
+++ b/swaynagbar/swaynagbar.1.scd
@@ -0,0 +1,41 @@
+swaynagbar(1)
+
+# NAME
+
+swaynagbar - Show a warning or error message with buttons
+
+# SYNOPSIS
+
+_swaynagbar_ [options...]
+
+# OPTIONS
+*-b, --button* <text> <action>
+	Create a button with the text _text_ that executes _action_ when pressed.
+	Multiple buttons can be defined by providing the flag multiple times.
+
+*-d, --debug*
+	Enable debugging.
+
+*-e, --edge top|bottom*
+	Set the edge to use.
+
+*-f, --font <font>*
+	Set the font to use.
+
+*-h, --help*
+	Show help message and quit.
+
+*-m, --message <msg>*
+	Set the message text.
+
+*-o, --output <output>*
+	Set the output to use. This should be the name of a _xdg\_output_. If
+	_xdg\_output\_manager_ is not supported, then the first detected output
+	will be used
+
+*-t, --type error|warning*
+	Set the message type.
+
+*-v, --version
+	Show the version number and quit.
+