Address first round review for swaynag

5 files changed, 1038 insertions, 0 deletions

diff --git a/swaynag/main.c b/swaynag/main.c
new file mode 100644
index 00000000..60560c72
--- /dev/null
+++ b/swaynag/main.c
@@ -0,0 +1,246 @@
+#define _XOPEN_SOURCE 500
+#include <getopt.h>
+#include <signal.h>
+#include "log.h"
+#include "list.h"
+#include "readline.h"
+#include "swaynag/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;
+        }
+}
+
+static char *read_from_stdin() {
+        char *buffer = NULL;
+        while (!feof(stdin)) {
+                char *line = read_line(stdin);
+                if (!line) {
+                        continue;
+                }
+
+                if (!buffer) {
+                        buffer = strdup(line);
+                } else {
+                        buffer = realloc(buffer, strlen(buffer) + strlen(line) + 2);
+                        strcat(buffer, line);
+                        strcat(buffer, "\n");
+                }
+
+                free(line);
+        }
+
+        if (buffer && buffer[strlen(buffer) - 1] == '\n') {
+                buffer[strlen(buffer) - 1] = '\0';
+        }
+
+        return buffer;
+}
+
+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 10");
+        nagbar.buttons = create_list();
+
+        struct sway_nagbar_button *button_close =
+                calloc(sizeof(struct sway_nagbar_button), 1);
+        button_close->text = strdup("X");
+        button_close->type = NAGBAR_ACTION_DISMISS;
+        list_add(nagbar.buttons, button_close);
+
+        struct sway_nagbar_button *button_details =
+                calloc(sizeof(struct sway_nagbar_button), 1);
+        button_details->text = strdup("Toggle Details");
+        button_details->type = NAGBAR_ACTION_EXPAND;
+
+        static struct option opts[] = {
+                {"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'},
+                {"detailed-message", no_argument, NULL, 'l'},
+                {"detailed-button", required_argument, NULL, 'L'},
+                {"message", required_argument, NULL, 'm'},
+                {"output", required_argument, NULL, 'o'},
+                {"dismiss-button", required_argument, NULL, 's'},
+                {"type", required_argument, NULL, 't'},
+                {"version", no_argument, NULL, 'v'},
+                {0, 0, 0, 0}
+        };
+
+        const char *usage =
+                "Usage: swaynag [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"
+                "  -l, --detailed-message        Read a detailed message from stdin.\n"
+                "  -L, --detailed-button <text>  Set the text of the detail button.\n"
+                "  -m, --message <msg>           Set the message text.\n"
+                "  -o, --output <output>         Set the output to use.\n"
+                "  -s, --dismiss-button <text>   Set the dismiss button text.\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:hlL:m:o:s:t:v", opts, NULL);
+                if (c == -1) {
+                        break;
+                }
+                switch (c) {
+                case 'b': // Button
+                        if (optind >= argc) {
+                                fprintf(stderr, "Missing action for button %s\n", 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->type = NAGBAR_ACTION_COMMAND;
+                        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 'l': // Detailed Message
+                        free(nagbar.details.message);
+                        nagbar.details.message = read_from_stdin();
+                        nagbar.details.button_up.text = strdup("▲");
+                        nagbar.details.button_down.text = strdup("▼");
+                        break;
+                case 'L': // Detailed Button Text
+                        free(button_details->text);
+                        button_details->text = 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 's': // Dismiss Button Text
+                        free(button_close->text);
+                        button_close->text = 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'\n");
+                                exit_code = EXIT_FAILURE;
+                                goto cleanup;
+                        }
+                        set_nagbar_colors();
+                        break;
+                case 'v': // Version
+                        fprintf(stdout, "swaynag 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;
+        }
+
+        if (nagbar.details.message) {
+                list_add(nagbar.buttons, button_details);
+        } else {
+                free(button_details->text);
+                free(button_details);
+        }
+
+        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:
+        free(button_details->text);
+        free(button_details);
+        nagbar_destroy(&nagbar);
+        return exit_code;
+}
+
diff --git a/swaynag/meson.build b/swaynag/meson.build
new file mode 100644
index 00000000..6492e4dc
--- /dev/null
+++ b/swaynag/meson.build
@@ -0,0 +1,20 @@
+executable(
+        'swaynag', [
+                '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/swaynag/nagbar.c b/swaynag/nagbar.c
new file mode 100644
index 00000000..6647e8c2
--- /dev/null
+++ b/swaynag/nagbar.c
@@ -0,0 +1,420 @@
+#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 "swaynag/nagbar.h"
+#include "swaynag/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/swaynagXXXXXX";
+        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->type == NAGBAR_ACTION_DISMISS) {
+                nagbar->run_display = false;
+        } else if (button->type == NAGBAR_ACTION_EXPAND) {
+                nagbar->details.visible = !nagbar->details.visible;
+                render_frame(nagbar);
+        } 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);
+                        return;
+                }
+        }
+
+        if (nagbar->details.visible &&
+                        nagbar->details.total_lines != nagbar->details.visible_lines) {
+                struct sway_nagbar_button button_up = nagbar->details.button_up;
+                if (x >= button_up.x
+                                && y >= button_up.y
+                                && x < button_up.x + button_up.width
+                                && y < button_up.y + button_up.height
+                                && nagbar->details.offset > 0) {
+                        nagbar->details.offset--;
+                        render_frame(nagbar);
+                        return;
+                }
+
+                struct sway_nagbar_button button_down = nagbar->details.button_down;
+                int bot = nagbar->details.total_lines - nagbar->details.visible_lines;
+                if (x >= button_down.x
+                                && y >= button_down.y
+                                && x < button_down.x + button_down.width
+                                && y < button_down.y + button_down.height
+                                && nagbar->details.offset < bot) {
+                        nagbar->details.offset++;
+                        render_frame(nagbar);
+                        return;
+                }
+        }
+}
+
+static void wl_pointer_axis(void *data, struct wl_pointer *wl_pointer,
+                uint32_t time, uint32_t axis, wl_fixed_t value) {
+        struct sway_nagbar *nagbar = data;
+        if (!nagbar->details.visible
+                        || nagbar->pointer.x < nagbar->details.x
+                        || nagbar->pointer.y < nagbar->details.y
+                        || nagbar->pointer.x >= nagbar->details.x + nagbar->details.width
+                        || nagbar->pointer.y >= nagbar->details.y + nagbar->details.height
+                        || nagbar->details.total_lines == nagbar->details.visible_lines) {
+                return;
+        }
+
+        int direction = wl_fixed_to_int(value);
+        int bot = nagbar->details.total_lines - nagbar->details.visible_lines;
+        if (direction < 0 && nagbar->details.offset > 0) {
+                nagbar->details.offset--;
+        } else if (direction > 0 && nagbar->details.offset < bot) {
+                nagbar->details.offset++;
+        }
+
+        render_frame(nagbar);
+}
+
+static struct wl_pointer_listener pointer_listener = {
+        .enter = wl_pointer_enter,
+        .leave = nop,
+        .motion = wl_pointer_motion,
+        .button = wl_pointer_button,
+        .axis = wl_pointer_axis,
+        .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_TOP, "swaynag");
+        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);
+        free(nagbar->details.message);
+        free(nagbar->details.button_up.text);
+        free(nagbar->details.button_down.text);
+
+        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/swaynag/render.c b/swaynag/render.c
new file mode 100644
index 00000000..150ae3f2
--- /dev/null
+++ b/swaynag/render.c
@@ -0,0 +1,300 @@
+#include <stdint.h>
+#include "cairo.h"
+#include "log.h"
+#include "pango.h"
+#include "pool-buffer.h"
+#include "swaynag/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)(ideal_height - text_height) / 2);
+        pango_printf(cairo, nagbar->font, nagbar->scale, true, "%s",
+                        nagbar->message);
+
+        return ideal_height;
+}
+
+static void render_details_scroll_button(cairo_t *cairo,
+                struct sway_nagbar *nagbar, struct sway_nagbar_button *button) {
+        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;
+
+        cairo_set_source_u32(cairo, nagbar->colors.border);
+        cairo_rectangle(cairo, button->x, button->y,
+                        button->width, button->height);
+        cairo_fill(cairo);
+
+        cairo_set_source_u32(cairo, nagbar->colors.button_background);
+        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.text);
+        cairo_move_to(cairo, button->x + border + padding,
+                        button->y + border + (button->height - text_height) / 2);
+        pango_printf(cairo, nagbar->font, nagbar->scale, true, "%s", button->text);
+}
+
+static int get_detailed_scroll_button_width(cairo_t *cairo,
+                struct sway_nagbar *nagbar) {
+        int up_width, down_width, temp_height;
+        get_text_size(cairo, nagbar->font, &up_width, &temp_height,
+                        nagbar->scale, true, "%s", nagbar->details.button_up.text);
+        get_text_size(cairo, nagbar->font, &down_width, &temp_height,
+                        nagbar->scale, true, "%s", nagbar->details.button_down.text);
+
+        int text_width =  up_width > down_width ? up_width : down_width;
+        int border = NAGBAR_BUTTON_BORDER_THICKNESS * nagbar->scale;
+        int padding = NAGBAR_BUTTON_PADDING * nagbar->scale;
+
+        return text_width + border * 2 + padding * 2;
+}
+
+static uint32_t render_detailed(cairo_t *cairo, struct sway_nagbar *nagbar,
+                uint32_t y) {
+        uint32_t width = nagbar->width * nagbar->scale;
+        uint32_t height = nagbar->height * nagbar->scale;
+        height -= NAGBAR_BAR_BORDER_THICKNESS * nagbar->scale;
+
+        int border = NAGBAR_DETAILS_BORDER_THICKNESS * nagbar->scale;
+        int padding = NAGBAR_MESSAGE_PADDING * nagbar->scale;
+        int decor = padding + border;
+
+        nagbar->details.x = decor;
+        nagbar->details.y = y + decor;
+        nagbar->details.width = width - decor * 2;
+
+        PangoLayout *layout = get_pango_layout(cairo, nagbar->font,
+                        nagbar->details.message, nagbar->scale, true);
+        pango_layout_set_width(layout,
+                        (nagbar->details.width - padding * 2) * PANGO_SCALE);
+        pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
+        pango_layout_set_single_paragraph_mode(layout, false);
+        pango_cairo_update_layout(cairo, layout);
+        nagbar->details.total_lines = pango_layout_get_line_count(layout);
+
+        PangoLayoutLine *line;
+        line = pango_layout_get_line_readonly(layout, nagbar->details.offset);
+        gint offset = line->start_index;
+        const char *text = pango_layout_get_text(layout);
+        pango_layout_set_text(layout, text + offset, strlen(text) - offset);
+
+        int text_width, text_height;
+        pango_cairo_update_layout(cairo, layout);
+        pango_layout_get_pixel_size(layout, &text_width, &text_height);
+
+        bool show_buttons = nagbar->details.offset > 0;
+        int button_width = get_detailed_scroll_button_width(cairo, nagbar);
+        if (show_buttons) {
+                nagbar->details.width -= button_width;
+                pango_layout_set_width(layout,
+                                (nagbar->details.width - padding * 2) * PANGO_SCALE);
+        }
+
+        uint32_t ideal_height;
+        do {
+                ideal_height = nagbar->details.y + text_height + decor + padding * 2;
+                if (ideal_height > NAGBAR_MAX_HEIGHT) {
+                        ideal_height = NAGBAR_MAX_HEIGHT;
+
+                        if (!show_buttons) {
+                                show_buttons = true;
+                                nagbar->details.width -= button_width;
+                                pango_layout_set_width(layout,
+                                                (nagbar->details.width - padding * 2) * PANGO_SCALE);
+                        }
+                }
+
+                nagbar->details.height = ideal_height - nagbar->details.y - decor;
+                pango_layout_set_height(layout,
+                                (nagbar->details.height - padding * 2) * PANGO_SCALE);
+                pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
+                pango_cairo_update_layout(cairo, layout);
+                pango_layout_get_pixel_size(layout, &text_width, &text_height);
+        } while (text_height != (nagbar->details.height - padding * 2));
+
+        nagbar->details.visible_lines = pango_layout_get_line_count(layout);
+
+        if (show_buttons) {
+                nagbar->details.button_up.x =
+                        nagbar->details.x + nagbar->details.width;
+                nagbar->details.button_up.y = nagbar->details.y;
+                nagbar->details.button_up.width = button_width;
+                nagbar->details.button_up.height = nagbar->details.height / 2;
+                render_details_scroll_button(cairo, nagbar,
+                                &nagbar->details.button_up);
+
+                nagbar->details.button_down.x =
+                        nagbar->details.x + nagbar->details.width;
+                nagbar->details.button_down.y =
+                        nagbar->details.button_up.y + nagbar->details.button_up.height;
+                nagbar->details.button_down.width = button_width;
+                nagbar->details.button_down.height = nagbar->details.height / 2;
+                render_details_scroll_button(cairo, nagbar,
+                                &nagbar->details.button_down);
+        }
+
+        cairo_set_source_u32(cairo, nagbar->colors.border);
+        cairo_rectangle(cairo, nagbar->details.x, nagbar->details.y,
+                        nagbar->details.width, nagbar->details.height);
+        cairo_fill(cairo);
+
+        cairo_move_to(cairo, nagbar->details.x + padding,
+                        nagbar->details.y + padding);
+        cairo_set_source_u32(cairo, nagbar->colors.text);
+        pango_cairo_show_layout(cairo, layout);
+        g_object_unref(layout);
+
+        return ideal_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)(ideal_height - text_height) / 2 - 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 ideal_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;
+                }
+        }
+
+        if (nagbar->details.visible) {
+                h = render_detailed(cairo, nagbar, max_height);
+                max_height = h > max_height ? h : max_height;
+        }
+
+        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;
+}
+
+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);
+                if (!nagbar->current_buffer) {
+                        wlr_log(WLR_DEBUG, "Failed to get buffer. Skipping frame.");
+                        goto cleanup;
+                }
+
+                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);
+        }
+
+cleanup:
+        cairo_surface_destroy(recorder);
+        cairo_destroy(cairo);
+}
diff --git a/swaynag/swaynag.1.scd b/swaynag/swaynag.1.scd
new file mode 100644
index 00000000..879aaf2e
--- /dev/null
+++ b/swaynag/swaynag.1.scd
@@ -0,0 +1,52 @@
+swaynagbar(1)
+
+# NAME
+
+swaynag - Show a warning or error message with buttons
+
+# SYNOPSIS
+
+_swaynag_ [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.
+
+*-l, --detailed-message*
+        Read a detailed message from stdin. A button to toggle details will be
+        added. Details are shown in a scrollable multi-line text area.
+
+*-L, --detailed-button <text>*
+        Set the text for the button that toggles details. This has no effect if
+        there is not a detailed message. The default is _Toggle Details_.
+
+*-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
+
+*-s, --dismiss-button <text>*
+        Sets the text for the dismiss nagbar button. The default is _X_.
+
+*-t, --type error|warning*
+        Set the message type.
+
+*-v, --version
+        Show the version number and quit.
+