Add swaybg_command

include/sway/commands.h

@@ -141,6 +141,7 @@ sway_cmd cmd_splith;
 sway_cmd cmd_splitt;
 sway_cmd cmd_splitv;
 sway_cmd cmd_sticky;
+sway_cmd cmd_swaybg_command;
 sway_cmd cmd_unmark;
 sway_cmd cmd_workspace;
 sway_cmd cmd_ws_auto_back_and_forth;

include/sway/config.h

@@ -282,6 +282,7 @@ struct sway_config {
 	list_t *active_bar_modifiers;
 	struct sway_mode *current_mode;
 	struct bar_config *current_bar;
+	char *swaybg_command;
 	uint32_t floating_mod;
 	uint32_t dragging_key;
 	uint32_t resizing_key;

sway/commands.c

@@ -149,6 +149,7 @@ static struct cmd_handler bar_colors_handlers[] = {
 /* Config-time only commands. Keep alphabetized */
 static struct cmd_handler config_handlers[] = {
 	{ "set", cmd_set },
+	{ "swaybg_command", cmd_swaybg_command },
 };
 
 /* Runtime-only commands. Keep alphabetized */

sway/commands/swaybg_command.c

@@ -0,0 +1,20 @@
+#include <string.h>
+#include "sway/commands.h"
+#include "log.h"
+#include "stringop.h"
+
+struct cmd_results *cmd_swaybg_command(int argc, char **argv) {
+	struct cmd_results *error = NULL;
+	if ((error = checkarg(argc, "swaybg_command", EXPECTED_AT_LEAST, 1))) {
+		return error;
+	}
+
+	if (config->swaybg_command) {
+		free(config->swaybg_command);
+	}
+	config->swaybg_command = join_args(argv, argc);
+	wlr_log(L_DEBUG, "Using custom swaybg command: %s",
+			config->swaybg_command);
+
+	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}

sway/config/output.c

@@ -180,19 +180,20 @@ void apply_output_config(struct output_config *oc, swayc_t *output) {
 		wlr_log(L_DEBUG, "Setting background for output %d to %s",
 				output_i, oc->background);
 
-		size_t bufsize = 12;
-		char output_id[bufsize];
-		snprintf(output_id, bufsize, "%d", output_i);
-		output_id[bufsize-1] = 0;
-
-		char *const cmd[] = {
-			"swaybg",
-			output_id,
-			oc->background,
-			oc->background_option,
-			NULL,
-		};
+		size_t len = snprintf(NULL, 0, "%s %d %s %s",
+				config->swaybg_command ? config->swaybg_command : "swaybg",
+				output_i, oc->background, oc->background_option);
+		char *command = malloc(len + 1);
+		if (!command) {
+			wlr_log(L_DEBUG, "Unable to allocate swaybg command");
+			return;
+		}
+		snprintf(command, len + 1, "%s %d %s %s",
+				config->swaybg_command ? config->swaybg_command : "swaybg",
+				output_i, oc->background, oc->background_option);
+		wlr_log(L_DEBUG, "-> %s", command);
 
+		char *const cmd[] = { "sh", "-c", command, NULL };
 		output->sway_output->bg_pid = fork();
 		if (output->sway_output->bg_pid == 0) {
 			execvp(cmd[0], cmd);

sway/meson.build

@@ -20,6 +20,7 @@ sway_sources = files(
 	'commands/seat/attach.c',
 	'commands/seat/fallback.c',
 	'commands/set.c',
+	'commands/swaybg_command.c',
 	'commands/bar/activate_button.c',
 	'commands/bar/binding_mode_indicator.c',
 	'commands/bar/bindsym.c',

sway/sway.5.txt

@@ -43,6 +43,9 @@ The following commands may only be used in the configuration file.
 	Sets variable $name to _value_. You can use the new variable in the arguments
 	of future commands.
 
+**swaybg_command** <command>::
+	Executes custom bg command, default is _swaybg_.
+
 The following commands cannot be used directly in the configuration file.
 They are expected to be used with **bindsym** or at runtime through **swaymsg**(1).