click_events as documented at https://i3wm.org/docs/i3bar-protocol.html

include/swaybar/bar.h

@@ -14,6 +14,7 @@ struct bar {
 	int ipc_event_socketfd;
 	int ipc_socketfd;
 	int status_read_fd;
+	int status_write_fd;
 	pid_t status_command_pid;
 };
 

include/swaybar/status_line.h

@@ -13,6 +13,7 @@ struct status_line {
 	list_t *block_line;
 	const char *text_line;
 	command_protocol protocol;
+	bool click_events;
 };
 
 struct status_block {
@@ -31,6 +32,10 @@ struct status_block {
 	int border_bottom;
 	int border_left;
 	int border_right;
+
+	// Set during rendering
+	int x;
+	int width;
 };
 
 /**
@@ -43,6 +48,11 @@ struct status_line *init_status_line();
  */
 bool handle_status_line(struct bar *bar);
 
+/**
+ * Handle mouse clicks.
+ */
+bool status_line_mouse_event(struct bar *bar, int x, int y, uint32_t button);
+
 /**
  * Free status line struct.
  */

swaybar/bar.c

@@ -7,6 +7,7 @@
 #include <sys/wait.h>
 #include <signal.h>
 #include <poll.h>
+#include <linux/input-event-codes.h>
 #ifdef ENABLE_TRAY
 #include <dbus/dbus.h>
 #include "swaybar/tray/sni_watcher.h"
@@ -31,16 +32,30 @@ static void bar_init(struct bar *bar) {
 
 static void spawn_status_cmd_proc(struct bar *bar) {
 	if (bar->config->status_command) {
-		int pipefd[2];
-		if (pipe(pipefd) != 0) {
-			sway_log(L_ERROR, "Unable to create pipe for status_command fork");
+		int pipe_read_fd[2];
+		int pipe_write_fd[2];
+
+		if (pipe(pipe_read_fd) != 0) {
+			sway_log(L_ERROR, "Unable to create pipes for status_command fork");
 			return;
 		}
+		if (pipe(pipe_write_fd) != 0) {
+			sway_log(L_ERROR, "Unable to create pipe for status_command fork (write)");
+			close(pipe_read_fd[0]);
+			close(pipe_read_fd[1]);
+			return;
+		}
+
 		bar->status_command_pid = fork();
 		if (bar->status_command_pid == 0) {
-			close(pipefd[0]);
-			dup2(pipefd[1], STDOUT_FILENO);
-			close(pipefd[1]);
+			close(pipe_read_fd[0]);
+			dup2(pipe_read_fd[1], STDOUT_FILENO);
+			close(pipe_read_fd[1]);
+			
+			dup2(pipe_write_fd[0], STDIN_FILENO);
+			close(pipe_write_fd[0]);
+			close(pipe_write_fd[1]);
+			
 			char *const cmd[] = {
 				"sh",
 				"-c",
@@ -51,9 +66,13 @@ static void spawn_status_cmd_proc(struct bar *bar) {
 			return;
 		}
 
-		close(pipefd[1]);
-		bar->status_read_fd = pipefd[0];
+		close(pipe_read_fd[1]);
+		bar->status_read_fd = pipe_read_fd[0];
 		fcntl(bar->status_read_fd, F_SETFL, O_NONBLOCK);
+		
+		close(pipe_write_fd[0]);
+		bar->status_write_fd = pipe_write_fd[1];
+		fcntl(bar->status_write_fd, F_SETFL, O_NONBLOCK);
 	}
 }
 
@@ -103,9 +122,22 @@ static void mouse_button_notify(struct window *window, int x, int y,
 		}
 	}
 
+	switch (button) {
+		case BTN_LEFT:
+			status_line_mouse_event(&swaybar, x, y, 1);
+			break;
+		case BTN_MIDDLE:
+			status_line_mouse_event(&swaybar, x, y, 2);
+			break;
+		case BTN_RIGHT:
+			status_line_mouse_event(&swaybar, x, y, 3);
+			break;
+	}
+
 #ifdef ENABLE_TRAY
 	tray_mouse_event(clicked_output, x, y, button, state_w);
 #endif
+
 }
 
 static void mouse_scroll_notify(struct window *window, enum scroll_direction direction) {
@@ -318,6 +350,10 @@ void bar_teardown(struct bar *bar) {
 		close(bar->status_read_fd);
 	}
 
+	if (bar->status_write_fd) {
+		close(bar->status_write_fd);
+	}
+
 	if (bar->ipc_socketfd) {
 		close(bar->ipc_socketfd);
 	}

swaybar/render.c

@@ -94,6 +94,9 @@ static void render_block(struct window *window, struct config *config, struct st
 
 	double pos = *x;
 
+	block->x = (int) pos;
+	block->width = (int) block_width;
+
 	// render background
 	if (block->background != 0x0) {
 		cairo_set_source_u32(window->cairo, block->background);

swaybar/status_line.c

@@ -27,6 +27,8 @@ struct {
 static char line[1024];
 static char line_rest[1024];
 
+static char event_buff[1024];
+
 static void free_status_block(void *item) {
 	if (!item) {
 		return;
@@ -391,6 +393,67 @@ static int i3json_handle_fd(struct bar *bar) {
 	return i3json_parse(bar);
 }
 
+bool status_line_mouse_event(struct bar *bar, int x, int y, uint32_t button) {
+	sway_log(L_DEBUG, "status_line_mouse_event.");
+	if (!bar->status->click_events) {
+		sway_log(L_DEBUG, "click_events are not enabled.");
+		return false;
+	}
+
+	if (bar->status->protocol == I3BAR) {
+		sway_log(L_DEBUG, "Sending click event.");
+
+		// find clicked block
+		struct status_block *clicked_block = NULL;
+		struct status_block *current_block = NULL;
+		int num_blocks = bar->status->block_line->length;
+
+		if (num_blocks == 0) {
+			return false;
+		}
+		else {
+			current_block = bar->status->block_line->items[0];
+			if (x < current_block->x) {
+				return false;
+			}
+		}
+
+		for (int i = 0; i < num_blocks; i++) {
+			current_block = bar->status->block_line->items[i];
+			if (x < (current_block->x + current_block->width)) {
+				clicked_block = current_block;
+				break;
+			}
+		}
+
+		if (!clicked_block || !clicked_block->name) {
+			return false;
+		}
+
+		// event example {"name":"capture","instance":"label","button":1,"x":3431,"y":18}
+	
+		struct json_object *event_json = json_object_new_object();
+		json_object_object_add(event_json, "name", json_object_new_string(clicked_block->name));
+		if (clicked_block->instance) {
+			json_object_object_add(event_json, "instance", json_object_new_string(clicked_block->instance));
+		}
+		json_object_object_add(event_json, "button", json_object_new_int(button));
+		json_object_object_add(event_json, "x", json_object_new_int(x));
+		json_object_object_add(event_json, "y", json_object_new_int(y));
+
+		int len = snprintf(event_buff, sizeof(event_buff), "%s,\n", json_object_to_json_string(event_json));
+
+		json_object_put(event_json);
+
+		if (len <= (int)sizeof(event_buff)) { // if not truncated
+			write(bar->status_write_fd, event_buff, len);
+			return true;
+		}
+	}
+
+	return false;
+}
+
 bool handle_status_line(struct bar *bar) {
 	bool dirty = false;
 
@@ -418,15 +481,29 @@ bool handle_status_line(struct bar *bar) {
 		if (line[0] == '{') {
 			// detect i3bar json protocol
 			json_object *proto = json_tokener_parse(line);
-			json_object *version;
 			if (proto) {
+
+				json_object *version;
 				if (json_object_object_get_ex(proto, "version", &version)
 							&& json_object_get_int(version) == 1
 				) {
 					sway_log(L_DEBUG, "Switched to i3bar protocol.");
 					bar->status->protocol = I3BAR;
-					i3json_handle_data(bar, line_rest);
 				}
+
+				json_object *click_events;
+				if (json_object_object_get_ex(proto, "click_events", &click_events)
+							&& json_object_get_boolean(click_events)
+				) {
+					sway_log(L_DEBUG, "Enabling click events.");
+					bar->status->click_events = true;
+
+					const char *events_array = "[\n";
+					write(bar->status_write_fd, events_array, strlen(events_array));
+				}
+
+				i3json_handle_data(bar, line_rest);
+
 				json_object_put(proto);
 			}
 		}
@@ -441,6 +518,7 @@ struct status_line *init_status_line() {
 	line->block_line = create_list();
 	line->text_line = NULL;
 	line->protocol = UNDEF;
+	line->click_events = false;
 
 	return line;
 }