From adadb109a766ce70791fad38b02cc62a7b2e6b54 Mon Sep 17 00:00:00 2001
From: Drew DeVault <sir@cmpwn.com>
Date: Wed, 16 Dec 2015 20:09:23 -0500
Subject: [PATCH] Only re-render swaybar when it has changed

Fixes #345
---
 swaybar/main.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/swaybar/main.c b/swaybar/main.c
index 65d2a4939..60687bc51 100644
--- a/swaybar/main.c
+++ b/swaybar/main.c
@@ -51,6 +51,7 @@ FILE *command;
 char *line, *output, *status_command;
 struct registry *registry;
 struct window *window;
+bool dirty = true;
 
 struct colors colors = {
 	.background = 0x000000FF,
@@ -278,6 +279,7 @@ void update() {
 			if (line[l] == '\n') {
 				line[l] = '\0';
 			}
+			dirty = true;
 		}
 	}
 	if (ioctl(socketfd, FIONREAD, &pending) != -1 && pending > 0) {
@@ -285,6 +287,7 @@ void update() {
 		char *buf = ipc_recv_response(socketfd, &len);
 		free(buf);
 		ipc_update_workspaces();
+		dirty = true;
 	}
 }
 
@@ -425,8 +428,8 @@ int main(int argc, char **argv) {
 	window->height = height + MARGIN * 2;
 
 	do {
-		if (window_prerender(window) && window->cairo) {
-			update();
+		update();
+		if (dirty && window_prerender(window) && window->cairo) {
 			render();
 			window_render(window);
 		}