systray: Delay icon rendering only when throttling is necessary

src/systray/systraybar.c

@@ -603,7 +603,18 @@ void systray_render_icon_now(void* t)
 	// we made also sure, that we always have a 32 bit visual, i.e. we can safely create 32 bit pixmaps here
 	TrayWindow* traywin = t;
 
-	traywin->render_timeout = 0;
+    // wine tray icons update whenever mouse is over them, so we limit the updates to 50 ms
+    struct timespec now;
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    struct timespec earliest_render = add_msec_to_timespec(traywin->time_last_render, 50);
+    if (compare_timespecs(&earliest_render, &now) > 0) {
+        traywin->render_timeout = add_timeout(50, 0, systray_render_icon_now, traywin, &traywin->render_timeout);
+        return;
+    }
+    traywin->time_last_render.tv_sec = now.tv_sec;
+    traywin->time_last_render.tv_nsec = now.tv_nsec;
+    traywin->render_timeout = NULL;
+
 	if ( traywin->width == 0 || traywin->height == 0 ) {
 		// reschedule rendering since the geometry information has not yet been processed (can happen on slow cpu)
 		systray_render_icon(traywin);
@@ -698,9 +709,8 @@ void systray_render_icon_now(void* t)
 void systray_render_icon(TrayWindow* traywin)
 {
 	if (FORCE_COMPOSITED_RENDERING || server.real_transparency || systray.alpha != 100 || systray.brightness != 0 || systray.saturation != 0) {
-		// wine tray icons update whenever mouse is over them, so we limit the updates to 50 ms
+        if (!traywin->render_timeout)
-		if (!traywin->render_timeout)
+            systray_render_icon_now(traywin);
-			traywin->render_timeout = add_timeout(50, 0, systray_render_icon_now, traywin, &traywin->render_timeout);
 	}
 	else {
 		//			Pixmap pix = XCreatePixmap(server.dsp, server.root_win, traywin->width, traywin->height, server.depth);

src/systray/systraybar.h

@@ -47,6 +47,7 @@ typedef struct
 	int empty;
 	int pid;
 	int chrono;
+    struct timespec time_last_render;
 } TrayWindow;
 
 

src/util/timer.c

@@ -49,9 +49,7 @@ struct _timeout {
 
 void add_timeout_intern(int value_msec, int interval_msec, void(*_callback)(void*), void* arg, timeout* t);
 gint compare_timeouts(gconstpointer t1, gconstpointer t2);
-gint compare_timespecs(const struct timespec* t1, const struct timespec* t2);
 int timespec_subtract(struct timespec* result, struct timespec* x, struct timespec* y);
-struct timespec add_msec_to_timespec(struct timespec ts, int msec);
 
 
 int align_with_existing_timeouts(timeout* t);

src/util/timer.h

@@ -20,6 +20,8 @@
 #define TIMER_H
 
 #include <glib.h>
+#include <time.h>
+#include <sys/time.h>
 
 extern struct timeval next_timeout;
 
@@ -66,4 +68,9 @@ void update_next_timeout();
 /** Callback of all expired timeouts **/
 void callback_timeout_expired();
 
+/** Returns -1 if t1 < t2, 0 if t1 == t2, 1 if t1 > t2 **/
+gint compare_timespecs(const struct timespec* t1, const struct timespec* t2);
+
+struct timespec add_msec_to_timespec(struct timespec ts, int msec);
+
 #endif // TIMER_H