Greatly reduce redundant window refreshing

This should substantially reduce CPU usage and possibly fix some
issues with interface jittering/flashing

src/chat.c

@@ -1072,12 +1072,11 @@ static void draw_infobox(ToxWindow *self)
 
     time_t curtime = get_unix_time();
 
-    /* update elapsed time string once per second */
-    if (curtime > infobox->lastupdate) {
+    /* update interface once per second */
+    if (timed_out(infobox->lastupdate, 1)) {
         get_elapsed_time_str(infobox->timestr, sizeof(infobox->timestr), curtime - infobox->starttime);
-    }
-
         infobox->lastupdate = curtime;
+    }
 
     const char *in_is_muted = infobox->in_is_muted ? "yes" : "no";
     const char *out_is_muted = infobox->out_is_muted ? "yes" : "no";

src/input.c

@@ -346,5 +346,9 @@ bool input_handle(ToxWindow *self, wint_t key, int x, int mx_x)
         }
     }
 
+    if (match) {
+        flag_interface_change(1);
+    }
+
     return match;
 }

src/line_info.c

@@ -444,6 +444,8 @@ int line_info_add(ToxWindow *self, bool show_timestamp, const char *name1, const
 
     hst->queue[hst->queue_size++] = new_line;
 
+    flag_interface_change(1);
+
     return new_line->id;
 }
 
@@ -454,6 +456,7 @@ static void line_info_check_queue(ToxWindow *self)
     struct line_info *line = line_info_ret_queue(hst);
 
     if (line == NULL) {
+        flag_interface_change(0);
         return;
     }
 
@@ -469,6 +472,8 @@ static void line_info_check_queue(ToxWindow *self)
     if (!self->scroll_pause) {
         line_info_reset_start(self, hst);
     }
+
+    flag_interface_change(1);
 }
 
 #define NOREAD_FLAG_TIMEOUT 5    /* seconds before a sent message with no read receipt is flagged as unread */
@@ -763,6 +768,8 @@ void line_info_set(ToxWindow *self, uint32_t id, char *msg)
 
         line = line->prev;
     }
+
+    flag_interface_change(1);
 }
 
 static void line_info_scroll_up(ToxWindow *self, struct history *hst)
@@ -771,6 +778,8 @@ static void line_info_scroll_up(ToxWindow *self, struct history *hst)
         hst->line_start = hst->line_start->prev;
         self->scroll_pause = true;
     }
+
+    flag_interface_change(1);
 }
 
 static void line_info_scroll_down(ToxWindow *self, struct history *hst)
@@ -786,6 +795,8 @@ static void line_info_scroll_down(ToxWindow *self, struct history *hst)
     } else {
         line_info_reset_start(self, hst);
     }
+
+    flag_interface_change(1);
 }
 
 static void line_info_page_up(ToxWindow *self, struct history *hst)
@@ -805,6 +816,8 @@ static void line_info_page_up(ToxWindow *self, struct history *hst)
     }
 
     self->scroll_pause = true;
+
+    flag_interface_change(1);
 }
 
 static void line_info_page_down(ToxWindow *self, struct history *hst)
@@ -834,6 +847,8 @@ static void line_info_page_down(ToxWindow *self, struct history *hst)
         hst->line_start = next;
         next = hst->line_start->next;
     }
+
+    flag_interface_change(1);
 }
 
 bool line_info_onKey(ToxWindow *self, wint_t key)
@@ -855,6 +870,10 @@ bool line_info_onKey(ToxWindow *self, wint_t key)
         match = false;
     }
 
+    if (match) {
+        flag_interface_change(1);
+    }
+
     return match;
 }
 
@@ -862,4 +881,6 @@ void line_info_clear(struct history *hst)
 {
     hst->line_start = hst->line_end;
     hst->start_id = hst->line_start->id;
+
+    flag_interface_change(1);
 }

src/toxic.c

@@ -1072,8 +1072,24 @@ static void do_toxic(Tox *m)
     pthread_mutex_unlock(&Winthread.lock);
 }
 
+/* How often we refresh windows that aren't focused */
 #define INACTIVE_WIN_REFRESH_RATE 10
 
+/* Set interface change flag. This should be called whenever the interface changes.
+ *
+ * `flag` should be a non-zero value if we need to redraw the window or 0 if we want to idle.
+ */
+void flag_interface_change(unsigned int flag)
+{
+    if (flag == 0 && timed_out(Winthread.flag_refresh_timeout, 1)) {
+        Winthread.flag_refresh = flag;
+    } else if (flag != 0) {
+        Winthread.flag_refresh = 1;
+    }
+
+    Winthread.flag_refresh_timeout = get_unix_time();
+}
+
 void *thread_winref(void *data)
 {
     Tox *m = (Tox *) data;
@@ -1082,8 +1098,8 @@ void *thread_winref(void *data)
     init_signal_catchers();
 
     while (true) {
-        draw_active_window(m);
         draw_count++;
+        draw_active_window(m);
 
         if (Winthread.flag_resize) {
             on_window_resize();
@@ -1470,6 +1486,8 @@ int main(int argc, char **argv)
     /* Make sure all written files are read/writeable only by the current user. */
     umask(S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
 
+    flag_interface_change(1);
+
     srand(time(NULL)); // We use rand() for trivial/non-security related things
 
     parse_args(argc, argv);

src/toxic.h

@@ -102,6 +102,8 @@ typedef enum _FATAL_ERRS {
 void lock_status(void);
 void unlock_status(void);
 
+void flag_interface_change(unsigned int flag);
+
 void exit_toxic_success(Tox *m);
 void exit_toxic_err(const char *errmsg, int errcode);
 

src/windows.c

@@ -77,6 +77,8 @@ void on_friend_connection_status(Tox *m, uint32_t friendnumber, Tox_Connection c
             windows[i]->onConnectionChange(windows[i], m, friendnumber, connection_status);
         }
     }
+
+    flag_interface_change(1);
 }
 
 void on_friend_typing(Tox *m, uint32_t friendnumber, bool is_typing, void *userdata)
@@ -92,6 +94,8 @@ void on_friend_typing(Tox *m, uint32_t friendnumber, bool is_typing, void *userd
             windows[i]->onTypingChange(windows[i], m, friendnumber, is_typing);
         }
     }
+
+    flag_interface_change(1);
 }
 
 void on_friend_message(Tox *m, uint32_t friendnumber, Tox_Message_Type type, const uint8_t *string, size_t length,
@@ -123,6 +127,8 @@ void on_friend_name(Tox *m, uint32_t friendnumber, const uint8_t *string, size_t
         }
     }
 
+    flag_interface_change(1);
+
     store_data(m, DATA_FILE);
 }
 
@@ -140,6 +146,8 @@ void on_friend_status_message(Tox *m, uint32_t friendnumber, const uint8_t *stri
             windows[i]->onStatusMessageChange(windows[i], friendnumber, msg, length);
         }
     }
+
+    flag_interface_change(1);
 }
 
 void on_friend_status(Tox *m, uint32_t friendnumber, Tox_User_Status status, void *userdata)
@@ -151,6 +159,8 @@ void on_friend_status(Tox *m, uint32_t friendnumber, Tox_User_Status status, voi
             windows[i]->onStatusChange(windows[i], m, friendnumber, status);
         }
     }
+
+    flag_interface_change(1);
 }
 
 void on_friend_added(Tox *m, uint32_t friendnumber, bool sort)
@@ -200,6 +210,8 @@ void on_conference_peer_list_changed(Tox *m, uint32_t conferencenumber, void *us
             windows[i]->onConferenceNameListChange(windows[i], m, conferencenumber);
         }
     }
+
+    flag_interface_change(1);
 }
 
 void on_conference_peer_name(Tox *m, uint32_t conferencenumber, uint32_t peernumber, const uint8_t *name,
@@ -423,11 +435,13 @@ void set_active_window_index(uint8_t index)
  */
 void set_next_window(int ch)
 {
+    uint8_t index = 0;
+
     if (ch == user_settings->key_next_tab) {
         for (uint8_t i = active_window_index + 1; i < MAX_WINDOWS_NUM; ++i) {
             if (windows[i] != NULL) {
-                set_active_window_index(i);
-                return;
+                index = i;
+                break;
             }
         }
     } else {
@@ -435,13 +449,15 @@ void set_next_window(int ch)
 
         for (uint8_t i = start; i > 0; --i) {
             if (windows[i] != NULL) {
-                set_active_window_index(i);
-                return;
+                index = i;
+                break;
             }
         }
     }
 
-    set_active_window_index(0);
+    set_active_window_index(index);
+
+    flag_interface_change(1);
 }
 
 /* Deletes window w and cleans up */
@@ -784,21 +800,33 @@ void draw_active_window(Tox *m)
     pthread_mutex_lock(&Winthread.lock);
     a->alert = WINDOW_ALERT_NONE;
     a->pending_messages = 0;
+    bool flag_refresh = Winthread.flag_refresh;
     pthread_mutex_unlock(&Winthread.lock);
 
+    if (flag_refresh || (a->is_call && timed_out(a->chatwin->infobox.lastupdate, 1))) {
         touchwin(a->window);
         a->onDraw(a, m);
         wrefresh(a->window);
+    }
 
 #ifdef GAMES
-
     if (a->type == WINDOW_TYPE_GAME) {
+        if (!flag_refresh) {  // we always want to be continously refreshing game windows
+            touchwin(a->window);
+            a->onDraw(a, m);
+            wrefresh(a->window);
+        }
+
         int ch = getch();
 
         if (ch == ERR) {
             return;
         }
 
+        pthread_mutex_lock(&Winthread.lock);
+        flag_interface_change(1);
+        pthread_mutex_unlock(&Winthread.lock);
+
         if (ch == user_settings->key_next_tab || ch == user_settings->key_prev_tab) {
             set_next_window(ch);
         }
@@ -817,6 +845,10 @@ void draw_active_window(Tox *m)
         return;
     }
 
+    pthread_mutex_lock(&Winthread.lock);
+    flag_interface_change(1);
+    pthread_mutex_unlock(&Winthread.lock);
+
     if (printable == 0 && (ch == user_settings->key_next_tab || ch == user_settings->key_prev_tab)) {
         set_next_window((int) ch);
         return;

src/windows.h

@@ -103,6 +103,8 @@ struct Winthread {
     pthread_mutex_t lock;
     volatile sig_atomic_t sig_exit_toxic;
     volatile sig_atomic_t flag_resize;
+    volatile sig_atomic_t flag_refresh;
+    volatile sig_atomic_t flag_refresh_timeout;
 };
 
 struct cqueue_thread {