Avoid rapid transitions between the cells banner and the normal terminal view when live resizing on systems without live resizing notifications

Author: kovidgoyal

kitty/child-monitor.c

@@ -831,7 +831,12 @@ process_pending_resizes(double now) {
             if (w->live_resize.from_os_notification) {
                 if (w->live_resize.os_says_resize_complete || (now - w->live_resize.last_resize_event_at) > 1) update_viewport = true;
             } else {
-                if (now - w->live_resize.last_resize_event_at >= OPT(resize_debounce_time)) update_viewport = true;
+                double debounce_time = OPT(resize_debounce_time);
+                // if more than one resize event has occurred, wait at least 0.2 secs
+                // before repainting, to avoid rapid transitions between the cells banner
+                // and the normal screen
+                if (w->live_resize.num_of_resize_events > 1) debounce_time = MAX(0.2, debounce_time);
+                if (now - w->live_resize.last_resize_event_at >= debounce_time) update_viewport = true;
                 else {
                     global_state.has_pending_resizes = true;
                     set_maximum_wait(OPT(resize_debounce_time) - now + w->live_resize.last_resize_event_at);

kitty/glfw.c

@@ -159,6 +159,7 @@ framebuffer_size_callback(GLFWwindow *w, int width, int height) {
         window->live_resize.in_progress = true;
         window->live_resize.last_resize_event_at = monotonic();
         window->live_resize.width = MAX(0, width); window->live_resize.height = MAX(0, height);
+        window->live_resize.num_of_resize_events++;
         make_os_window_context_current(window);
         update_surface_size(width, height, window->offscreen_texture_id);
         request_tick_callback();

kitty/state.h

@@ -113,7 +113,7 @@ typedef struct {
     bool in_progress;
     bool from_os_notification;
     bool os_says_resize_complete;
-    unsigned int width, height;
+    unsigned int width, height, num_of_resize_events;
 } LiveResizeInfo;