From 10bcc7adcfd5e0e980bb156de8a38fe5a6484a33 Mon Sep 17 00:00:00 2001
From: cancel <cancel@cancel.fm>
Date: Mon, 6 Jan 2020 05:53:16 +0900
Subject: [PATCH] Fix dialogs and menus when terminal is resized
 big->small->big

Used regular curses newwin WINDOWs before. Now uses newpad/subpad. The
buffers will be clipped correctly to the visible terminal area, and will
not be erased when the window is made too small and then resized to be
big again.
---
 term_util.c |  9 +++++++--
 term_util.h |  1 +
 tui_main.c  | 20 ++++++++++++++++++--
 3 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/term_util.c b/term_util.c
index fe4034b..bbf97b3 100644
--- a/term_util.c
+++ b/term_util.c
@@ -142,8 +142,13 @@ void qnav_stack_push(Qblock* qb, int height, int width) {
   }
   qnav_stack.blocks[qnav_stack.count] = qb;
   ++qnav_stack.count;
-  qb->outer_window = newwin(total_h, total_w, top, left);
-  qb->content_window = derwin(qb->outer_window, height, width, 1, 1);
+  qb->outer_window = newpad(total_h, total_w);
+  // This used to be derwin when when used newwin instead of newpad -- not sure
+  // if we should use derwin or subpad now. subpad is probably more compatible.
+  // ncurses docs state that it handles it correctly, unlike some others?
+  qb->content_window = subpad(qb->outer_window, height, width, 1, 1);
+  qb->y = top;
+  qb->x = left;
   qnav_stack.stack_changed = true;
 }
 
diff --git a/term_util.h b/term_util.h
index ee41810..e57fdf8 100644
--- a/term_util.h
+++ b/term_util.h
@@ -64,6 +64,7 @@ typedef struct {
   WINDOW* outer_window;
   WINDOW* content_window;
   char const* title;
+  int y, x;
 } Qblock;
 
 typedef struct {
diff --git a/tui_main.c b/tui_main.c
index bab1510..1b1e3b6 100644
--- a/tui_main.c
+++ b/tui_main.c
@@ -2668,6 +2668,9 @@ int main(int argc, char** argv) {
         wnoutrefresh(cont_window);
         drew_any = true;
       }
+      int term_h, term_w;
+      if (qnav_stack.count > 0) // todo lame, move this
+        getmaxyx(stdscr, term_h, term_w);
       for (Usz i = 0; i < qnav_stack.count; ++i) {
         Qblock* qb = qnav_stack.blocks[i];
         if (qnav_stack.stack_changed) {
@@ -2684,8 +2687,21 @@ int main(int argc, char** argv) {
             break;
           }
         }
-        touchwin(qb->outer_window);
-        wnoutrefresh(qb->outer_window);
+        touchwin(qb->outer_window); // here? or after continue?
+        if (term_h < 1 || term_w < 1)
+          continue;
+        int qbwin_h, qbwin_w;
+        getmaxyx(qb->outer_window, qbwin_h, qbwin_w);
+        int qbwin_endy = qb->y + qbwin_h;
+        int qbwin_endx = qb->x + qbwin_w;
+        if (qbwin_endy >= term_h)
+          qbwin_endy = term_h - 1;
+        if (qbwin_endx >= term_w)
+          qbwin_endx = term_w - 1;
+        if (qb->y >= qbwin_endy || qb->x >= qbwin_endx)
+          continue;
+        pnoutrefresh(qb->outer_window, 0, 0, qb->y, qb->x, qbwin_endy,
+                     qbwin_endx);
         drew_any = true;
       }
       qnav_stack.stack_changed = false;