From daa63ba8799f8874e3c87b6cb7f81c4c4b80b800 Mon Sep 17 00:00:00 2001
From: nojhan <nojhan@nojhan.net>
Date: Mon, 5 Apr 2021 20:21:48 +0200
Subject: [PATCH 1/3] [feat] add ui_options: padding_char & padding_fill

In some cases, it may be difficult to easily spot the area out of the buffer
(bad color scheme, small font, superimposed windows).

This patch adds two ncurses ui_options to bypass this problem:
- `ncurses_padding_char`, to configure the padding character,
- `ncurses_padding_fill`, to indicate whether to fill the padding line
  (or to display a single character).

The default config is the legacy one (a single "~").
---
 doc/pages/options.asciidoc |  9 +++++++++
 src/ncurses_ui.cc          | 25 ++++++++++++++++++++++++-
 src/ncurses_ui.hh          |  3 +++
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/doc/pages/options.asciidoc b/doc/pages/options.asciidoc
index a63fe39a..c12c9721 100644
--- a/doc/pages/options.asciidoc
+++ b/doc/pages/options.asciidoc
@@ -353,6 +353,15 @@ are exclusively available to built-in options.
             Function key from which shifted function key start, if the
             terminal sends F13 for <s-F1>, this should be set to 12.
 
+        *ncurses_padding_char*:::
+            character used to indicate the area out of the displayed buffer
+            (defaults to '~')
+
+        *ncurses_padding_fill*:::
+            if *yes* or *true*, fill the padding area with the padding character
+            instead of displaying a single character at the beginning of the
+            padding line (defaults to *false*)
+
 [[startup-info]]
 *startup_info_version* `int`::
     _default_ 0 +
diff --git a/src/ncurses_ui.cc b/src/ncurses_ui.cc
index 17006c13..d2d93b0e 100644
--- a/src/ncurses_ui.cc
+++ b/src/ncurses_ui.cc
@@ -474,7 +474,14 @@ void NCursesUI::draw(const DisplayBuffer& display_buffer,
     while (line_index < dim.line + line_offset)
     {
         m_window.move_cursor(line_index++);
-        m_window.draw(m_palette, DisplayAtom("~"), face);
+        if (m_padding_fill)
+        {
+            ColumnCount column_index = 0;
+            while (column_index++ < dim.column)
+                m_window.draw(m_palette, m_padding_char, face);
+        }
+        else
+            m_window.draw(m_palette, m_padding_char, face);
     }
 
     m_dirty = true;
@@ -1361,6 +1368,22 @@ void NCursesUI::set_ui_options(const Options& options)
         m_wheel_scroll_amount = wheel_scroll_amount_it != options.end() ?
             str_to_int_ifp(wheel_scroll_amount_it->value).value_or(3) : 3;
     }
+
+    {
+        auto it = options.find("ncurses_padding_char"_sv);
+        if (it == options.end())
+            m_padding_char = DisplayAtom("~");
+        else if (it->value.length() < 1)
+            m_padding_char = DisplayAtom(" ");
+        else
+            m_padding_char = DisplayAtom(it->value);
+    }
+
+    {
+        auto it = options.find("ncurses_padding_fill"_sv);
+        m_padding_fill = it != options.end() and
+            (it->value == "yes" or it->value == "true");
+    }
 }
 
 }
diff --git a/src/ncurses_ui.hh b/src/ncurses_ui.hh
index 693e6608..4cc354cd 100644
--- a/src/ncurses_ui.hh
+++ b/src/ncurses_ui.hh
@@ -169,6 +169,9 @@ private:
 
     bool m_set_title = true;
 
+    DisplayAtom m_padding_char = DisplayAtom("~");
+    bool m_padding_fill = false;
+
     bool m_dirty = false;
 
     bool m_resize_pending = false;

From a9d33a879696818b556fab00080fcabb8a120db9 Mon Sep 17 00:00:00 2001
From: nojhan <nojhan@nojhan.net>
Date: Tue, 27 Apr 2021 15:27:57 +0200
Subject: [PATCH 3/3] fix ncurses' padding option

- Use less iterations when drawing padding fill with multiple characters.
- Use column_length to handle null-width character as no character.
---
 src/ncurses_ui.cc | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/ncurses_ui.cc b/src/ncurses_ui.cc
index d2d93b0e..86fcedec 100644
--- a/src/ncurses_ui.cc
+++ b/src/ncurses_ui.cc
@@ -477,8 +477,11 @@ void NCursesUI::draw(const DisplayBuffer& display_buffer,
         if (m_padding_fill)
         {
             ColumnCount column_index = 0;
-            while (column_index++ < dim.column)
+            while (column_index < dim.column)
+            {
                 m_window.draw(m_palette, m_padding_char, face);
+                column_index += m_padding_char.length();
+            }
         }
         else
             m_window.draw(m_palette, m_padding_char, face);
@@ -1372,8 +1375,10 @@ void NCursesUI::set_ui_options(const Options& options)
     {
         auto it = options.find("ncurses_padding_char"_sv);
         if (it == options.end())
+            // Defaults to tilde.
             m_padding_char = DisplayAtom("~");
-        else if (it->value.length() < 1)
+        else if (it->value.column_length() < 1)
+            // Do not allow empty string, use space instead.
             m_padding_char = DisplayAtom(" ");
         else
             m_padding_char = DisplayAtom(it->value);