Support hinting if an inline info should be above or below the anchor

Used by ctags function info, we always want it *above* the opening
parenthesis so that it does not hide multi line parameter lists.

rc/ctags.kak

@@ -39,7 +39,7 @@ def funcinfo %{
         %sh{
             sigs=$(readtags -e ${kak_selection%(} | grep kind:f | sed -re 's/^(\S+).*((class|struct|namespace):(\S+))?.*signature:(.*)$/\5 [\4::\1]/')
             if [ -n "$sigs" ]; then
-                echo "eval -client ${kak_client} %{info -anchor $kak_cursor_line.$kak_cursor_column '$sigs'}"
+                echo "eval -client ${kak_client} %{info -anchor $kak_cursor_line.$kak_cursor_column -placement above '$sigs'}"
             fi
         }
     }

src/commands.cc

@@ -1224,6 +1224,7 @@ const CommandDesc info_cmd = {
     "info <switches> <params>...: display an info box with the params as content",
     ParameterDesc{
         SwitchMap{ { "anchor", { true, "set info anchoring <line>.<column>" } },
+                   { "placement", { true, "set placement relative to anchor (above, below)" } },
                    { "title", { true, "set info title" } } },
         ParameterDesc::Flags::None, 0, 1
     },
@@ -1247,6 +1248,16 @@ const CommandDesc info_cmd = {
                                 str_to_int(anchor.substr(dotb+1))-1};
                 pos = context.window().display_position(coord);
                 style = InfoStyle::Inline;
+                if (parser.has_option("placement"))
+                {
+                    auto placement = parser.option_value("placement");
+                    if (placement == "above")
+                        style = InfoStyle::InlineAbove;
+                    else if (placement == "below")
+                        style = InfoStyle::InlineBelow;
+                    else
+                        throw runtime_error("invalid placement " + placement);
+                }
             }
             const String& title = parser.has_option("title") ? parser.option_value("title") : "";
             context.ui().info_show(title, parser[0], pos, get_face("Information"), style);

src/ncurses.cc

@@ -642,12 +642,23 @@ static CharCoord compute_needed_size(StringView str)
 }
 
 static CharCoord compute_pos(CharCoord anchor, CharCoord size,
-                             WINDOW* opt_window_to_avoid = nullptr)
+                             WINDOW* opt_window_to_avoid = nullptr,
+                             bool prefer_above = false)
 {
     CharCoord scrsize = window_size(stdscr);
-    CharCoord pos = { anchor.line+1, anchor.column };
-    if (pos.line + size.line >= scrsize.line)
-        pos.line = max(0_line, anchor.line - size.line);
+    CharCoord pos;
+    if (prefer_above)
+    {
+        pos = anchor - CharCoord{size.line};
+        if (pos.line < 0)
+            prefer_above = false;
+    }
+    if (not prefer_above)
+    {
+        pos = anchor + CharCoord{1_line};
+        if (pos.line + size.line >= scrsize.line)
+            pos.line = max(0_line, anchor.line - size.line);
+    }
     if (pos.column + size.column >= scrsize.column)
         pos.column = max(0_char, anchor.column - size.column+1);
 
@@ -790,7 +801,7 @@ void NCursesUI::info_show(StringView title, StringView content,
         pos = window_pos(m_menu_win) +
              CharCoord{0_line, window_size(m_menu_win).column};
     else
-        pos = compute_pos(anchor, size, m_menu_win);
+        pos = compute_pos(anchor, size, m_menu_win, style == InfoStyle::InlineAbove);
 
     m_info_win = (NCursesWin*)newwin((int)size.line, (int)size.column,
                                      (int)pos.line,  (int)pos.column);

src/user_interface.hh

@@ -24,6 +24,8 @@ enum class InfoStyle
 {
     Prompt,
     Inline,
+    InlineAbove,
+    InlineBelow,
     MenuDoc
 };