[textinput] add hotkeys to increase/decrease the multi-line prompt size

Author: tstack

NEWS.md

@@ -26,6 +26,11 @@ Features:
   - `⌘-X` to cut the current selection to the
     clipboard.
   - `⌘-Z` to undo the last change.
+* The multi-line prompt can now be resized with the
+  keyboard: `ALT-=` grows the prompt by one line and
+  `ALT--` shrinks it by one line.  This complements
+  the existing click-and-drag resize on the prompt's
+  status bar.
 * Additional readline-style key bindings in the
   prompt (issue #1676):
   - `ALT-f` / `ALT-b` move forward/backward by word.

docs/source/hotkeys.rst

@@ -460,6 +460,13 @@ editing:
       -
       - In search mode, search for the previous occurrence.  Otherwise,
         search history using current contents of the prompt
+    * - :kbd:`Alt` + :kbd:`=`
+      -
+      - In multi-line mode, grow the prompt by one line.  The prompt's
+        status bar can also be dragged with the mouse to resize.
+    * - :kbd:`Alt` + :kbd:`-`
+      -
+      - In multi-line mode, shrink the prompt by one line.
 
 Customizing
 -----------

src/lnav.cc

@@ -1751,6 +1751,17 @@ VALUES ('org.lnav.mouse-support', -1, DATETIME('now', '+1 minute'),
             = std::max(2, full_height - (prompt.p_editor.get_y() + me.me_y));
         prompt.p_editor.set_height(std::min(max_height, new_height));
     };
+    lnav::prompt::get().p_editor.tc_on_height_change
+        = [](textinput_curses& tc, int delta) {
+              if (tc.tc_height == 1) {
+                  return;
+              }
+              auto full_height = (int) ncplane_dim_y(tc.tc_window);
+              auto max_height = std::max(2, full_height - 16);
+              auto new_height
+                  = std::clamp(tc.tc_height + delta, 2, max_height);
+              tc.set_height(new_height);
+          };
     lnav_data.ld_bottom_source.get_field(bottom_status_source::BSF_HELP)
         .on_click
         = [](status_field&) { ensure_view(&lnav_data.ld_views[LNV_HELP]); };

src/textinput_curses.cc

@@ -168,6 +168,19 @@ textinput_curses::get_help_text()
               .append("CTRL-O"_hotkey)
               .append("    - Open the contents in an external editor\n")
               .append("\n")
+              .append("Resizing"_h2)
+              .append("\n ")
+              .append("•"_list_glyph)
+              .append(" ")
+              .append("ALT-="_hotkey)
+              .append(
+                  "     - Grow the multi-line prompt by one line\n ")
+              .append("•"_list_glyph)
+              .append(" ")
+              .append("ALT--"_hotkey)
+              .append(
+                  "     - Shrink the multi-line prompt by one line\n")
+              .append("\n")
               .append("History"_h2)
               .append("\n ")
               .append("\u2022"_list_glyph)
@@ -1160,6 +1173,20 @@ textinput_curses::handle_key(const ncinput& ch)
                 this->change_word_case(uc_toupper);
                 return true;
             }
+            case '=':
+            case '+': {
+                if (this->tc_on_height_change) {
+                    this->tc_on_height_change(*this, 1);
+                }
+                return true;
+            }
+            case '-':
+            case '_': {
+                if (this->tc_on_height_change) {
+                    this->tc_on_height_change(*this, -1);
+                }
+                return true;
+            }
         }
     }
 

src/textinput_curses.hh

@@ -525,6 +525,7 @@ public:
     std::function<void(textinput_curses&)> tc_on_reformat;
     std::function<void(textinput_curses&)> tc_on_perform;
     std::function<void(textinput_curses&)> tc_on_external_open;
+    std::function<void(textinput_curses&, int)> tc_on_height_change;
 };
 
 #endif

src/third-party/notcurses/src/lib/in.c

@@ -220,6 +220,10 @@ prep_xtmodkeys(inputctx* ictx){
         .modifiers = NCKEY_MOD_ALT },
     { .esc = "\033z", .key = 'z',
         .modifiers = NCKEY_MOD_ALT },
+{ .esc = "\033-", .key = '-',
+    .modifiers = NCKEY_MOD_ALT },
+{ .esc = "\033=", .key = '=',
+    .modifiers = NCKEY_MOD_ALT },
 { .esc = "\033\x7f", .key = NCKEY_BACKSPACE,
     .modifiers = NCKEY_MOD_ALT },