feat(terminal): forward X1 and X2 mouse events

Ref:
https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h3-Other-buttons

src/nvim/terminal.c

@@ -792,17 +792,23 @@ static int terminal_execute(VimState *state, int key)
   case K_LEFTMOUSE:
   case K_LEFTDRAG:
   case K_LEFTRELEASE:
-  case K_MOUSEMOVE:
   case K_MIDDLEMOUSE:
   case K_MIDDLEDRAG:
   case K_MIDDLERELEASE:
   case K_RIGHTMOUSE:
   case K_RIGHTDRAG:
   case K_RIGHTRELEASE:
+  case K_X1MOUSE:
+  case K_X1DRAG:
+  case K_X1RELEASE:
+  case K_X2MOUSE:
+  case K_X2DRAG:
+  case K_X2RELEASE:
   case K_MOUSEDOWN:
   case K_MOUSEUP:
   case K_MOUSELEFT:
   case K_MOUSERIGHT:
+  case K_MOUSEMOVE:
     if (send_mouse_event(s->term, key)) {
       return 0;
     }
@@ -1804,8 +1810,6 @@ static bool send_mouse_event(Terminal *term, int c)
       pressed = true; FALLTHROUGH;
     case K_LEFTRELEASE:
       button = 1; break;
-    case K_MOUSEMOVE:
-      button = 0; break;
     case K_MIDDLEDRAG:
     case K_MIDDLEMOUSE:
       pressed = true; FALLTHROUGH;
@@ -1816,6 +1820,16 @@ static bool send_mouse_event(Terminal *term, int c)
       pressed = true; FALLTHROUGH;
     case K_RIGHTRELEASE:
       button = 3; break;
+    case K_X1DRAG:
+    case K_X1MOUSE:
+      pressed = true; FALLTHROUGH;
+    case K_X1RELEASE:
+      button = 8; break;
+    case K_X2DRAG:
+    case K_X2MOUSE:
+      pressed = true; FALLTHROUGH;
+    case K_X2RELEASE:
+      button = 9; break;
     case K_MOUSEDOWN:
       pressed = true; button = 4; break;
     case K_MOUSEUP:
@@ -1824,6 +1838,8 @@ static bool send_mouse_event(Terminal *term, int c)
       pressed = true; button = 7; break;
     case K_MOUSERIGHT:
       pressed = true; button = 6; break;
+    case K_MOUSEMOVE:
+      button = 0; break;
     default:
       return false;
     }

src/nvim/vterm/mouse.c

@@ -1,3 +1,4 @@
+#include "nvim/math.h"
 #include "nvim/tui/termkey/termkey.h"
 #include "nvim/vterm/mouse.h"
 #include "nvim/vterm/vterm.h"
@@ -24,6 +25,9 @@ static void output_mouse(VTermState *state, int code, int pressed, int modifiers
       code = 3;
     }
 
+    if (code & 0x80) {
+      break;
+    }
     vterm_push_output_sprintf_ctrl(state->vt, C1_CSI, "M%c%c%c",
                                    (code | modifiers) + 0x20, col + 0x21, row + 0x21);
     break;
@@ -74,11 +78,16 @@ void vterm_mouse_move(VTerm *vt, int row, int col, VTermModifier mod)
 
   if ((state->mouse_flags & MOUSE_WANT_DRAG && state->mouse_buttons)
       || (state->mouse_flags & MOUSE_WANT_MOVE)) {
-    int button = state->mouse_buttons & 0x01 ? 1
+    if (state->mouse_buttons) {
-                                             : state->mouse_buttons & 0x02 ? 2
+      int button = xctz((uint64_t)state->mouse_buttons) + 1;
-                                                                           : state->mouse_buttons &
+      if (button < 4) {
-                 0x04 ? 3 : 4;
+        output_mouse(state, button - 1 + 0x20, 1, (int)mod, col, row);
-    output_mouse(state, button - 1 + 0x20, 1, (int)mod, col, row);
+      } else if (button >= 8 && button < 12) {
+        output_mouse(state, button - 8 + 0x80 + 0x20, 1, (int)mod, col, row);
+      }
+    } else {
+      output_mouse(state, 3 + 0x20, 1, (int)mod, col, row);
+    }
   }
 }
 
@@ -88,7 +97,7 @@ void vterm_mouse_button(VTerm *vt, int button, bool pressed, VTermModifier mod)
 
   int old_buttons = state->mouse_buttons;
 
-  if (button > 0 && button <= 3) {
+  if ((button > 0 && button <= 3) || (button >= 8 && button <= 11)) {
     if (pressed) {
       state->mouse_buttons |= (1 << (button - 1));
     } else {
@@ -96,8 +105,8 @@ void vterm_mouse_button(VTerm *vt, int button, bool pressed, VTermModifier mod)
     }
   }
 
-  // Most of the time we don't get button releases from 4/5
+  // Most of the time we don't get button releases from 4/5/6/7
-  if (state->mouse_buttons == old_buttons && button < 4) {
+  if (state->mouse_buttons == old_buttons && (button < 4 || button > 7)) {
     return;
   }
 
@@ -109,5 +118,7 @@ void vterm_mouse_button(VTerm *vt, int button, bool pressed, VTermModifier mod)
     output_mouse(state, button - 1, pressed, (int)mod, state->mouse_col, state->mouse_row);
   } else if (button < 8) {
     output_mouse(state, button - 4 + 0x40, pressed, (int)mod, state->mouse_col, state->mouse_row);
+  } else if (button < 12) {
+    output_mouse(state, button - 8 + 0x80, pressed, (int)mod, state->mouse_col, state->mouse_row);
   }
 }

test/functional/terminal/buffer_spec.lua

@@ -594,18 +594,36 @@ describe('terminal input', function()
       '<S-End>',
       '<C-End>',
       '<End>',
-      '<C-LeftMouse>',
+      '<C-LeftMouse><0,0>',
-      '<C-LeftRelease>',
+      '<C-LeftDrag><0,1>',
-      '<2-LeftMouse>',
+      '<C-LeftRelease><0,1>',
-      '<2-LeftRelease>',
+      '<2-LeftMouse><0,1>',
-      '<S-RightMouse>',
+      '<2-LeftDrag><0,0>',
-      '<S-RightRelease>',
+      '<2-LeftRelease><0,0>',
-      '<2-RightMouse>',
+      '<M-MiddleMouse><0,0>',
-      '<2-RightRelease>',
+      '<M-MiddleDrag><0,1>',
-      '<M-MiddleMouse>',
+      '<M-MiddleRelease><0,1>',
-      '<M-MiddleRelease>',
+      '<2-MiddleMouse><0,1>',
-      '<2-MiddleMouse>',
+      '<2-MiddleDrag><0,0>',
-      '<2-MiddleRelease>',
+      '<2-MiddleRelease><0,0>',
+      '<S-RightMouse><0,0>',
+      '<S-RightDrag><0,1>',
+      '<S-RightRelease><0,1>',
+      '<2-RightMouse><0,1>',
+      '<2-RightDrag><0,0>',
+      '<2-RightRelease><0,0>',
+      '<S-X1Mouse><0,0>',
+      '<S-X1Drag><0,1>',
+      '<S-X1Release><0,1>',
+      '<2-X1Mouse><0,1>',
+      '<2-X1Drag><0,0>',
+      '<2-X1Release><0,0>',
+      '<S-X2Mouse><0,0>',
+      '<S-X2Drag><0,1>',
+      '<S-X2Release><0,1>',
+      '<2-X2Mouse><0,1>',
+      '<2-X2Drag><0,0>',
+      '<2-X2Release><0,0>',
       '<S-ScrollWheelUp>',
       '<S-ScrollWheelDown>',
       '<ScrollWheelUp>',
@@ -622,7 +640,7 @@ describe('terminal input', function()
         {5:[No Name]                       0,0-1          All}|
         %s^ {MATCH: *}|
         {3:-- TERMINAL --}                                    |
-      ]]):format(key))
+      ]]):format(key:gsub('<%d+,%d+>$', '')))
     end
   end)
 

test/unit/vterm_spec.lua

@@ -2079,6 +2079,18 @@ putglyph 1f3f4,200d,2620,fe0f 2 0,4]])
     mousebtn('u', 1, vt)
     expect_output('\x1b[<0;301;301m')
 
+    -- Button 8 on SGR extended encoding mode
+    mousebtn('d', 8, vt)
+    expect_output('\x1b[<128;301;301M')
+    mousebtn('u', 8, vt)
+    expect_output('\x1b[<128;301;301m')
+
+    -- Button 9 on SGR extended encoding mode
+    mousebtn('d', 9, vt)
+    expect_output('\x1b[<129;301;301M')
+    mousebtn('u', 9, vt)
+    expect_output('\x1b[<129;301;301m')
+
     -- DECRQM on SGR extended encoding mode
     push('\x1b[?1005$p', vt)
     expect_output('\x1b[?1005;2$y')
@@ -2094,6 +2106,18 @@ putglyph 1f3f4,200d,2620,fe0f 2 0,4]])
     mousebtn('u', 1, vt)
     expect_output('\x1b[3;301;301M')
 
+    -- Button 8 on rxvt extended encoding mode
+    mousebtn('d', 8, vt)
+    expect_output('\x1b[128;301;301M')
+    mousebtn('u', 8, vt)
+    expect_output('\x1b[3;301;301M')
+
+    -- Button 9 on rxvt extended encoding mode
+    mousebtn('d', 9, vt)
+    expect_output('\x1b[129;301;301M')
+    mousebtn('u', 9, vt)
+    expect_output('\x1b[3;301;301M')
+
     -- DECRQM on rxvt extended encoding mode
     push('\x1b[?1005$p', vt)
     expect_output('\x1b[?1005;2$y')