vim: change cursor shape when only one cursor

In vim mode, change the cursor shape depending on the mode. This is only
applicable if `enable_terminal_cursor` is set to true and there is only
one cursor in the editor.

src/tui/editor.zig

@@ -765,7 +765,11 @@ pub const Editor = struct {
     fn render_terminal_cursor(self: *const Self, cursor_: *const Cursor) !void {
         if (self.screen_cursor(cursor_)) |cursor| {
             const y, const x = self.plane.rel_yx_to_abs(@intCast(cursor.row), @intCast(cursor.col));
-            tui.current().rdr.cursor_enable(y, x) catch {};
+            const shape = if (tui.current().input_mode) |mode|
+                mode.cursor_shape
+            else
+                .block;
+            tui.current().rdr.cursor_enable(y, x, shape) catch {};
         } else {
             tui.current().rdr.cursor_disable();
         }
@@ -774,6 +778,8 @@ pub const Editor = struct {
     fn render_cursors(self: *Self, theme: *const Widget.Theme) !void {
         const frame = tracy.initZone(@src(), .{ .name = "editor render cursors" });
         defer frame.deinit();
+        if (self.cursels.items.len == 1 and self.enable_terminal_cursor)
+            return self.render_terminal_cursor(&self.get_primary().cursor);
         for (self.cursels.items) |*cursel_| if (cursel_.*) |*cursel|
             try self.render_cursor(&cursel.cursor, theme);
         if (self.enable_terminal_cursor)

src/tui/mode/input/vim/insert.zig

@@ -35,6 +35,7 @@ pub fn create(a: Allocator) !tui.Mode {
         .name = "INSERT",
         .description = "vim",
         .line_numbers = if (tui.current().config.vim_insert_gutter_line_numbers_relative) .relative else .absolute,
+        .cursor_shape = .beam,
     };
 }
 

src/tui/mode/input/vim/normal.zig

@@ -37,6 +37,7 @@ pub fn create(a: Allocator) !tui.Mode {
         .description = "vim",
         .line_numbers = if (tui.current().config.vim_normal_gutter_line_numbers_relative) .relative else .absolute,
         .keybind_hints = &hints,
+        .cursor_shape = .block,
     };
 }
 

src/tui/mode/input/vim/visual.zig

@@ -37,6 +37,7 @@ pub fn create(a: Allocator) !tui.Mode {
         .description = "vim",
         .line_numbers = if (tui.current().config.vim_visual_gutter_line_numbers_relative) .relative else .absolute,
         .keybind_hints = &hints,
+        .cursor_shape = .underline,
     };
 }
 

src/tui/tui.zig

@@ -717,6 +717,7 @@ pub const Mode = struct {
     description: []const u8,
     line_numbers: enum { absolute, relative } = .absolute,
     keybind_hints: ?*const KeybindHints = null,
+    cursor_shape: renderer.CursorShape = .block,
 
     fn deinit(self: *Mode) void {
         self.handler.deinit();