feat: draw IME cursor

include/ghostty.h

@@ -1124,7 +1124,7 @@ GHOSTTY_API bool ghostty_surface_key_is_binding(ghostty_surface_t,
                                                    ghostty_input_key_s,
                                                    ghostty_binding_flags_e*);
 GHOSTTY_API void ghostty_surface_text(ghostty_surface_t, const char*, uintptr_t);
-GHOSTTY_API void ghostty_surface_preedit(ghostty_surface_t, const char*, uintptr_t);
+GHOSTTY_API void ghostty_surface_preedit(ghostty_surface_t, const char*, uintptr_t, int32_t);
 GHOSTTY_API bool ghostty_surface_mouse_captured(ghostty_surface_t);
 GHOSTTY_API bool ghostty_surface_mouse_button(ghostty_surface_t,
                                                  ghostty_input_mouse_state_e,

macos/Sources/Ghostty/Surface View/SurfaceView_AppKit.swift

@@ -218,6 +218,7 @@ extension Ghostty {
         var notificationIdentifiers: Set<String> = []
 
         private var markedText: NSMutableAttributedString
+        private var markedTextSelectedLocation: Int = 0
         private(set) var focused: Bool = true
         private var prevPressureStage: Int = 0
         private var appearanceObserver: NSKeyValueObservation?
@@ -1835,9 +1836,11 @@ extension Ghostty.SurfaceView: NSTextInputClient {
         switch string {
         case let v as NSAttributedString:
             self.markedText = NSMutableAttributedString(attributedString: v)
+            self.markedTextSelectedLocation = selectedRange.location
 
         case let v as String:
             self.markedText = NSMutableAttributedString(string: v)
+            self.markedTextSelectedLocation = selectedRange.location
 
         default:
             print("unknown marked text: \(string)")
@@ -2026,13 +2029,18 @@ extension Ghostty.SurfaceView: NSTextInputClient {
             if len > 0 {
                 markedText.string.withCString { ptr in
                     // Subtract 1 for the null terminator
-                    ghostty_surface_preedit(surface, ptr, UInt(len - 1))
+                    ghostty_surface_preedit(
+                        surface,
+                        ptr,
+                        UInt(len - 1),
+                        Int32(markedTextSelectedLocation)
+                    )
                 }
             }
         } else if clearIfNeeded {
             // If we had marked text before but don't now, we're no longer
             // in a preedit state so we can clear it.
-            ghostty_surface_preedit(surface, nil, 0)
+            ghostty_surface_preedit(surface, nil, 0, 0)
         }
     }
 }

src/Surface.zig

@@ -2499,7 +2499,7 @@ fn balancePaddingIfNeeded(self: *Surface) void {
 /// the preedit state correctly.
 ///
 /// The preedit input must be UTF-8 encoded.
-pub fn preeditCallback(self: *Surface, preedit_: ?[]const u8) !void {
+pub fn preeditCallback(self: *Surface, preedit_: ?[]const u8, cursor_pos: i32) !void {
     // log.debug("text preeditCallback value={any}", .{preedit_});
 
     // Crash metadata in case we crash in here
@@ -2566,6 +2566,7 @@ pub fn preeditCallback(self: *Surface, preedit_: ?[]const u8) !void {
 
     self.renderer_state.preedit = .{
         .codepoints = try codepoints.toOwnedSlice(self.alloc),
+        .cursor_pos = cursor_pos
     };
     try self.queueRender();
 }

src/apprt/embedded.zig

@@ -889,8 +889,8 @@ pub const Surface = struct {
         };
     }
 
-    pub fn preeditCallback(self: *Surface, preedit_: ?[]const u8) void {
-        _ = self.core_surface.preeditCallback(preedit_) catch |err| {
+    pub fn preeditCallback(self: *Surface, preedit_: ?[]const u8, cursor_pos: i32) void {
+        _ = self.core_surface.preeditCallback(preedit_, cursor_pos) catch |err| {
             log.err("error in preedit callback err={}", .{err});
             return;
         };
@@ -1810,8 +1810,9 @@ pub const CAPI = struct {
         surface: *Surface,
         ptr: [*]const u8,
         len: usize,
+        cursor_pos: i32
     ) void {
-        surface.preeditCallback(if (len == 0) null else ptr[0..len]);
+        surface.preeditCallback(if (len == 0) null else ptr[0..len], cursor_pos);
     }
 
     /// Returns true if the surface currently has mouse capturing

src/apprt/gtk/class/surface.zig

@@ -637,6 +637,7 @@ pub const Surface = extern struct {
         im_composing: bool = false,
         im_buf: [128]u8 = undefined,
         im_len: u7 = 0,
+        im_show_cursor: bool = false,
 
         /// True when we have a precision scroll in progress
         precision_scroll: bool = false,
@@ -1420,7 +1421,7 @@ pub const Surface = extern struct {
                 // such as quotation mark ordering for Chinese input.
                 if (priv.im_composing) {
                     priv.im_context.as(gtk.IMContext).reset();
-                    surface.preeditCallback(null) catch {};
+                    surface.preeditCallback(null, 0) catch {};
                 }
 
                 // Bell stops ringing when any key is pressed that is used by
@@ -3038,6 +3039,7 @@ pub const Surface = extern struct {
         const priv = self.private();
         priv.im_composing = true;
         priv.im_len = 0;
+        priv.im_show_cursor = false;
     }
 
     fn imPreeditChanged(
@@ -3061,17 +3063,28 @@ pub const Surface = extern struct {
 
         // Get our pre-edit string that we'll use to show the user.
         var buf: [*:0]u8 = undefined;
+        var cursor_pos: i32 = 0;
         ctx.as(gtk.IMContext).getPreeditString(
             &buf,
             null,
-            null,
+            &cursor_pos,
         );
         defer glib.free(buf);
         const str = std.mem.sliceTo(buf, 0);
 
+        // some IME may hard code the cursor as a bar,
+        // in which case, cursor_pos would always be 0
+        // if cursor_pos has never been non-zero,
+        // set it to -1 to hide the cursor to avoid conflict
+        if (cursor_pos > 0) {
+            priv.im_show_cursor = true;
+        } else if (!priv.im_show_cursor) {
+            cursor_pos = -1;
+        }
+
         // Update our preedit state in Ghostty core
         // log.warn("GTKIM: preedit change str={s}", .{str});
-        surface.preeditCallback(str) catch |err| {
+        surface.preeditCallback(str, cursor_pos) catch |err| {
             log.warn(
                 "error in preedit callback err={}",
                 .{err},
@@ -3091,7 +3104,7 @@ pub const Surface = extern struct {
 
         // End our preedit state in Ghostty core
         const surface = priv.core_surface orelse return;
-        surface.preeditCallback(null) catch |err| {
+        surface.preeditCallback(null, 0) catch |err| {
             log.warn("error in preedit callback err={}", .{err});
         };
     }
@@ -3160,7 +3173,7 @@ pub const Surface = extern struct {
         if (priv.core_surface) |surface| {
             // End our preedit state. Well-behaved input methods do this for us
             // by triggering a preedit-end event but some do not (ibus 1.5.29).
-            surface.preeditCallback(null) catch |err| {
+            surface.preeditCallback(null, 0) catch |err| {
                 log.warn("error in preedit callback err={}", .{err});
             };
 

src/config/Config.zig

@@ -914,6 +914,23 @@ palette: Palette = .{},
 /// behavior around edge cases is possible.
 @"cursor-click-to-move": bool = true,
 
+/// The style of the cursor when editing the preedit text using
+/// an IME (Input Method Editor).
+///
+/// All other cursor configs are applicable to IME cursor as well,
+/// with the exception of `cursor-click-to-move` and `cursor-style-blink`
+///
+/// Note: Some IME hardcodes the cursor as a bar as a part of the preedit text.
+/// To avoid showing two cursors, the native Ghostty cursor would be hidden.
+///
+/// Valid values are:
+///
+///   * `block`
+///   * `bar`
+///   * `underline`
+///   * `block_hollow`
+@"ime-cursor-style": terminal.CursorStyle = .bar,
+
 /// Hide the mouse immediately when typing. The mouse becomes visible again
 /// when the mouse is used (button, movement, etc.). Platform-specific behavior
 /// may dictate other scenarios where the mouse is shown. For example on macOS,

src/renderer/State.zig

@@ -46,6 +46,7 @@ pub const Mouse = struct {
 pub const Preedit = struct {
     /// The codepoints to render as preedit text.
     codepoints: []const Codepoint = &.{},
+    cursor_pos: i32,
 
     /// A single codepoint to render as preedit text.
     pub const Codepoint = struct {
@@ -62,6 +63,7 @@ pub const Preedit = struct {
     pub fn clone(self: *const Preedit, alloc: Allocator) !Preedit {
         return .{
             .codepoints = try alloc.dupe(Codepoint, self.codepoints),
+            .cursor_pos = self.cursor_pos
         };
     }