feat(renderer): add Mode 2031 dark/light theme detection

packages/core/src/renderer.ts

@@ -4,6 +4,7 @@ import {
   type CursorStyle,
   DebugOverlayCorner,
   type RenderContext,
+  type ThemeMode,
   type ViewportBounds,
   type WidthMethod,
 } from "./types"
@@ -429,6 +430,7 @@ export class CliRenderer extends EventEmitter implements RenderContext {
   private _cachedPalette: TerminalColors | null = null
   private _paletteDetectionPromise: Promise<TerminalColors> | null = null
   private _onDestroy?: () => void
+  private _themeMode: ThemeMode | null = null
 
   private inputHandlers: ((sequence: string) => boolean)[] = []
   private prependedInputHandlers: ((sequence: string) => boolean)[] = []
@@ -848,6 +850,10 @@ export class CliRenderer extends EventEmitter implements RenderContext {
     return this._capabilities
   }
 
+  public get themeMode(): ThemeMode | null {
+    return this._themeMode
+  }
+
   public getDebugInputs(): Array<{ timestamp: string; sequence: string }> {
     return [...this._debugInputs]
   }
@@ -1065,6 +1071,24 @@ export class CliRenderer extends EventEmitter implements RenderContext {
     return false
   }).bind(this)
 
+  private themeModeHandler: (sequence: string) => boolean = ((sequence: string) => {
+    if (sequence === "\x1b[?997;1n") {
+      if (this._themeMode !== "dark") {
+        this._themeMode = "dark"
+        this.emit("theme_mode", "dark")
+      }
+      return true
+    }
+    if (sequence === "\x1b[?997;2n") {
+      if (this._themeMode !== "light") {
+        this._themeMode = "light"
+        this.emit("theme_mode", "light")
+      }
+      return true
+    }
+    return false
+  }).bind(this)
+
   private setupInput(): void {
     for (const handler of this.prependedInputHandlers) {
       this.addInputHandler(handler)
@@ -1083,6 +1107,7 @@ export class CliRenderer extends EventEmitter implements RenderContext {
     })
     this.addInputHandler(this.capabilityHandler)
     this.addInputHandler(this.focusHandler)
+    this.addInputHandler(this.themeModeHandler)
     this.addInputHandler((sequence: string) => {
       return this._keyHandler.processInput(sequence)
     })

packages/core/src/types.ts

@@ -28,6 +28,8 @@ export function getBaseAttributes(attr: number): number {
   return attr & ATTRIBUTE_BASE_MASK
 }
 
+export type ThemeMode = "dark" | "light"
+
 export type CursorStyle = "block" | "line" | "underline"
 
 export interface CursorStyleOptions {
@@ -50,6 +52,7 @@ export interface RendererEvents {
   "memory:snapshot": (snapshot: { heapUsed: number; heapTotal: number; arrayBuffers: number }) => void
   selection: (selection: Selection) => void
   "debugOverlay:toggle": (enabled: boolean) => void
+  theme_mode: (mode: ThemeMode) => void
 }
 
 export interface RenderContext extends EventEmitter {

packages/core/src/zig/terminal.zig

@@ -166,8 +166,7 @@ pub fn resetState(self: *Terminal, tty: anytype) !void {
     }
 
     if (self.state.color_scheme_updates) {
-        try tty.writeAll(ansi.ANSI.colorSchemeReset);
-        self.state.color_scheme_updates = false;
+        try self.setColorSchemeUpdates(tty, false);
     }
 
     self.setTerminalTitle(tty, "");
@@ -271,6 +270,11 @@ pub fn enableDetectedFeatures(self: *Terminal, tty: anytype, use_kitty_keyboard:
     if (self.caps.focus_tracking) {
         try self.setFocusTracking(tty, true);
     }
+
+    if (!self.state.color_scheme_updates) {
+        try self.setColorSchemeUpdates(tty, true);
+        try tty.writeAll(ansi.ANSI.colorSchemeRequest);
+    }
 }
 
 fn checkEnvironmentOverrides(self: *Terminal) void {
@@ -491,6 +495,12 @@ pub fn setModifyOtherKeys(self: *Terminal, tty: anytype, enable: bool) !void {
     self.state.modify_other_keys = enable;
 }
 
+pub fn setColorSchemeUpdates(self: *Terminal, tty: anytype, enable: bool) !void {
+    const seq = if (enable) ansi.ANSI.colorSchemeSet else ansi.ANSI.colorSchemeReset;
+    try tty.writeAll(seq);
+    self.state.color_scheme_updates = enable;
+}
+
 /// Re-send all currently-active terminal mode escape sequences unconditionally.
 ///
 /// When the terminal loses and regains focus (e.g. alt-tab, tab switch, minimize),
@@ -562,7 +572,7 @@ pub fn processCapabilityResponse(self: *Terminal, response: []const u8) void {
     if (std.mem.indexOf(u8, response, "2027;2$y")) |_| {
         self.caps.unicode = .unicode;
     }
-    if (std.mem.indexOf(u8, response, "2031;2$y")) |_| {
+    if (std.mem.indexOf(u8, response, "2031;1$y") != null or std.mem.indexOf(u8, response, "2031;2$y") != null) {
         self.caps.color_scheme_updates = true;
     }
     if (std.mem.indexOf(u8, response, "1004;1$y") != null or std.mem.indexOf(u8, response, "1004;2$y") != null) {