feat(v0.22.2): AutoComplete focus + Text Metrics + cursor 300ms

AutoComplete:
- Integración sistema focus (registerFocusable, requestFocus, hasFocus)
- Fix input: event.char → ctx.input.getTextInput()
- Fix dropdown al iniciar: is_first_frame guard

Text Metrics:
- Nuevo ctx.measureText() y ctx.measureTextToCursor()
- text_measure_fn callback para fuentes TTF
- char_width fallback para bitmap (8px)

Cursor:
- text_input.zig y autocomplete.zig usan métricas reales
- Blink rate: 500ms → 300ms (más responsive)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -39,6 +39,9 @@
 | 2025-12-17 | v0.21.0 | AdvancedTable: +990 LOC (multi-select, search, validation) |
 | 2025-12-17 | v0.21.1 | Fix: AdvancedTable teclado - result.selected_row/col en handleKeyboard |
 | 2025-12-19 | v0.21.2 | AdvancedTable: selected_row_unfocus, color selección según focus |
+| 2025-12-19 | v0.22.0 | ⭐ AutoComplete: focus system integration, getTextInput(), first_frame guard |
+| 2025-12-19 | v0.22.1 | ⭐ Text Metrics: ctx.measureText/measureTextToCursor para fuentes TTF de ancho variable |
+| 2025-12-19 | v0.22.2 | Cursor blink rate: 500ms→300ms (más responsive durante edición) |
 
 ---
 
@@ -55,3 +58,9 @@ Sistema de rendering dual (simple/fancy), esquinas redondeadas, sombras, transic
 ### v0.20.0-v0.21.1 - AdvancedTable (2025-12-17)
 Widget de tabla avanzada con schema, CRUD, sorting, lookup, multi-select, search, validation.
 → Detalle: `docs/ADVANCED_TABLE_MERGE_PLAN.md`
+
+### v0.22.0-v0.22.2 - AutoComplete + Text Metrics (2025-12-19)
+- **AutoComplete**: Integración completa con sistema de focus (registerFocusable, requestFocus, hasFocus)
+- **Text Metrics**: Nuevo sistema ctx.measureText() para posicionamiento correcto del cursor con fuentes TTF
+- **Cursor**: Velocidad de parpadeo aumentada (500ms→300ms) para mejor feedback durante edición
+→ Archivos: `context.zig`, `text_input.zig`, `autocomplete.zig`

src/core/context.zig

@@ -99,12 +99,20 @@ pub const Context = struct {
     /// Used for idle detection (e.g., cursor stops blinking after inactivity)
     last_input_time_ms: u64 = 0,
 
+    /// Optional text measurement function (set by application with TTF font)
+    /// Returns pixel width of text. If null, falls back to char_width * len.
+    text_measure_fn: ?*const fn ([]const u8) u32 = null,
+
+    /// Default character width for fallback measurement (bitmap fonts)
+    char_width: u32 = 8,
+
     /// Idle timeout for cursor blinking (ms). After this time without input,
     /// cursor becomes solid and no animation frames are needed.
     pub const CURSOR_IDLE_TIMEOUT_MS: u64 = 5000;
 
     /// Cursor blink period (ms). Cursor toggles visibility at this rate.
-    pub const CURSOR_BLINK_PERIOD_MS: u64 = 500;
+    /// 300ms = ~3.3 blinks/sec (faster for better editing feedback)
+    pub const CURSOR_BLINK_PERIOD_MS: u64 = 300;
 
     const Self = @This();
 
@@ -285,6 +293,38 @@ pub const Context = struct {
         self.current_time_ms = time_ms;
     }
 
+    // =========================================================================
+    // Text Metrics
+    // =========================================================================
+
+    /// Measure text width in pixels.
+    /// Uses TTF font metrics if text_measure_fn is set, otherwise falls back to char_width * len.
+    pub fn measureText(self: *const Self, text: []const u8) u32 {
+        if (self.text_measure_fn) |measure_fn| {
+            return measure_fn(text);
+        }
+        // Fallback: fixed-width calculation
+        return @as(u32, @intCast(text.len)) * self.char_width;
+    }
+
+    /// Measure text width up to cursor position (for cursor placement).
+    /// text: the full text
+    /// cursor_pos: character position (byte index for ASCII, needs UTF-8 handling for unicode)
+    pub fn measureTextToCursor(self: *const Self, text: []const u8, cursor_pos: usize) u32 {
+        const end = @min(cursor_pos, text.len);
+        return self.measureText(text[0..end]);
+    }
+
+    /// Set the text measurement function (typically from TTF font)
+    pub fn setTextMeasureFn(self: *Self, measure_fn: ?*const fn ([]const u8) u32) void {
+        self.text_measure_fn = measure_fn;
+    }
+
+    /// Set character width for fallback measurement (bitmap fonts)
+    pub fn setCharWidth(self: *Self, width: u32) void {
+        self.char_width = width;
+    }
+
     /// Get current time in milliseconds
     pub fn getTime(self: Self) u64 {
         return self.current_time_ms;

src/widgets/autocomplete.zig

@@ -36,6 +36,10 @@ pub const AutoCompleteState = struct {
     /// Last filter text (for change detection)
     last_filter: [256]u8 = [_]u8{0} ** 256,
     last_filter_len: usize = 0,
+    /// Track previous focus state for detecting focus changes
+    was_focused: bool = false,
+    /// First frame flag to avoid false focus detection
+    first_frame: bool = true,
 
     const Self = @This();
 
@@ -84,6 +88,29 @@ pub const AutoCompleteState = struct {
         self.cursor += 1;
     }
 
+    /// Insert text at cursor (for pasting or text input)
+    pub fn insert(self: *Self, new_text: []const u8) void {
+        const available = self.buffer.len - self.len;
+        const to_insert = @min(new_text.len, available);
+
+        if (to_insert == 0) return;
+
+        // Move text after cursor
+        const after_cursor = self.len - self.cursor;
+        if (after_cursor > 0) {
+            std.mem.copyBackwards(
+                u8,
+                self.buffer[self.cursor + to_insert .. self.len + to_insert],
+                self.buffer[self.cursor..self.len],
+            );
+        }
+
+        // Insert new text
+        @memcpy(self.buffer[self.cursor..][0..to_insert], new_text[0..to_insert]);
+        self.len += to_insert;
+        self.cursor += to_insert;
+    }
+
     /// Delete character before cursor (backspace)
     pub fn backspace(self: *Self) void {
         if (self.cursor == 0) return;
@@ -255,19 +282,46 @@ pub fn autocompleteRect(
 
     if (bounds.isEmpty()) return result;
 
+    // Generate unique ID for this widget based on buffer memory address
+    const widget_id: u64 = @intFromPtr(&state.buffer);
+
+    // Register as focusable in the active focus group (for Tab navigation)
+    ctx.registerFocusable(widget_id);
+
     const mouse = ctx.input.mousePos();
     const input_hovered = bounds.contains(mouse.x, mouse.y);
     const input_clicked = input_hovered and ctx.input.mousePressed(.left);
 
-    // Determine if we should be focused (simple focus tracking)
-    var is_focused = state.open;
+    // Handle click to request focus
     if (input_clicked and !config.disabled) {
-        is_focused = true;
+        ctx.requestFocus(widget_id);
         if (config.show_on_focus) {
             state.openDropdown();
         }
     }
 
+    // Check if this widget has focus using the Context focus system
+    const is_focused = ctx.hasFocus(widget_id);
+
+    // Capture first_frame state before any modifications
+    const is_first_frame = state.first_frame;
+
+    // Handle focus changes: open dropdown when gaining focus, close when losing
+    // Skip first frame to avoid false detection (was_focused starts as false)
+    if (!is_first_frame) {
+        if (is_focused and !state.was_focused) {
+            // Just gained focus
+            if (config.show_on_focus) {
+                state.openDropdown();
+            }
+        } else if (!is_focused and state.was_focused) {
+            // Just lost focus - close dropdown
+            state.closeDropdown();
+        }
+    }
+    state.was_focused = is_focused;
+    state.first_frame = false;
+
     // Draw input field background
     const border_color = if (is_focused and !config.disabled)
         colors.input_border_focus
@@ -280,20 +334,24 @@ pub fn autocompleteRect(
     // Get current filter text
     const filter_text = state.text();
 
-    // Check if text changed
+    // Check if text changed (but not on first frame - that's just initialization)
     const text_changed = !std.mem.eql(u8, filter_text, state.last_filter[0..state.last_filter_len]);
     if (text_changed) {
-        result.text_changed = true;
         // Update last filter
         const copy_len = @min(filter_text.len, state.last_filter.len);
         @memcpy(state.last_filter[0..copy_len], filter_text[0..copy_len]);
         state.last_filter_len = copy_len;
-        // Reset selection when text changes
-        state.highlighted = 0;
-        state.scroll_offset = 0;
-        // Open dropdown when typing
-        if (filter_text.len >= config.min_chars) {
-            state.open = true;
+
+        // Only trigger changes after first frame (first frame is just sync)
+        if (!is_first_frame) {
+            result.text_changed = true;
+            // Reset selection when text changes
+            state.highlighted = 0;
+            state.scroll_offset = 0;
+            // Open dropdown when typing
+            if (filter_text.len >= config.min_chars) {
+                state.open = true;
+            }
         }
     }
 
@@ -314,7 +372,9 @@ pub fn autocompleteRect(
 
     // Draw cursor if focused
     if (is_focused and !config.disabled) {
-        const cursor_x = inner.x + @as(i32, @intCast(state.cursor * 8));
+        // Use ctx.measureTextToCursor for accurate cursor positioning with variable-width fonts
+        const cursor_offset = ctx.measureTextToCursor(filter_text, state.cursor);
+        const cursor_x = inner.x + @as(i32, @intCast(cursor_offset));
         ctx.pushCommand(Command.rect(cursor_x, text_y, 2, char_height, Style.Color.rgb(200, 200, 200)));
     }
 
@@ -439,16 +499,16 @@ pub fn autocompleteRect(
                 .end => {
                     state.cursor = state.len;
                 },
-                else => {
-                    // Handle text input
-                    if (event.char) |c| {
-                        if (c >= 32 and c < 127) {
-                            state.insertChar(@intCast(c));
-                        }
-                    }
-                },
+                else => {},
             }
         }
+
+        // Handle typed text (after key events, like TextInput does)
+        const text_in = ctx.input.getTextInput();
+        if (text_in.len > 0) {
+            state.insert(text_in);
+            result.text_changed = true;
+        }
     }
 
     // Draw dropdown if open and has items

src/widgets/text_input.zig

@@ -371,8 +371,9 @@ pub fn textInputRect(
     // Draw cursor if focused
     // Hybrid behavior: blinks while active, solid after idle timeout
     if (has_focus and !config.readonly) {
-        const char_width: u32 = 8;
-        const cursor_x = inner.x + @as(i32, @intCast(state.cursor * char_width));
+        // Use ctx.measureTextToCursor for accurate cursor positioning with variable-width fonts
+        const cursor_offset = ctx.measureTextToCursor(display_text, state.cursor);
+        const cursor_x = inner.x + @as(i32, @intCast(cursor_offset));
         const cursor_color = theme.foreground;
 
         // Determine if cursor should be visible
@@ -405,11 +406,13 @@ pub fn textInputRect(
 
     // Draw selection if any
     if (state.selection_start) |sel_start| {
-        const char_width: u32 = 8;
         const start = @min(sel_start, state.cursor);
         const end = @max(sel_start, state.cursor);
-        const sel_x = inner.x + @as(i32, @intCast(start * char_width));
-        const sel_w: u32 = @intCast((end - start) * char_width);
+        // Use ctx.measureTextToCursor for accurate selection with variable-width fonts
+        const start_offset = ctx.measureTextToCursor(display_text, start);
+        const end_offset = ctx.measureTextToCursor(display_text, end);
+        const sel_x = inner.x + @as(i32, @intCast(start_offset));
+        const sel_w: u32 = end_offset - start_offset;
 
         if (sel_w > 0) {
             ctx.pushCommand(Command.rect(