/*
 * meow_ui_widget.c — 控件层（B1.3）：按钮/滑条/开关/列表最小集。
 *
 * 控件只负责绘制与状态；命中分发由应用在 on_tap 里调 meow_widget_hit 完成
 * （与 MEOW_APP_SDK.md §5 一致）。绘制读当前主题（meow_theme_get）走 back_buf。
 */
#include "meow_ui.h"
#include "meow_ui_internal.h"
#include <stdlib.h>
#include <string.h>

enum { W_BTN = 0, W_SLIDER = 1, W_SWITCH = 2, W_LIST = 3,
       W_CUSTOM = 4, W_LAYOUT = 5, W_SPACER = 6 };

/* 布局子项数组上限（固定尺寸子项先做；超出静默拒收）。 */
#define MEOW_LAYOUT_MAX_CHILD 32

/* 按钮「按住」（长按）判定阈值（ms）：超过即进入更强态（更深状态层）。
 * 视觉区分「短按按下」与「按住」；触发语义不变（on_tap 仍按抬手判定）。 */
#define MEOW_BTN_HOLD_MS 500u

/* MD3 状态层混色：c 为基色、o 为状态色、t 为 o 的占比(0-100)。
 * 用于把主题 accent 向黑/白调出「按下/按住」状态层（日/夜主题各配色）。 */
static uint32_t blend_color(uint32_t c, uint32_t o, int t)
{
    int rr = (((c >> 16) & 0xFF) * (100 - t) + ((o >> 16) & 0xFF) * t) / 100;
    int gg = (((c >> 8) & 0xFF) * (100 - t) + ((o >> 8) & 0xFF) * t) / 100;
    int bb = ((c & 0xFF) * (100 - t) + (o & 0xFF) * t) / 100;
    return ((uint32_t)rr << 16) | ((uint32_t)gg << 8) | (uint32_t)bb;
}

struct meow_widget {
    int type;
    int x, y, w, h;
    int owner;              /* §6.1 ①：创建时绑定的 Activity；命中只在 owner==active 才生效 */
    char label[128];
    int pressed;            /* 按钮按下视觉态（遗留字面；状态机用 MEOW_WS_PRESSED 位） */
    int min, max, val;      /* 滑条 */
    int on;                 /* 开关 */
    int count, sel;         /* 列表 */
    meow_list_source src;
    void *ctx;

    /* §5.8 batch1：统一状态机（§5.8.3）+ 通用 Options（§5.8.2）+ 自定义回调（§5.8.1）+ 布局（§5.8.5） */
    unsigned state;                  /* MEOW_WS_* 位掩码（默认 MEOW_WS_ENABLED） */
    meow_widget_opts opts;           /* 通用修饰（浅拷；opts_used==0 时按控件内建默认） */
    int opts_used;                   /* 1=set_opts 显式挂载过 */
    meow_widget_render_fn render_cb; /* W_CUSTOM：自绘回调 */
    meow_widget_hit_fn hit_cb;       /* W_CUSTOM：自定义命中回调 */
    int kind;                        /* W_LAYOUT：MEOW_LAYOUT_ROW/COLUMN/BOX */
    int spacing;                     /* W_LAYOUT：项间间距 */
    meow_widget *children[MEOW_LAYOUT_MAX_CHILD];  /* W_LAYOUT：子控件 */
    int nchildren;
};

/* ---- §5.8 batch1 内部辅助：opts 取值（opts_used==0 时按控件内建默认）----
 * 注意：必须先定义 struct meow_widget，才能访问其成员（C 要求类型完整）。 */
static uint32_t widget_bg(const meow_widget *w, const meow_theme *th, uint32_t def)
{ (void)th; return (w->opts_used && w->opts.bg) ? w->opts.bg : def; }
static uint32_t widget_fg(const meow_widget *w, const meow_theme *th, uint32_t def)
{ (void)th; return (w->opts_used && w->opts.fg) ? w->opts.fg : def; }
static int widget_radius(const meow_widget *w, int def)
{ return (w->opts_used && w->opts.radius >= 0) ? w->opts.radius : def; }
static int widget_pady(const meow_widget *w)
{ return (w->opts_used && w->opts.pad_y > 0) ? w->opts.pad_y : 0; }

/* 是否禁用（状态机：MEOW_WS_ENABLED 未置位）。 */
static int widget_disabled(const meow_widget *w) { return !(w->state & MEOW_WS_ENABLED); }

/* MD3 状态层叠色：把基色向 onSurface 叠 t% 调出按下/按住/聚焦状态层（§5.8.4）。 */
static uint32_t state_tint(uint32_t base, const meow_theme *th, int t)
{ return blend_color(base, th->onSurface, t); }

/* ---- §5.8.2/§5.8.3 公共 API：Options + 状态机 ---- */
int meow_widget_set_opts(meow_widget *w, const meow_widget_opts *opts)
{
    if (!w || !opts) return -1;
    w->opts = *opts;
    w->opts_used = 1;
    /* disabled/selected 立即反映到状态机位（§5.8.3）。 */
    if (opts->disabled) w->state &= ~MEOW_WS_ENABLED;
    else               w->state |=  MEOW_WS_ENABLED;
    if (opts->selected) w->state |=  MEOW_WS_SELECTED;
    else               w->state &= ~MEOW_WS_SELECTED;
    meow_gfx_mark_dirty(w->x, w->y, w->w, w->h);   /* 挂载会改变绘制：标区域脏 */
    return 0;
}

int meow_widget_opts_get(const meow_widget *w, meow_widget_opts *out)
{
    if (!w || !out) return -1;
    if (!w->opts_used) {
        /* 默认视图：radius=-1（控件默认）、disabled/selected 取状态位。 */
        memset(out, 0, sizeof *out);
        out->radius = -1;
        out->disabled = widget_disabled(w) ? 1 : 0;
        out->selected = (w->state & MEOW_WS_SELECTED) ? 1 : 0;
        return 0;
    }
    *out = w->opts;
    return 0;
}

void meow_widget_set_state(meow_widget *w, unsigned bits, int on)
{
    if (!w) return;
    if (on) w->state |= bits;
    else    w->state &= ~bits;
    meow_gfx_mark_dirty(w->x, w->y, w->w, w->h);   /* 状态变化会改变绘制 */
}
unsigned meow_widget_state(const meow_widget *w) { return w ? w->state : MEOW_WS_ENABLED; }
int  meow_widget_enabled(const meow_widget *w) { return w ? (w->state & MEOW_WS_ENABLED) != 0 : 0; }
void meow_widget_set_enabled(meow_widget *w, int on) { meow_widget_set_state(w, MEOW_WS_ENABLED, on ? 1 : 0); }
int  meow_widget_selected(const meow_widget *w) { return w ? (w->state & MEOW_WS_SELECTED) != 0 : 0; }
void meow_widget_set_selected(meow_widget *w, int on) { meow_widget_set_state(w, MEOW_WS_SELECTED, on ? 1 : 0); }

/* 一键叠状态层（自定义画布可选；标准控件由 SDK 自动叠，不调用）：半透明状态层 + 焦点描边。 */
void meow_widget_draw_state_layer(meow_widget *w, const meow_theme *th)
{
    if (!w || !th) return;
    if (widget_disabled(w)) {
        meow_ui_fill_rect_alpha(w->x, w->y, w->w, w->h, th->onSurface, 90);
        return;                       /* 禁用不再叠按下/聚焦 */
    }
    if (w->state & MEOW_WS_PRESSED) {
        /* 向 onSurface 叠半透明状态层铺满控件矩形（按下/按住） */
        int t = (w->opts_used && w->opts.bg) ? 24 : 12;
        meow_ui_fill_rect_alpha(w->x, w->y, w->w, w->h, th->onSurface, t * 255 / 100);
    }
    if (w->state & MEOW_WS_FOCUSED) {
        int r = widget_radius(w, 10);
        meow_ui_draw_rect_round(w->x, w->y, w->w, w->h, r, th->primary);
    }
}

/* ---- 实时按压即时刷新（agent-119）----
 * 按压/按住视觉由 meow_widget_draw 读实时触摸（meow_input_touch_*）呈现，但 app 只在
 * on_tick(1s)/on_tap 重绘 → 快速点/按住时按压态刷新滞后/漏。此处在 SDK 触摸按下/释放/
 * 按住达阈值时主动重绘命中的按钮区域并局部上屏（不等 app 重绘），即时反映按下变深/
 * 释放恢复，连续快速点击每按都反映。仅针对 SDK 控件按钮（W_BTN）；app 纯自绘不适用。
 * 语义不变：on_tap / meow_btn_pressed / meow_widget_hit 零改动；非按钮区域不动。 */
#define MEOW_LIVE_BTN_MAX 64
static meow_widget *g_live_btns[MEOW_LIVE_BTN_MAX];
static int g_live_btn_n = 0;
static meow_widget *g_live_btn = NULL;   /* 实时按压中最上层按钮（无 = NULL） */
static int g_live_prev_hold = 0;         /* 该按钮上次渲染是否为按住态 */

static void live_btn_register(meow_widget *w)
{
    if (!w || w->type != W_BTN) return;
    for (int i = 0; i < g_live_btn_n; i++)
        if (g_live_btns[i] == w) return;
    if (g_live_btn_n < MEOW_LIVE_BTN_MAX) g_live_btns[g_live_btn_n++] = w;
}

static void live_btn_unregister(meow_widget *w)
{
    for (int i = 0; i < g_live_btn_n; i++) {
        if (g_live_btns[i] == w) {
            g_live_btns[i] = g_live_btns[--g_live_btn_n];
            if (g_live_btn == w) g_live_btn = NULL;
            return;
        }
    }
    if (g_live_btn == w) g_live_btn = NULL;
}

/* 命中：返回坐标所在的「当前 active Activity」的最上层按钮（创建序 = 绘制序，最后者在上）。
 * §6.1 ①：仅扫描 owner == 当前 active Activity 的按钮 —— 非 active Activity 的控件
 * 绝不参与命中（根治 agent-119 遗留的「全屏页触摸到主页按钮位置 → 闪现 accent 底」）。 */
static meow_widget *live_btn_hit(int x, int y)
{
    int active = meow_ui_activity_active();
    meow_widget *r = NULL;
    for (int i = 0; i < g_live_btn_n; i++) {
        meow_widget *w = g_live_btns[i];
        if (w->owner != active) continue;          /* 非 active activity：跳过 */
        if (x >= w->x && x < w->x + w->w && y >= w->y && y < w->y + w->h)
            r = w;   /* 越后创建越上：保留最后命中 */
    }
    return r;
}

/* 重绘并局部刷新一个按钮区（绘制内部调 meow_gfx_fill_round 已标脏；flush_region 合区+上屏）。 */
static void live_btn_redraw(meow_widget *w)
{
    if (!w) return;
    meow_widget_draw(w);
    meow_ui_flush_region(w->x, w->y, w->w, w->h);
}

/* 由 meow_ui_run 每帧调用（主线程）：检测实时触摸状态迁移，即时重绘命中按钮的按压/按住/
 * 释放，不等 app on_tick/on_tap。仅在触摸状态相对上次渲染发生变化时动作（非全屏、省性能）。 */
void meow_widget_touch_refresh(void)
{
    int active = meow_ui_activity_active();
    /* §6.1 ①：若当前按住按钮已不属于 active activity（按压期间发生了 Activity 切换，
     * 例如点 FULLSCREEN 后进入全屏），静默清引用——不绘制、不闪现（否则会在新页面底上
     * 画出旧按钮的 accent 残留）。 */
    if (g_live_btn && g_live_btn->owner != active) {
        g_live_btn->state &= ~MEOW_WS_PRESSED;   /* §5.8.3：清除按压态（跨页面不残留） */
        g_live_btn = NULL;
        g_live_prev_hold = 0;
    }
    int down = meow_input_touch_down();
    meow_widget *hit = down ? live_btn_hit(meow_input_touch_x(), meow_input_touch_y()) : NULL;
    int hold = down && hit && meow_input_touch_hold_ms() >= MEOW_BTN_HOLD_MS;

    if (!down) {
        /* 释放：把最近按压按钮恢复为常态 */
        if (g_live_btn) {
            g_live_btn->state &= ~MEOW_WS_PRESSED;
            live_btn_redraw(g_live_btn);
            g_live_btn = NULL;
        }
        g_live_prev_hold = 0;
        return;
    }
    if (hit != g_live_btn) {
        /* 按下/滑至新按钮：先恢复旧（若手指滑离），再按压新 */
        if (g_live_btn) {
            g_live_btn->state &= ~MEOW_WS_PRESSED;
            live_btn_redraw(g_live_btn);
        }
        g_live_btn = hit;
        g_live_prev_hold = hold;
        if (hit) {
            if (widget_disabled(hit)) { g_live_btn = NULL; }   /* 禁用不响应按压 */
            else { hit->state |= MEOW_WS_PRESSED; live_btn_redraw(hit); }
        }
    } else if (hit && hold != g_live_prev_hold) {
        /* 同一按钮按住达阈值：升级到更强态 */
        hit->state |= MEOW_WS_PRESSED;
        live_btn_redraw(hit);
        g_live_prev_hold = hold;
    }
}

meow_widget *meow_btn_create(int x, int y, int w, int h, const char *label)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_BTN; t->x = x; t->y = y; t->w = w; t->h = h;
    t->owner = meow_ui_activity_active();   /* §6.1 ①：绑定当前 active Activity */
    t->state = MEOW_WS_ENABLED;             /* §5.8.3：默认 ENABLED */
    if (label) { strncpy(t->label, label, sizeof t->label - 1); t->label[sizeof t->label - 1] = 0; }
    live_btn_register(t);
    return t;
}

meow_widget *meow_slider_create(int x, int y, int w, int min, int max, int val)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_SLIDER; t->x = x; t->y = y; t->w = w; t->h = 40;
    t->owner = meow_ui_activity_active();
    t->state = MEOW_WS_ENABLED;
    t->min = min; t->max = (max > min) ? max : min + 1; t->val = (val < min) ? min : (val > t->max) ? t->max : val;
    return t;
}

meow_widget *meow_switch_create(int x, int y, int on)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_SWITCH; t->x = x; t->y = y; t->w = 56; t->h = 32;
    t->owner = meow_ui_activity_active();
    t->state = MEOW_WS_ENABLED;
    t->on = on ? 1 : 0;
    if (t->on) t->state |= MEOW_WS_SELECTED;   /* §5.8.3：开关 on → selected */
    return t;
}

meow_widget *meow_list_create(int x, int y, int w, int h, int count,
                              meow_list_source src, void *ctx)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_LIST; t->x = x; t->y = y; t->w = w; t->h = h;
    t->owner = meow_ui_activity_active();
    t->state = MEOW_WS_ENABLED;
    t->count = count; t->src = src; t->ctx = ctx; t->sel = 0;
    return t;
}

void meow_widget_free(meow_widget *w)
{
    if (!w) return;
    live_btn_unregister(w);
    free(w);
}

/* ---- §5.8.1 自定义画布：App 提供 render/hit 回调，同一个 meow_widget 基座 ---- */
meow_widget *meow_widget_custom_create(int x, int y, int w, int h,
                                       meow_widget_render_fn render_cb,
                                       meow_widget_hit_fn hit_cb,
                                       void *ctx)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_CUSTOM; t->x = x; t->y = y; t->w = w; t->h = h;
    t->owner = meow_ui_activity_active();   /* §6.1 ①：同既有控件绑当前 active Activity */
    t->state = MEOW_WS_ENABLED;
    t->render_cb = render_cb;
    t->hit_cb = hit_cb;
    t->ctx = ctx;
    return t;
}

/* ---- §5.8.5 可组合布局：Row / Column / Box + Spacer ---- */
meow_widget *meow_row_create(int x, int y, int w, int h, int spacing)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_LAYOUT; t->kind = MEOW_LAYOUT_ROW; t->x = x; t->y = y; t->w = w; t->h = h;
    t->owner = meow_ui_activity_active();
    t->state = MEOW_WS_ENABLED;
    t->spacing = spacing > 0 ? spacing : 0;
    return t;
}
meow_widget *meow_column_create(int x, int y, int w, int h, int spacing)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_LAYOUT; t->kind = MEOW_LAYOUT_COLUMN; t->x = x; t->y = y; t->w = w; t->h = h;
    t->owner = meow_ui_activity_active();
    t->state = MEOW_WS_ENABLED;
    t->spacing = spacing > 0 ? spacing : 0;
    return t;
}
meow_widget *meow_box_create(int x, int y, int w, int h)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_LAYOUT; t->kind = MEOW_LAYOUT_BOX; t->x = x; t->y = y; t->w = w; t->h = h;
    t->owner = meow_ui_activity_active();
    t->state = MEOW_WS_ENABLED;
    t->spacing = 0;
    return t;
}
meow_widget *meow_layout_spacer(int w, int h)
{
    meow_widget *t = (meow_widget *)calloc(1, sizeof *t);
    if (!t) return NULL;
    t->type = W_SPACER; t->x = 0; t->y = 0; t->w = w > 0 ? w : 0; t->h = h > 0 ? h : 0;
    t->owner = meow_ui_activity_active();
    t->state = MEOW_WS_ENABLED;
    return t;
}

int meow_layout_add(meow_widget *layout, meow_widget *child)
{
    if (!layout || layout->type != W_LAYOUT || !child) return -1;
    if (layout->nchildren >= MEOW_LAYOUT_MAX_CHILD) return -1;
    for (int i = 0; i < layout->nchildren; i++)
        if (layout->children[i] == child) return -1;   /* 同子项去重 */
    layout->children[layout->nchildren++] = child;
    return 0;
}

/* 把子控件算成绝对坐标（写进各 child 的 x,y；w/h 固定尺寸，先不做弹性）。
 * Row：子项水平排（垂直居中于容器 h）；Column：垂直排（水平居中）；Box：叠放（各放容器左上角）。
 * 子项的 margin_x/margin_y（Options）参与排布；子项为布局时递归 arrange。 */
void meow_layout_arrange(meow_widget *layout)
{
    if (!layout || layout->type != W_LAYOUT) return;
    int kind = layout->kind;
    int cur = (kind == MEOW_LAYOUT_COLUMN) ? layout->y : layout->x;
    for (int i = 0; i < layout->nchildren; i++) {
        meow_widget *c = layout->children[i];
        if (!c) continue;
        int mx = (c->opts_used && c->opts.margin_x > 0) ? c->opts.margin_x : 0;
        int my = (c->opts_used && c->opts.margin_y > 0) ? c->opts.margin_y : 0;
        if (kind == MEOW_LAYOUT_ROW) {
            cur += mx;
            c->x = cur;
            c->y = layout->y + (layout->h - c->h) / 2;   /* 垂直居中 */
            if (c->y < layout->y) c->y = layout->y;
            cur += c->w + mx + layout->spacing;
        } else if (kind == MEOW_LAYOUT_COLUMN) {
            cur += my;
            c->y = cur;
            c->x = layout->x + (layout->w - c->w) / 2;   /* 水平居中 */
            if (c->x < layout->x) c->x = layout->x;
            cur += c->h + my + layout->spacing;
        } else {   /* BOX：叠放，各放容器左上角 */
            c->x = layout->x;
            c->y = layout->y;
        }
        if (c->type == W_LAYOUT) meow_layout_arrange(c);   /* 嵌套递归 */
    }
}

static int hit(meow_widget *w, int x, int y)
{
    if (!w) return 0;
    return x >= w->x && x < w->x + w->w && y >= w->y && y < w->y + w->h;
}

int meow_widget_hit(meow_widget *w, int x, int y)
{
    if (!w) return 0;
    /* §6.1 ①：页面控件只对自身 Activity 负责，不跨页面复用命中。 */
    if (w->owner != meow_ui_activity_active()) return 0;
    /* §5.8.3：禁用不响应命中（也不进 pressed）。 */
    if (widget_disabled(w)) return 0;
    /* §5.8.1：自定义画布用 App 回调判定命中（可非矩形）；其余矩形内含。 */
    if (w->type == W_CUSTOM)
        return w->hit_cb ? w->hit_cb(w, x, y, w->ctx) : hit(w, x, y);
    return hit(w, x, y);
}
int  meow_btn_pressed(meow_widget *w)
{ return w && w->type == W_BTN ? (w->pressed || (w->state & MEOW_WS_PRESSED)) : 0; }

void meow_slider_set(meow_widget *w, int val)
{
    if (!w || w->type != W_SLIDER) return;
    if (val < w->min) val = w->min; if (val > w->max) val = w->max;
    w->val = val;
}
int meow_slider_get(meow_widget *w) { return w && w->type == W_SLIDER ? w->val : 0; }
void meow_switch_set(meow_widget *w, int on)
{
    if (w && w->type == W_SWITCH) {
        w->on = on ? 1 : 0;
        if (w->on) w->state |= MEOW_WS_SELECTED;   /* §5.8.3：on → selected */
        else       w->state &= ~MEOW_WS_SELECTED;
        meow_gfx_mark_dirty(w->x, w->y, w->w, w->h);
    }
}
int  meow_switch_get(meow_widget *w) { return w && w->type == W_SWITCH ? w->on : 0; }

/* 供应用在 on_tap 里对外可控回馈：这里不存命中态（由 app 分发），仅暴露绘制。
 * §5.8 升级：统一取语义色（meow_theme），读 opts（背景/圆角/描边/pad/fg）与状态机位
 * （disabled/selected/pressed/focused），标准控件由 SDK 自动叠状态层；自定义画布（W_CUSTOM）
 * 由 App render_cb 全权自绘（SDK 只注入主题、不画背景/状态层）；布局（W_LAYOUT）递归绘制子控件。 */
void meow_widget_draw(meow_widget *w)
{
    if (!w) return;
    const meow_theme *th = meow_theme_get();
    int disabled = widget_disabled(w);

    switch (w->type) {
    case W_BTN: {
        /* 按下/按住 = 视觉态（不改 on_tap/btn_pressed/hit 语义）。按下来源三路：
         *   - 状态机 MEOW_WS_PRESSED（App 经 set_state 或 SDK 触摸层置位）；
         *   - w->pressed（既有字面，保留）；
         *   - 实时触摸命中：SDK 输入层当前正按在该控件内（无需 app 追踪）。
         * 按住=实时触摸命中且持续 ≥MEOW_BTN_HOLD_MS；按下=任一来源。禁用时不叠按下底。 */
        int live = meow_input_touch_down() &&
                   meow_input_touch_x() >= w->x && meow_input_touch_x() < w->x + w->w &&
                   meow_input_touch_y() >= w->y && meow_input_touch_y() < w->y + w->h;
        int press = (w->state & MEOW_WS_PRESSED) || w->pressed || live;
        int hold  = live && meow_input_touch_hold_ms() >= MEOW_BTN_HOLD_MS;
        if (disabled) press = 0;
        /* 底色：选中态用 primaryContainer（onPrimaryContainer 文字）；否则 primary（onPrimary 文字）。
         * 可被 opts.bg 覆盖（此时文字用 opts.fg 或 onPrimary）。 */
        int selected = (w->state & MEOW_WS_SELECTED);
        uint32_t base, default_fg;
        if (selected && !(w->opts_used && w->opts.bg)) { base = th->primaryContainer; default_fg = th->onPrimaryContainer; }
        else { base = widget_bg(w, th, th->primary); default_fg = th->onPrimary; }
        uint32_t bg;
        if (hold)       bg = state_tint(base, th, 24);   /* 按住 = 深状态层 */
        else if (press) bg = state_tint(base, th, 12);   /* 按下 = 状态层 */
        else            bg = base;
        int r = widget_radius(w, 10);
        meow_gfx_fill_round(w->x, w->y, w->w, w->h, r, bg);
        /* 内容区受 pad 垂直内缩（水平居中文本，pad_x 不影响中心） */
        int pady = widget_pady(w);
        int cx = w->x + w->w / 2;
        int cy = w->y + pady + (w->h - 2 * pady - meow_ui_text_height(th->font_body)) / 2;
        uint32_t tc = widget_fg(w, th, default_fg);
        meow_ui_text_center(cx, cy, w->label, th->font_body, tc);
        /* opts 描边 / 焦点外圈 */
        if (w->opts_used && w->opts.stroke && w->opts.stroke_w > 0)
            meow_ui_draw_rect_round(w->x, w->y, w->w, w->h, r, w->opts.stroke);
        if (w->state & MEOW_WS_FOCUSED)
            meow_ui_draw_rect_round(w->x, w->y, w->w, w->h, r, th->primary);
        /* 禁用：整体变暗（状态层向 onSurface 叠 α） */
        if (disabled) meow_ui_fill_rect_alpha(w->x, w->y, w->w, w->h, th->onSurface, 90);
        break;
    }
    case W_SLIDER: {
        /* 语义色：轨道=onSurfaceVariant(dim)、填充=primary(accent)、滑块=fg(onSurface)。 */
        int trace_y = w->y + w->h / 2 - 3;
        meow_ui_fill_rect(w->x, trace_y, w->w, 6, th->onSurfaceVariant);
        int range = w->max - w->min;
        int frac = range ? (w->val - w->min) * w->w / range : 0;
        if (frac > 0) meow_ui_fill_rect(w->x, trace_y, frac, 6, th->primary);
        int tx = w->x + frac;
        int ty = w->y + w->h / 2;
        meow_gfx_fill_round(tx - 10, ty - 10, 20, 20, 10, th->onSurface);
        if (disabled) meow_ui_fill_rect_alpha(w->x, w->y, w->w, w->h, th->onSurface, 90);
        break;
    }
    case W_SWITCH: {
        uint32_t bg = w->on ? th->primary : th->onSurfaceVariant;
        meow_gfx_fill_round(w->x, w->y, w->w, w->h, w->h / 2, bg);
        int knob_r = w->h / 2 - 3;
        int kx = w->on ? w->x + w->w - knob_r * 2 - 3 : w->x + 3;
        meow_gfx_fill_round(kx, w->y + 3, knob_r * 2, knob_r * 2, knob_r, 0xFFFFFF);
        if (disabled) meow_ui_fill_rect_alpha(w->x, w->y, w->w, w->h, th->onSurface, 90);
        break;
    }
    case W_LIST: {
        int rowh = 44, pad = 16;
        for (int i = 0; i < w->count; i++) {
            int ry = w->y + i * rowh;
            if (ry >= w->y + w->h) break;
            if (i == w->sel) meow_ui_fill_rect(w->x, ry, w->w, rowh, th->primary);
            char label[64] = "";
            if (w->src && w->src(i, label, (int)sizeof label, w->ctx)) {
                uint32_t col = (i == w->sel) ? 0xFFFFFF : th->onSurface;
                meow_ui_text(w->x + pad, ry + (rowh - meow_ui_text_height(th->font_body)) / 2,
                             label, th->font_body, col);
            }
            meow_ui_fill_rect(w->x, ry + rowh - 1, w->w, 1, th->onSurfaceVariant);
        }
        if (disabled) meow_ui_fill_rect_alpha(w->x, w->y, w->w, w->h, th->onSurface, 90);
        break;
    }
    case W_CUSTOM:
        /* SDK 不替自定义画布画背景/状态层；App 在 render_cb 里自绘（th 供取色），
         * 可读 meow_widget_state（状态位）/ meow_widget_opts_get（通用修饰）自行叠。 */
        if (w->render_cb) w->render_cb(w, th, w->ctx);
        break;
    case W_LAYOUT:
        /* 递归绘制子控件（子控件坐标已由 meow_layout_arrange 算成绝对坐标）。 */
        for (int i = 0; i < w->nchildren; i++)
            if (w->children[i]) meow_widget_draw(w->children[i]);
        break;
    case W_SPACER:
        break;   /* 不可见空白 */
    default:
        break;
    }
}