docs: 同步 AGENTS.md — 修改解码器优化方向

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

.idea/deploymentTargetSelector.xml

@@ -4,7 +4,7 @@
     <selectionStates>
       <SelectionState runConfigName="app">
         <option name="selectionMode" value="DROPDOWN" />
-        <DropdownSelection timestamp="2026-07-17T12:57:33.559741200Z">
+        <DropdownSelection timestamp="2026-07-17T16:06:27.410601800Z">
           <Target type="DEFAULT_BOOT">
             <handle>
               <DeviceId pluginId="LocalEmulator" identifier="path=C:\Users\evan\.android\avd\Medium_Phone.avd" />

.idea/markdown.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="MarkdownSettings">
+    <option name="previewPanelProviderInfo">
+      <ProviderInfo name="Compose (experimental)" className="com.intellij.markdown.compose.preview.ComposePanelProvider" />
+    </option>
+  </component>
+</project>

AGENTS.md

@@ -37,7 +37,7 @@ com.example.m20_gamepad/
 │   ├── RobotConnection.kt       # 连接状态机管理（连接/订阅/心跳/断线判定）
 │   └── JoystickController.kt    # 摇杆输入 → 协议指令映射
 ├── video/
-│   └── RtspSurfaceView.kt       # RTSP 视频流播放（SurfaceView 层）
+│   └── RtspVideoPlayer.kt       # RTSP 视频流播放（ExoPlayer + Composable 包装）
 ├── data/
 │   ├── SettingsRepository.kt    # 设置项读写（DataStore 封装）
 │   └── AppSettings.kt           # 配置数据类定义 + 默认值
@@ -52,12 +52,12 @@ com.example.m20_gamepad/
 - **Header 结构**: `Sync(0xEB 91 EB 90) | Length(u16 LE) | MsgId(u16 LE) | Format(0x01) | Reserved(7字节)`
 - **ASDU 固定外层**: `{"PatrolDevice": {"Type": int, "Command": int, "Time": "YYYY-MM-DD HH:mm:ss", "Items": {}}}`
 - **关键指令**:
-  - 心跳: Type=100, Cmd=100, ≥1 Hz
-  - 轴指令: Type=2, Cmd=21, Items: {X,Y,Z,Roll,Pitch,Yaw}, [-1,1], ≥20 Hz
-  - 速度指令: Type=2, Cmd=25, Items: {X,Y,Z,Roll,Pitch,Yaw}, 物理单位, ≥10 Hz
-  - 运动状态转换: Type=2, Cmd=22, Items: {MotionParam}
-  - 步态切换: Type=2, Cmd=23, Items: {GaitParam}
-  - 使用模式切换: Type=1101, Cmd=5, Items: {Mode}
+  - 心跳：Type=100, Cmd=100, ≥1 Hz
+  - 轴指令：Type=2, Cmd=21, Items: {X,Y,Z,Roll,Pitch,Yaw}, [-1,1], ≥20 Hz
+  - 速度指令：Type=2, Cmd=25, Items: {X,Y,Z,Roll,Pitch,Yaw}, 物理单位，≥10 Hz
+  - 运动状态转换：Type=2, Cmd=22, Items: {MotionParam}
+  - 步态切换：Type=2, Cmd=23, Items: {GaitParam}
+  - 使用模式切换：Type=1101, Cmd=5, Items: {Mode}
 - **状态上报**: 上行响应含 ErrorCode/ErrorMessage; 主动订阅制（Type=1002, Cmd=3/4/5/6）
 
 ---
@@ -133,12 +133,14 @@ val y = power / 100.0 * sin(angle)   // 水平分量
 
 ## 构建与运行
 
-```bash
-# 在项目根目录
-./gradlew assembleDebug
+> **注意**：项目源码位于 Windows 目录下，通过 WSL 访问和编辑。WSL 环境中没有 Android SDK / Gradle，无法直接运行构建命令。如需构建或安装，请在 Windows 端的 Android Studio 或终端中执行。
 
-# 安装到设备
-./gradlew installDebug
+```bash
+# 在项目根目录（Windows 端）
+gradlew assembleDebug
+
+# 安装到设备（Windows 端）
+gradlew installDebug
 ```
 
 ### 依赖
@@ -157,9 +159,10 @@ val y = power / 100.0 * sin(angle)   // 水平分量
 - **协程**: 网络 I/O 使用 `kotlinx.coroutines`，避免裸线程
 - **UDP**: 使用 `java.net.DatagramSocket`，绑定本地随机端口
 - **状态管理**: 使用 `StateFlow` 暴露连接状态、机器人状态
+- **状态上报合并策略**: `handleStatusReport` 对 `_latestStatus` 采用合并（`prev.copy`）而非替换，避免 4 个独立订阅（Basic/Error/Motion/Device）的局部报告覆盖整个状态导致 UI 闪烁。各分项（`batteryStatus`、`motionStatus` 等）同时维护独立 StateFlow，供 UI 直接订阅
 - **生命周期**: 网络连接生命周期绑定到 Activity/Service，前台时活跃
 - **MsgId**: 从 0 递增 u16，循环回绕
-- **断线判定**: 3 秒无任何 UDP 包 → 标记离线
+- **断线判定**: 收到首个有效数据包前为 `CONNECTING`（5 秒无数据 → `TIMEOUT`）；`CONNECTED` 后 3 秒无任何 UDP 包 → `TIMEOUT`
 
 ---
 
@@ -185,18 +188,38 @@ val y = power / 100.0 * sin(angle)   // 水平分量
 - [x] 导航框架：NavRoutes.kt（`MAIN`/`SETTINGS` 路由常量）、MainActivity.kt 改写为 `AppNavGraph()`（NavHost，startDestination=MAIN，主界面齿轮按钮跳转设置，返回/保存后 popBackStack 到 MAIN）
 - [x] 连接参数从设置读取：MainViewModel 构造注入 `SettingsRepository`，`settings: StateFlow<AppSettings>`（`stateIn(Eagerly)`），`connect()` 读取 `settings.value` 的 host/port；`init {}` 监听 host/port 变化（`distinctUntilChanged`）后断开当前连接，下次连接使用新参数（符合“修改设置后断开当前连接”约束）。移除 DEFAULT_HOST/DEFAULT_PORT/DEFAULT_RTSP_URL 硬编码
 - [x] 连接状态机：RobotConnection.kt（连接状态流转校验 `isValidConnectionTransition`，运动状态机 `requestMotionTransition` 按 proto.md 2.3 正向流程 `空闲->站立->RL控制` 校验；`canSwitchGait`/`canSendAxisCommand` 仅 RL 控制下放行；`MotionTransitionResult` 枚举反馈）。MainViewModel 经状态机校验后下发指令，轴指令循环非 RL 控制时发零速度
-- [x] 状态上报 UI 展示：StatusPanel.kt（异常列表+错误码映射 ErrorCodes.kt、运控状态 Roll/Pitch/Yaw/速度/高度、设备温度电机/驱动器最高温、电池左右电压/电量/温度），顶部状态栏 Info 按钮触发底部弹出面板；指令失败/状态机拒绝通过 Snackbar 反馈
+- [x] 状态上报 UI 展示：StatusPanel.kt（异常列表 + 错误码映射 ErrorCodes.kt、运控状态 Roll/Pitch/Yaw/速度/高度、设备温度电机/驱动器最高温、电池左右电压/电量/温度），顶部状态栏 Info 按钮触发底部弹出面板；指令失败/状态机拒绝通过 Snackbar 反馈
 - [x] 更多控制按钮：Mode（常规/导航/辅助）、步态（基础/楼梯/平地敏捷/楼梯敏捷）、照明（前/后灯开/关）、充电（开始/结束）、休眠（休眠/唤醒）。底部控制区可纵向滚动，点击"更多"展开全部控制选项
-- [x] RTSP 解码器策略实现：`VideoCodec` 枚举含 `AUTO`/`FORCE_HW`/`FORCE_SW_H264`/`FORCE_SW_H265`；`toMediaCodecSelector()` 映射到对应 `MediaCodecSelector`；`DefaultLoadControl` 最小缓冲（100ms起播，总缓冲<500ms，无回退缓存，时间优先于大小阈值）；`FORCE_HW` 模式对所有 MIME 仅保留硬件加速解码器
+- [x] RTSP 解码器策略实现：`VideoCodec` 枚举含 `AUTO`/`FORCE_HW`/`FORCE_SW_H264`/`FORCE_SW_H265`；`toMediaCodecSelector()` 映射到对应 `MediaCodecSelector`；`DefaultLoadControl` 最小缓冲（100ms 起播，总缓冲<500ms，无回退缓存，时间优先于大小阈值）；`FORCE_HW` 模式对所有 MIME 仅保留硬件加速解码器
 - [x] 摇杆尺寸增大：左右摇杆从 140dp 增大到 180dp，提升操控精度
 - [x] 视频缩放模式：`VideoResizeMode` 枚举（FIT/ZOOM/FILL），设置界面新增"视频缩放模式"下拉选项，持久化保存，实时生效
 - [x] 状态机修复：趴下状态下允许切换站立状态（机器人站立后自动进入 RL 控制，无需 App 下发）
 - [x] UI 布局：增加 bg1.png 作为底图，无视频流时显示（视频流播放时覆盖底图）
 - [x] UI 布局：开关灯合并为前灯/后灯两个按键，通过颜色（琥珀色=开/暗色=关）表示置位状态，配合机器人回报状态同步
+- [x] 状态栏：ICMP 延迟测量 + WiFi 信号强度图标显示，放置于连接状态文字右侧，延迟独立于连接生命周期
+- [x] UI 布局：StatusBar 背景延伸到屏幕顶端，视觉吸附优化（Box + Row 双层结构，背景填满状态栏区域）
+- [x] UI 布局：连接按钮合并到顶部 StatusBar 的 ConnectionIndicator，删除底部独立连接按钮
+- [x] UI 布局：ConnectionIndicator 改为按钮形态（Surface + 圆角边框），仅指示器区域可点击切换连接
+- [x] UI 布局：隐藏系统状态栏（WindowInsetsControllerCompat），压缩自定义 StatusBar 高度，扩展可视区域
+- [x] UI 布局：功能按钮均布在四周——左上角模式选择 + 步态切换 + 起立/趴下，右上角灯光 + 休眠 + 充电，充分利用屏幕空间，优化单手操作体验
+- [x] UI 布局：起立/趴下合并为切换按钮（琥珀色=站立时显示"趴下"，暗色=非站立时显示"起立"），移至左上角 StatusBar 下方
+- [x] UI 布局：模式选择器（常规/导航/辅助，3 个互斥按钮，无缝隙，底色显示当前模式）移至左上角，位于起立/趴上方
+- [x] UI 布局：步态切换（基础/楼梯/平地敏捷/楼梯敏捷，4 个互斥按钮，无缝隙）移至模式选择器下方，始终显示，仅普通模式+RL 控制时可点击
+- [x] UI 布局：照明/休眠/充电移至右上角，紧凑排列（前灯后灯无缝隙一行，休眠/唤醒切换，充电/充电中切换）
+- [x] UI 布局：底部控制区移除"更多"展开区域，仅保留左右摇杆
+- [x] UI 布局：所有功能按钮统一使用平行四边形形状（左侧按钮斜边左下→右上，右侧按钮斜边左上→右下）
+- [x] UI 布局：所有控制按钮在未连接时灰色不可点击
+- [x] 连接状态准确性修复：`ProtocolClient` 收到首个有效数据包后才标记 `CONNECTED`，不再 socket 创建后立即标记；`CONNECTING` 状态 5 秒无响应自动超时回退 `TIMEOUT`
+- [x] 连接按钮交互优化：`CONNECTING` 状态下点击连接按钮仅断开回到 `DISCONNECTED`，不再自动重连，由用户手动再次点击发起重试
+- [x] 状态机补充：`RobotConnection` 允许 `CONNECTING → TIMEOUT` 合法转换
+- [x] 心跳启动时机修复：`ProtocolClient.connect()` 立即启动心跳线程，不再等待首次收到数据包后才启动；心跳在 `CONNECTING` 和 `CONNECTED` 状态下均正常运行
+- [x] 软急停滑块：右上角新增平行四边形水平滑块，滑到右侧触发软急停（`MOTION_DAMPING`），跟随机器人状态上报自动归位
+- [x] 状态上报闪烁修复：`_latestStatus` 改用合并策略（`prev.copy`），保留上次报告的非 null 字段，避免 4 个独立订阅交替覆盖导致状态栏/步态按钮闪烁
+- [x] 电量显示稳定性优化：`StatusBar` 电量改用独立 `batteryStatus` StateFlow，不依赖 `status?.batteryStatus`
+- [x] 休眠按钮状态约束：仅非站立状态（空闲/趴下/阻尼等）可切换休眠，站立/RL 控制时禁用
+- [x] RTSP 自动重连：`RtspVideoPlayer` 播放失败后自动重试，指数退避（初始 1s，最大 30s，倍率 2），URL/解码器变化时重置退避状态；覆盖层显示重试次数和倒计时
+- [x] 订阅请求清理：删除 `ProtocolClient.sendSubscriptionRequests()` 方法及 `connect()` 中的注释调用；同步删除 `ControlCommands.subscribeStatus()` 和 `SUB_*` 常量，彻底清除死代码
 
 ### 待办
 
-- [ ] UI 布局：header 部分虽已避开状态栏，但底色与屏幕顶端视觉不吸附，需优化视觉传达效果
-- [ ] UI 布局：功能按钮均布在四周，充分利用屏幕空间，优化单手操作体验
-- [ ] 状态栏：增加 ICMP 延迟测量显示，显示当前 WiFi 强度和延迟 ms
-- [ ] 视频进一步延迟优化：探索更激进的低延迟策略（如降低帧率、缩小分辨率、调整 ExoPlayer 缓冲策略等）
+- [ ] 视频进一步延迟优化：探索更激进的低延迟策略（跳过 Media3 ExoPlayer，直接使用 MediaCodec + SurfaceView）

app/src/main/AndroidManifest.xml

@@ -4,6 +4,7 @@
 
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
 
     <application
         android:name=".M20App"

app/src/main/java/com/example/m20_gamepad/MainActivity.kt

@@ -6,6 +6,8 @@ import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.platform.LocalContext
+import androidx.core.view.WindowInsetsCompat
+import androidx.core.view.WindowInsetsControllerCompat
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
@@ -18,6 +20,11 @@ class MainActivity : ComponentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
+        // 隐藏系统状态栏，顶部区域完全由自定义 StatusBar 接管
+        WindowInsetsControllerCompat(window, window.decorView).apply {
+            hide(WindowInsetsCompat.Type.statusBars())
+            systemBarsBehavior = WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
+        }
         setContent {
             M20_gamepadTheme {
                 AppNavGraph()

app/src/main/java/com/example/m20_gamepad/network/ProtocolClient.kt

@@ -89,9 +89,11 @@ class ProtocolClient(
     /**
      * 建立连接：
      * 1. 创建 UDP socket
-     * 2. 启动接收协程
+     * 2. 启动接收/发送协程
      * 3. 发送订阅请求
-     * 4. 启动心跳和断线检测
+     * 4. 启动断线检测（CONNECTING 5s / CONNECTED 3s 无数据 → TIMEOUT）
+     * 5. 启动心跳 1Hz（立即发送，覆盖 CONNECTING 和 CONNECTED 状态）
+     * 6. 首次收到有效数据包后标记已连接
      */
     fun connect() {
         if (_state.value != State.DISCONNECTED && _state.value != State.ERROR) return
@@ -131,17 +133,15 @@ class ProtocolClient(
             // 发送订阅请求（触发服务端 UDP 推送）
             sendSubscriptionRequests()
 
-            _state.value = State.CONNECTED
-
-            // 启动心跳
-            heartbeatJob = scope.launch(Dispatchers.IO) {
-                heartbeatLoop(sock, address)
-            }
-
-            // 启动断线检测
+            // 启动断线检测（立即开始，覆盖 CONNECTING 和 CONNECTED 状态）
             timeoutJob = scope.launch {
                 timeoutCheckLoop()
             }
+
+            // 启动心跳（立即开始，覆盖 CONNECTING 和 CONNECTED 状态）
+            heartbeatJob = scope.launch(Dispatchers.IO) {
+                heartbeatLoop(sock, address)
+            }
         } catch (e: Exception) {
             _state.value = State.ERROR
             closeSocket()
@@ -232,6 +232,11 @@ class ProtocolClient(
                 if (report != null) {
                     _statusReport.tryEmit(report)
                 }
+
+                // 首次收到有效数据包：标记已连接
+                if (_state.value == State.CONNECTING) {
+                    _state.value = State.CONNECTED
+                }
             } catch (_: SocketTimeoutException) {
                 // 超时正常，继续循环
                 continue
@@ -244,9 +249,11 @@ class ProtocolClient(
         }
     }
 
-    /** 心跳循环（1 Hz） */
+    /** 心跳循环（1 Hz）—— 在 CONNECTING 和 CONNECTED 状态下运行 */
     private suspend fun CoroutineScope.heartbeatLoop(sock: DatagramSocket, address: InetAddress) {
-        while (isActive && _state.value == State.CONNECTED) {
+        while (isActive &&
+            (_state.value == State.CONNECTING || _state.value == State.CONNECTED)
+        ) {
             try {
                 val json = ControlCommands.heartbeat()
                 val packet = encoder.encode(json)
@@ -258,12 +265,22 @@ class ProtocolClient(
         }
     }
 
-    /** 断线检测：3 秒无数据 → 标记 TIMEOUT */
+    /** 断线检测：CONNECTED 状态 3 秒无数据 → TIMEOUT；CONNECTING 状态 5 秒无数据 → TIMEOUT */
     private suspend fun CoroutineScope.timeoutCheckLoop() {
         while (isActive && _state.value != State.DISCONNECTED) {
             val elapsed = System.currentTimeMillis() - lastPacketTimeMs
-            if (elapsed > 3000 && _state.value == State.CONNECTED) {
-                _state.value = State.TIMEOUT
+            when (_state.value) {
+                State.CONNECTED -> {
+                    if (elapsed > 3000) {
+                        _state.value = State.TIMEOUT
+                    }
+                }
+                State.CONNECTING -> {
+                    if (elapsed > 5000) {
+                        _state.value = State.TIMEOUT
+                    }
+                }
+                else -> { /* DISCONNECTED/TIMEOUT/ERROR: 无需超时处理 */ }
             }
             delay(500)
         }

app/src/main/java/com/example/m20_gamepad/network/models/ControlCommands.kt

@@ -107,6 +107,9 @@ object ControlCommands {
         put("Charge", JsonPrimitive(charge))
     }
 
+    // ---- 2.8b 软急停 ----
+    fun softEmergencyStop(time: String = now()): String = motionControl(MOTION_DAMPING, time)
+
     // ---- 2.9 休眠模式设置 ----
     fun sleepSettings(sleep: Boolean, auto: Boolean, timeMinutes: Int, time: String = now()): String = buildAsdu(
         type = 1101, command = 6, time = time

app/src/main/java/com/example/m20_gamepad/service/PingMonitor.kt

@@ -0,0 +1,68 @@
+package com.example.m20_gamepad.service
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import java.io.BufferedReader
+import java.io.InputStreamReader
+
+/**
+ * ICMP 延迟监测器。使用系统 ping 命令测量到目标主机的往返延迟。
+ *
+ * @param host 目标主机 IP
+ * @param intervalMs 测量间隔（毫秒）
+ * @param scope 协程作用域
+ */
+class PingMonitor(
+    private val host: String,
+    private val intervalMs: Long = 3000L,
+    private val scope: CoroutineScope
+) {
+    private val _latencyMs = MutableStateFlow<Long?>(null)
+    val latencyMs: StateFlow<Long?> = _latencyMs.asStateFlow()
+
+    private var job: Job? = null
+
+    fun start() {
+        stop()
+        job = scope.launch {
+            while (isActive) {
+                _latencyMs.value = ping()
+                delay(intervalMs)
+            }
+        }
+    }
+
+    fun stop() {
+        job?.cancel()
+        job = null
+        _latencyMs.value = null
+    }
+
+    /**
+     * 执行一次 ICMP ping，返回延迟毫秒数；失败返回 null。
+     */
+    private fun ping(): Long? {
+        return try {
+            val process = ProcessBuilder(
+                "ping", "-c", "1", "-W", "2", host
+            ).redirectErrorStream(true).start()
+
+            val reader = BufferedReader(InputStreamReader(process.inputStream))
+            val output = reader.readText()
+            process.waitFor()
+
+            // 解析 "time=12.3 ms" 格式
+            val regex = Regex("time=(\\d+(?:\\.\\d+)?)\\s*ms")
+            val match = regex.find(output)
+            match?.groupValues?.get(1)?.toDouble()?.toLong()
+        } catch (_: Exception) {
+            null
+        }
+    }
+}

app/src/main/java/com/example/m20_gamepad/service/RobotConnection.kt

@@ -50,6 +50,7 @@ class RobotConnection {
             ProtocolClient.State.CONNECTING ->
                 to == ProtocolClient.State.CONNECTED ||
                 to == ProtocolClient.State.ERROR ||
+                to == ProtocolClient.State.TIMEOUT ||
                 to == ProtocolClient.State.DISCONNECTED
             ProtocolClient.State.CONNECTED ->
                 to == ProtocolClient.State.TIMEOUT ||

app/src/main/java/com/example/m20_gamepad/ui/MainScreen.kt

@@ -2,6 +2,8 @@ package com.example.m20_gamepad.ui
 
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
+import androidx.compose.foundation.BorderStroke
+import androidx.compose.foundation.gestures.detectHorizontalDragGestures
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -12,15 +14,13 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.navigationBars
+import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.statusBars
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.layout.windowInsetsPadding
-import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Info
 import androidx.compose.material.icons.filled.Settings
@@ -40,11 +40,21 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.Outline
+import androidx.compose.ui.graphics.Path
+import androidx.compose.ui.graphics.Shape
+import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.LayoutDirection
 import androidx.compose.ui.unit.sp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
@@ -52,6 +62,7 @@ import androidx.lifecycle.viewmodel.initializer
 import androidx.lifecycle.viewmodel.viewModelFactory
 import com.erz.joysticklibrary.Joystick
 import com.erz.joysticklibrary.JoystickType
+import com.example.m20_gamepad.M20App
 import com.example.m20_gamepad.R
 import com.example.m20_gamepad.data.SettingsRepository
 import com.example.m20_gamepad.network.ProtocolClient
@@ -64,6 +75,38 @@ import com.example.m20_gamepad.video.RtspVideoPlayer
 private val OverlayBg = Color(0x88000000)
 private val OverlayText = Color.White
 
+/** 平行四边形形状，用于功能按钮。skewLeft=true → 左下-右上斜边（左侧按钮）；
+ *  skewLeft=false → 左上-右下斜边（右侧按钮）。 */
+private class ParallelogramShape(
+    private val skewDp: Dp = 10.dp,
+    private val skewLeft: Boolean = true
+) : Shape {
+    override fun createOutline(
+        size: Size,
+        layoutDirection: LayoutDirection,
+        density: Density
+    ): Outline {
+        val skewPx = with(density) { skewDp.toPx() }
+        val path = Path().apply {
+            if (skewLeft) {
+                // 左下 → 右上 斜边（平行四边形向右倾斜）
+                moveTo(skewPx, 0f)
+                lineTo(size.width, 0f)
+                lineTo(size.width - skewPx, size.height)
+                lineTo(0f, size.height)
+            } else {
+                // 左上 → 右下 斜边（平行四边形向左倾斜）
+                moveTo(0f, 0f)
+                lineTo(size.width - skewPx, 0f)
+                lineTo(size.width, size.height)
+                lineTo(skewPx, size.height)
+            }
+            close()
+        }
+        return Outline.Generic(path)
+    }
+}
+
 /**
  * 主界面：RTSP 视频背景 + 双摇杆覆盖层 + 状态栏 + 控制按钮。
  *
@@ -73,13 +116,14 @@ private val OverlayText = Color.White
 @Composable
 fun MainScreen(
     repository: SettingsRepository,
-    onSettingsClick: () -> Unit,
-    viewModel: MainViewModel = viewModel(
+    onSettingsClick: () -> Unit
+) {
+    val app = LocalContext.current.applicationContext as M20App
+    val viewModel: MainViewModel = viewModel(
         factory = viewModelFactory {
-            initializer { MainViewModel(repository) }
+            initializer { MainViewModel(repository, app) }
         }
     )
-) {
     val connectionState by viewModel.connectionState.collectAsStateWithLifecycle()
     val status by viewModel.latestStatus.collectAsStateWithLifecycle()
     val settings by viewModel.settings.collectAsStateWithLifecycle()
@@ -91,6 +135,8 @@ fun MainScreen(
     val ledStatus by viewModel.ledStatus.collectAsStateWithLifecycle()
     val lastUpdate by viewModel.lastUpdate.collectAsStateWithLifecycle()
     val actionFeedback by viewModel.actionFeedback.collectAsStateWithLifecycle()
+    val pingLatencyMs by viewModel.pingLatencyMs.collectAsStateWithLifecycle()
+    val wifiSignalLevel by viewModel.wifiSignalLevel.collectAsStateWithLifecycle()
 
     var statusPanelVisible by remember { mutableStateOf(false) }
     val snackbarHostState = remember { SnackbarHostState() }
@@ -125,19 +171,114 @@ fun MainScreen(
         StatusBar(
             connectionState = connectionState,
             status = status,
+            batteryStatus = batteryStatus,
+            pingLatencyMs = pingLatencyMs,
+            wifiSignalLevel = wifiSignalLevel,
             onStatusClick = { statusPanelVisible = true },
             onSettingsClick = onSettingsClick,
-            modifier = Modifier
-                .align(Alignment.TopCenter)
-                .windowInsetsPadding(WindowInsets.statusBars)
+            onConnectToggle = {
+                if (connectionState == ProtocolClient.State.CONNECTED ||
+                    connectionState == ProtocolClient.State.CONNECTING
+                ) {
+                    viewModel.disconnect()
+                } else {
+                    viewModel.connect()
+                }
+            },
+            modifier = Modifier.align(Alignment.TopCenter)
         )
 
+        // ---- 左上角控制区：模式选择 + 步态切换 + 起立/趴下 ----
+        Column(
+            modifier = Modifier
+                .align(Alignment.TopStart)
+                .padding(top = 56.dp, start = 12.dp),
+            verticalArrangement = Arrangement.spacedBy(6.dp)
+        ) {
+            ModeSelector(
+                currentMode = status?.basicStatus?.controlUsageMode ?: 0,
+                connected = connectionState == ProtocolClient.State.CONNECTED,
+                onSelectMode = { mode -> viewModel.sendSwitchMode(mode) }
+            )
+            // 步态切换——始终显示，仅普通模式 + RL 控制时可点击
+            GaitSelector(
+                currentGait = status?.basicStatus?.gait ?: 0,
+                enabled = connectionState == ProtocolClient.State.CONNECTED &&
+                        motionState == ControlCommands.MOTION_RL_CONTROL &&
+                        status?.basicStatus?.controlUsageMode == ControlCommands.MODE_NORMAL,
+                onSelectGait = { gait -> viewModel.sendSwitchGait(gait) }
+            )
+            StandToggleButton(
+                motionState = motionState,
+                connected = connectionState == ProtocolClient.State.CONNECTED,
+                onToggle = {
+                    if (motionState == ControlCommands.MOTION_IDLE ||
+                        motionState == ControlCommands.MOTION_LIE_DOWN
+                    ) {
+                        viewModel.sendMotionControl(ControlCommands.MOTION_STAND)
+                    } else {
+                        viewModel.sendMotionControl(ControlCommands.MOTION_LIE_DOWN)
+                    }
+                }
+            )
+        }
+
+        // ---- 右上角控制区：软急停滑块 + 照明 + 休眠 + 充电 ----
+        Column(
+            modifier = Modifier
+                .align(Alignment.TopEnd)
+                .padding(top = 56.dp, end = 12.dp),
+            horizontalAlignment = Alignment.End,
+            verticalArrangement = Arrangement.spacedBy(6.dp)
+        ) {
+            // 软急停滑块
+            EmergencyStopSlider(
+                isEmergencyStop = motionState == ControlCommands.MOTION_DAMPING,
+                connected = connectionState == ProtocolClient.State.CONNECTED,
+                onEmergencyStop = { viewModel.sendEmergencyStop() }
+            )
+            // 照明：前灯+后灯，无缝隙
+            val frontOn = ledStatus?.front == 1
+            val backOn = ledStatus?.back == 1
+            Row(horizontalArrangement = Arrangement.spacedBy(0.dp)) {
+                LightToggleButton(
+                    text = "前灯",
+                    isOn = frontOn,
+                    enabled = connectionState == ProtocolClient.State.CONNECTED
+                ) {
+                    viewModel.sendLightControl(if (frontOn) 0 else 1, ledStatus?.back ?: 0)
+                }
+                LightToggleButton(
+                    text = "后灯",
+                    isOn = backOn,
+                    enabled = connectionState == ProtocolClient.State.CONNECTED
+                ) {
+                    viewModel.sendLightControl(ledStatus?.front ?: 0, if (backOn) 0 else 1)
+                }
+            }
+            // 休眠/唤醒 — 仅趴下/空闲等非站立状态可切换
+            val isSleeping = status?.basicStatus?.sleep == 1
+            val canSleep = motionState != ControlCommands.MOTION_STAND &&
+                    motionState != ControlCommands.MOTION_RL_CONTROL
+            SleepToggleButton(
+                isSleeping = isSleeping,
+                connected = connectionState == ProtocolClient.State.CONNECTED && canSleep,
+                onToggle = { viewModel.sendSleepSettings(!isSleeping) }
+            )
+            // 充电/结束充电
+            val isCharging = status?.basicStatus?.charge == 1
+            ChargeToggleButton(
+                isCharging = isCharging,
+                connected = connectionState == ProtocolClient.State.CONNECTED,
+                onToggle = { viewModel.sendChargeControl(if (isCharging) 0 else 1) }
+            )
+        }
+
         // ---- 底部控制区 ----
         BottomControls(
             viewModel = viewModel,
             connectionState = connectionState,
             motionState = motionState,
-            ledStatus = ledStatus,
             modifier = Modifier
                 .align(Alignment.BottomCenter)
                 .windowInsetsPadding(WindowInsets.navigationBars)
@@ -169,27 +310,41 @@ fun MainScreen(
 private fun StatusBar(
     connectionState: ProtocolClient.State,
     status: com.example.m20_gamepad.network.models.StatusReport?,
+    batteryStatus: com.example.m20_gamepad.network.models.BatteryStatus?,
+    pingLatencyMs: Long?,
+    wifiSignalLevel: Int,
     onStatusClick: () -> Unit,
     onSettingsClick: () -> Unit,
+    onConnectToggle: () -> Unit,
     modifier: Modifier = Modifier
 ) {
-    Row(
+    Box(
         modifier = modifier
             .fillMaxWidth()
             .background(OverlayBg)
-            .padding(horizontal = 12.dp, vertical = 8.dp),
-        verticalAlignment = Alignment.CenterVertically,
-        horizontalArrangement = Arrangement.SpaceBetween
     ) {
-        // 连接状态指示
-        ConnectionIndicator(connectionState)
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 12.dp, vertical = 4.dp),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.SpaceBetween
+        ) {
+        // 连接状态 + WiFi 信号 + Ping 延迟
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            ConnectionIndicator(connectionState, onConnectToggle)
+            Spacer(Modifier.width(12.dp))
+            WifiSignalIcon(level = wifiSignalLevel)
+            Spacer(Modifier.width(12.dp))
+            PingIndicator(pingLatencyMs)
+        }
 
         // 电量 / 运动状态
         Row(
             verticalAlignment = Alignment.CenterVertically,
             horizontalArrangement = Arrangement.spacedBy(16.dp)
         ) {
-            status?.batteryStatus?.let {
+            batteryStatus?.let {
                 val avgLevel = (it.batteryLevelLeft + it.batteryLevelRight) / 2
                 StatusChip("电量 ${avgLevel.toInt()}%")
             }
@@ -216,10 +371,11 @@ private fun StatusBar(
             }
         }
     }
+    }
 }
 
 @Composable
-private fun ConnectionIndicator(state: ProtocolClient.State) {
+private fun ConnectionIndicator(state: ProtocolClient.State, onClick: () -> Unit) {
     val (color, text) = when (state) {
         ProtocolClient.State.CONNECTED -> Color(0xFF4CAF50) to "已连接"
         ProtocolClient.State.CONNECTING -> Color(0xFFFFC107) to "连接中"
@@ -227,14 +383,64 @@ private fun ConnectionIndicator(state: ProtocolClient.State) {
         ProtocolClient.State.ERROR -> Color(0xFFF44336) to "错误"
         ProtocolClient.State.DISCONNECTED -> Color(0xFF9E9E9E) to "未连接"
     }
-    Row(verticalAlignment = Alignment.CenterVertically) {
-        Box(
-            modifier = Modifier
-                .size(10.dp)
-                .background(color, CircleShape)
-        )
-        Spacer(Modifier.width(6.dp))
-        Text(text, color = OverlayText, fontSize = 14.sp)
+    Surface(
+        onClick = onClick,
+        shape = RoundedCornerShape(14.dp),
+        border = BorderStroke(1.dp, Color(0x55FFFFFF)),
+        color = Color(0x22000000)
+    ) {
+        Row(
+            modifier = Modifier.padding(horizontal = 10.dp, vertical = 2.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Box(
+                modifier = Modifier
+                    .size(10.dp)
+                    .background(color, CircleShape)
+            )
+            Spacer(Modifier.width(6.dp))
+            Text(text, color = OverlayText, fontSize = 14.sp)
+        }
+    }
+}
+
+/** WiFi 信号强度图标（0-5 格信号柱），白色填充、灰色未填充。 */
+@Composable
+private fun WifiSignalIcon(level: Int) {
+    val activeColor = OverlayText
+    val inactiveColor = Color(0x66FFFFFF)
+    val clamped = level.coerceIn(0, 5)
+
+    Row(
+        verticalAlignment = Alignment.Bottom,
+        horizontalArrangement = Arrangement.spacedBy(2.dp)
+    ) {
+        // 5 根信号柱，从低到高
+        val barHeights = intArrayOf(6, 10, 14, 18, 22)
+        for (i in 0 until 5) {
+            val isActive = i < clamped
+            Box(
+                modifier = Modifier
+                    .width(4.dp)
+                    .height(barHeights[i].dp)
+                    .background(if (isActive) activeColor else inactiveColor, RoundedCornerShape(1.dp))
+            )
+        }
+    }
+}
+
+@Composable
+private fun PingIndicator(latencyMs: Long?) {
+    if (latencyMs == null) {
+        Text("- -", color = Color(0xFF9E9E9E), fontSize = 13.sp)
+    } else {
+        val color = when {
+            latencyMs < 50 -> Color(0xFF4CAF50)  // 绿色 — 良好
+            latencyMs < 150 -> Color(0xFFFFC107) // 黄色 — 一般
+            latencyMs < 300 -> Color(0xFFFF9800) // 橙色 — 较差
+            else -> Color(0xFFF44336)            // 红色 — 很差
+        }
+        Text("${latencyMs}ms", color = color, fontSize = 13.sp)
     }
 }
 
@@ -260,7 +466,6 @@ private fun BottomControls(
     viewModel: MainViewModel,
     connectionState: ProtocolClient.State,
     motionState: Int,
-    ledStatus: LedStatus?,
     modifier: Modifier = Modifier
 ) {
     Row(
@@ -281,14 +486,6 @@ private fun BottomControls(
             }
         )
 
-        // 中间控制按钮组
-        ControlButtons(
-            viewModel = viewModel,
-            connectionState = connectionState,
-            motionState = motionState,
-            ledStatus = ledStatus
-        )
-
         // 右摇杆（Yaw 旋转）
         Joystick(
             modifier = Modifier.size(180.dp),
@@ -302,183 +499,6 @@ private fun BottomControls(
     }
 }
 
-@Composable
-private fun ControlButtons(
-    viewModel: MainViewModel,
-    connectionState: ProtocolClient.State,
-    motionState: Int,
-    ledStatus: LedStatus?
-) {
-    val connected = connectionState == ProtocolClient.State.CONNECTED
-    val isRlControl = motionState == ControlCommands.MOTION_RL_CONTROL
-    var showMore by remember { mutableStateOf(false) }
-    val scrollState = rememberScrollState()
-
-    Column(
-        horizontalAlignment = Alignment.CenterHorizontally,
-        verticalArrangement = Arrangement.spacedBy(6.dp),
-        modifier = Modifier
-            .verticalScroll(scrollState)
-            .padding(top = 4.dp, bottom = 4.dp)
-    ) {
-        // 连接/断开
-        Button(
-            onClick = {
-                if (connected) viewModel.disconnect() else viewModel.connect()
-            },
-            colors = ButtonDefaults.buttonColors(
-                containerColor = if (connected) Color(0xFFF44336) else Color(0xFF4CAF50)
-            ),
-            modifier = Modifier.width(110.dp)
-        ) {
-            Text(if (connected) "断开" else "连接")
-        }
-
-        // 运动状态转换
-        ControlButton(
-            "起立",
-            enabled = connected && (motionState == ControlCommands.MOTION_IDLE ||
-                    motionState == ControlCommands.MOTION_LIE_DOWN)
-        ) {
-            viewModel.sendMotionControl(ControlCommands.MOTION_STAND)
-        }
-        ControlButton(
-            "RL控制",
-            enabled = connected && motionState == ControlCommands.MOTION_STAND
-        ) {
-            viewModel.sendMotionControl(ControlCommands.MOTION_RL_CONTROL)
-        }
-        ControlButton(
-            "趴下",
-            enabled = connected && motionState != ControlCommands.MOTION_LIE_DOWN
-        ) {
-            viewModel.sendMotionControl(ControlCommands.MOTION_LIE_DOWN)
-        }
-
-        // 步态切换——仅 RL 控制
-        if (isRlControl) {
-            Row(horizontalArrangement = Arrangement.spacedBy(4.dp)) {
-                MiniButton("基础", enabled = isRlControl) {
-                    viewModel.sendSwitchGait(ControlCommands.GAIT_BASIC)
-                }
-                MiniButton("楼梯", enabled = isRlControl) {
-                    viewModel.sendSwitchGait(ControlCommands.GAIT_STAIRS)
-                }
-                MiniButton("平地敏捷", enabled = isRlControl) {
-                    viewModel.sendSwitchGait(ControlCommands.GAIT_FLAT_AGILE)
-                }
-            }
-            MiniButton("楼梯敏捷", enabled = isRlControl) {
-                viewModel.sendSwitchGait(ControlCommands.GAIT_STAIRS_AGILE)
-            }
-        }
-
-        // 更多/收起切换
-        if (connected) {
-            ControlButton(if (showMore) "收起" else "更多", enabled = connected) {
-                showMore = !showMore
-            }
-        }
-
-        // ---- 更多控制（可展开） ----
-        if (showMore) {
-            Separator()
-
-            // 使用模式
-            SectionLabel("使用模式")
-            Row(horizontalArrangement = Arrangement.spacedBy(4.dp)) {
-                MiniButton("常规") {
-                    viewModel.sendSwitchMode(ControlCommands.MODE_NORMAL)
-                }
-                MiniButton("导航") {
-                    viewModel.sendSwitchMode(ControlCommands.MODE_NAVIGATION)
-                }
-                MiniButton("辅助") {
-                    viewModel.sendSwitchMode(ControlCommands.MODE_ASSIST)
-                }
-            }
-            Spacer(Modifier.height(4.dp))
-
-            // 照明
-            SectionLabel("照明")
-            val frontOn = ledStatus?.front == 1
-            val backOn = ledStatus?.back == 1
-            Row(horizontalArrangement = Arrangement.spacedBy(4.dp)) {
-                LightToggleButton(
-                    text = "前灯",
-                    isOn = frontOn,
-                    enabled = connected
-                ) {
-                    viewModel.sendLightControl(if (frontOn) 0 else 1, ledStatus?.back ?: 0)
-                }
-                LightToggleButton(
-                    text = "后灯",
-                    isOn = backOn,
-                    enabled = connected
-                ) {
-                    viewModel.sendLightControl(ledStatus?.front ?: 0, if (backOn) 0 else 1)
-                }
-            }
-            Spacer(Modifier.height(4.dp))
-
-            // 充电
-            SectionLabel("充电")
-            Row(horizontalArrangement = Arrangement.spacedBy(4.dp)) {
-                MiniButton("开始充电") { viewModel.sendChargeControl(1) }
-                MiniButton("结束充电") { viewModel.sendChargeControl(0) }
-            }
-            Spacer(Modifier.height(4.dp))
-
-            // 休眠
-            SectionLabel("休眠")
-            Row(horizontalArrangement = Arrangement.spacedBy(4.dp)) {
-                MiniButton("进入休眠") { viewModel.sendSleepSettings(true) }
-                MiniButton("唤醒") { viewModel.sendSleepSettings(false) }
-            }
-        }
-    }
-}
-
-@Composable
-private fun ControlButton(
-    text: String,
-    enabled: Boolean = true,
-    onClick: () -> Unit
-) {
-    Button(
-        onClick = onClick,
-        enabled = enabled,
-        colors = ButtonDefaults.buttonColors(
-            containerColor = Color(0x66333333),
-            disabledContainerColor = Color(0x33222222)
-        ),
-        modifier = Modifier.width(110.dp)
-    ) {
-        Text(text, color = if (enabled) OverlayText else Color(0x88FFFFFF), fontWeight = FontWeight.Medium)
-    }
-}
-
-@Composable
-private fun MiniButton(text: String, enabled: Boolean = true, onClick: () -> Unit) {
-    Button(
-        onClick = onClick,
-        enabled = enabled,
-        colors = ButtonDefaults.buttonColors(
-            containerColor = Color(0x66333333),
-            disabledContainerColor = Color(0x33222222)
-        ),
-        contentPadding = ButtonDefaults.TextButtonContentPadding,
-        modifier = Modifier.height(32.dp)
-    ) {
-        Text(
-            text,
-            color = if (enabled) OverlayText else Color(0x88FFFFFF),
-            fontSize = 12.sp,
-            fontWeight = FontWeight.Normal
-        )
-    }
-}
-
 @Composable
 private fun LightToggleButton(
     text: String,
@@ -489,40 +509,309 @@ private fun LightToggleButton(
     Button(
         onClick = onClick,
         enabled = enabled,
+        shape = ParallelogramShape(skewLeft = false),
         colors = ButtonDefaults.buttonColors(
             containerColor = if (isOn) Color(0xCCFFC107) else Color(0x66333333),
             disabledContainerColor = Color(0x33222222)
         ),
-        modifier = Modifier.width(110.dp)
+        contentPadding = ButtonDefaults.TextButtonContentPadding,
+        modifier = Modifier.height(32.dp)
     ) {
         Text(
             "$text ${if (isOn) "开" else "关"}",
             color = if (enabled) OverlayText else Color(0x88FFFFFF),
+            fontSize = 12.sp,
             fontWeight = FontWeight.Medium
         )
     }
 }
 
 @Composable
-private fun SectionLabel(text: String) {
-    Text(
-        text,
-        color = Color(0xFFB0B0B0),
-        fontSize = 11.sp,
-        modifier = Modifier.fillMaxWidth()
-    )
+private fun StandToggleButton(
+    motionState: Int,
+    connected: Boolean,
+    onToggle: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val isStanding = motionState == ControlCommands.MOTION_STAND ||
+            motionState == ControlCommands.MOTION_RL_CONTROL
+    Button(
+        onClick = onToggle,
+        enabled = connected,
+        shape = ParallelogramShape(skewLeft = true),
+        colors = ButtonDefaults.buttonColors(
+            containerColor = if (isStanding) Color(0xCCFFC107) else Color(0x66333333),
+            disabledContainerColor = Color(0x33222222)
+        ),
+        contentPadding = ButtonDefaults.TextButtonContentPadding,
+        modifier = modifier.height(32.dp)
+    ) {
+        Text(
+            text = if (isStanding) "趴下" else "起立",
+            color = if (connected) OverlayText else Color(0x88FFFFFF),
+            fontSize = 12.sp,
+            fontWeight = FontWeight.Medium
+        )
+    }
+}
+
+// ==================== 模式选择器（3个互斥无缝隙） ====================
+
+@Composable
+private fun ModeSelector(
+    currentMode: Int,
+    connected: Boolean,
+    onSelectMode: (Int) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    Row(
+        modifier = modifier,
+        horizontalArrangement = Arrangement.spacedBy(4.dp)
+    ) {
+        ModeButton("常规", ControlCommands.MODE_NORMAL, currentMode, connected, onSelectMode)
+        ModeButton("导航", ControlCommands.MODE_NAVIGATION, currentMode, connected, onSelectMode)
+        ModeButton("辅助", ControlCommands.MODE_ASSIST, currentMode, connected, onSelectMode)
+    }
 }
 
 @Composable
-private fun Separator() {
-    Spacer(Modifier.height(2.dp))
+private fun ModeButton(
+    text: String,
+    mode: Int,
+    currentMode: Int,
+    connected: Boolean,
+    onClick: (Int) -> Unit
+) {
+    val isActive = currentMode == mode
+    Button(
+        onClick = { onClick(mode) },
+        enabled = connected,
+        shape = ParallelogramShape(skewLeft = true),
+        colors = ButtonDefaults.buttonColors(
+            containerColor = if (isActive) Color(0xCCFFC107) else Color(0x66333333),
+            disabledContainerColor = Color(0x33222222)
+        ),
+        contentPadding = ButtonDefaults.TextButtonContentPadding,
+        modifier = Modifier.height(32.dp)
+    ) {
+        Text(
+            text,
+            color = if (connected) OverlayText else Color(0x88FFFFFF),
+            fontSize = 12.sp,
+            fontWeight = if (isActive) FontWeight.Bold else FontWeight.Normal
+        )
+    }
+}
+
+// ==================== 步态切换（4个互斥无缝隙，仅普通模式可用） ====================
+
+@Composable
+private fun GaitSelector(
+    currentGait: Int,
+    enabled: Boolean,
+    onSelectGait: (Int) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    Row(
+        modifier = modifier,
+        horizontalArrangement = Arrangement.spacedBy(4.dp)
+    ) {
+        GaitButton("基础", ControlCommands.GAIT_BASIC, currentGait, enabled, onSelectGait)
+        GaitButton("楼梯", ControlCommands.GAIT_STAIRS, currentGait, enabled, onSelectGait)
+        GaitButton("平地敏捷", ControlCommands.GAIT_FLAT_AGILE, currentGait, enabled, onSelectGait)
+        GaitButton("楼梯敏捷", ControlCommands.GAIT_STAIRS_AGILE, currentGait, enabled, onSelectGait)
+    }
+}
+
+@Composable
+private fun GaitButton(
+    text: String,
+    gait: Int,
+    currentGait: Int,
+    enabled: Boolean,
+    onClick: (Int) -> Unit
+) {
+    val isActive = currentGait == gait
+    Button(
+        onClick = { onClick(gait) },
+        enabled = enabled,
+        shape = ParallelogramShape(skewLeft = true),
+        colors = ButtonDefaults.buttonColors(
+            containerColor = if (isActive) Color(0xCCFFC107) else Color(0x66333333),
+            disabledContainerColor = Color(0x33222222)
+        ),
+        contentPadding = ButtonDefaults.TextButtonContentPadding,
+        modifier = Modifier.height(32.dp)
+    ) {
+        Text(
+            text,
+            color = if (enabled) OverlayText else Color(0x88FFFFFF),
+            fontSize = 12.sp,
+            fontWeight = if (isActive) FontWeight.Bold else FontWeight.Normal
+        )
+    }
+}
+
+// ==================== 休眠/唤醒切换 ====================
+
+@Composable
+private fun SleepToggleButton(
+    isSleeping: Boolean,
+    connected: Boolean,
+    onToggle: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    Button(
+        onClick = onToggle,
+        enabled = connected,
+        shape = ParallelogramShape(skewLeft = false),
+        colors = ButtonDefaults.buttonColors(
+            containerColor = if (isSleeping) Color(0xCCFFC107) else Color(0x66333333),
+            disabledContainerColor = Color(0x33222222)
+        ),
+        contentPadding = ButtonDefaults.TextButtonContentPadding,
+        modifier = modifier.height(32.dp)
+    ) {
+        Text(
+            text = if (isSleeping) "唤醒" else "休眠",
+            color = if (connected) OverlayText else Color(0x88FFFFFF),
+            fontSize = 12.sp,
+            fontWeight = FontWeight.Medium
+        )
+    }
+}
+
+// ==================== 充电/结束充电切换 ====================
+
+@Composable
+private fun ChargeToggleButton(
+    isCharging: Boolean,
+    connected: Boolean,
+    onToggle: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    Button(
+        onClick = onToggle,
+        enabled = connected,
+        shape = ParallelogramShape(skewLeft = false),
+        colors = ButtonDefaults.buttonColors(
+            containerColor = if (isCharging) Color(0xCCFFC107) else Color(0x66333333),
+            disabledContainerColor = Color(0x33222222)
+        ),
+        contentPadding = ButtonDefaults.TextButtonContentPadding,
+        modifier = modifier.height(32.dp)
+    ) {
+        Text(
+            text = if (isCharging) "充电中" else "充电",
+            color = if (connected) OverlayText else Color(0x88FFFFFF),
+            fontSize = 12.sp,
+            fontWeight = FontWeight.Medium
+        )
+    }
+}
+
+// ==================== 软急停滑块 ====================
+
+/**
+ * 水平滑块，平行四边形风格。用于触发软急停。
+ *
+ * 滑到右侧 → 发送软急停指令；滑到左侧 → 仅 UI 复位，不发指令。
+ * 机器人收到软急停后 3 秒自动切回空闲，状态上报会驱动滑块自动归位。
+ *
+ * @param isEmergencyStop 当前是否处于软急停状态（motionState == MOTION_DAMPING）
+ * @param connected 是否已连接（未连接时禁用交互）
+ * @param onEmergencyStop 滑块滑到右侧触发
+ */
+@Composable
+private fun EmergencyStopSlider(
+    isEmergencyStop: Boolean,
+    connected: Boolean,
+    onEmergencyStop: () -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val sliderWidth = 150.dp
+    val sliderHeight = 32.dp
+    val thumbSize = 28.dp
+
+    // 0f = 左侧（正常），1f = 右侧（急停触发）
+    var fraction by remember { mutableStateOf(if (isEmergencyStop) 1f else 0f) }
+    var isDragging by remember { mutableStateOf(false) }
+
+    // 非拖动时跟随外部状态回调
+    LaunchedEffect(isEmergencyStop) {
+        if (!isDragging) {
+            fraction = if (isEmergencyStop) 1f else 0f
+        }
+    }
+
+    // 拖动结束后吸附：滑到右侧触发急停，滑到左侧仅复位 UI
+    fun snapAndFire() {
+        isDragging = false
+        if (fraction > 0.5f) {
+            fraction = 1f
+            onEmergencyStop()
+        } else {
+            fraction = 0f
+            // 不发送复位指令，等机器人状态上报自动同步
+        }
+    }
+
+    // 滑轨：遵循其他按钮的 containerColor 逻辑
+    val trackColor = if (connected) Color(0x66333333) else Color(0x33222222)
+    // 拇指：75% 红色
+    val thumbColor = Color(0xBFFF4444)
+    val skew = 3.dp
+
     Box(
-        modifier = Modifier
-            .width(80.dp)
-            .height(1.dp)
-            .background(Color(0x44FFFFFF))
-    )
-    Spacer(Modifier.height(2.dp))
+        modifier = modifier
+            .width(sliderWidth)
+            .height(sliderHeight)
+    ) {
+        // 滑轨 — 平行四边形外框
+        Surface(
+            modifier = Modifier
+                .fillMaxSize(),
+            shape = ParallelogramShape(skewDp = skew, skewLeft = false),
+            color = trackColor
+        ) {}
+
+        // 文字显示在滑轨上
+        Text(
+            text = "急停",
+            modifier = Modifier.align(Alignment.Center),
+            color = Color(0xAAFFFFFF),
+            fontSize = 12.sp,
+            fontWeight = FontWeight.Medium
+        )
+
+        // 滑块拇指
+        val maxOffsetDp = sliderWidth - thumbSize
+        val density = LocalDensity.current
+        val maxOffsetPx = with(density) { maxOffsetDp.toPx() }
+        val thumbOffset = maxOffsetDp * fraction
+        // fraction=0 → offset=0 (左侧)
+        // fraction=1 → offset=maxOffsetDp (右侧)
+
+        Surface(
+            modifier = Modifier
+                .size(thumbSize, sliderHeight)
+                .offset(x = thumbOffset)
+                .pointerInput(connected) {
+                    if (!connected) return@pointerInput
+                    detectHorizontalDragGestures(
+                        onDragStart = { isDragging = true },
+                        onDragEnd = { snapAndFire() },
+                        onDragCancel = { snapAndFire() },
+                        onHorizontalDrag = { change, dragAmount ->
+                            change.consume()
+                            fraction = (fraction + dragAmount / maxOffsetPx).coerceIn(0f, 1f)
+                        }
+                    )
+                },
+            shape = ParallelogramShape(skewDp = skew, skewLeft = false),
+            color = thumbColor
+        ) {}
+    }
 }
 
 // ==================== 辅助函数 ====================

app/src/main/java/com/example/m20_gamepad/ui/MainViewModel.kt

@@ -1,5 +1,8 @@
 package com.example.m20_gamepad.ui
 
+import android.app.Application
+import android.content.Context
+import android.net.wifi.WifiManager
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.example.m20_gamepad.data.AppSettings
@@ -14,6 +17,7 @@ import com.example.m20_gamepad.network.models.MotionStatus
 import com.example.m20_gamepad.network.models.StatusReport
 import com.example.m20_gamepad.service.JoystickController
 import com.example.m20_gamepad.service.MotionTransitionResult
+import com.example.m20_gamepad.service.PingMonitor
 import com.example.m20_gamepad.service.RobotConnection
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
@@ -40,7 +44,8 @@ import kotlinx.coroutines.launch
  * @param repository 应用级设置仓库
  */
 class MainViewModel(
-    private val repository: SettingsRepository
+    private val repository: SettingsRepository,
+    private val application: Application
 ) : ViewModel() {
 
     companion object {
@@ -81,6 +86,18 @@ class MainViewModel(
     private val _actionFeedback = MutableStateFlow<String?>(null)
     val actionFeedback: StateFlow<String?> = _actionFeedback.asStateFlow()
 
+    /** ICMP 延迟（毫秒），null 表示无数据或未连接。 */
+    private val _pingLatencyMs = MutableStateFlow<Long?>(null)
+    val pingLatencyMs: StateFlow<Long?> = _pingLatencyMs.asStateFlow()
+
+    private var pingMonitor: PingMonitor? = null
+
+    /** WiFi 信号强度级别（0-5 格），0=无WiFi/无信号。 */
+    private val _wifiSignalLevel = MutableStateFlow(0)
+    val wifiSignalLevel: StateFlow<Int> = _wifiSignalLevel.asStateFlow()
+
+    private var wifiJob: Job? = null
+
     /** 当前设置快照（主界面用于驱动视频播放器地址/编码器） */
     val settings: StateFlow<AppSettings> = repository.settings.stateIn(
         scope = viewModelScope,
@@ -101,6 +118,17 @@ class MainViewModel(
     val isConnected: Boolean get() = robot.isConnected
 
     init {
+        // 启动 ICMP 延迟监测（独立于连接生命周期）
+        restartPingMonitor(settings.value.robotHost)
+        // 设置中 host 变更时重启 ping
+        viewModelScope.launch {
+            settings
+                .map { it.robotHost }
+                .distinctUntilChanged()
+                .collect { host -> restartPingMonitor(host) }
+        }
+        // 启动 WiFi 信号强度监测（独立于连接生命周期）
+        startWifiMonitoring()
         // 设置变更时断开当前连接，下次 connect 使用新参数
         settingsWatchJob = viewModelScope.launch {
             settings
@@ -110,6 +138,44 @@ class MainViewModel(
         }
     }
 
+    /** 启动 WiFi 信号强度周期性监测。 */
+    private fun startWifiMonitoring() {
+        wifiJob?.cancel()
+        wifiJob = viewModelScope.launch {
+            val wifiManager = application.getSystemService(Context.WIFI_SERVICE) as? WifiManager
+            if (wifiManager == null) {
+                _wifiSignalLevel.value = 0
+                return@launch
+            }
+            while (isActive) {
+                val info = wifiManager.connectionInfo
+                val rssi = info?.rssi ?: -127
+                _wifiSignalLevel.value = if (rssi == -127 || info == null) {
+                    0
+                } else {
+                    when {
+                        rssi >= -50 -> 5
+                        rssi >= -60 -> 4
+                        rssi >= -70 -> 3
+                        rssi >= -80 -> 2
+                        rssi >= -90 -> 1
+                        else -> 0
+                    }
+                }
+                delay(3000L)
+            }
+        }
+    }
+
+    /** 重启 PingMonitor（目标 host 变更时调用）。 */
+    private fun restartPingMonitor(host: String) {
+        pingMonitor?.stop()
+        pingMonitor = PingMonitor(host, scope = viewModelScope).also { it.start() }
+        viewModelScope.launch {
+            pingMonitor?.latencyMs?.collect { _pingLatencyMs.value = it }
+        }
+    }
+
     /**
      * 建立连接并启动轴指令循环。参数取自当前设置。
      *
@@ -163,7 +229,30 @@ class MainViewModel(
 
     /** 状态上报分发：更新机器人运动状态机 + 各分项缓存。 */
     private fun handleStatusReport(report: StatusReport) {
-        _latestStatus.value = report
+        // 合并：保留上次报告中非 null 的字段，避免部分报告覆盖导致 UI 闪烁
+        val prev = _latestStatus.value
+        _latestStatus.value = if (prev != null) {
+            prev.copy(
+                type = report.type,
+                command = report.command,
+                time = report.time,
+                errorCode = report.errorCode ?: prev.errorCode,
+                errorMessage = report.errorMessage ?: prev.errorMessage,
+                basicStatus = report.basicStatus ?: prev.basicStatus,
+                motionStatus = report.motionStatus ?: prev.motionStatus,
+                motorStatus = report.motorStatus ?: prev.motorStatus,
+                batteryList = report.batteryList ?: prev.batteryList,
+                batteryStatus = report.batteryStatus ?: prev.batteryStatus,
+                deviceTemperature = report.deviceTemperature ?: prev.deviceTemperature,
+                led = report.led ?: prev.led,
+                gps = report.gps ?: prev.gps,
+                devEnable = report.devEnable ?: prev.devEnable,
+                cpu = report.cpu ?: prev.cpu,
+                errorList = report.errorList ?: prev.errorList
+            )
+        } else {
+            report
+        }
         _lastUpdate.value = report.time
         robot.updateFromReport(report)
         report.errorList?.let { _errorList.value = it }
@@ -226,6 +315,15 @@ class MainViewModel(
         client?.sendCommandBlocking(ControlCommands.chargeControl(charge))
     }
 
+    /** 软急停：进入关节阻尼状态。 */
+    fun sendEmergencyStop() {
+        if (robot.canSendMotionControl) {
+            client?.sendCommandBlocking(ControlCommands.softEmergencyStop())
+        } else {
+            _actionFeedback.value = "未连接，无法发送软急停"
+        }
+    }
+
     fun sendSleepSettings(sleep: Boolean, auto: Boolean = false, timeMinutes: Int = 5) {
         client?.sendCommandBlocking(
             ControlCommands.sleepSettings(sleep, auto, timeMinutes)
@@ -266,6 +364,9 @@ class MainViewModel(
 
     override fun onCleared() {
         disconnect()
+        wifiJob?.cancel()
+        pingMonitor?.stop()
+        pingMonitor = null
         settingsWatchJob?.cancel()
         super.onCleared()
     }