Feat: TV remote control via D-pad focus navigation using AccessibilityService

android/app/src/main/java/com/yama/client/ControlService.kt

@@ -14,7 +14,9 @@ import android.os.Handler
 import android.os.Looper
 import android.os.SystemClock
 import android.util.Log
+import android.view.View
 import android.view.accessibility.AccessibilityEvent
+import android.view.accessibility.AccessibilityNodeInfo
 
 /**
  * AccessibilityService that injects touch gestures and global key actions
@@ -88,6 +90,22 @@ class ControlService : AccessibilityService() {
     // ── Main-thread handler ───────────────────────────────────────────────
     private val handler = Handler(Looper.getMainLooper())
 
+    // ── TV (Google TV / Android TV) D-pad mode ───────────────────────────
+    // Activated when FEATURE_LEANBACK is present. Mouse events are translated
+    // to accessibility focus navigation — no touchscreen or root required.
+    private var isTV = false
+    private var tvLastEncX = -1f
+    private var tvLastEncY = -1f
+    private var tvAccumDX  = 0f
+    private var tvAccumDY  = 0f
+    private val TV_STEP    = 40f   // encoding-space pixels per D-pad step
+    // Touch-drag disambiguation: fire click on LBUTTONUP only if finger barely moved
+    private var tvTouchDown  = false
+    private var tvTouchDownX = 0f
+    private var tvTouchDownY = 0f
+    private var tvTouchMoved = false
+    private val TV_TAP_THRESHOLD = 15f  // encoding pixels — below this = tap, above = drag
+
     // ── Left-button drag accumulator ─────────────────────────────────────
     private var lbuttonDown  = false
     private var gestureStart = 0L
@@ -100,6 +118,8 @@ class ControlService : AccessibilityService() {
     override fun onServiceConnected() {
         super.onServiceConnected()
         instance = this
+        isTV = packageManager.hasSystemFeature("android.software.leanback")
+        if (isTV) Log.i(TAG, "TV mode: D-pad navigation enabled")
         val filter = IntentFilter().apply {
             addAction(Intent.ACTION_SCREEN_OFF)
             addAction(Intent.ACTION_USER_PRESENT)
@@ -127,6 +147,7 @@ class ControlService : AccessibilityService() {
     // Event routing (runs on main thread)
 
     private fun handleEvent(message: Int, wParam: Long, ptX: Int, ptY: Int) {
+        if (isTV) { handleEventTV(message, wParam, ptX, ptY); return }
         // Scale encoding-space coords to physical screen
         val x = if (encW > 0) ptX.toFloat() * physW / encW else ptX.toFloat()
         val y = if (encH > 0) ptY.toFloat() * physH / encH else ptY.toFloat()
@@ -265,6 +286,119 @@ class ControlService : AccessibilityService() {
         if (!ok) Log.e(TAG, "dispatchGesture returned false (service not ready?)")
     }
 
+    // ─────────────────────────────────────────────────────────────────────
+    // TV D-pad mode — translates mouse events to accessibility focus actions
+
+    private fun handleEventTV(message: Int, wParam: Long, ptX: Int, ptY: Int) {
+        when (message) {
+            WM_MOUSEMOVE -> {
+                if (tvLastEncX >= 0) {
+                    tvAccumDX += ptX - tvLastEncX
+                    tvAccumDY += ptY - tvLastEncY
+                    while (tvAccumDX >  TV_STEP) { tvMoveFocus(View.FOCUS_RIGHT); tvAccumDX -= TV_STEP }
+                    while (tvAccumDX < -TV_STEP) { tvMoveFocus(View.FOCUS_LEFT);  tvAccumDX += TV_STEP }
+                    while (tvAccumDY >  TV_STEP) { tvMoveFocus(View.FOCUS_DOWN);  tvAccumDY -= TV_STEP }
+                    while (tvAccumDY < -TV_STEP) { tvMoveFocus(View.FOCUS_UP);    tvAccumDY += TV_STEP }
+                }
+                if (tvTouchDown) {
+                    val dx = ptX - tvTouchDownX
+                    val dy = ptY - tvTouchDownY
+                    if (dx * dx + dy * dy > TV_TAP_THRESHOLD * TV_TAP_THRESHOLD) tvTouchMoved = true
+                }
+                tvLastEncX = ptX.toFloat()
+                tvLastEncY = ptY.toFloat()
+            }
+            WM_LBUTTONDOWN -> {
+                tvTouchDown  = true
+                tvTouchDownX = ptX.toFloat()
+                tvTouchDownY = ptY.toFloat()
+                tvTouchMoved = false
+                tvAccumDX    = 0f
+                tvAccumDY    = 0f
+                tvLastEncX   = ptX.toFloat()
+                tvLastEncY   = ptY.toFloat()
+            }
+            WM_LBUTTONUP -> {
+                if (tvTouchDown && !tvTouchMoved) tvClick()
+                tvTouchDown = false
+            }
+            WM_LBUTTONDBLCLK -> tvClick()
+            WM_RBUTTONDOWN  -> performGlobalAction(GLOBAL_ACTION_BACK)
+            WM_MOUSEWHEEL   -> {
+                val delta = (wParam.toInt() ushr 16).toShort().toInt()
+                tvScroll(delta < 0)
+            }
+            WM_KEYDOWN, WM_SYSKEYDOWN -> {
+                val vk = wParam.toInt() and 0xFFFF
+                when (vk) {
+                    0x25 -> tvMoveFocus(View.FOCUS_LEFT)   // VK_LEFT
+                    0x26 -> tvMoveFocus(View.FOCUS_UP)     // VK_UP
+                    0x27 -> tvMoveFocus(View.FOCUS_RIGHT)  // VK_RIGHT
+                    0x28 -> tvMoveFocus(View.FOCUS_DOWN)   // VK_DOWN
+                    0x0D -> tvClick()                       // VK_RETURN
+                    else -> handleKeyDown(vk)
+                }
+            }
+        }
+    }
+
+    @Suppress("DEPRECATION")
+    private fun tvMoveFocus(direction: Int) {
+        val root = rootInActiveWindow ?: return
+        val focused = root.findFocus(AccessibilityNodeInfo.FOCUS_INPUT)
+            ?: root.findFocus(AccessibilityNodeInfo.FOCUS_ACCESSIBILITY)
+        if (focused == null) {
+            val first = findFirstFocusable(root)
+            first?.performAction(AccessibilityNodeInfo.ACTION_FOCUS)
+            first?.recycle()
+        } else {
+            val next = focused.focusSearch(direction)
+            next?.performAction(AccessibilityNodeInfo.ACTION_FOCUS)
+            focused.recycle()
+            next?.recycle()
+        }
+        root.recycle()
+    }
+
+    @Suppress("DEPRECATION")
+    private fun tvClick() {
+        val root = rootInActiveWindow ?: return
+        val focused = root.findFocus(AccessibilityNodeInfo.FOCUS_INPUT)
+            ?: root.findFocus(AccessibilityNodeInfo.FOCUS_ACCESSIBILITY)
+        if (focused != null) {
+            focused.performAction(AccessibilityNodeInfo.ACTION_CLICK)
+            focused.recycle()
+        } else {
+            Log.w(TAG, "tvClick: no focused node")
+        }
+        root.recycle()
+    }
+
+    @Suppress("DEPRECATION")
+    private fun tvScroll(forward: Boolean) {
+        val root = rootInActiveWindow ?: return
+        val action = if (forward) AccessibilityNodeInfo.ACTION_SCROLL_FORWARD
+                     else         AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD
+        val focused = root.findFocus(AccessibilityNodeInfo.FOCUS_INPUT)
+            ?: root.findFocus(AccessibilityNodeInfo.FOCUS_ACCESSIBILITY)
+        if (focused == null || !focused.performAction(action)) root.performAction(action)
+        focused?.recycle()
+        root.recycle()
+    }
+
+    // Walk accessibility tree depth-first, return first visible focusable node (caller must recycle)
+    @Suppress("DEPRECATION")
+    private fun findFirstFocusable(node: AccessibilityNodeInfo): AccessibilityNodeInfo? {
+        if (node.isFocusable && node.isVisibleToUser) return AccessibilityNodeInfo.obtain(node)
+        for (i in 0 until node.childCount) {
+            val child = node.getChild(i) ?: continue
+            val hit = findFirstFocusable(child)
+            child.recycle()
+            if (hit != null) return hit
+        }
+        return null
+    }
+
     private fun handleKeyDown(vk: Int) {
         when (vk) {
             0x08, 0x1B -> performGlobalAction(GLOBAL_ACTION_BACK)       // Backspace / Esc