add function to subtitle layer

android/sample-app/src/main/java/cn/learningpad/oraltrainer/sample/ui/PlayerChrome.kt

@@ -8,6 +8,7 @@ import android.graphics.drawable.GradientDrawable
 import android.graphics.drawable.InsetDrawable
 import android.graphics.Typeface
 import android.text.TextUtils
+import android.view.MotionEvent
 import android.view.Gravity
 import android.view.View
 import android.view.ViewGroup
@@ -166,7 +167,28 @@ internal class PlayerChrome(
                             addView(createPlayerView())
                         },
                     )
-                    val subtitleContainer = LinearLayout(activity).apply {
+                    val subtitleContainer = object : LinearLayout(activity) {
+                        private var forwardTouchToPlayer = false
+
+                        override fun dispatchTouchEvent(event: MotionEvent): Boolean {
+                            if (event.actionMasked == MotionEvent.ACTION_DOWN) {
+                                forwardTouchToPlayer = !isTouchOverInteractiveControl(this, event)
+                            }
+                            val forwarded = if (forwardTouchToPlayer) {
+                                bindings.playerView.forwardGestureFrom(this, event)
+                            } else {
+                                false
+                            }
+                            val handled = forwarded || super.dispatchTouchEvent(event)
+                            if (event.actionMasked == MotionEvent.ACTION_UP ||
+                                event.actionMasked == MotionEvent.ACTION_CANCEL
+                            ) {
+                                forwardTouchToPlayer = false
+                            }
+                            return handled
+                        }
+
+                    }.apply {
                         orientation = LinearLayout.VERTICAL
                         layoutParams = FrameLayout.LayoutParams(
                             ViewGroup.LayoutParams.MATCH_PARENT,
@@ -503,4 +525,33 @@ internal class PlayerChrome(
         }
         view.startAnimation(animation)
     }
+
+    /** Lets controls own their touches while the subtitle background drives player gestures. */
+    private fun isTouchOverInteractiveControl(root: View, event: MotionEvent): Boolean =
+        hasInteractiveTouchTarget(root, event.rawX, event.rawY)
+
+    private fun hasInteractiveTouchTarget(view: View, screenX: Float, screenY: Float): Boolean {
+        if (view.visibility != View.VISIBLE || !view.isEnabled) {
+            return false
+        }
+        if (view.isClickable || view.isLongClickable || view.isContextClickable) {
+            val location = IntArray(2).also(view::getLocationOnScreen)
+            if (screenX >= location[0] &&
+                screenX < location[0] + view.width &&
+                screenY >= location[1] &&
+                screenY < location[1] + view.height
+            ) {
+                return true
+            }
+        }
+        if (view !is ViewGroup) {
+            return false
+        }
+        for (index in view.childCount - 1 downTo 0) {
+            if (hasInteractiveTouchTarget(view.getChildAt(index), screenX, screenY)) {
+                return true
+            }
+        }
+        return false
+    }
 }