Reader seekbar now moves with the chapter bottom sheet

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt

@@ -22,6 +22,7 @@ import android.view.animation.AnimationUtils
 import android.widget.SeekBar
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.core.graphics.ColorUtils
+import androidx.core.view.GestureDetectorCompat
 import com.afollestad.materialdialogs.MaterialDialog
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import com.google.android.material.bottomsheet.BottomSheetBehavior
@@ -63,6 +64,7 @@ import eu.kanade.tachiyomi.util.view.collapse
 import eu.kanade.tachiyomi.util.view.doOnApplyWindowInsets
 import eu.kanade.tachiyomi.util.view.gone
 import eu.kanade.tachiyomi.util.view.hide
+import eu.kanade.tachiyomi.util.view.isCollapsed
 import eu.kanade.tachiyomi.util.view.isExpanded
 import eu.kanade.tachiyomi.util.view.snack
 import eu.kanade.tachiyomi.util.view.updateLayoutParams
@@ -336,6 +338,7 @@ class ReaderActivity :
     /**
      * Initializes the reader menu. It sets up click listeners and the initial visibility.
      */
+    @SuppressLint("ClickableViewAccessibility")
     private fun initializeMenu() {
         // Set binding.toolbar
         setSupportActionBar(binding.toolbar)
@@ -373,6 +376,28 @@ class ReaderActivity :
             }
         }
 
+        val gestureDetector = GestureDetectorCompat(this, ReaderNavGestureDetector(this))
+        with(binding.readerNav) {
+            listOf(root, leftChapter, rightChapter, pageSeekbar).forEach {
+                it.setOnTouchListener { _, event ->
+                    val result = gestureDetector.onTouchEvent(event)
+                    if (event?.action == MotionEvent.ACTION_UP) {
+                        if (!result) {
+                            val sheetBehavior = binding.chaptersSheet.root.sheetBehavior
+                            if (sheetBehavior?.state != BottomSheetBehavior.STATE_SETTLING && !sheetBehavior.isCollapsed()) {
+                                binding.chaptersSheet.root.dispatchTouchEvent(event)
+                                sheetBehavior?.collapse()
+                            }
+                        }
+                    } else if ((event?.action != MotionEvent.ACTION_UP || event.action != MotionEvent.ACTION_DOWN) && result) {
+                        event.action = MotionEvent.ACTION_CANCEL
+                        return@setOnTouchListener false
+                    }
+                    result
+                }
+            }
+        }
+
         // Init listeners on bottom menu
         binding.readerNav.pageSeekbar.setOnSeekBarChangeListener(
             object : SimpleSeekBarListener() {

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderNavGestureDetector.kt

@@ -0,0 +1,90 @@
+package eu.kanade.tachiyomi.ui.reader
+
+import android.view.GestureDetector
+import android.view.MotionEvent
+import eu.kanade.tachiyomi.util.system.dpToPx
+import eu.kanade.tachiyomi.util.view.collapse
+import eu.kanade.tachiyomi.util.view.expand
+import kotlin.math.abs
+
+class ReaderNavGestureDetector(private val activity: ReaderActivity) : GestureDetector
+.SimpleOnGestureListener() {
+
+    private val lastPixel = 0f
+    private var buttonY: Float = 20f.dpToPx
+    private var hasScrollHorizontal = false
+    private var lockVertical = false
+
+    override fun onDown(e: MotionEvent): Boolean {
+        lockVertical = false
+        hasScrollHorizontal = false
+        val modE = MotionEvent.obtain(e)
+        modE.setLocation(e.x, 56f.dpToPx)
+        activity.binding.chaptersSheet.root.dispatchTouchEvent(modE)
+        modE.recycle()
+        return false
+    }
+
+    override fun onScroll(
+        e1: MotionEvent?,
+        e2: MotionEvent?,
+        distanceX: Float,
+        distanceY: Float
+    ): Boolean {
+        val newDistanceX = (e1?.rawX ?: 0f) - (e2?.rawX ?: 0f)
+        val newDistanceY = (e1?.rawY ?: 0f) - (e2?.rawY ?: 0f)
+        if ((!hasScrollHorizontal || lockVertical) && e2 != null) {
+            hasScrollHorizontal = abs(newDistanceX) > abs(newDistanceY) && abs(newDistanceX) > 80
+
+            val modE = MotionEvent.obtain(e2)
+            modE.setLocation(
+                e2.x,
+                buttonY + modE.y +
+                    (if (activity.binding.readerNav.root.alpha == 0f) activity.binding.readerNav.root.height.toFloat() else 0f)
+            )
+            activity.binding.chaptersSheet.root.dispatchTouchEvent(modE)
+            modE.recycle()
+            if (!lockVertical) {
+                lockVertical = abs(newDistanceX) < abs(newDistanceY) && abs(newDistanceY) > 150
+            }
+        }
+        if (hasScrollHorizontal) {
+            activity.binding.chaptersSheet.root.sheetBehavior?.collapse()
+        }
+        return lockVertical
+    }
+
+    override fun onFling(
+        e1: MotionEvent,
+        e2: MotionEvent,
+        velocityX: Float,
+        velocityY: Float
+    ): Boolean {
+        var result = false
+        val diffY = e2.rawY - e1.rawY
+        val diffX = e2.rawX - e1.rawX
+        val sheetBehavior = activity.binding.chaptersSheet.root.sheetBehavior
+        if (!hasScrollHorizontal && abs(diffX) < abs(diffY)
+            && (abs(diffY) > SWIPE_THRESHOLD || abs(velocityY) > SWIPE_VELOCITY_THRESHOLD)
+            && diffY <= 0
+        ) {
+            sheetBehavior?.expand()
+            result = true
+        }
+
+        val modE = MotionEvent.obtain(e2)
+        modE.setLocation(lastPixel, buttonY + modE.y)
+        modE.action = MotionEvent.ACTION_UP
+        activity.binding.chaptersSheet.root.dispatchTouchEvent(modE)
+        modE.recycle()
+        if (!result) {
+            activity.binding.chaptersSheet.root.sheetBehavior?.collapse()
+        }
+        return result
+    }
+
+    private companion object {
+        const val SWIPE_THRESHOLD = 500
+        const val SWIPE_VELOCITY_THRESHOLD = 600
+    }
+}

app/src/main/java/eu/kanade/tachiyomi/ui/reader/chapter/ReaderChapterSheet.kt

@@ -128,8 +128,6 @@ class ReaderChapterSheet @JvmOverloads constructor(context: Context, attrs: Attr
                     }
                     binding.chapterRecycler.isClickable = state == BottomSheetBehavior.STATE_EXPANDED
                     binding.chapterRecycler.isFocusable = state == BottomSheetBehavior.STATE_EXPANDED
-                    binding.chapterRecycler.isClickable = state == BottomSheetBehavior.STATE_COLLAPSED
-                    binding.chapterRecycler.isFocusable = state == BottomSheetBehavior.STATE_COLLAPSED
 //                    binding.webviewButton.visibleIf(state != BottomSheetBehavior.STATE_COLLAPSED)
 //                    binding.chaptersButton.visInvisIf(state != BottomSheetBehavior.STATE_EXPANDED)
                 }