Add swipe to delete downloads and minor performance improvements

This could honestly be a horrible way to impliment this (or maybe you don't want it at all) but figured I would give it a try as I often am used to you being able to on other apps so often out of habbit try like this and of course does not work.

This also seems to fix an issue where downloaded icon becomes mixed with in progress and downloaded overlapping on scroll if you have inprogress downloads as well as size becoming inaccurate while scrolling (it used the wrong file's size sometimes) which seems to be fixed with `setItemViewCacheSize`. `setHasFixedSize` also improves performance by reducing the need to continue re-requesting layout when it does not need to (testing did not show any issues with it anyway, but not sure if this is the best way to do either of these things.

Known issues:
* Does not work for series/individual episodes
* Delete icon UI needs improvements

TODO (for further download improvements; maybe in follow-ups):
* Show more information (IE synopsis/descriptions) for downloaded content
* Further performance improvements for UI threads etc...


If the entire concept of this idea is undesired I suppose we can close it and I will just do some of the other things to improve performance etc... (IE when having a moderate amount of downloads scroll is very laggy which this also seems to at least improve quite a lot.

app/src/main/java/com/lagradost/cloudstream3/ui/download/DownloadButtonSetup.kt

@@ -1,6 +1,5 @@
 package com.lagradost.cloudstream3.ui.download
 
-import android.app.Activity
 import android.content.DialogInterface
 import android.widget.Toast
 import androidx.appcompat.app.AlertDialog
@@ -21,6 +20,10 @@ import com.lagradost.cloudstream3.utils.VideoDownloadManager
 
 object DownloadButtonSetup {
     fun handleDownloadClick(click: DownloadClickEvent) {
+        handleDownloadClick(click) {}
+    }
+
+    fun handleDownloadClick(click: DownloadClickEvent, deleteCallback: (Boolean) -> Unit) {
         val id = click.data.id
         if (click.data !is VideoDownloadHelper.DownloadEpisodeCached) return
         when (click.action) {
@@ -32,8 +35,10 @@ object DownloadButtonSetup {
                             when (which) {
                                 DialogInterface.BUTTON_POSITIVE -> {
                                     VideoDownloadManager.deleteFileAndUpdateSettings(ctx, id)
+                                    deleteCallback.invoke(true)
                                 }
                                 DialogInterface.BUTTON_NEGATIVE -> {
+                                    deleteCallback.invoke(false)
                                 }
                             }
                         }

app/src/main/java/com/lagradost/cloudstream3/ui/download/DownloadFragment.kt

@@ -1,8 +1,13 @@
 package com.lagradost.cloudstream3.ui.download
 
+import android.annotation.SuppressLint
 import android.app.Dialog
 import android.content.ClipboardManager
 import android.content.Context
+import android.graphics.Canvas
+import android.graphics.Color
+import android.graphics.drawable.ColorDrawable
+import android.graphics.drawable.Drawable
 import android.os.Build
 import android.os.Bundle
 import android.text.format.Formatter.formatShortFileSize
@@ -12,11 +17,13 @@ import android.view.ViewGroup
 import android.widget.LinearLayout
 import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
+import androidx.core.content.ContextCompat
 import androidx.core.view.isGone
 import androidx.core.view.isVisible
 import androidx.core.widget.doOnTextChanged
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.ViewModelProvider
+import androidx.recyclerview.widget.ItemTouchHelper
 import androidx.recyclerview.widget.RecyclerView
 import com.lagradost.cloudstream3.CommonActivity.showToast
 import com.lagradost.cloudstream3.R
@@ -44,6 +51,9 @@ import com.lagradost.cloudstream3.utils.UIHelper.navigate
 import com.lagradost.cloudstream3.utils.UIHelper.setAppBarNoScrollFlagsOnTV
 import com.lagradost.cloudstream3.utils.VideoDownloadHelper
 import com.lagradost.cloudstream3.utils.VideoDownloadManager
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
 import java.net.URI
 
 
@@ -61,6 +71,7 @@ class DownloadFragment : Fragment() {
         this.layoutParams = param
     }
 
+    @SuppressLint("NotifyDataSetChanged")
     private fun setList(list: List<VisualDownloadHeaderCached>) {
         main {
             (binding?.downloadList?.adapter as DownloadHeaderAdapter?)?.cardList = list
@@ -182,7 +193,6 @@ class DownloadFragment : Fragment() {
             if (list != null) {
                 if (list.any { it.data.id == id }) {
                     context?.let { ctx ->
-                        setList(ArrayList())
                         downloadsViewModel.updateList(ctx)
                     }
                 }
@@ -192,6 +202,8 @@ class DownloadFragment : Fragment() {
         downloadDeleteEventListener?.let { VideoDownloadManager.downloadDeleteEvent += it }
 
         binding?.downloadList?.apply {
+            setHasFixedSize(true)
+            setItemViewCacheSize(20)
             this.adapter = adapter
             setLinearListLayout(
                 isHorizontal = false,
@@ -200,6 +212,9 @@ class DownloadFragment : Fragment() {
                 nextDown = FOCUS_SELF
             )
             //layoutManager = GridLayoutManager(context, 1)
+
+            val itemTouchHelper = ItemTouchHelper(SwipeToDeleteCallback(this.adapter as DownloadHeaderAdapter))
+            itemTouchHelper.attachToRecyclerView(binding?.downloadList)
         }
 
         // Should be visible in emulator layout
@@ -280,4 +295,84 @@ class DownloadFragment : Fragment() {
 
         fixPaddingStatusbar(binding?.downloadRoot)
     }
+}
+
+class SwipeToDeleteCallback(private val adapter: DownloadHeaderAdapter) :
+    ItemTouchHelper.SimpleCallback(ItemTouchHelper.LEFT, 0) {
+
+    private var isActive = false
+
+    override fun onMove(
+        recyclerView: RecyclerView,
+        viewHolder: RecyclerView.ViewHolder,
+        target: RecyclerView.ViewHolder
+    ): Boolean {
+        return false
+    }
+
+    override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
+        val position = viewHolder.bindingAdapterPosition
+        val item = adapter.cardList[position]
+
+        CoroutineScope(Dispatchers.Main).launch {
+            item.child?.let { clickEvent ->
+                handleDownloadClick(
+                    DownloadClickEvent(
+                        DOWNLOAD_ACTION_DELETE_FILE,
+                        clickEvent
+                    )
+                ) {
+                    if (it) adapter.notifyItemRemoved(viewHolder.absoluteAdapterPosition)
+                    isActive = false
+                }
+            }
+        }
+    }
+
+    override fun onChildDraw(
+        c: Canvas,
+        recyclerView: RecyclerView,
+        viewHolder: RecyclerView.ViewHolder,
+        dX: Float,
+        dY: Float,
+        actionState: Int,
+        isCurrentlyActive: Boolean
+    ) {
+        super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)
+
+        val deleteIcon: Drawable? = ContextCompat.getDrawable(recyclerView.context, R.drawable.ic_baseline_delete_outline_24)
+        val background: ColorDrawable = ColorDrawable(Color.RED)
+
+        val itemView = viewHolder.itemView
+        val backgroundCornerOffset = 20
+
+        val iconMargin = (itemView.height - deleteIcon?.intrinsicHeight!!) / 2
+        val iconTop = itemView.top + (itemView.height - deleteIcon.intrinsicHeight) / 2
+        val iconBottom = iconTop + deleteIcon.intrinsicHeight
+
+        if (dX < 0) { // Swiping to the left
+            val iconLeft = itemView.right - iconMargin - deleteIcon.intrinsicWidth
+            val iconRight = itemView.right - iconMargin
+            deleteIcon.setBounds(iconLeft, iconTop, iconRight, iconBottom)
+
+            background.setBounds(
+                itemView.right + dX.toInt() - backgroundCornerOffset,
+                itemView.top,
+                itemView.right,
+                itemView.bottom
+            )
+        } else background.setBounds(0, 0, 0, 0)
+
+        background.draw(c)
+        deleteIcon.draw(c)
+
+        val swipeDistance = itemView.width / 3
+
+        if (dX <= -swipeDistance && !isCurrentlyActive && !isActive) {
+            // If the item is dragged by at least one-third of its width to the left
+            // Trigger onSwiped action
+            onSwiped(viewHolder, ItemTouchHelper.LEFT)
+            isActive = true
+        }
+    }
 }