Implemented zoom listener to dynamically change span count

app/src/main/kotlin/com/simplemobiletools/dialer/adapters/ContactsAdapter.kt

@@ -7,13 +7,11 @@ import android.graphics.drawable.Icon
 import android.net.Uri
 import android.text.TextUtils
 import android.util.TypedValue
-import android.view.Menu
+import android.view.*
-import android.view.MotionEvent
-import android.view.View
-import android.view.ViewGroup
 import android.widget.ImageView
 import android.widget.TextView
 import androidx.constraintlayout.widget.ConstraintLayout
+import androidx.recyclerview.widget.GridLayoutManager
 import androidx.recyclerview.widget.ItemTouchHelper
 import androidx.recyclerview.widget.RecyclerView
 import com.bumptech.glide.Glide
@@ -42,21 +40,27 @@ class ContactsAdapter(
     recyclerView: MyRecyclerView,
     highlightText: String = "",
     private val refreshItemsListener: RefreshItemsListener? = null,
-    private val viewType: Int = VIEW_TYPE_LIST,
+    var viewType: Int = VIEW_TYPE_LIST,
     private val showDeleteButton: Boolean = true,
     private val enableDrag: Boolean = false,
     itemClick: (Any) -> Unit
-) : MyRecyclerViewAdapter(activity, recyclerView, itemClick), ItemTouchHelperContract {
+) : MyRecyclerViewAdapter(activity, recyclerView, itemClick),
+    ItemTouchHelperContract, MyRecyclerView.MyZoomListener {
 
     private var textToHighlight = highlightText
     private var fontSize = activity.getTextSize()
     private var touchHelper: ItemTouchHelper? = null
     private var startReorderDragListener: StartReorderDragListener? = null
     var onDragEndListener: (() -> Unit)? = null
+    var onSpanCountListener: (Int) -> Unit = {}
 
     init {
         setupDragListener(true)
 
+        if (recyclerView.layoutManager is GridLayoutManager) {
+            setupZoomListener(this)
+        }
+
         if (enableDrag) {
             touchHelper = ItemTouchHelper(ItemMoveCallback(this, viewType == VIEW_TYPE_GRID))
             touchHelper!!.attachToRecyclerView(recyclerView)
@@ -340,4 +344,33 @@ class ContactsAdapter(
     override fun onRowClear(myViewHolder: ViewHolder?) {
         onDragEndListener?.invoke()
     }
+
+    override fun zoomIn() {
+        val layoutManager = recyclerView.layoutManager
+        if (layoutManager is GridLayoutManager) {
+            val currentSpanCount = layoutManager.spanCount
+            val newSpanCount = (currentSpanCount - 1).coerceIn(MIN_COLUMNS, MAX_COLUMNS)
+            layoutManager.spanCount = newSpanCount
+            recyclerView.requestLayout()
+            onSpanCountListener(newSpanCount)
+        }
+    }
+
+    override fun zoomOut() {
+        val layoutManager = recyclerView.layoutManager
+        if (layoutManager is GridLayoutManager) {
+            val currentSpanCount = layoutManager.spanCount
+            val newSpanCount = (currentSpanCount + 1).coerceIn(MIN_COLUMNS, MAX_COLUMNS)
+            layoutManager.spanCount = newSpanCount
+            recyclerView.requestLayout()
+            onSpanCountListener(newSpanCount)
+        }
+    }
+
+    companion object {
+        private const val MIN_COLUMNS = 2
+        private const val MAX_COLUMNS = 6
+    }
+
+
 }

app/src/main/kotlin/com/simplemobiletools/dialer/fragments/FavoritesFragment.kt

@@ -91,42 +91,56 @@ class FavoritesFragment(context: Context, attributeSet: AttributeSet) : MyViewPa
         val viewType = context.config.viewType
         setViewType(viewType)
 
-        ContactsAdapter(
+
-            activity = activity as SimpleActivity,
+        val currAdapter = fragment_list.adapter as ContactsAdapter?
-            contacts = allContacts,
+        if (currAdapter == null) {
-            recyclerView = fragment_list,
+            ContactsAdapter(
-            refreshItemsListener = this,
+                activity = activity as SimpleActivity,
-            viewType = viewType,
+                contacts = allContacts,
-            showDeleteButton = false,
+                recyclerView = fragment_list,
-            enableDrag = true,
+                refreshItemsListener = this,
-        ) {
+                viewType = viewType,
-            if (context.config.showCallConfirmation) {
+                showDeleteButton = false,
-                CallConfirmationDialog(activity as SimpleActivity, (it as Contact).getNameToDisplay()) {
+                enableDrag = true,
+            ) {
+                if (context.config.showCallConfirmation) {
+                    CallConfirmationDialog(activity as SimpleActivity, (it as Contact).getNameToDisplay()) {
+                        activity?.apply {
+                            initiateCall(it) { launchCallIntent(it) }
+                        }
+                    }
+                } else {
                     activity?.apply {
-                        initiateCall(it) { launchCallIntent(it) }
+                        initiateCall(it as Contact) { launchCallIntent(it) }
                     }
                 }
-            } else {
+            }.apply {
-                activity?.apply {
+                fragment_list.adapter = this
-                    initiateCall(it as Contact) { launchCallIntent(it) }
+
+                onDragEndListener = {
+                    val adapter = fragment_list?.adapter
+                    if (adapter is ContactsAdapter) {
+                        val items = adapter.contacts
+                        saveCustomOrderToPrefs(items)
+                        setupLetterFastScroller(items)
+                    }
+                }
+
+                onSpanCountListener = { newSpanCount ->
+                    context.config.gridLayoutSpanCount = newSpanCount
                 }
             }
-        }.apply {
-            fragment_list.adapter = this
 
-            onDragEndListener = {
+
-                val adapter = fragment_list?.adapter
+            if (context.areSystemAnimationsEnabled) {
-                if (adapter is ContactsAdapter) {
+                fragment_list.scheduleLayoutAnimation()
-                    val items = adapter.contacts
-                    saveCustomOrderToPrefs(items)
-                    setupLetterFastScroller(items)
-                }
             }
+        } else {
+            currAdapter.updateItems(allContacts)
+            currAdapter.viewType = viewType
+            currAdapter.recyclerView.requestLayout()
         }
 
-        if (context.areSystemAnimationsEnabled) {
-            fragment_list.scheduleLayoutAnimation()
-        }
     }
 
     private fun sortByCustomOrder(favorites: List<Contact>): ArrayList<Contact> {
@@ -182,9 +196,11 @@ class FavoritesFragment(context: Context, attributeSet: AttributeSet) : MyViewPa
     }
 
     private fun setViewType(viewType: Int) {
+        val spanCount = context.config.gridLayoutSpanCount
+
         val layoutManager = if (viewType == VIEW_TYPE_GRID) {
             letter_fastscroller.beGone()
-            MyGridLayoutManager(context, 3)
+            MyGridLayoutManager(context, spanCount)
         } else {
             letter_fastscroller.beVisible()
             MyLinearLayoutManager(context)