Multi-selection: Selection mode

app/src/main/java/com/duckduckgo/app/browser/tabs/adapter/TabSwitcherItemDiffCallback.kt

@@ -19,8 +19,12 @@ package com.duckduckgo.app.browser.tabs.adapter
 import android.os.Bundle
 import androidx.recyclerview.widget.DiffUtil
 import com.duckduckgo.app.tabs.ui.TabSwitcherItem
+import com.duckduckgo.app.tabs.ui.TabSwitcherItem.Tab.SelectableTab
 
-class TabSwitcherItemDiffCallback(old: List<TabSwitcherItem>, new: List<TabSwitcherItem>) : DiffUtil.Callback() {
+class TabSwitcherItemDiffCallback(
+    old: List<TabSwitcherItem>,
+    new: List<TabSwitcherItem>,
+) : DiffUtil.Callback() {
 
     // keep a local copy of the lists to avoid any changes to the lists during the diffing process
     private val oldList = old.toList()
@@ -42,7 +46,8 @@ class TabSwitcherItemDiffCallback(old: List<TabSwitcherItem>, new: List<TabSwitc
                 oldItem.tabEntity.tabPreviewFile == newItem.tabEntity.tabPreviewFile &&
                     oldItem.tabEntity.viewed == newItem.tabEntity.viewed &&
                     oldItem.tabEntity.title == newItem.tabEntity.title &&
-                    oldItem.tabEntity.url == newItem.tabEntity.url
+                    oldItem.tabEntity.url == newItem.tabEntity.url &&
+                    (oldItem as? SelectableTab)?.isSelected == (newItem as? SelectableTab)?.isSelected
             }
             else -> false
         }
@@ -71,6 +76,10 @@ class TabSwitcherItemDiffCallback(old: List<TabSwitcherItem>, new: List<TabSwitc
                 if (oldItem.tabEntity.tabPreviewFile != newItem.tabEntity.tabPreviewFile) {
                     diffBundle.putString(DIFF_KEY_PREVIEW, newItem.tabEntity.tabPreviewFile)
                 }
+
+                if ((oldItem as? SelectableTab)?.isSelected != (newItem as? SelectableTab)?.isSelected) {
+                    diffBundle.putString(DIFF_KEY_SELECTION, null)
+                }
             }
         }
 
@@ -114,5 +123,6 @@ class TabSwitcherItemDiffCallback(old: List<TabSwitcherItem>, new: List<TabSwitc
         const val DIFF_KEY_URL = "url"
         const val DIFF_KEY_PREVIEW = "previewImage"
         const val DIFF_KEY_VIEWED = "viewed"
+        const val DIFF_KEY_SELECTION = "selection"
     }
 }

app/src/main/java/com/duckduckgo/app/tabs/ui/TabItemDecorator.kt

@@ -23,52 +23,60 @@ import android.graphics.RectF
 import android.util.TypedValue
 import android.view.View
 import androidx.core.content.ContextCompat
+import androidx.core.view.children
 import androidx.recyclerview.widget.RecyclerView
+import com.duckduckgo.app.tabs.ui.TabSwitcherItem.Tab.NormalTab
+import com.duckduckgo.app.tabs.ui.TabSwitcherItem.Tab.SelectableTab
 import com.duckduckgo.common.ui.view.toPx
 import com.duckduckgo.mobile.android.R as CommonR
 
-class TabItemDecorator(
-    context: Context,
-    var tabSwitcherItemId: String?,
-) : RecyclerView.ItemDecoration() {
-
-    private val borderStroke: Paint = Paint().apply {
+class TabItemDecorator(context: Context) : RecyclerView.ItemDecoration() {
+    private val activeTabBorderStroke: Paint = Paint().apply {
         isAntiAlias = true
         style = Paint.Style.STROKE
-        strokeWidth = BORDER_WIDTH
+        strokeWidth = ACTIVE_TAB_BORDER_WIDTH
 
         val typedValue = TypedValue()
         context.theme.resolveAttribute(CommonR.attr.daxColorBackgroundInverted, typedValue, true)
         color = ContextCompat.getColor(context, typedValue.resourceId)
     }
 
+    private val selectionBorderStroke: Paint = Paint().apply {
+        isAntiAlias = true
+        style = Paint.Style.STROKE
+        strokeWidth = SELECTION_BORDER_WIDTH
+
+        val typedValue = TypedValue()
+        context.theme.resolveAttribute(CommonR.attr.daxColorAccentBlue, typedValue, true)
+        color = ContextCompat.getColor(context, typedValue.resourceId)
+    }
+
     override fun onDrawOver(
         canvas: Canvas,
         recyclerView: RecyclerView,
         state: RecyclerView.State,
     ) {
         val adapter = recyclerView.adapter as TabSwitcherAdapter? ?: return
-
-        for (i in 0 until recyclerView.childCount) {
-            val child = recyclerView.getChildAt(i)
-
+        recyclerView.children.forEach { child ->
             val positionInAdapter = recyclerView.getChildAdapterPosition(child)
             adapter.getTabSwitcherItem(positionInAdapter)?.let { tabSwitcherItem ->
-                if (tabSwitcherItem.id == tabSwitcherItemId) {
-                    drawSelectedTabDecoration(child, canvas)
+                when {
+                    tabSwitcherItem is SelectableTab && tabSwitcherItem.isSelected -> {
+                        drawTabDecoration(child, canvas, selectionBorderStroke)
+                    }
+                    tabSwitcherItem is NormalTab && tabSwitcherItem.isActive -> {
+                        drawTabDecoration(child, canvas, activeTabBorderStroke)
+                    }
                 }
             }
         }
 
         super.onDrawOver(canvas, recyclerView, state)
     }
 
-    private fun drawSelectedTabDecoration(
-        child: View,
-        c: Canvas,
-    ) {
-        borderStroke.alpha = (child.alpha * 255).toInt()
-        c.drawRoundRect(child.getBounds(), BORDER_RADIUS, BORDER_RADIUS, borderStroke)
+    private fun drawTabDecoration(child: View, c: Canvas, paint: Paint) {
+        selectionBorderStroke.alpha = (child.alpha * 255).toInt()
+        c.drawRoundRect(child.getBounds(), BORDER_RADIUS, BORDER_RADIUS, paint)
     }
 
     private fun View.getBounds(): RectF {
@@ -83,7 +91,8 @@ class TabItemDecorator(
 
     companion object {
         private val BORDER_RADIUS = 12.toPx().toFloat()
-        private val BORDER_WIDTH = 2.toPx().toFloat()
+        private val ACTIVE_TAB_BORDER_WIDTH = 2.toPx().toFloat()
+        private val SELECTION_BORDER_WIDTH = 4.toPx().toFloat()
         private val BORDER_PADDING = 3.toPx().toFloat()
     }
 }