[(∩｀-´)⊃━☆ﾟ.*･｡ﾟ] Payment methods recycler animations

app/src/main/java/com/kickstarter/ui/activities/PaymentMethodsSettingsActivity.kt

@@ -5,6 +5,7 @@ import android.app.Activity
 import android.content.Intent
 import android.os.Bundle
 import android.support.v7.app.AlertDialog
+import android.support.v7.util.DiffUtil
 import android.support.v7.widget.LinearLayoutManager
 import com.kickstarter.R
 import com.kickstarter.extensions.showConfirmationSnackbar
@@ -72,7 +73,16 @@ class PaymentMethodsSettingsActivity : BaseActivity<PaymentMethodsViewModel.View
     private fun setCards(cards: MutableList<UserPaymentsQuery.Node>) = this.adapter.populateCards(cards)
 
     private fun setUpRecyclerView() {
-        this.adapter = PaymentMethodsAdapter(this.viewModel)
+        this.adapter = PaymentMethodsAdapter(this.viewModel, object: DiffUtil.ItemCallback<Any>() {
+            override fun areItemsTheSame(oldItem: Any?, newItem: Any?): Boolean {
+                return (oldItem as UserPaymentsQuery.Node).id() == (newItem as UserPaymentsQuery.Node).id()
+            }
+
+            override fun areContentsTheSame(oldItem: Any?, newItem: Any?): Boolean {
+                return (oldItem as UserPaymentsQuery.Node).id() == (newItem as UserPaymentsQuery.Node).id()
+            }
+
+        })
         recycler_view.adapter = this.adapter
         recycler_view.layoutManager = LinearLayoutManager(this)
     }

app/src/main/java/com/kickstarter/ui/adapters/KSListAdapter.kt

@@ -0,0 +1,193 @@
+package com.kickstarter.ui.adapters
+
+import android.support.annotation.LayoutRes
+import android.support.v7.recyclerview.extensions.ListAdapter
+import android.support.v7.util.DiffUtil
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import com.crashlytics.android.Crashlytics
+import com.kickstarter.BuildConfig
+import com.kickstarter.libs.utils.ExceptionUtils
+import com.kickstarter.ui.viewholders.KSViewHolder
+import com.trello.rxlifecycle.ActivityEvent
+
+abstract class KSListAdapter(diffUtil: DiffUtil.ItemCallback<Any>) : ListAdapter<Any, KSViewHolder>(diffUtil) {
+    private val sections = ArrayList<List<Any>>()
+
+    fun sections(): List<List<Any>> {
+        return this.sections
+    }
+
+    fun clearSections() {
+        this.sections.clear()
+    }
+
+    fun <T> addSection(section: List<T>) {
+        this.sections.add(ArrayList<Any>(section))
+    }
+
+    fun <T> addSections(sections: List<List<T>>) {
+        for (section in sections) {
+            addSection(section)
+        }
+    }
+
+    protected fun items(): MutableList<Any> {
+        val items = ArrayList<Any>()
+        for (section in sections) {
+            items.addAll(section)
+        }
+
+        return items
+    }
+
+    fun <T> setSection(location: Int, section: List<T>) {
+        this.sections[location] = ArrayList<Any>(section)
+    }
+
+    fun <T> insertSection(location: Int, section: List<T>) {
+        this.sections.add(location, ArrayList<Any>(section))
+    }
+
+    /**
+     * Fetch the layout id associated with a sectionRow.
+     */
+    protected abstract fun layout(sectionRow: SectionRow): Int
+
+    /**
+     * Returns a new KSViewHolder given a layout and view.
+     */
+    protected abstract fun viewHolder(@LayoutRes layout: Int, view: View): KSViewHolder
+
+    override fun onViewDetachedFromWindow(holder: KSViewHolder) {
+        super.onViewDetachedFromWindow(holder)
+
+        // View holders are "stopped" when they are detached from the window for recycling
+        holder.lifecycleEvent(ActivityEvent.STOP)
+
+        // View holders are "destroy" when they are detached from the window and no adapter is listening
+        // to events, so ostensibly the view holder is being deallocated.
+        if (!hasObservers()) {
+            holder.lifecycleEvent(ActivityEvent.DESTROY)
+        }
+    }
+
+    override fun onViewAttachedToWindow(holder: KSViewHolder) {
+        super.onViewAttachedToWindow(holder)
+
+        // View holders are "started" when they are attached to the new window because this means
+        // it has been recycled.
+        holder.lifecycleEvent(ActivityEvent.START)
+    }
+
+    override fun onCreateViewHolder(viewGroup: ViewGroup, @LayoutRes layout: Int): KSViewHolder {
+        val view = inflateView(viewGroup, layout)
+        val viewHolder = viewHolder(layout, view)
+
+        viewHolder.lifecycleEvent(ActivityEvent.CREATE)
+
+        return viewHolder
+    }
+
+    override fun onBindViewHolder(viewHolder: KSViewHolder, position: Int) {
+        val data = objectFromPosition(position)
+
+        try {
+            viewHolder.bindData(data)
+        } catch (e: Exception) {
+            if (BuildConfig.DEBUG) {
+                ExceptionUtils.rethrowAsRuntimeException(e)
+            } else {
+                // TODO: alter the exception message to say we are just reporting it and it's not a real crash.
+                Crashlytics.logException(e)
+            }
+        }
+
+    }
+
+    override fun getItemViewType(position: Int): Int {
+        return layout(sectionRowFromPosition(position))
+    }
+
+    override fun getItemCount(): Int {
+        return items().size
+    }
+
+    /**
+     * Gets the data object associated with a sectionRow.
+     */
+    protected fun objectFromSectionRow(sectionRow: SectionRow): Any {
+        return this.sections[sectionRow.section()][sectionRow.row()]
+    }
+
+    protected fun sectionCount(section: Int): Int {
+        return if (section > sections().size - 1) {
+            0
+        } else sections()[section].size
+    }
+
+    /**
+     * Gets the data object associated with a position.
+     */
+    protected fun objectFromPosition(position: Int): Any {
+        return objectFromSectionRow(sectionRowFromPosition(position))
+    }
+
+    private fun sectionRowFromPosition(position: Int): SectionRow {
+        val sectionRow = SectionRow()
+        var cursor = 0
+        for (section in this.sections) {
+            for (item in section) {
+                if (cursor == position) {
+                    return sectionRow
+                }
+                cursor++
+                sectionRow.nextRow()
+            }
+            sectionRow.nextSection()
+        }
+
+        throw RuntimeException("Position $position not found in sections")
+    }
+
+    private fun inflateView(viewGroup: ViewGroup, @LayoutRes viewType: Int): View {
+        val layoutInflater = LayoutInflater.from(viewGroup.context)
+        return layoutInflater.inflate(viewType, viewGroup, false)
+    }
+
+    /**
+     * SectionRows allow RecyclerViews to be structured into sections of rows.
+     */
+    protected inner class SectionRow {
+        private var section: Int = 0
+        private var row: Int = 0
+
+        constructor() {
+            this.section = 0
+            this.row = 0
+        }
+
+        constructor(section: Int, row: Int) {
+            this.section = section
+            this.row = row
+        }
+
+        fun section(): Int {
+            return this.section
+        }
+
+        fun row(): Int {
+            return this.row
+        }
+
+        fun nextRow() {
+            this.row++
+        }
+
+        fun nextSection() {
+            this.section++
+            this.row = 0
+        }
+    }
+}

app/src/main/java/com/kickstarter/ui/adapters/PaymentMethodsAdapter.kt

@@ -1,12 +1,15 @@
 package com.kickstarter.ui.adapters
 
 import UserPaymentsQuery
+import android.support.v7.util.DiffUtil
 import android.view.View
 import com.kickstarter.R
 import com.kickstarter.ui.viewholders.KSViewHolder
 import com.kickstarter.ui.viewholders.PaymentMethodsViewHolder
 
-class PaymentMethodsAdapter(private val delegate: PaymentMethodsViewHolder.Delegate): KSAdapter() {
+const val SECTION_CARDS = 0
+
+class PaymentMethodsAdapter(private val delegate: PaymentMethodsViewHolder.Delegate, diffCallback: DiffUtil.ItemCallback<Any>): KSListAdapter(diffCallback) {
 
     init {
         addSection(emptyList<Any>())
@@ -19,7 +22,7 @@ class PaymentMethodsAdapter(private val delegate: PaymentMethodsViewHolder.Deleg
     override fun viewHolder(layout: Int, view: View): KSViewHolder = PaymentMethodsViewHolder(view, delegate)
 
     fun populateCards(cards: MutableList<UserPaymentsQuery.Node>) {
-        setSection(0, cards)
-        notifyDataSetChanged()
+        setSection(SECTION_CARDS, cards)
+        submitList(items())
     }
 }

app/src/main/java/com/kickstarter/viewmodels/PaymentMethodsViewModel.kt

@@ -91,7 +91,7 @@ interface PaymentMethodsViewModel {
         }
 
         override fun deleteCardButtonClicked(paymentMethodsViewHolder: PaymentMethodsViewHolder, paymentSourceId: String) {
-            return this.deleteCardClicked(paymentSourceId)
+            deleteCardClicked(paymentSourceId)
         }
 
         override fun confirmDeleteCardClicked() = this.confirmDeleteCardClicked.onNext(null)