[fenix] For https://github.com/mozilla-mobile/fenix/issues/357 - Handles back press in edit mode

app/src/main/java/org/mozilla/fenix/library/history/HistoryAdapter.kt

@@ -0,0 +1,152 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+   License, v. 2.0. If a copy of the MPL was not distributed with this
+   file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.library.history
+
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.CheckBox
+import android.widget.CompoundButton
+import android.widget.ImageView
+import android.widget.TextView
+import androidx.recyclerview.widget.RecyclerView
+import io.reactivex.Observer
+import org.mozilla.fenix.R
+
+class HistoryAdapter(
+    private val actionEmitter: Observer<HistoryAction>
+) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
+    class HistoryListItemViewHolder(
+        view: View,
+        private val actionEmitter: Observer<HistoryAction>
+    ) : RecyclerView.ViewHolder(view) {
+
+        private val checkbox = view.findViewById<CheckBox>(R.id.should_remove_checkbox)
+        private val favicon = view.findViewById<ImageView>(R.id.history_favicon)
+        private val title = view.findViewById<TextView>(R.id.history_title)
+        private val url = view.findViewById<TextView>(R.id.history_url)
+        private var item: HistoryItem? = null
+        private var mode: HistoryState.Mode = HistoryState.Mode.Normal
+        private val checkListener = CompoundButton.OnCheckedChangeListener { _, isChecked ->
+            if (mode is HistoryState.Mode.Normal) {
+                return@OnCheckedChangeListener
+            }
+
+            item?.apply {
+                val action = if (isChecked) {
+                    HistoryAction.AddItemForRemoval(this)
+                } else {
+                    HistoryAction.RemoveItemForRemoval(this)
+                }
+
+                actionEmitter.onNext(action)
+            }
+        }
+
+        init {
+            view.setOnClickListener {
+                if (mode is HistoryState.Mode.Editing) {
+                    checkbox.isChecked = !checkbox.isChecked
+                    return@setOnClickListener
+                }
+
+                item?.apply {
+                    actionEmitter.onNext(HistoryAction.Select(this))
+                }
+            }
+
+            view.setOnLongClickListener {
+                item?.apply {
+                    actionEmitter.onNext(HistoryAction.EnterEditMode(this))
+                }
+
+                true
+            }
+
+            checkbox.setOnCheckedChangeListener(checkListener)
+        }
+
+        fun bind(item: HistoryItem, mode: HistoryState.Mode) {
+            this.item = item
+            this.mode = mode
+
+            title.text = item.title
+            url.text = item.url
+
+            val isEditing = mode is HistoryState.Mode.Editing
+            checkbox.visibility = if (isEditing) { View.VISIBLE } else { View.GONE }
+            favicon.visibility = if (isEditing) { View.INVISIBLE } else { View.VISIBLE }
+
+            if (mode is HistoryState.Mode.Editing) {
+                checkbox.setOnCheckedChangeListener(null)
+
+                // Don't set the checkbox if it already contains the right value.
+                // This prevent us from cutting off the animation
+                val shouldCheck = mode.selectedItems.contains(item)
+                if (checkbox.isChecked != shouldCheck) {
+                    checkbox.isChecked = mode.selectedItems.contains(item)
+                }
+                checkbox.setOnCheckedChangeListener(checkListener)
+            }
+        }
+
+        companion object {
+            const val LAYOUT_ID = R.layout.history_list_item
+        }
+    }
+
+    class HistoryHeaderViewHolder(
+        view: View
+    ) : RecyclerView.ViewHolder(view) {
+        private val title = view.findViewById<TextView>(R.id.history_header_title)
+
+        fun bind(title: String) {
+            this.title.text = title
+        }
+
+        companion object {
+            const val LAYOUT_ID = R.layout.history_header
+        }
+    }
+
+    private var items: List<HistoryItem> = emptyList()
+    private var mode: HistoryState.Mode = HistoryState.Mode.Normal
+
+    fun updateData(items: List<HistoryItem>, mode: HistoryState.Mode) {
+        this.items = items
+        this.mode = mode
+        notifyDataSetChanged()
+    }
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
+        val view = LayoutInflater.from(parent.context).inflate(viewType, parent, false)
+
+        return when (viewType) {
+            HistoryHeaderViewHolder.LAYOUT_ID -> HistoryHeaderViewHolder(view)
+            HistoryListItemViewHolder.LAYOUT_ID -> HistoryListItemViewHolder(view, actionEmitter)
+            else -> throw IllegalStateException("viewType $viewType does not match to a ViewHolder")
+        }
+    }
+
+    override fun getItemViewType(position: Int): Int {
+        return when (position) {
+            0 -> HistoryHeaderViewHolder.LAYOUT_ID
+            else -> HistoryListItemViewHolder.LAYOUT_ID
+        }
+    }
+
+    override fun getItemCount(): Int = items.count() + NUMBER_OF_SECTIONS
+
+    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
+        when (holder) {
+            is HistoryHeaderViewHolder -> holder.bind("Today")
+            is HistoryListItemViewHolder -> holder.bind(items[position - NUMBER_OF_SECTIONS], mode)
+        }
+    }
+
+    companion object {
+        private const val NUMBER_OF_SECTIONS = 1
+    }
+}

app/src/main/java/org/mozilla/fenix/library/history/HistoryComponent.kt

@@ -57,6 +57,7 @@ class HistoryComponent(
                     state
                 }
             }
+            is HistoryChange.ExitEditMode -> state.copy(mode = HistoryState.Mode.Normal)
         }
     }
 
@@ -77,6 +78,7 @@ data class HistoryState(val items: List<HistoryItem>, val mode: Mode) : ViewStat
 sealed class HistoryAction : Action {
     data class Select(val item: HistoryItem) : HistoryAction()
     data class EnterEditMode(val item: HistoryItem) : HistoryAction()
+    object onBackPressed : HistoryAction()
     data class AddItemForRemoval(val item: HistoryItem) : HistoryAction()
     data class RemoveItemForRemoval(val item: HistoryItem) : HistoryAction()
 }
@@ -84,6 +86,7 @@ sealed class HistoryAction : Action {
 sealed class HistoryChange : Change {
     data class Change(val list: List<HistoryItem>) : HistoryChange()
     data class EnterEditMode(val item: HistoryItem) : HistoryChange()
+    object ExitEditMode : HistoryChange()
     data class AddItemForRemoval(val item: HistoryItem) : HistoryChange()
     data class RemoveItemForRemoval(val item: HistoryItem) : HistoryChange()
 }

app/src/main/java/org/mozilla/fenix/library/history/HistoryFragment.kt

@@ -22,6 +22,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
 import org.mozilla.fenix.HomeActivity
+import mozilla.components.support.base.feature.BackHandler
 import org.mozilla.fenix.R
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.mvi.ActionBusFactory
@@ -29,9 +30,11 @@ import org.mozilla.fenix.mvi.getManagedEmitter
 import org.mozilla.fenix.mvi.getSafeManagedObservable
 import kotlin.coroutines.CoroutineContext
 
-class HistoryFragment : Fragment(), CoroutineScope {
+class HistoryFragment : Fragment(), CoroutineScope, BackHandler {
 
     private lateinit var job: Job
+    private lateinit var historyComponent: HistoryComponent
+
     override val coroutineContext: CoroutineContext
         get() = Dispatchers.Main + job
 
@@ -41,7 +44,7 @@ class HistoryFragment : Fragment(), CoroutineScope {
         savedInstanceState: Bundle?
     ): View? {
         val view = inflater.inflate(R.layout.fragment_history, container, false)
-        HistoryComponent(view.history_layout, ActionBusFactory.get(this))
+        historyComponent = HistoryComponent(view.history_layout, ActionBusFactory.get(this))
 
         return view
     }
@@ -64,6 +67,8 @@ class HistoryFragment : Fragment(), CoroutineScope {
                         .onNext(HistoryChange.AddItemForRemoval(it.item))
                     is HistoryAction.RemoveItemForRemoval -> getManagedEmitter<HistoryChange>()
                         .onNext(HistoryChange.RemoveItemForRemoval(it.item))
+                    is HistoryAction.onBackPressed -> getManagedEmitter<HistoryChange>()
+                        .onNext(HistoryChange.ExitEditMode)
                 }
             }
     }
@@ -118,4 +123,9 @@ class HistoryFragment : Fragment(), CoroutineScope {
             else -> super.onOptionsItemSelected(item)
         }
     }
+
+    override fun onBackPressed(): Boolean {
+        if((historyComponent.uiView as HistoryUIView).onBackPressed()) { return true }
+        return false
+    }
 }

app/src/main/java/org/mozilla/fenix/library/history/HistoryUIView.kt

@@ -1,4 +1,3 @@
-
 /* This Source Code Form is subject to the terms of the Mozilla Public
    License, v. 2.0. If a copy of the MPL was not distributed with this
    file, You can obtain one at http://mozilla.org/MPL/2.0/. */
@@ -6,17 +5,13 @@
 package org.mozilla.fenix.library.history
 
 import android.view.LayoutInflater
-import android.view.View
 import android.view.ViewGroup
-import android.widget.CheckBox
-import android.widget.CompoundButton
-import android.widget.ImageView
-import android.widget.TextView
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import io.reactivex.Observable
 import io.reactivex.Observer
 import io.reactivex.functions.Consumer
+import mozilla.components.support.base.feature.BackHandler
 import org.mozilla.fenix.R
 import org.mozilla.fenix.mvi.UIView
 
@@ -25,7 +20,11 @@ class HistoryUIView(
     actionEmitter: Observer<HistoryAction>,
     changesObservable: Observable<HistoryChange>
 ) :
-    UIView<HistoryState, HistoryAction, HistoryChange>(container, actionEmitter, changesObservable) {
+    UIView<HistoryState, HistoryAction, HistoryChange>(container, actionEmitter, changesObservable),
+    BackHandler {
+
+    var mode: HistoryState.Mode = HistoryState.Mode.Normal
+        private set
 
     override val view: RecyclerView = LayoutInflater.from(container.context)
         .inflate(R.layout.component_history, container, true)
@@ -39,143 +38,16 @@ class HistoryUIView(
     }
 
     override fun updateView() = Consumer<HistoryState> {
+        mode = it.mode
         (view.adapter as HistoryAdapter).updateData(it.items, it.mode)
     }
-}
-
-private class HistoryAdapter(
-    private val actionEmitter: Observer<HistoryAction>
-) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
-    class HistoryListItemViewHolder(
-        view: View,
-        private val actionEmitter: Observer<HistoryAction>
-    ) : RecyclerView.ViewHolder(view) {
-
-        private val checkbox = view.findViewById<CheckBox>(R.id.should_remove_checkbox)
-        private val favicon = view.findViewById<ImageView>(R.id.history_favicon)
-        private val title = view.findViewById<TextView>(R.id.history_title)
-        private val url = view.findViewById<TextView>(R.id.history_url)
-        private var item: HistoryItem? = null
-        private var mode: HistoryState.Mode = HistoryState.Mode.Normal
-        private val checkListener = object : CompoundButton.OnCheckedChangeListener {
-            override fun onCheckedChanged(buttonView: CompoundButton?, isChecked: Boolean) {
-                if (mode is HistoryState.Mode.Normal) { return }
-
-                item?.apply {
-                    val action = if (isChecked) {
-                        HistoryAction.AddItemForRemoval(this)
-                    } else {
-                        HistoryAction.RemoveItemForRemoval(this)
-                    }
-
-                    actionEmitter.onNext(action)
-                }
-            }
-        }
-
-        init {
-            view.setOnClickListener {
-                if (mode is HistoryState.Mode.Editing) {
-                    checkbox.isChecked = !checkbox.isChecked
-                    return@setOnClickListener
-                }
-
-                item?.apply {
-                    actionEmitter.onNext(HistoryAction.Select(this))
-                }
-            }
-
-            view.setOnLongClickListener {
-                item?.apply {
-                    actionEmitter.onNext(HistoryAction.EnterEditMode(this))
-                }
-
-                true
-            }
-
-            checkbox.setOnCheckedChangeListener(checkListener)
-        }
-
-        fun bind(item: HistoryItem, mode: HistoryState.Mode) {
-            this.item = item
-            this.mode = mode
-
-            title.text = item.title
-            url.text = item.url
-
-            val isEditing = mode is HistoryState.Mode.Editing
-            checkbox.visibility = if (isEditing) { View.VISIBLE } else { View.GONE }
-            favicon.visibility = if (isEditing) { View.INVISIBLE } else { View.VISIBLE }
-
-            if (mode is HistoryState.Mode.Editing) {
-                checkbox.setOnCheckedChangeListener(null)
-
-                // Don't set the checkbox if it already contains the right value.
-                // This prevent us from cutting off the animation
-                val shouldCheck = mode.selectedItems.contains(item)
-                if (checkbox.isChecked != shouldCheck) {
-                    checkbox.isChecked = mode.selectedItems.contains(item)
-                }
-                checkbox.setOnCheckedChangeListener(checkListener)
-            }
-        }
-
-        companion object {
-            const val LAYOUT_ID = R.layout.history_list_item
-        }
-    }
-
-    class HistoryHeaderViewHolder(
-        view: View
-    ) : RecyclerView.ViewHolder(view) {
-        private val title = view.findViewById<TextView>(R.id.history_header_title)
 
-        fun bind(title: String) {
+    override fun onBackPressed(): Boolean {
-            this.title.text = title
+        if (mode is HistoryState.Mode.Editing) {
+            actionEmitter.onNext(HistoryAction.onBackPressed)
+            return true
         }
 
-        companion object {
+        return false
-            const val LAYOUT_ID = R.layout.history_header
-        }
-    }
-
-    private var items: List<HistoryItem> = emptyList()
-    private var mode: HistoryState.Mode = HistoryState.Mode.Normal
-
-    fun updateData(items: List<HistoryItem>, mode: HistoryState.Mode) {
-        this.items = items
-        this.mode = mode
-        notifyDataSetChanged()
-    }
-
-    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
-        val view = LayoutInflater.from(parent.context).inflate(viewType, parent, false)
-
-        return when (viewType) {
-            HistoryHeaderViewHolder.LAYOUT_ID -> HistoryHeaderViewHolder(view)
-            HistoryListItemViewHolder.LAYOUT_ID -> HistoryListItemViewHolder(view, actionEmitter)
-            else -> throw IllegalStateException("viewType $viewType does not match to a ViewHolder")
-        }
-    }
-
-    override fun getItemViewType(position: Int): Int {
-        return when (position) {
-            0 -> HistoryHeaderViewHolder.LAYOUT_ID
-            else -> HistoryListItemViewHolder.LAYOUT_ID
-        }
-    }
-
-    override fun getItemCount(): Int = items.count() + NUMBER_OF_SECTIONS
-
-    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
-
-        when (holder) {
-            is HistoryHeaderViewHolder -> holder.bind("Today")
-            is HistoryListItemViewHolder -> holder.bind(items[position - NUMBER_OF_SECTIONS], mode)
-        }
-    }
-
-    companion object {
-        private const val NUMBER_OF_SECTIONS = 1
     }
 }