allow selecting multiple directories

app/src/main/kotlin/com/simplemobiletools/gallery/adapters/DirectoryAdapter.kt

@@ -1,27 +1,62 @@
 package com.simplemobiletools.gallery.adapters
 
-import android.content.Context
+import android.support.v7.view.ActionMode
 import android.support.v7.widget.RecyclerView
-import android.view.LayoutInflater
-import android.view.View
-import android.view.ViewGroup
+import android.view.*
+import com.bignerdranch.android.multiselector.ModalMultiSelectorCallback
 import com.bignerdranch.android.multiselector.MultiSelector
 import com.bignerdranch.android.multiselector.SwappingHolder
 import com.bumptech.glide.Glide
 import com.bumptech.glide.load.engine.DiskCacheStrategy
 import com.bumptech.glide.signature.StringSignature
 import com.simplemobiletools.gallery.R
+import com.simplemobiletools.gallery.activities.SimpleActivity
 import com.simplemobiletools.gallery.models.Directory
 import kotlinx.android.synthetic.main.directory_item.view.*
 import kotlinx.android.synthetic.main.directory_tmb.view.*
+import java.util.*
 
-class DirectoryAdapter(val mContext: Context, val mDirs: MutableList<Directory>, val itemClick: (Directory) -> Unit) :
+class DirectoryAdapter(val activity: SimpleActivity, val dirs: MutableList<Directory>, val itemClick: (Directory) -> Unit) :
         RecyclerView.Adapter<DirectoryAdapter.ViewHolder>() {
 
-    override fun getItemCount() = mDirs.size
+    val multiSelector = MultiSelector()
+    val views = ArrayList<View>()
+
+    companion object {
+        var actMode: ActionMode? = null
+    }
+
+    val multiSelectorMode = object : ModalMultiSelectorCallback(multiSelector) {
+        override fun onActionItemClicked(mode: ActionMode?, item: MenuItem): Boolean {
+            return when (item.itemId) {
+                R.id.cab_edit -> {
+                    true
+                }
+                else -> false
+            }
+        }
+
+        override fun onCreateActionMode(actionMode: ActionMode?, menu: Menu?): Boolean {
+            super.onCreateActionMode(actionMode, menu)
+            actMode = actionMode
+            activity.menuInflater.inflate(R.menu.cab_directories, menu)
+            return true
+        }
+
+        override fun onPrepareActionMode(actionMode: ActionMode?, menu: Menu?): Boolean {
+            val menuItem = menu?.findItem(R.id.cab_edit)
+            menuItem?.isVisible = multiSelector.selectedPositions.size == 1
+            return true
+        }
+
+        override fun onDestroyActionMode(actionMode: ActionMode?) {
+            super.onDestroyActionMode(actionMode)
+            views.forEach { it.dir_thumbnail.isSelected = false }
+        }
+    }
 
     override fun onBindViewHolder(holder: ViewHolder, position: Int) {
-        holder.bindView(mContext, mDirs[position])
+        views.add(holder.bindView(activity, multiSelectorMode, multiSelector, dirs[position]))
     }
 
     override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): ViewHolder {
@@ -29,22 +64,52 @@ class DirectoryAdapter(val mContext: Context, val mDirs: MutableList<Directory>,
         return ViewHolder(view, itemClick)
     }
 
+    override fun getItemCount() = dirs.size
+
     class ViewHolder(view: View, val itemClick: (Directory) -> (Unit)) : SwappingHolder(view, MultiSelector()) {
-        fun bindView(context: Context, directory: Directory) {
+        fun bindView(activity: SimpleActivity, multiSelectorCallback: ModalMultiSelectorCallback, multiSelector: MultiSelector, directory: Directory): View {
             itemView.dir_name.text = directory.name
             itemView.photo_cnt.text = directory.mediaCnt.toString()
 
             val tmb = directory.thumbnail
             val timestampSignature = StringSignature(directory.timestamp.toString())
             if (tmb.endsWith(".gif")) {
-                Glide.with(context).load(tmb).asGif().diskCacheStrategy(DiskCacheStrategy.NONE).signature(timestampSignature)
+                Glide.with(activity.applicationContext).load(tmb).asGif().diskCacheStrategy(DiskCacheStrategy.NONE).signature(timestampSignature)
                         .placeholder(R.color.tmb_background).centerCrop().crossFade().into(itemView.dir_thumbnail)
             } else {
-                Glide.with(context).load(tmb).diskCacheStrategy(DiskCacheStrategy.RESULT).signature(timestampSignature)
+                Glide.with(activity.applicationContext).load(tmb).diskCacheStrategy(DiskCacheStrategy.RESULT).signature(timestampSignature)
                         .placeholder(R.color.tmb_background).centerCrop().crossFade().into(itemView.dir_thumbnail)
             }
 
-            itemView.setOnClickListener { itemClick(directory) }
+            itemView.setOnClickListener { viewClicked(multiSelector, directory) }
+            itemView.setOnLongClickListener {
+                if (!multiSelector.isSelectable) {
+                    activity.startSupportActionMode(multiSelectorCallback)
+                    multiSelector.setSelected(this, true)
+                    actMode?.title = multiSelector.selectedPositions.size.toString()
+                    itemView.dir_thumbnail.isSelected = true
+                }
+                true
+            }
+            return itemView
+        }
+
+        fun viewClicked(multiSelector: MultiSelector, directory: Directory) {
+            if (multiSelector.isSelectable) {
+                val isSelected = multiSelector.selectedPositions.contains(layoutPosition)
+                multiSelector.setSelected(this, !isSelected)
+                itemView.dir_thumbnail.isSelected = !isSelected
+
+                val selectedCnt = multiSelector.selectedPositions.size
+                if (selectedCnt == 0) {
+                    actMode?.finish()
+                } else {
+                    actMode?.title = selectedCnt.toString()
+                }
+                actMode?.invalidate()
+            } else {
+                itemClick(directory)
+            }
         }
     }
 }

app/src/main/kotlin/com/simplemobiletools/gallery/dialogs/PickAlbumDialog.kt

@@ -1,15 +1,15 @@
 package com.simplemobiletools.gallery.dialogs
 
-import android.app.Activity
 import android.support.v7.app.AlertDialog
 import android.view.LayoutInflater
 import com.simplemobiletools.gallery.R
+import com.simplemobiletools.gallery.activities.SimpleActivity
 import com.simplemobiletools.gallery.adapters.DirectoryAdapter
 import com.simplemobiletools.gallery.asynctasks.GetDirectoriesAsynctask
 import com.simplemobiletools.gallery.models.Directory
 import java.util.*
 
-class PickAlbumDialog(val activity: Activity, val listener: OnPickAlbumListener) : GetDirectoriesAsynctask.GetDirectoriesListener {
+class PickAlbumDialog(val activity: SimpleActivity, val listener: OnPickAlbumListener) : GetDirectoriesAsynctask.GetDirectoriesListener {
     val context = activity.applicationContext
     var dialog: AlertDialog
 
@@ -29,7 +29,7 @@ class PickAlbumDialog(val activity: Activity, val listener: OnPickAlbumListener)
     }
 
     override fun gotDirectories(dirs: ArrayList<Directory>) {
-        DirectoryAdapter(context, dirs) {
+        DirectoryAdapter(activity, dirs) {
             listener.onSuccess(it.path)
             dialog.dismiss()
         }

app/src/main/res/drawable-v21/selector.xml

@@ -4,7 +4,7 @@
         <selector>
             <item
                 android:drawable="@color/activated_item_foreground"
-                android:state_activated="true"/>
+                android:state_selected="true"/>
         </selector>
     </item>
     <item>

app/src/main/res/drawable/selector.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <selector xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:drawable="@drawable/selected_pressed_mask" android:state_pressed="true"/>
-    <item android:drawable="@drawable/selected_mask" android:state_activated="true"/>
+    <item android:drawable="@drawable/selected_mask" android:state_selected="true"/>
 </selector>