Show total number of selected items

app/src/main/java/sushi/hardcore/droidfs/MainActivity.kt

@@ -35,7 +35,7 @@ import java.io.File
 import java.util.*
 import kotlin.NoSuchElementException
 
-class MainActivity : BaseActivity() {
+class MainActivity : BaseActivity(), VolumeAdapter.Listener {
 
     companion object {
         const val DEFAULT_VOLUME_KEY = "default_volume"
@@ -101,8 +101,7 @@ class MainActivity : BaseActivity() {
             volumeDatabase,
             !pickMode && !dropMode,
             !dropMode,
-            ::onVolumeItemClick,
+            this,
-            ::onVolumeItemLongClick,
         )
         binding.recyclerViewVolumes.adapter = volumeAdapter
         binding.recyclerViewVolumes.layoutManager = LinearLayoutManager(this)
@@ -147,14 +146,22 @@ class MainActivity : BaseActivity() {
         defaultVolumeName = sharedPrefs.getString(DEFAULT_VOLUME_KEY, null)
     }
 
-    private fun onVolumeItemClick(volume: Volume, position: Int) {
+    override fun onSelectionChanged(size: Int) {
+        title = if (size == 0) {
+            getString(R.string.app_name)
+        } else {
+            getString(R.string.elements_selected, size, volumeAdapter.volumes.size)
+        }
+    }
+
+    override fun onVolumeItemClick(volume: Volume, position: Int) {
         if (volumeAdapter.selectedItems.isEmpty())
             openVolume(volume, position)
         else
             invalidateOptionsMenu()
     }
 
-    private fun onVolumeItemLongClick() {
+    override fun onVolumeItemLongClick() {
         invalidateOptionsMenu()
     }
 
@@ -174,6 +181,7 @@ class MainActivity : BaseActivity() {
     private fun unselect(position: Int) {
         volumeAdapter.selectedItems.remove(position)
         volumeAdapter.onVolumeChanged(position)
+        onSelectionChanged(0) // unselect() is always called when only one element is selected
         invalidateOptionsMenu()
     }
 

app/src/main/java/sushi/hardcore/droidfs/adapters/ExplorerElementAdapter.kt

@@ -26,10 +26,9 @@ import java.util.*
 class ExplorerElementAdapter(
     val activity: AppCompatActivity,
     val gocryptfsVolume: GocryptfsVolume?,
-    val onExplorerElementClick: (Int) -> Unit,
+    private val listener: Listener,
-    val onExplorerElementLongClick: (Int) -> Unit,
     val thumbnailMaxSize: Long,
-) : SelectableAdapter<ExplorerElement>() {
+) : SelectableAdapter<ExplorerElement>(listener::onSelectionChanged) {
     val dateFormat: DateFormat = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.getDefault())
     var explorerElements = listOf<ExplorerElement>()
     @SuppressLint("NotifyDataSetChanged")
@@ -47,6 +46,12 @@ class ExplorerElementAdapter(
         }
     }
 
+    interface Listener {
+        fun onSelectionChanged(size: Int)
+        fun onExplorerElementClick(position: Int)
+        fun onExplorerElementLongClick(position: Int)
+    }
+
     override fun getItems(): List<ExplorerElement> {
         return explorerElements
     }
@@ -60,12 +65,12 @@ class ExplorerElementAdapter(
     }
 
     override fun onItemClick(position: Int): Boolean {
-        onExplorerElementClick(position)
+        listener.onExplorerElementClick(position)
         return super.onItemClick(position)
     }
 
     override fun onItemLongClick(position: Int): Boolean {
-        onExplorerElementLongClick(position)
+        listener.onExplorerElementLongClick(position)
         return super.onItemLongClick(position)
     }
 

app/src/main/java/sushi/hardcore/droidfs/adapters/SelectableAdapter.kt

@@ -4,7 +4,7 @@ import android.view.View
 import androidx.recyclerview.widget.RecyclerView
 import sushi.hardcore.droidfs.R
 
-abstract class SelectableAdapter<T> : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
+abstract class SelectableAdapter<T>(private val onSelectionChanged: (Int) -> Unit) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
     var selectedItems: MutableSet<Int> = HashSet()
 
     protected abstract fun getItems(): List<T>
@@ -14,13 +14,15 @@ abstract class SelectableAdapter<T> : RecyclerView.Adapter<RecyclerView.ViewHold
     }
 
     protected open fun toggleSelection(position: Int): Boolean {
-        return if (selectedItems.contains(position)) {
+        val isSelected = if (selectedItems.contains(position)) {
             selectedItems.remove(position)
             false
         } else {
             selectedItems.add(position)
             true
         }
+        onSelectionChanged(selectedItems.size)
+        return isSelected
     }
 
     protected open fun onItemClick(position: Int): Boolean {
@@ -45,6 +47,7 @@ abstract class SelectableAdapter<T> : RecyclerView.Adapter<RecyclerView.ViewHold
                 notifyItemChanged(i)
             }
         }
+        onSelectionChanged(selectedItems.size)
     }
 
     fun unSelectAll(notifyChange: Boolean) {
@@ -57,6 +60,7 @@ abstract class SelectableAdapter<T> : RecyclerView.Adapter<RecyclerView.ViewHold
         } else {
             selectedItems.clear()
         }
+        onSelectionChanged(selectedItems.size)
     }
 
     private fun setBackground(rootView: View, isSelected: Boolean) {

app/src/main/java/sushi/hardcore/droidfs/adapters/VolumeAdapter.kt

@@ -17,9 +17,8 @@ class VolumeAdapter(
     private val volumeDatabase: VolumeDatabase,
     private val allowSelection: Boolean,
     private val showReadOnly: Boolean,
-    private val onVolumeItemClick: (Volume, Int) -> Unit,
+    private val listener: Listener,
-    private val onVolumeItemLongClick: () -> Unit,
+) : SelectableAdapter<Volume>(listener::onSelectionChanged) {
-) : SelectableAdapter<Volume>() {
     private val inflater: LayoutInflater = LayoutInflater.from(context)
     lateinit var volumes: List<Volume>
 
@@ -27,6 +26,12 @@ class VolumeAdapter(
         reloadVolumes()
     }
 
+    interface Listener {
+        fun onSelectionChanged(size: Int)
+        fun onVolumeItemClick(volume: Volume, position: Int)
+        fun onVolumeItemLongClick()
+    }
+
     override fun getItems(): List<Volume> {
         return volumes
     }
@@ -40,7 +45,7 @@ class VolumeAdapter(
     }
 
     override fun onItemClick(position: Int): Boolean {
-        onVolumeItemClick(volumes[position], position)
+        listener.onVolumeItemClick(volumes[position], position)
         return if (allowSelection) {
             super.onItemClick(position)
         } else {
@@ -49,7 +54,7 @@ class VolumeAdapter(
     }
 
     override fun onItemLongClick(position: Int): Boolean {
-        onVolumeItemLongClick()
+        listener.onVolumeItemLongClick()
         return if (allowSelection)
             super.onItemLongClick(position)
         else

app/src/main/java/sushi/hardcore/droidfs/explorers/BaseExplorerActivity.kt

@@ -41,7 +41,7 @@ import sushi.hardcore.droidfs.util.PathUtils
 import sushi.hardcore.droidfs.widgets.CustomAlertDialogBuilder
 import sushi.hardcore.droidfs.widgets.EditTextDialog
 
-open class BaseExplorerActivity : BaseActivity() {
+open class BaseExplorerActivity : BaseActivity(), ExplorerElementAdapter.Listener {
     private lateinit var sortOrderEntries: Array<String>
     private lateinit var sortOrderValues: Array<String>
     private var foldersFirst = true
@@ -100,7 +100,7 @@ open class BaseExplorerActivity : BaseActivity() {
             titleText = customView.findViewById(R.id.title_text)
         }
         title = ""
-        titleText.text = getString(R.string.volume, volumeName)
+        setVolumeNameTitle()
         explorerAdapter = ExplorerElementAdapter(
             this,
             if (sharedPrefs.getBoolean("thumbnails", true)) {
@@ -108,8 +108,7 @@ open class BaseExplorerActivity : BaseActivity() {
             } else {
                 null
             },
-            ::onExplorerItemClick,
+            this,
-            ::onExplorerItemLongClick,
             sharedPrefs.getLong(ConstValues.THUMBNAIL_MAX_SIZE_KEY, ConstValues.DEFAULT_THUMBNAIL_MAX_SIZE)*1000,
         )
         explorerViewModel = ViewModelProvider(this).get(ExplorerViewModel::class.java)
@@ -209,7 +208,19 @@ open class BaseExplorerActivity : BaseActivity() {
             .show()
     }
 
-    protected open fun onExplorerItemClick(position: Int) {
+    private fun setVolumeNameTitle() {
+        titleText.text = getString(R.string.volume, volumeName)
+    }
+
+    override fun onSelectionChanged(size: Int) {
+        if (size == 0) {
+            setVolumeNameTitle()
+        } else {
+            titleText.text = getString(R.string.elements_selected, size, explorerElements.count { !it.isParentFolder })
+        }
+    }
+
+    override fun onExplorerElementClick(position: Int) {
         if (explorerAdapter.selectedItems.isEmpty()) {
             val fullPath = explorerElements[position].fullPath
             when {
@@ -240,7 +251,7 @@ open class BaseExplorerActivity : BaseActivity() {
         invalidateOptionsMenu()
     }
 
-    protected open fun onExplorerItemLongClick(position: Int) {
+    override fun onExplorerElementLongClick(position: Int) {
         invalidateOptionsMenu()
     }
 

app/src/main/java/sushi/hardcore/droidfs/explorers/ExplorerActivity.kt

@@ -217,8 +217,8 @@ class ExplorerActivity : BaseExplorerActivity() {
         usf_share = sharedPrefs.getBoolean("usf_share", false)
     }
 
-    override fun onExplorerItemLongClick(position: Int) {
+    override fun onExplorerElementLongClick(position: Int) {
-        super.onExplorerItemLongClick(position)
+        super.onExplorerElementLongClick(position)
         cancelItemAction()
     }
 

app/src/main/java/sushi/hardcore/droidfs/explorers/ExplorerActivityPick.kt

@@ -21,7 +21,7 @@ class ExplorerActivityPick : BaseExplorerActivity() {
         //don't bind
     }
 
-    override fun onExplorerItemClick(position: Int) {
+    override fun onExplorerElementClick(position: Int) {
         val wasSelecting = explorerAdapter.selectedItems.isNotEmpty()
         if (explorerAdapter.selectedItems.isEmpty()) {
             if (!wasSelecting) {

app/src/main/res/values/strings.xml

@@ -239,4 +239,5 @@
     <string name="multiple_folders">%d folders</string>
     <string name="default_open">Open this volume when launching the application</string>
     <string name="remove_default_open">Don\'t open by default</string>
+    <string name="elements_selected">%d/%d selected</string>
 </resources>