Allow user to delete note files

app/src/main/java/ro/code4/monitorizarevot/helper/FileUtils.kt

@@ -43,9 +43,13 @@ object FileUtils {
             contentResolver.query(uri, null, null, null, null)
                 ?.let { cursor ->
                     cursor.run {
-                        if (moveToFirst())
-                            getString(getColumnIndex(OpenableColumns.DISPLAY_NAME))
-                        else null
+                        if (moveToFirst()) {
+                            getString(getColumnIndex(OpenableColumns.DISPLAY_NAME))?.let { name ->
+                                "${System.currentTimeMillis()}_${name}"
+                            }
+                        } else {
+                            null
+                        }
                     }.also { cursor.close() }
                 }
         }.getOrNull()

app/src/main/java/ro/code4/monitorizarevot/ui/notes/NoteFragment.kt

@@ -14,6 +14,7 @@ import android.provider.Settings
 import android.text.TextWatcher
 import android.view.MotionEvent
 import android.view.View
+import android.widget.ImageButton
 import android.widget.LinearLayout
 import android.widget.TextView
 import androidx.appcompat.app.AlertDialog
@@ -79,12 +80,16 @@ class NoteFragment : ViewModelFragment<NoteViewModel>(), PermissionManager.Permi
         viewModel.filesNames().observe(viewLifecycleOwner, Observer {
             noteFileContainer.visibility = View.VISIBLE
             noteFileContainer.removeAllViews()
-            it.forEach { filename ->
-                val newTextView = requireActivity().layoutInflater.inflate(
+            it.forEachIndexed { index, filename ->
+                val attachmentView = requireActivity().layoutInflater.inflate(
                     R.layout.include_note_filename, noteFileContainer, false
-                ) as TextView
-                newTextView.text = filename
-                noteFileContainer.addView(newTextView)
+                ).also { view ->
+                    view.findViewById<TextView>(R.id.filenameText).text = filename
+                    view.findViewById<ImageButton>(R.id.deleteFile).setOnClickListener {
+                        viewModel.deleteFile(filename, index)
+                    }
+                }
+                noteFileContainer.addView(attachmentView)
             }
         })
         viewModel.submitCompleted().observe(this, Observer {

app/src/main/java/ro/code4/monitorizarevot/ui/notes/NoteViewModel.kt

@@ -32,7 +32,7 @@ class NoteViewModel : BaseFormViewModel() {
     private val notesLiveData = MutableLiveData<ArrayList<ListItem>>()
     private val filesNamesLiveData = MutableLiveData<List<String>>()
     private val submitCompletedLiveData = SingleLiveEvent<Void>()
-    private val noteFiles = mutableListOf<File>()
+    private var noteFiles = mutableListOf<File>()
     private val listObserver =
         Observer<List<Note>> { list ->
             processList(list)
@@ -131,6 +131,21 @@ class NoteViewModel : BaseFormViewModel() {
         }
     }
 
+    fun deleteFile(filename: String, position: Int) {
+        val targetFiles = noteFiles.filter { it.absolutePath.endsWith("/$filename") }
+        if (targetFiles.isNotEmpty() && targetFiles.size == 1) {
+            try {
+                targetFiles[0].delete()
+            } catch (ex: Exception) {
+                // ignored
+                // this try-catch block will prevent the app from crashing if the file can't be deleted(which
+                // is ok because we dereference the file below and it is safe to remain on disk)
+            }
+        }
+        noteFiles = noteFiles.filterIndexed { index, _ -> index != position }.toMutableList()
+        filesNamesLiveData.postValue(noteFiles.map { file -> file.name }.toList())
+    }
+
     fun addUserGeneratedFile(file: File?) {
         file?.let { noteFiles.add(it) }
     }
@@ -144,4 +159,4 @@ class NoteViewModel : BaseFormViewModel() {
             app.sendBroadcast(mediaScanIntent)
         }
     }
-}
+}

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

@@ -0,0 +1,15 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="64"
+    android:viewportHeight="64">
+    <path
+        android:strokeColor="#ff0000"
+        android:strokeWidth="3"
+        android:pathData="M32,8 A24,24 0 1 1 31.99,8 z" />
+
+    <path
+        android:strokeColor="#ff0000"
+        android:strokeWidth="3"
+        android:pathData="M24,24 L40,40 M40,24 L24,40" />
+</vector>

app/src/main/res/layout/include_note_filename.xml

@@ -1,11 +1,29 @@
 <?xml version="1.0" encoding="utf-8"?>
-<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
-    android:id="@+id/filenameText"
-    style="@style/Text.Small"
-    android:layout_width="wrap_content"
+    android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:layout_marginTop="@dimen/margin"
-    android:drawableStart="@drawable/ic_file"
-    android:drawablePadding="@dimen/small_margin"
-    tools:text="Frauda_0342.jpg" />
+    android:orientation="horizontal">
+
+    <TextView
+        android:id="@+id/filenameText"
+        style="@style/Text.Small"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_vertical"
+        android:layout_weight="1"
+        android:drawableStart="@drawable/ic_file"
+        android:drawablePadding="@dimen/small_margin"
+        tools:text="Frauda_0342.jpg" />
+
+    <ImageButton
+        android:id="@+id/deleteFile"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_vertical"
+        android:background="@null"
+        android:contentDescription="@null"
+        app:srcCompat="@drawable/ic_note_file_delete" />
+</LinearLayout>