Fix "None on top" sort mode

app/src/main/java/com/amaze/filemanager/adapters/RecyclerAdapter.java

@@ -21,6 +21,7 @@
 package com.amaze.filemanager.adapters;
 
 import static com.amaze.filemanager.filesystem.compressed.CompressedHelper.*;
+import static com.amaze.filemanager.filesystem.files.FileListSorter.SORT_NONE_ON_TOP;
 import static com.amaze.filemanager.ui.fragments.preferencefragments.PreferencesConstants.PREFERENCE_COLORIZE_ICONS;
 import static com.amaze.filemanager.ui.fragments.preferencefragments.PreferencesConstants.PREFERENCE_SHOW_FILE_SIZE;
 import static com.amaze.filemanager.ui.fragments.preferencefragments.PreferencesConstants.PREFERENCE_SHOW_GOBACK_BUTTON;
@@ -609,34 +610,43 @@ private void setItems(
   }
 
   public void createHeaders(boolean invalidate, List<IconDataParcelable> uris) {
-    boolean[] headers = new boolean[] {false, false};
+    if ((mainFragment.getMainFragmentViewModel() != null
+            && mainFragment.getMainFragmentViewModel().getDsort() == SORT_NONE_ON_TOP)
+        || getItemsDigested() == null
+        || getItemsDigested().isEmpty()) {
+      return;
+    } else {
+      boolean[] headers = new boolean[] {false, false};
 
-    for (int i = 0; i < getItemsDigested().size(); i++) {
+      for (int i = 0; i < getItemsDigested().size(); i++) {
 
-      if (getItemsDigested().get(i).layoutElementParcelable != null) {
-        LayoutElementParcelable nextItem = getItemsDigested().get(i).layoutElementParcelable;
+        if (getItemsDigested().get(i).layoutElementParcelable != null) {
+          LayoutElementParcelable nextItem = getItemsDigested().get(i).layoutElementParcelable;
 
-        if (!headers[0] && nextItem.isDirectory) {
-          headers[0] = true;
-          getItemsDigested().add(i, new ListItem(TYPE_HEADER_FOLDERS));
-          uris.add(i, null);
-          continue;
-        }
+          if (nextItem != null) {
+            if (!headers[0] && nextItem.isDirectory) {
+              headers[0] = true;
+              getItemsDigested().add(i, new ListItem(TYPE_HEADER_FOLDERS));
+              uris.add(i, null);
+              continue;
+            }
 
-        if (!headers[1]
-            && !nextItem.isDirectory
-            && !nextItem.title.equals(".")
-            && !nextItem.title.equals("..")) {
-          headers[1] = true;
-          getItemsDigested().add(i, new ListItem(TYPE_HEADER_FILES));
-          uris.add(i, null);
-          continue; // leave this continue for symmetry
+            if (!headers[1]
+                && !nextItem.isDirectory
+                && !nextItem.title.equals(".")
+                && !nextItem.title.equals("..")) {
+              headers[1] = true;
+              getItemsDigested().add(i, new ListItem(TYPE_HEADER_FILES));
+              uris.add(i, null);
+              continue; // leave this continue for symmetry
+            }
+          }
         }
       }
-    }
 
-    if (invalidate) {
-      notifyDataSetChanged();
+      if (invalidate) {
+        notifyDataSetChanged();
+      }
     }
   }
 

app/src/main/java/com/amaze/filemanager/asynchronous/asynctasks/LoadFilesListTask.java

@@ -22,6 +22,8 @@
 
 import static android.os.Build.VERSION.SDK_INT;
 import static android.os.Build.VERSION_CODES.Q;
+import static com.amaze.filemanager.filesystem.files.FileListSorter.SORT_ASC;
+import static com.amaze.filemanager.filesystem.files.FileListSorter.SORT_DSC;
 
 import java.io.File;
 import java.lang.ref.WeakReference;
@@ -258,9 +260,9 @@ private void postListCustomPathProcess(
 
     if (sortType <= 3) {
       sortBy = sortType;
-      isAscending = 1;
+      isAscending = SORT_ASC;
     } else {
-      isAscending = -1;
+      isAscending = SORT_DSC;
       sortBy = sortType - 4;
     }
 

app/src/main/java/com/amaze/filemanager/filesystem/files/FileListSorter.kt

@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2014-2020 Arpit Khurana <[email protected]>, Vishal Nehra <[email protected]>,
+ * Emmanuel Messulam<[email protected]>, Raymond Lai <airwave209gt at gmail.com> and Contributors.
+ *
+ * This file is part of Amaze File Manager.
+ *
+ * Amaze File Manager is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.amaze.filemanager.filesystem.files
+
+import androidx.annotation.IntDef
+import com.amaze.filemanager.adapters.data.LayoutElementParcelable
+import java.util.Locale
+
+/**
+ * [Comparator] implementation to sort [LayoutElementParcelable]s.
+ */
+class FileListSorter(
+    @DirSortMode dirArg: Int,
+    @SortBy sortArg: Int,
+    @SortOrder ascArg: Int
+) : Comparator<LayoutElementParcelable> {
+    private var dirsOnTop = dirArg
+    private val asc = ascArg
+    private val sort = sortArg
+
+    private fun isDirectory(path: LayoutElementParcelable): Boolean {
+        return path.isDirectory
+    }
+
+    /**
+     * Compares two elements and return negative, zero and positive integer if first argument is less
+     * than, equal to or greater than second
+     */
+    override fun compare(file1: LayoutElementParcelable, file2: LayoutElementParcelable): Int {
+        /*File f1;
+
+    if(!file1.hasSymlink()) {
+
+        f1=new File(file1.getDesc());
+    } else {
+        f1=new File(file1.getSymlink());
+    }
+
+    File f2;
+
+    if(!file2.hasSymlink()) {
+
+        f2=new File(file2.getDesc());
+    } else {
+        f2=new File(file1.getSymlink());
+    }*/
+        if (dirsOnTop == SORT_DIR_ON_TOP) {
+            if (isDirectory(file1) && !isDirectory(file2)) {
+                return -1
+            } else if (isDirectory(file2) && !isDirectory(file1)) {
+                return 1
+            }
+        } else if (dirsOnTop == SORT_FILE_ON_TOP) {
+            if (isDirectory(file1) && !isDirectory(file2)) {
+                return 1
+            } else if (isDirectory(file2) && !isDirectory(file1)) {
+                return -1
+            }
+        }
+
+        when (sort) {
+            SORT_BY_NAME -> {
+                // sort by name
+                return asc * file1.title.compareTo(file2.title, ignoreCase = true)
+            }
+            SORT_BY_LAST_MODIFIED -> {
+                // sort by last modified
+                return asc * java.lang.Long.valueOf(file1.date).compareTo(file2.date)
+            }
+            SORT_BY_SIZE -> {
+                // sort by size
+                return if (!file1.isDirectory && !file2.isDirectory) {
+                    asc * java.lang.Long.valueOf(file1.longSize).compareTo(file2.longSize)
+                } else {
+                    file1.title.compareTo(file2.title, ignoreCase = true)
+                }
+            }
+            SORT_BY_TYPE -> {
+                // sort by type
+                return if (!file1.isDirectory && !file2.isDirectory) {
+                    val ext_a = getExtension(file1.title)
+                    val ext_b = getExtension(file2.title)
+                    val res = asc * ext_a.compareTo(ext_b)
+                    if (res == 0) {
+                        asc * file1.title.compareTo(file2.title, ignoreCase = true)
+                    } else {
+                        res
+                    }
+                } else {
+                    file1.title.compareTo(file2.title, ignoreCase = true)
+                }
+            }
+            else -> return 0
+        }
+    }
+
+    companion object {
+
+        const val SORT_BY_NAME = 0
+        const val SORT_BY_LAST_MODIFIED = 1
+        const val SORT_BY_SIZE = 2
+        const val SORT_BY_TYPE = 3
+
+        const val SORT_DIR_ON_TOP = 0
+        const val SORT_FILE_ON_TOP = 1
+        const val SORT_NONE_ON_TOP = 2
+
+        const val SORT_ASC = 1
+        const val SORT_DSC = -1
+
+        @Retention(AnnotationRetention.SOURCE)
+        @IntDef(SORT_BY_NAME, SORT_BY_LAST_MODIFIED, SORT_BY_SIZE, SORT_BY_TYPE)
+        annotation class SortBy
+
+        @Retention(AnnotationRetention.SOURCE)
+        @IntDef(SORT_DIR_ON_TOP, SORT_FILE_ON_TOP, SORT_NONE_ON_TOP)
+        annotation class DirSortMode
+
+        @Retention(AnnotationRetention.SOURCE)
+        @IntDef(SORT_ASC, SORT_DSC)
+        annotation class SortOrder
+
+        /**
+         * Convenience method to get the file extension in given path.
+         *
+         * TODO: merge with same definition somewhere else (if any)
+         */
+        @JvmStatic
+        fun getExtension(a: String): String {
+            return a.substringAfterLast('.').lowercase(Locale.getDefault())
+        }
+    }
+}