allow selecting multiple items

app/src/main/java/com/simplemobiletools/filemanager/fragments/ItemsFragment.java

@@ -7,7 +7,10 @@ import android.os.Bundle;
 import android.support.annotation.Nullable;
 import android.support.v4.widget.SwipeRefreshLayout;
 import android.support.v7.app.AlertDialog;
+import android.view.ActionMode;
 import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.WindowManager;
@@ -35,7 +38,7 @@ import butterknife.ButterKnife;
 import butterknife.OnClick;
 
 public class ItemsFragment extends android.support.v4.app.Fragment
-        implements AdapterView.OnItemClickListener, SwipeRefreshLayout.OnRefreshListener {
+        implements AdapterView.OnItemClickListener, SwipeRefreshLayout.OnRefreshListener, ListView.MultiChoiceModeListener {
     @BindView(R.id.items_list) ListView mListView;
     @BindView(R.id.items_swipe_refresh) SwipeRefreshLayout mSwipeRefreshLayout;
 
@@ -44,6 +47,7 @@ public class ItemsFragment extends android.support.v4.app.Fragment
     private String mPath;
 
     private boolean mShowHidden;
+    private int mSelectedItemsCnt;
 
     @Nullable
     @Override
@@ -84,6 +88,7 @@ public class ItemsFragment extends android.support.v4.app.Fragment
         final ItemsAdapter adapter = new ItemsAdapter(getContext(), mItems);
         mListView.setAdapter(adapter);
         mListView.setOnItemClickListener(this);
+        mListView.setMultiChoiceModeListener(this);
     }
 
     public void setListener(ItemInteractionListener listener) {
@@ -216,6 +221,48 @@ public class ItemsFragment extends android.support.v4.app.Fragment
         return type + "/*";
     }
 
+    @Override
+    public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) {
+        if (checked) {
+            mSelectedItemsCnt++;
+        } else {
+            mSelectedItemsCnt--;
+        }
+
+        if (mSelectedItemsCnt > 0) {
+            mode.setTitle(String.valueOf(mSelectedItemsCnt));
+        }
+
+        mode.invalidate();
+    }
+
+    @Override
+    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
+        mode.getMenuInflater().inflate(R.menu.cab, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
+        return false;
+    }
+
+    @Override
+    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
+        switch (item.getItemId()) {
+            case R.id.cab_delete:
+                mode.finish();
+                return true;
+            default:
+                return false;
+        }
+    }
+
+    @Override
+    public void onDestroyActionMode(ActionMode mode) {
+        mSelectedItemsCnt = 0;
+    }
+
     public interface ItemInteractionListener {
         void itemClicked(String path);
     }

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

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item>
+        <selector>
+            <item
+                android:drawable="@color/activated_item_foreground"
+                android:state_activated="true"/>
+        </selector>
+    </item>
+    <item>
+        <ripple android:color="@color/pressed_item_foreground">
+            <item android:id="@android:id/mask">
+                <color android:color="@android:color/white"/>
+            </item>
+        </ripple>
+    </item>
+</layer-list>

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

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@color/pressed_item_foreground" android:state_pressed="true"/>
+    <item android:drawable="@color/activated_item_foreground" android:state_activated="true"/>
+</selector>

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

@@ -14,6 +14,7 @@
             android:id="@+id/items_list"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
+            android:choiceMode="multipleChoiceModal"
             android:clipToPadding="false"
             android:paddingLeft="@dimen/activity_margin"/>
     </android.support.v4.widget.SwipeRefreshLayout>

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

@@ -4,6 +4,7 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
+    android:foreground="@drawable/selector"
     android:paddingRight="@dimen/activity_margin">
 
     <ImageView

app/src/main/res/menu/cab.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+      xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item
+        android:id="@+id/cab_delete"
+        android:icon="@mipmap/delete"
+        android:title="@string/delete"
+        app:showAsAction="ifRoom"/>
+</menu>

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

@@ -5,4 +5,6 @@
     <color name="colorAccent">@color/colorPrimary</color>
 
     <color name="lightGrey">#33000000</color>
+    <color name="pressed_item_foreground">#08000000</color>
+    <color name="activated_item_foreground">#11000000</color>
 </resources>

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

@@ -7,6 +7,7 @@
     <string name="file">File</string>
     <string name="invalid_name">The name contains invalid characters</string>
     <string name="error_occurred">An unknown error occurred</string>
+    <string name="delete">Delete</string>
 
     <!-- About -->
     <string name="about">About</string>