Add ability to define a list divider in theme

README.md

@@ -112,6 +112,9 @@ you like..
         <item name="colorPrimaryDark">@color/primary_dark</item>
         <item name="colorAccent">@color/accent</item>
 
+        <!-- Setting a divider is entirely optional -->
+        <item name="nnf_list_item_divider">?android:attr/listDivider</item>
+
         <!-- Need to set this also to style create folder dialog -->
         <item name="alertDialogTheme">@style/FilePickerAlertDialogTheme</item>
 

library/src/main/java/com/nononsenseapps/filepicker/AbstractFilePickerFragment.java

@@ -8,6 +8,8 @@
 
 import android.app.Activity;
 import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
@@ -33,13 +35,11 @@
 import android.widget.TextView;
 import android.widget.Toast;
 
-import java.net.URI;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 
 import static com.nononsenseapps.filepicker.Utils.appendPath;
-import static com.nononsenseapps.filepicker.Utils.isValidFileName;
 
 /**
  * A fragment representing a list of Files.
@@ -85,6 +85,8 @@ public abstract class AbstractFilePickerFragment<T> extends Fragment
     protected FileItemAdapter<T> mAdapter = null;
     protected TextView mCurrentDirView;
     protected EditText mEditTextFileName;
+    protected RecyclerView recyclerView;
+    protected LinearLayoutManager layoutManager;
     protected SortedList<T> mFiles = null;
     protected Toast mToast = null;
     // Keep track if we are currently loading a directory, in case it takes a long time
@@ -167,13 +169,15 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container,
             setupToolbar(toolbar);
         }
 
-        RecyclerView recyclerView = (RecyclerView) view.findViewById(android.R.id.list);
+        recyclerView = (RecyclerView) view.findViewById(android.R.id.list);
         // improve performance if you know that changes in content
         // do not change the size of the RecyclerView
         recyclerView.setHasFixedSize(true);
         // use a linear layout manager
-        LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
+        layoutManager = new LinearLayoutManager(getActivity());
         recyclerView.setLayoutManager(layoutManager);
+        // Set Item Decoration if exists
+        configureItemDecoration(inflater, recyclerView);
         // Set adapter
         mAdapter = new FileItemAdapter<>(this);
         recyclerView.setAdapter(mAdapter);
@@ -231,6 +235,22 @@ public void afterTextChanged(Editable s) {
         return view;
     }
 
+    /**
+     * Checks if a divider drawable has been defined in the current theme. If it has, will apply
+     * an item decoration with the divider. If no divider has been specified, then does nothing.
+     */
+    protected void configureItemDecoration(@NonNull LayoutInflater inflater,
+                                           @NonNull RecyclerView recyclerView) {
+        final TypedArray attributes =
+                getActivity().obtainStyledAttributes(new int[]{R.attr.nnf_list_item_divider});
+        Drawable divider = attributes.getDrawable(0);
+        attributes.recycle();
+
+        if (divider != null) {
+            recyclerView.addItemDecoration(new DividerItemDecoration(divider));
+        }
+    }
+
     /**
      * Called when the cancel-button is pressed.
      *

library/src/main/java/com/nononsenseapps/filepicker/DividerItemDecoration.java

@@ -0,0 +1,48 @@
+package com.nononsenseapps.filepicker;
+
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+
+/**
+ * Basic ItemDecoration which loads a drawable as a divider.
+ */
+public class DividerItemDecoration extends RecyclerView.ItemDecoration {
+    private Drawable mDivider;
+
+    public DividerItemDecoration(Drawable divider) {
+        mDivider = divider;
+    }
+
+    @Override
+    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
+        super.getItemOffsets(outRect, view, parent, state);
+
+        if (parent.getChildAdapterPosition(view) == 0) {
+            return;
+        }
+
+        outRect.top = mDivider.getIntrinsicHeight();
+    }
+
+    @Override
+    public void onDraw(Canvas canvas, RecyclerView parent, RecyclerView.State state) {
+        int dividerLeft = parent.getPaddingLeft();
+        int dividerRight = parent.getWidth() - parent.getPaddingRight();
+
+        int childCount = parent.getChildCount();
+        for (int i = 0; i < childCount - 1; i++) {
+            View child = parent.getChildAt(i);
+
+            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
+
+            int dividerTop = child.getBottom() + params.bottomMargin;
+            int dividerBottom = dividerTop + mDivider.getIntrinsicHeight();
+
+            mDivider.setBounds(dividerLeft, dividerTop, dividerRight, dividerBottom);
+            mDivider.draw(canvas);
+        }
+    }
+}

library/src/main/res/values/attr.xml

@@ -15,4 +15,6 @@
     <attr name="nnf_save_icon_color" format="color"/>
     <!-- Color to apply to the directory icons in list -->
     <attr name="nnf_dir_icon_color" format="color"/>
+    <!-- Drawable to use as a divider between list items (optional) -->
+    <attr name="nnf_list_item_divider" format="reference"/>
 </resources>

sample/src/main/res/values/styles.xml

@@ -15,6 +15,8 @@
     </style>
 
     <style name="SampleThemeLight" parent="NNF_BaseTheme.Light">
+        <item name="nnf_list_item_divider">?android:attr/listDivider</item>
+
         <item name="colorPrimary">@color/primary</item>
         <item name="colorPrimaryDark">@color/primary_dark</item>
         <item name="colorAccent">@color/accent</item>