display a grid of photos on a directory selection

app/src/main/java/gallery/simplemobiletools/com/MainActivity.java

@@ -24,7 +24,7 @@ public class MainActivity extends AppCompatActivity implements OnItemClickListen
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        final GridView gridView = (GridView) findViewById(R.id.photo_grid);
+        final GridView gridView = (GridView) findViewById(R.id.directories_grid);
 
         dirs = new ArrayList<>(getDirectories().values());
         final DirectoryAdapter adapter = new DirectoryAdapter(this, dirs);
@@ -41,7 +41,8 @@ public class MainActivity extends AppCompatActivity implements OnItemClickListen
         if (cursor != null && cursor.moveToFirst()) {
             final int pathIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
             do {
-                final File file = new File(cursor.getString(pathIndex));
+                final String path = cursor.getString(pathIndex);
+                final File file = new File(path);
                 final String fileDir = file.getParent().toLowerCase();
 
                 if (directories.containsKey(fileDir)) {
@@ -49,9 +50,8 @@ public class MainActivity extends AppCompatActivity implements OnItemClickListen
                     final int newImageCnt = directory.getPhotoCnt() + 1;
                     directory.setPhotoCnt(newImageCnt);
                 } else {
-                    final String thumbnail = file.getAbsolutePath();
                     final String dirName = fileDir.substring(fileDir.lastIndexOf("/") + 1);
-                    directories.put(fileDir, new Directory(fileDir, thumbnail, dirName, 1));
+                    directories.put(fileDir, new Directory(fileDir, path, dirName, 1));
                 }
             } while (cursor.moveToNext());
             cursor.close();

app/src/main/java/gallery/simplemobiletools/com/PhotosActivity.java

@@ -1,15 +1,51 @@
 package gallery.simplemobiletools.com;
 
+import android.database.Cursor;
+import android.net.Uri;
 import android.os.Bundle;
+import android.provider.MediaStore;
 import android.support.v7.app.AppCompatActivity;
+import android.view.View;
+import android.widget.AdapterView;
+import android.widget.GridView;
 
-public class PhotosActivity extends AppCompatActivity {
+import java.util.ArrayList;
+import java.util.List;
+
+public class PhotosActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_photos);
 
+        final GridView gridView = (GridView) findViewById(R.id.photos_grid);
+        final PhotosAdapter adapter = new PhotosAdapter(this, getPhotos());
+        gridView.setAdapter(adapter);
+        gridView.setOnItemClickListener(this);
+    }
+
+    private List<String> getPhotos() {
+        final List<String> photos = new ArrayList<>();
         final String path = getIntent().getStringExtra(Constants.DIRECTORY);
+        final Uri uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
+        final String where = MediaStore.Images.Media.DATA + " like ? ";
+        final String[] args = new String[]{path + "%"};
+        final String[] columns = {MediaStore.Images.Media.DATA};
+        final Cursor cursor = getContentResolver().query(uri, columns, where, args, null);
+
+        if (cursor != null && cursor.moveToFirst()) {
+            final int pathIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
+            do {
+                photos.add(cursor.getString(pathIndex));
+            } while (cursor.moveToNext());
+            cursor.close();
+        }
+        return photos;
+    }
+
+    @Override
+    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+
     }
 }

app/src/main/java/gallery/simplemobiletools/com/PhotosAdapter.java

@@ -0,0 +1,64 @@
+package gallery.simplemobiletools.com;
+
+import android.content.Context;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.BaseAdapter;
+import android.widget.ImageView;
+
+import com.bumptech.glide.Glide;
+
+import java.util.List;
+
+public class PhotosAdapter extends BaseAdapter {
+    private final Context context;
+    private final List<String> photos;
+    private final LayoutInflater inflater;
+
+    public PhotosAdapter(Context context, List<String> photos) {
+        this.context = context;
+        this.photos = photos;
+        this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+    }
+
+    @Override
+    public View getView(int position, View view, ViewGroup parent) {
+        ViewHolder holder;
+        if (view == null) {
+            view = inflater.inflate(R.layout.photo_item, parent, false);
+            holder = new ViewHolder(view);
+            view.setTag(holder);
+        } else {
+            holder = (ViewHolder) view.getTag();
+        }
+
+        String path = photos.get(position);
+        Glide.with(context).load(path).centerCrop().crossFade().into(holder.photoThumbnail);
+
+        return view;
+    }
+
+    @Override
+    public int getCount() {
+        return photos.size();
+    }
+
+    @Override
+    public Object getItem(int position) {
+        return photos.get(position);
+    }
+
+    @Override
+    public long getItemId(int position) {
+        return 0;
+    }
+
+    static class ViewHolder {
+        ImageView photoThumbnail;
+
+        public ViewHolder(View view) {
+            photoThumbnail = (ImageView) view.findViewById(R.id.photo_thumbnail);
+        }
+    }
+}

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

@@ -1,18 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout
+<GridView
+    android:id="@+id/directories_grid"
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:background="@android:color/black">
-
-    <GridView
-        android:id="@+id/photo_grid"
-        android:layout_width="match_parent"
     android:layout_height="wrap_content"
-        android:columnWidth="@dimen/photo_size"
+    android:background="@android:color/black"
-        android:horizontalSpacing="2dp"
+    android:columnWidth="@dimen/dir_tmb_size"
+    android:horizontalSpacing="1dp"
     android:numColumns="auto_fit"
     android:stretchMode="columnWidth"
-        android:verticalSpacing="2dp"/>
+    android:verticalSpacing="1dp"/>
-
-</RelativeLayout>

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

@@ -1,8 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout
+<GridView
+    android:id="@+id/photos_grid"
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:background="@android:color/black">
+    android:background="@android:color/black"
-
+    android:columnWidth="@dimen/photo_tmb_size"
-</RelativeLayout>
+    android:horizontalSpacing="1dp"
+    android:numColumns="auto_fit"
+    android:stretchMode="columnWidth"
+    android:verticalSpacing="1dp"/>

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

@@ -2,13 +2,13 @@
 <RelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    android:background="@color/tmb_background">
 
     <gallery.simplemobiletools.com.MyImageView
         android:id="@+id/dir_thumbnail"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_height="match_parent"/>
-        android:background="@android:color/white"/>
 
     <RelativeLayout
         android:layout_width="match_parent"
@@ -33,5 +33,6 @@
             android:layout_height="wrap_content"
             android:layout_below="@id/dir_name"
             android:textColor="@android:color/white"/>
+
     </RelativeLayout>
 </RelativeLayout>

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

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:background="@color/tmb_background">
+
+    <gallery.simplemobiletools.com.MyImageView
+        android:id="@+id/photo_thumbnail"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"/>
+
+</FrameLayout>

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

@@ -3,4 +3,5 @@
     <color name="colorPrimary">#3F51B5</color>
     <color name="colorPrimaryDark">#303F9F</color>
     <color name="colorAccent">#FF4081</color>
+    <color name="tmb_background">#ff222222</color>
 </resources>

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

@@ -1,4 +1,5 @@
 <resources>
     <dimen name="activity_margin">16dp</dimen>
-    <dimen name="photo_size">150dp</dimen>
+    <dimen name="dir_tmb_size">150dp</dimen>
+    <dimen name="photo_tmb_size">100dp</dimen>
 </resources>