Add the ViewSubredditActivity. Add a OnClickListener in the subscribed subreddits RecyclerView to lauch the ViewSubredditActivity.

app/src/main/AndroidManifest.xml

@@ -3,8 +3,11 @@
     package="ml.docilealligator.infinityforreddit">
 
     <uses-permission android:name="android.permission.INTERNET" />
+
     <uses-permission-sdk-23 android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
-    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
+
+    <uses-permission
+        android:name="android.permission.WRITE_EXTERNAL_STORAGE"
         android:maxSdkVersion="22" />
 
     <application
@@ -39,6 +42,11 @@
         <activity
             android:name=".ViewPostDetailActivity"
             android:parentActivityName=".MainActivity" />
+        <activity
+            android:name=".ViewSubredditDetailActivity"
+            android:label="@string/title_activity_view_subreddit_detail"
+            android:theme="@style/AppTheme.NoActionBar"
+            android:parentActivityName=".MainActivity" />
     </application>
 
 </manifest>

app/src/main/java/ml/docilealligator/infinityforreddit/RedditUtils.java

@@ -34,7 +34,6 @@ class RedditUtils {
     static final String SCOPE_KEY = "scope";
     static final String SCOPE = "identity edit flair history modconfig modflair modlog modposts modwiki mysubreddits privatemessages read report save submit subscribe vote wikiedit wikiread";
     static final String ACCESS_TOKEN_KEY = "access_token";
-    static final String EXPIRES_IN_KEY = "expires_in";
 
     static final String AUTHORIZATION_KEY = "Authorization";
     static final String AUTHORIZATION_BASE = "bearer ";

app/src/main/java/ml/docilealligator/infinityforreddit/SubscribedSubredditRecyclerViewAdapter.java

@@ -1,6 +1,7 @@
 package ml.docilealligator.infinityforreddit;
 
 import android.content.Context;
+import android.content.Intent;
 import android.support.annotation.NonNull;
 import android.support.v7.widget.RecyclerView;
 import android.view.LayoutInflater;
@@ -33,6 +34,13 @@ class SubscribedSubredditRecyclerViewAdapter extends RecyclerView.Adapter<Recycl
 
     @Override
     public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int i) {
+        viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                Intent intent = new Intent(mContext, ViewSubredditDetailActivity.class);
+                mContext.startActivity(intent);
+            }
+        });
         if(!mSubscribedSubredditData.get(i).getIconUrl().equals("")) {
             glide.load(mSubscribedSubredditData.get(i).getIconUrl()).into(((SubredditViewHolder) viewHolder).iconCircleImageView);
         } else {

app/src/main/java/ml/docilealligator/infinityforreddit/ViewSubredditDetailActivity.java

@@ -0,0 +1,51 @@
+package ml.docilealligator.infinityforreddit;
+
+import android.os.Bundle;
+import android.support.design.widget.AppBarLayout;
+import android.support.design.widget.CollapsingToolbarLayout;
+import android.support.design.widget.FloatingActionButton;
+import android.support.design.widget.Snackbar;
+import android.support.v7.app.AppCompatActivity;
+import android.support.v7.widget.Toolbar;
+import android.view.View;
+
+public class ViewSubredditDetailActivity extends AppCompatActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_view_subreddit_detail);
+        Toolbar toolbar = findViewById(R.id.toolbar);
+        setSupportActionBar(toolbar);
+
+        final CollapsingToolbarLayout collapsingToolbarLayout = (CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar_layout_view_subreddit_detail_activity);
+        AppBarLayout appBarLayout = (AppBarLayout) findViewById(R.id.app_bar_layout_view_subreddit_detail_activity);
+        appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
+            boolean isShow = true;
+            int scrollRange = -1;
+
+            @Override
+            public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
+                if (scrollRange == -1) {
+                    scrollRange = appBarLayout.getTotalScrollRange();
+                }
+                if (scrollRange + verticalOffset == 0) {
+                    collapsingToolbarLayout.setTitle(getString(R.string.title_activity_view_subreddit_detail));
+                    isShow = true;
+                } else if(isShow) {
+                    collapsingToolbarLayout.setTitle(" ");//carefull there should a space between double quote otherwise it wont work
+                    isShow = false;
+                }
+            }
+        });
+
+        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
+        fab.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
+                        .setAction("Action", null).show();
+            }
+        });
+    }
+}

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

@@ -107,6 +107,7 @@
                             android:id="@+id/nsfw_text_view_view_post_detail"
                             android:layout_width="wrap_content"
                             android:layout_height="wrap_content"
+                            android:text="@string/nsfw"
                             android:layout_alignParentEnd="true"
                             android:layout_marginEnd="16dp"
                             android:layout_marginLeft="16dp"

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

@@ -0,0 +1,98 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.design.widget.CoordinatorLayout 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:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:fitsSystemWindows="true"
+    tools:context=".ViewSubredditDetailActivity">
+
+    <android.support.design.widget.AppBarLayout
+        android:id="@+id/app_bar_layout_view_subreddit_detail_activity"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:fitsSystemWindows="true"
+        android:theme="@style/AppTheme.AppBarOverlay">
+
+        <android.support.design.widget.CollapsingToolbarLayout
+            android:id="@+id/collapsing_toolbar_layout_view_subreddit_detail_activity"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:fitsSystemWindows="true"
+            app:contentScrim="?attr/colorPrimary"
+            app:layout_scrollFlags="scroll|exitUntilCollapsed"
+            app:toolbarId="@+id/toolbar">
+
+            <RelativeLayout
+                android:layout_width="match_parent"
+                android:layout_height="match_parent">
+
+                <ImageView
+                    android:id="@+id/banner_image_view_view_subreddit_detail_activity"
+                    android:src="@drawable/subreddit_default_icon"
+                    android:layout_width="match_parent"
+                    android:scaleType="centerCrop"
+                    android:layout_height="180dp" />
+
+                <de.hdodenhof.circleimageview.CircleImageView
+                    android:src="@drawable/subreddit_default_icon"
+                    android:layout_width="72dp"
+                    android:layout_height="72dp"
+                    android:layout_marginTop="-36dp"
+                    app:civ_border_color="@android:color/white"
+                    app:civ_border_width="1dp"
+                    android:layout_below="@id/banner_image_view_view_subreddit_detail_activity"
+                    android:layout_centerHorizontal="true"
+                    android:elevation="1000dp"/>
+
+                <LinearLayout
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:orientation="vertical"
+                    android:layout_below="@id/banner_image_view_view_subreddit_detail_activity"
+                    android:background="@android:color/white">
+
+                    <TextView
+                        android:id="@+id/name_text_view_view_subreddit_detail_activity"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:layout_marginTop="36dp"
+                        android:layout_marginStart="16dp"
+                        android:layout_marginEnd="16dp"
+                        android:textColor="@android:color/black"
+                        android:text="Dummy"/>
+
+                    <TextView
+                        android:id="@+id/subscriber_count_text_view_view_subreddit_detail_activity"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:layout_margin="16dp"
+                        android:textColor="@android:color/black"
+                        android:text="Subscriber: 10000"/>
+
+                </LinearLayout>
+
+            </RelativeLayout>
+
+            <android.support.v7.widget.Toolbar
+                android:id="@+id/toolbar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                app:layout_collapseMode="pin"
+                app:popupTheme="@style/AppTheme.PopupOverlay" />
+
+        </android.support.design.widget.CollapsingToolbarLayout>
+    </android.support.design.widget.AppBarLayout>
+
+    <include layout="@layout/content_view_subreddit_detail" />
+
+    <android.support.design.widget.FloatingActionButton
+        android:id="@+id/fab"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_margin="@dimen/fab_margin"
+        app:layout_anchor="@id/app_bar_layout_view_subreddit_detail_activity"
+        app:layout_anchorGravity="bottom|end"
+        app:srcCompat="@drawable/baseline_add_white_24" />
+
+</android.support.design.widget.CoordinatorLayout>

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

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.v4.widget.NestedScrollView 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:layout_width="match_parent"
+    android:layout_height="match_parent"
+    app:layout_behavior="@string/appbar_scrolling_view_behavior"
+    tools:context=".ViewSubredditDetailActivity"
+    tools:showIn="@layout/activity_view_subreddit_detail">
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_margin="@dimen/text_margin"
+        android:text="@string/large_text" />
+
+</android.support.v4.widget.NestedScrollView>

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

@@ -0,0 +1,10 @@
+<menu 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"
+    tools:context="ml.docilealligator.infinityforreddit.ViewSubredditDetailActivity">
+    <item
+        android:id="@+id/action_settings"
+        android:orderInCategory="100"
+        android:title="@string/action_settings"
+        app:showAsAction="never" />
+</menu>

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

@@ -5,4 +5,6 @@
     <dimen name="nav_header_vertical_spacing">8dp</dimen>
     <dimen name="nav_header_height">176dp</dimen>
     <dimen name="fab_margin">16dp</dimen>
+    <dimen name="app_bar_height">180dp</dimen>
+    <dimen name="text_margin">16dp</dimen>
 </resources>

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

@@ -19,4 +19,94 @@
     <string name="profile">Profile</string>
     <string name="following">Following</string>
     <string name="subscriptions">Subscriptions</string>
+    <string name="title_activity_view_subreddit_detail">ViewSubredditDetailActivity</string>
+    <string name="large_text">
+        "Material is the metaphor.\n\n"
+
+        "A material metaphor is the unifying theory of a rationalized space and a system of motion."
+        "The material is grounded in tactile reality, inspired by the study of paper and ink, yet "
+        "technologically advanced and open to imagination and magic.\n"
+        "Surfaces and edges of the material provide visual cues that are grounded in reality. The "
+        "use of familiar tactile attributes helps users quickly understand affordances. Yet the "
+        "flexibility of the material creates new affordances that supercede those in the physical "
+        "world, without breaking the rules of physics.\n"
+        "The fundamentals of light, surface, and movement are key to conveying how objects move, "
+        "interact, and exist in space and in relation to each other. Realistic lighting shows "
+        "seams, divides space, and indicates moving parts.\n\n"
+
+        "Bold, graphic, intentional.\n\n"
+
+        "The foundational elements of print based design typography, grids, space, scale, color, "
+        "and use of imagery guide visual treatments. These elements do far more than please the "
+        "eye. They create hierarchy, meaning, and focus. Deliberate color choices, edge to edge "
+        "imagery, large scale typography, and intentional white space create a bold and graphic "
+        "interface that immerse the user in the experience.\n"
+        "An emphasis on user actions makes core functionality immediately apparent and provides "
+        "waypoints for the user.\n\n"
+
+        "Motion provides meaning.\n\n"
+
+        "Motion respects and reinforces the user as the prime mover. Primary user actions are "
+        "inflection points that initiate motion, transforming the whole design.\n"
+        "All action takes place in a single environment. Objects are presented to the user without "
+        "breaking the continuity of experience even as they transform and reorganize.\n"
+        "Motion is meaningful and appropriate, serving to focus attention and maintain continuity. "
+        "Feedback is subtle yet clear. Transitions are efficient yet coherent.\n\n"
+
+        "3D world.\n\n"
+
+        "The material environment is a 3D space, which means all objects have x, y, and z "
+        "dimensions. The z-axis is perpendicularly aligned to the plane of the display, with the "
+        "positive z-axis extending towards the viewer. Every sheet of material occupies a single "
+        "position along the z-axis and has a standard 1dp thickness.\n"
+        "On the web, the z-axis is used for layering and not for perspective. The 3D world is "
+        "emulated by manipulating the y-axis.\n\n"
+
+        "Light and shadow.\n\n"
+
+        "Within the material environment, virtual lights illuminate the scene. Key lights create "
+        "directional shadows, while ambient light creates soft shadows from all angles.\n"
+        "Shadows in the material environment are cast by these two light sources. In Android "
+        "development, shadows occur when light sources are blocked by sheets of material at "
+        "various positions along the z-axis. On the web, shadows are depicted by manipulating the "
+        "y-axis only. The following example shows the card with a height of 6dp.\n\n"
+
+        "Resting elevation.\n\n"
+
+        "All material objects, regardless of size, have a resting elevation, or default elevation "
+        "that does not change. If an object changes elevation, it should return to its resting "
+        "elevation as soon as possible.\n\n"
+
+        "Component elevations.\n\n"
+
+        "The resting elevation for a component type is consistent across apps (e.g., FAB elevation "
+        "does not vary from 6dp in one app to 16dp in another app).\n"
+        "Components may have different resting elevations across platforms, depending on the depth "
+        "of the environment (e.g., TV has a greater depth than mobile or desktop).\n\n"
+
+        "Responsive elevation and dynamic elevation offsets.\n\n"
+
+        "Some component types have responsive elevation, meaning they change elevation in response "
+        "to user input (e.g., normal, focused, and pressed) or system events. These elevation "
+        "changes are consistently implemented using dynamic elevation offsets.\n"
+        "Dynamic elevation offsets are the goal elevation that a component moves towards, relative "
+        "to the component’s resting state. They ensure that elevation changes are consistent "
+        "across actions and component types. For example, all components that lift on press have "
+        "the same elevation change relative to their resting elevation.\n"
+        "Once the input event is completed or cancelled, the component will return to its resting "
+        "elevation.\n\n"
+
+        "Avoiding elevation interference.\n\n"
+
+        "Components with responsive elevations may encounter other components as they move between "
+        "their resting elevations and dynamic elevation offsets. Because material cannot pass "
+        "through other material, components avoid interfering with one another any number of ways, "
+        "whether on a per component basis or using the entire app layout.\n"
+        "On a component level, components can move or be removed before they cause interference. "
+        "For example, a floating action button (FAB) can disappear or move off screen before a "
+        "user picks up a card, or it can move if a snackbar appears.\n"
+        "On the layout level, design your app layout to minimize opportunities for interference. "
+        "For example, position the FAB to one side of stream of a cards so the FAB won’t interfere "
+        "when a user tries to pick up one of cards.\n\n"
+    </string>
 </resources>