2.02 The Detail Screen - Solution

app/src/main/java/com/udacity/firebase/shoppinglistplusplus/ui/activeListDetails/ActiveListDetailsActivity.java

@@ -3,42 +3,88 @@
 import android.app.DialogFragment;
 import android.os.Bundle;
 import android.support.v7.widget.Toolbar;
+import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.ListView;
 
+import com.firebase.client.DataSnapshot;
+import com.firebase.client.Firebase;
+import com.firebase.client.FirebaseError;
+import com.firebase.client.ValueEventListener;
 import com.udacity.firebase.shoppinglistplusplus.R;
 import com.udacity.firebase.shoppinglistplusplus.model.ShoppingList;
 import com.udacity.firebase.shoppinglistplusplus.ui.BaseActivity;
+import com.udacity.firebase.shoppinglistplusplus.utils.Constants;
 
 /**
  * Represents the details screen for the selected shopping list
  */
 public class ActiveListDetailsActivity extends BaseActivity {
     private static final String LOG_TAG = ActiveListDetailsActivity.class.getSimpleName();
+    private Firebase mActiveListRef;
     private ListView mListView;
     private ShoppingList mShoppingList;
 
+
     @Override
     protected void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_active_list_details);
 
+        /**
+         * Create Firebase references
+         */
+        mActiveListRef = new Firebase(Constants.FIREBASE_URL_ACTIVE_LIST);
+
+
         /**
          * Link layout elements from XML and setup the toolbar
          */
         initializeScreen();
 
-        // TODO Add the Firebase code here that will set the appropriate title for the
-        // detail screen using setTitle and passing in the name of the current
-        // shopping list. You might want to save this shopping list as well.
-        // You can but the invalidateOptionsMenu call inside of the same block of code.
-        // If the shopping list doesn't exist, close the activity using finish()
+        /**
+         * Save the most recent version of current shopping list into mShoppingList instance
+         * variable an update the UI to match the current list.
+         */
+        mActiveListRef.addValueEventListener(new ValueEventListener() {
+            @Override
+            public void onDataChange(DataSnapshot snapshot) {
+
+                /**
+                 * Saving the most recent version of current shopping list into mShoppingList if present
+                 * finish() the activity if the list is null (list was removed or unshared by it's owner
+                 * while current user is in the list details activity)
+                 */
+                ShoppingList shoppingList = snapshot.getValue(ShoppingList.class);
+
+                if (shoppingList == null) {
+                    finish();
+                    /**
+                     * Make sure to call return, otherwise the rest of the method will execute,
+                     * even after calling finish.
+                     */
+                    return;
+                }
+                mShoppingList = shoppingList;
+
+                /* Calling invalidateOptionsMenu causes onCreateOptionsMenu to be called */
+                invalidateOptionsMenu();
+
+                /* Set title appropriately. */
+                setTitle(shoppingList.getListName());
+            }
+
+            @Override
+            public void onCancelled(FirebaseError firebaseError) {
+                Log.e(LOG_TAG,
+                        getString(R.string.log_error_the_read_failed) +
+                                firebaseError.getMessage());
+            }
+        });
 
-        /* Calling invalidateOptionsMenu causes onCreateOptionsMenu to be called */
-        invalidateOptionsMenu();
 
         /**
          * Set up click listeners for interaction.

app/src/main/java/com/udacity/firebase/shoppinglistplusplus/ui/activeLists/AddListDialogFragment.java

@@ -103,7 +103,7 @@ public void addShoppingList() {
         // Go to the "activeList" child node of the root node.
         // This will create the node for you if it doesn't already exist.
         // Then using the setValue menu it will serialize the ShoppingList POJO
-        ref.child("activeList").setValue(currentList);
+        ref.child(Constants.FIREBASE_LOCATION_ACTIVE_LIST).setValue(currentList);
     }
 }
 

app/src/main/java/com/udacity/firebase/shoppinglistplusplus/ui/activeLists/ShoppingListsFragment.java

@@ -1,6 +1,7 @@
 package com.udacity.firebase.shoppinglistplusplus.ui.activeLists;
 
 
+import android.content.Intent;
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
@@ -16,6 +17,7 @@
 import com.firebase.client.ValueEventListener;
 import com.udacity.firebase.shoppinglistplusplus.R;
 import com.udacity.firebase.shoppinglistplusplus.model.ShoppingList;
+import com.udacity.firebase.shoppinglistplusplus.ui.activeListDetails.ActiveListDetailsActivity;
 import com.udacity.firebase.shoppinglistplusplus.utils.Constants;
 import com.udacity.firebase.shoppinglistplusplus.utils.Utils;
 
@@ -75,7 +77,7 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container,
         /**
          * Create Firebase references
          */
-        Firebase refListName = new Firebase(Constants.FIREBASE_URL).child("activeList");
+        Firebase refListName = new Firebase(Constants.FIREBASE_URL).child(Constants.FIREBASE_LOCATION_ACTIVE_LIST);
 
         /**
          * Add ValueEventListeners to Firebase references
@@ -121,8 +123,14 @@ public void onItemClick(AdapterView<?> parent, View view, int position, long id)
             }
         });
 
-        // TODO Add an OnClick listener here so that when the user clicks on the
-        // mTextViewListName it opens up an instance of ActiveListDetailsActivity
+        mTextViewListName.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                /* Starts an active showing the details for the selected list */
+                Intent intent = new Intent(getActivity(), ActiveListDetailsActivity.class);
+                startActivity(intent);
+            }
+        });
 
         return rootView;
     }

app/src/main/java/com/udacity/firebase/shoppinglistplusplus/utils/Constants.java

@@ -11,26 +11,26 @@ public final class Constants {
      * Constants related to locations in Firebase, such as the name of the node
      * where active lists are stored (ie "activeLists")
      */
-
+    public static final String FIREBASE_LOCATION_ACTIVE_LIST = "activeList";
 
     /**
      * Constants for Firebase object properties
      */
     public static final String FIREBASE_PROPERTY_LIST_NAME = "listName";
     public static final String FIREBASE_PROPERTY_TIMESTAMP = "timestamp";
-    // TODO Consider adding and using a constant here for the key where your lists are stored
 
-    
+
     /**
      * Constants for Firebase URL
      */
     public static final String FIREBASE_URL = BuildConfig.UNIQUE_FIREBASE_ROOT_URL;
-    // TODO Consider adding a constant for the URL for your lists
+    public static final String FIREBASE_URL_ACTIVE_LIST = FIREBASE_URL + "/" + FIREBASE_LOCATION_ACTIVE_LIST;
 
 
     /**
      * Constants for bundles, extras and shared preferences keys
      */
     public static final String KEY_LAYOUT_RESOURCE = "LAYOUT_RESOURCE";
 
+
 }