1.17 Create PetCursorAdapter to display list of pets in ListView

app/src/main/java/com/example/android/pets/CatalogActivity.java

@@ -25,7 +25,7 @@
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
-import android.widget.TextView;
+import android.widget.ListView;
 
 import com.example.android.pets.data.PetContract.PetEntry;
 
@@ -79,51 +79,14 @@ private void displayDatabaseInfo() {
                 null,                   // Selection criteria
                 null);                  // The sort order for the returned rows
 
-        TextView displayView = (TextView) findViewById(R.id.text_view_pet);
+        // Find the ListView which will be populated with the pet data
+        ListView petListView = (ListView) findViewById(R.id.list);
 
-        try {
-            // Create a header in the Text View that looks like this:
-            //
-            // The pets table contains <number of rows in Cursor> pets.
-            // _id - name - breed - gender - weight
-            //
-            // In the while loop below, iterate through the rows of the cursor and display
-            // the information from each column in this order.
-            displayView.setText("The pets table contains " + cursor.getCount() + " pets.\n\n");
-            displayView.append(PetEntry._ID + " - " +
-                    PetEntry.COLUMN_PET_NAME + " - " +
-                    PetEntry.COLUMN_PET_BREED + " - " +
-                    PetEntry.COLUMN_PET_GENDER + " - " +
-                    PetEntry.COLUMN_PET_WEIGHT + "\n");
+        // Setup an Adapter to create a list item for each row of pet data in the Cursor.
+        PetCursorAdapter adapter = new PetCursorAdapter(this, cursor);
 
-            // Figure out the index of each column
-            int idColumnIndex = cursor.getColumnIndex(PetEntry._ID);
-            int nameColumnIndex = cursor.getColumnIndex(PetEntry.COLUMN_PET_NAME);
-            int breedColumnIndex = cursor.getColumnIndex(PetEntry.COLUMN_PET_BREED);
-            int genderColumnIndex = cursor.getColumnIndex(PetEntry.COLUMN_PET_GENDER);
-            int weightColumnIndex = cursor.getColumnIndex(PetEntry.COLUMN_PET_WEIGHT);
-
-            // Iterate through all the returned rows in the cursor
-            while (cursor.moveToNext()) {
-                // Use that index to extract the String or Int value of the word
-                // at the current row the cursor is on.
-                int currentID = cursor.getInt(idColumnIndex);
-                String currentName = cursor.getString(nameColumnIndex);
-                String currentBreed = cursor.getString(breedColumnIndex);
-                int currentGender = cursor.getInt(genderColumnIndex);
-                int currentWeight = cursor.getInt(weightColumnIndex);
-                // Display the values from each column of the current row in the cursor in the TextView
-                displayView.append(("\n" + currentID + " - " +
-                        currentName + " - " +
-                        currentBreed + " - " +
-                        currentGender + " - " +
-                        currentWeight));
-            }
-        } finally {
-            // Always close the cursor when you're done reading from it. This releases all its
-            // resources and makes it invalid.
-            cursor.close();
-        }
+        // Attach the adapter to the ListView.
+        petListView.setAdapter(adapter);
     }
 
     /**

app/src/main/java/com/example/android/pets/PetCursorAdapter.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.pets;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.CursorAdapter;
+import android.widget.TextView;
+
+import com.example.android.pets.data.PetContract.PetEntry;
+
+/**
+ * {@link PetCursorAdapter} is an adapter for a list or grid view
+ * that uses a {@link Cursor} of pet data as its data source. This adapter knows
+ * how to create list items for each row of pet data in the {@link Cursor}.
+ */
+public class PetCursorAdapter extends CursorAdapter {
+
+    /**
+     * Constructs a new {@link PetCursorAdapter}.
+     *
+     * @param context The context
+     * @param c       The cursor from which to get the data.
+     */
+    public PetCursorAdapter(Context context, Cursor c) {
+        super(context, c, 0 /* flags */);
+    }
+
+    /**
+     * Makes a new blank list item view. No data is set (or bound) to the views yet.
+     *
+     * @param context app context
+     * @param cursor  The cursor from which to get the data. The cursor is already
+     *                moved to the correct position.
+     * @param parent  The parent to which the new view is attached to
+     * @return the newly created list item view.
+     */
+    @Override
+    public View newView(Context context, Cursor cursor, ViewGroup parent) {
+        // Inflate a list item view using the layout specified in list_item.xml
+        return LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);
+    }
+
+    /**
+     * This method binds the pet data (in the current row pointed to by cursor) to the given
+     * list item layout. For example, the name for the current pet can be set on the name TextView
+     * in the list item layout.
+     *
+     * @param view    Existing view, returned earlier by newView() method
+     * @param context app context
+     * @param cursor  The cursor from which to get the data. The cursor is already moved to the
+     *                correct row.
+     */
+    @Override
+    public void bindView(View view, Context context, Cursor cursor) {
+        // Find individual views that we want to modify in the list item layout
+        TextView nameTextView = (TextView) view.findViewById(R.id.name);
+        TextView summaryTextView = (TextView) view.findViewById(R.id.summary);
+
+        // Find the columns of pet attributes that we're interested in
+        int nameColumnIndex = cursor.getColumnIndex(PetEntry.COLUMN_PET_NAME);
+        int breedColumnIndex = cursor.getColumnIndex(PetEntry.COLUMN_PET_BREED);
+
+        // Read the pet attributes from the Cursor for the current pet
+        String petName = cursor.getString(nameColumnIndex);
+        String petBreed = cursor.getString(breedColumnIndex);
+
+        // Update the TextViews with the attributes for the current pet
+        nameTextView.setText(petName);
+        summaryTextView.setText(petBreed);
+    }
+}

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

@@ -18,11 +18,10 @@
     android:layout_height="match_parent"
     tools:context=".CatalogActivity">
 
-    <TextView
-        android:id="@+id/text_view_pet"
+    <ListView
+        android:id="@+id/list"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:padding="@dimen/activity_margin"/>
+        android:layout_height="match_parent"/>
 
     <android.support.design.widget.FloatingActionButton
         android:id="@+id/fab"

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

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2016 The Android Open Source Project
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+          http://www.apache.org/licenses/LICENSE-2.0
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<!-- Layout for a single list item in the list of pets -->
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:padding="@dimen/activity_margin">
+
+    <TextView
+        android:id="@+id/name"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:fontFamily="sans-serif-medium"
+        android:textAppearance="?android:textAppearanceMedium"
+        android:textColor="#2B3D4D"  />
+
+    <TextView
+        android:id="@+id/summary"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:fontFamily="sans-serif"
+        android:textAppearance="?android:textAppearanceSmall"
+        android:textColor="#AEB6BD"  />
+</LinearLayout>