From 9897558c53402e4e8a309f29b94a9bed3ea8db94 Mon Sep 17 00:00:00 2001
From: Vortana Say <vortana.say@gmail.com>
Date: Sun, 7 May 2017 20:22:38 -0500
Subject: [PATCH] create Master List Fragment with view holder pattern

---
 app/src/main/AndroidManifest.xml              |  5 +--
 .../android/android_me/ui/MainActivity.java   | 15 ++++++++
 .../android_me/ui/MasterListAdapter.java      | 33 +++++++++--------
 .../android_me/ui/MasterListFragment.java     | 35 +++++++++++++++++++
 app/src/main/res/layout/activity_main.xml     |  6 ++++
 .../main/res/layout/fragment_master_list.xml  | 13 +++++++
 app/src/main/res/layout/image_item.xml        |  8 +++++
 7 files changed, 98 insertions(+), 17 deletions(-)
 create mode 100644 app/src/main/java/com/example/android/android_me/ui/MainActivity.java
 create mode 100644 app/src/main/java/com/example/android/android_me/ui/MasterListFragment.java
 create mode 100644 app/src/main/res/layout/activity_main.xml
 create mode 100644 app/src/main/res/layout/fragment_master_list.xml
 create mode 100644 app/src/main/res/layout/image_item.xml

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index a4bb27364..7dfda4060 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -11,7 +11,8 @@
 
         <!-- TODO (5) Declare the MainActivity in the manifest and set it to launch upon opening this app -->
 
-        <activity android:name=".ui.AndroidMeActivity">
+        <activity android:name=".ui.AndroidMeActivity" />
+        <activity android:name=".ui.MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 
@@ -20,4 +21,4 @@
         </activity>
     </application>
 
-</manifest>
\ No newline at end of file
+</manifest>
diff --git a/app/src/main/java/com/example/android/android_me/ui/MainActivity.java b/app/src/main/java/com/example/android/android_me/ui/MainActivity.java
new file mode 100644
index 000000000..f51e46aee
--- /dev/null
+++ b/app/src/main/java/com/example/android/android_me/ui/MainActivity.java
@@ -0,0 +1,15 @@
+package com.example.android.android_me.ui;
+
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+
+import com.example.android.android_me.R;
+
+public class MainActivity extends AppCompatActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+    }
+}
diff --git a/app/src/main/java/com/example/android/android_me/ui/MasterListAdapter.java b/app/src/main/java/com/example/android/android_me/ui/MasterListAdapter.java
index ed4ee4158..d52c15be4 100755
--- a/app/src/main/java/com/example/android/android_me/ui/MasterListAdapter.java
+++ b/app/src/main/java/com/example/android/android_me/ui/MasterListAdapter.java
@@ -20,9 +20,10 @@
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
-import android.widget.GridView;
 import android.widget.ImageView;
 
+import com.example.android.android_me.R;
+
 import java.util.List;
 
 
@@ -35,6 +36,7 @@ public class MasterListAdapter extends BaseAdapter {
 
     /**
      * Constructor method
+     *
      * @param imageIds The list of images to display
      */
     public MasterListAdapter(Context context, List<Integer> imageIds) {
@@ -60,25 +62,26 @@ public long getItemId(int i) {
         return 0;
     }
 
-    /**
-     * Creates a new ImageView for each item referenced by the adapter
-     */
     public View getView(final int position, View convertView, ViewGroup parent) {
-        ImageView imageView;
         if (convertView == null) {
-            // If the view is not recycled, this creates a new ImageView to hold an image
-            imageView = new ImageView(mContext);
-            // Define the layout parameters
-            imageView.setAdjustViewBounds(true);
-            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
-            imageView.setPadding(8, 8, 8, 8);
-        } else {
-            imageView = (ImageView) convertView;
+            convertView = View.inflate(mContext, R.layout.image_item, null);
+
+            final ImageView imageView = (ImageView) convertView.findViewById(R.id.image_item);
+            final ViewHolder viewHolder = new ViewHolder(imageView);
+            convertView.setTag(viewHolder);
         }
 
         // Set the image resource and return the newly created ImageView
-        imageView.setImageResource(mImageIds.get(position));
-        return imageView;
+        final ViewHolder viewHolder = (ViewHolder) convertView.getTag();
+        viewHolder.imageViewItem.setImageResource(mImageIds.get(position));
+        return convertView;
     }
 
+    private class ViewHolder {
+        private final ImageView imageViewItem;
+
+        ViewHolder(ImageView imageViewItem) {
+            this.imageViewItem = imageViewItem;
+        }
+    }
 }
diff --git a/app/src/main/java/com/example/android/android_me/ui/MasterListFragment.java b/app/src/main/java/com/example/android/android_me/ui/MasterListFragment.java
new file mode 100644
index 000000000..145c1e403
--- /dev/null
+++ b/app/src/main/java/com/example/android/android_me/ui/MasterListFragment.java
@@ -0,0 +1,35 @@
+package com.example.android.android_me.ui;
+
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.v4.app.Fragment;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.GridView;
+
+import com.example.android.android_me.R;
+import com.example.android.android_me.data.AndroidImageAssets;
+
+/**
+ * Created by vsaya on 5/7/17.
+ */
+
+public class MasterListFragment extends Fragment {
+    private GridView gridView;
+    private MasterListAdapter masterListAdapter;
+
+    public MasterListFragment() {
+
+    }
+
+    @Nullable
+    @Override
+    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
+        View rootView = inflater.inflate(R.layout.fragment_master_list, container, false);
+        gridView = (GridView) rootView.findViewById(R.id.image_grid_view);
+        masterListAdapter = new MasterListAdapter(getActivity(), AndroidImageAssets.getAll());
+        gridView.setAdapter(masterListAdapter);
+        return rootView;
+    }
+}
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
new file mode 100644
index 000000000..fc9a9086b
--- /dev/null
+++ b/app/src/main/res/layout/activity_main.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<fragment xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/master_list_fragment"
+    android:name="com.example.android.android_me.ui.MasterListFragment"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent" />
diff --git a/app/src/main/res/layout/fragment_master_list.xml b/app/src/main/res/layout/fragment_master_list.xml
new file mode 100644
index 000000000..91a918703
--- /dev/null
+++ b/app/src/main/res/layout/fragment_master_list.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<GridView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/image_grid_view"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:adjustViewBounds="true"
+    android:columnWidth="180dp"
+    android:gravity="center"
+    android:horizontalSpacing="8dp"
+    android:numColumns="3"
+    android:padding="16dp"
+    android:stretchMode="columnWidth"
+    android:verticalSpacing="8dp" />
diff --git a/app/src/main/res/layout/image_item.xml b/app/src/main/res/layout/image_item.xml
new file mode 100644
index 000000000..9c47f1ac2
--- /dev/null
+++ b/app/src/main/res/layout/image_item.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/image_item"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:adjustViewBounds="true"
+    android:padding="8dp"
+    android:scaleType="centerCrop" />