Enhance performance by using ViewHolder

Change-Id: I8199b84b6822944383a79ab8ad3eb227f5e31508 Signed-off-by: Roger Chen <cxr514033970@gmail.com>
aosp-mirror · Dec 26, 2012 · da3bbf3 · da3bbf3
1 parent 04dc066
commit da3bbf3
Showing 1 changed file with 31 additions and 5 deletions.
diff --git a/src/com/android/mms/ui/IconListAdapter.java b/src/com/android/mms/ui/IconListAdapter.java
@@ -35,7 +35,33 @@
 public class IconListAdapter extends ArrayAdapter<IconListAdapter.IconListItem> {
     protected LayoutInflater mInflater;
     private static final int mResource = R.layout.icon_list_item;
+    private ViewHolder mViewHolder;
 
+    static class ViewHolder {
+        private View mView;
+        private TextView mTextView;
+        private ImageView mImageView;
+
+        public ViewHolder(View view) {
+            mView = view;
+        }
+
+        public TextView getTextView() {
+            if (mTextView == null) {
+                mTextView = (TextView) mView.findViewById(R.id.text1);
+            }
+
+            return mTextView;
+        }
+
+        public ImageView getImageView() {
+            if (mImageView == null) {
+                mImageView = (ImageView) mView.findViewById(R.id.icon);
+            }
+
+            return mImageView;
+        }
+    }
     public IconListAdapter(Context context,
             List<IconListItem> items) {
         super(context, mResource, items);
@@ -44,22 +70,22 @@ public IconListAdapter(Context context,
 
     @Override
     public View getView(int position, View convertView, ViewGroup parent) {
-        TextView text;
-        ImageView image;
-
         View view;
         if (convertView == null) {
             view = mInflater.inflate(mResource, parent, false);
+            mViewHolder = new ViewHolder(view);
+            view.setTag(mViewHolder);
         } else {
             view = convertView;
+            mViewHolder = (ViewHolder) view.getTag();
         }
 
         // Set text field
-        text = (TextView) view.findViewById(R.id.text1);
+        TextView text = mViewHolder.getTextView();
         text.setText(getItem(position).getTitle());
 
         // Set resource icon
-        image = (ImageView) view.findViewById(R.id.icon);
+        ImageView image = mViewHolder.getImageView();
         image.setImageResource(getItem(position).getResource());
 
         return view;