Android UI How to - Extends ArrayAdapter to create Iconic Adapter for ListView








The following code shows how to extend ArrayAdapter to create Iconic Adapter for ListView.

Example

Layout xml file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent" >
  <TextView
    android:id="@+id/selection"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"/>
  <ListView
    android:id="@android:id/list"
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    android:drawSelectorOnTop="false"
    />
</LinearLayout>

layout/row.xml 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:orientation="horizontal"
>
  <ImageView
    android:id="@+id/icon"
    android:layout_width="22px"
    android:paddingLeft="2px"
    android:paddingRight="2px"
    android:paddingTop="2px"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_launcher"
  />
  <TextView
    android:id="@+id/label"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="40sp"
  />
</LinearLayout>

Java code

//from   ww w .jav a  2s .  co  m
/***
  Copyright (c) 2008-2009 CommonsWare, LLC
  
  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.
*/


import android.app.Activity;
import android.os.Bundle;
import android.app.ListActivity;
import android.view.View;
import android.view.ViewGroup;
import android.view.LayoutInflater;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends ListActivity {
  TextView selection;
  String[] items={"lorem", "ipsum", "dolor", "sit", "amet",
          "consectetuer", "adipiscing", "elit", "morbi", "vel",
          "ligula", "vitae", "arcu", "aliquet", "mollis",
          "etiam", "vel", "erat", "placerat", "ante",
          "porttitor", "sodales", "pellentesque", "augue",
          "purus"};
  
  @Override
  public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.main);
    setListAdapter(new IconicAdapter(this));
    selection=(TextView)findViewById(R.id.selection);
  }
  
  public void onListItemClick(ListView parent, View v,
                              int position, long id) {
     selection.setText(items[position]);
  }
  
  class IconicAdapter extends ArrayAdapter {
    Activity context;
    
    IconicAdapter(Activity context) {
      super(context, R.layout.row, items);
      
      this.context=context;
    }
    
    public View getView(int position, View convertView,
                        ViewGroup parent) {
      LayoutInflater inflater=context.getLayoutInflater();
      View row=inflater.inflate(R.layout.row, null);
      TextView label=(TextView)row.findViewById(R.id.label);
      
      label.setText(items[position]);
      
      if (items[position].length()>4) {
        ImageView icon=(ImageView)row.findViewById(R.id.icon);
        
        icon.setImageResource(R.drawable.delete);
      }  
      
      return(row);
    }
  }
}
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