Android - ListView without ListActivity

ListView is easier to use and straight forward if we extend ListActivity. But what happens if the activity already extends some other activity. Unfortunately , we do not have an option to extend two activities.

No issues, we could still create our customized list without extending ListActivity.

In the below example 'selectprofile.xml', a list called profilelist is declared as below.

<?xml version="1.0" encoding="utf-8"?> <LinearLayout android:id="@+id/LinearLayout01" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_marginLeft="5dp" android:layout_marginRight="5dp" android:background="@color/bgcolor">      <TextView   android:id="@+id/header"  android:layout_width="fill_parent"  android:layout_height="50dp"  android:textColor="@color/headtxtcolor"  android:text="Select Profile"  android:textSize="20dp"  android:textStyle="bold"  android:gravity="center"  android:layout_gravity="center_horizontal"  android:background="@drawable/button_image" /> <ListView  android:id="@+id/profilelist" android:layout_width="fill_parent" android:layout_height="fill_parent" android:drawSelectorOnTop="false" android:layout_weight="1" android:dividerHeight="1dp"> </ListView> </LinearLayout>

In the code

static final ArrayList<HashMap<String,String>> list = new ArrayList<HashMap<String,String>>();  public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.selectprofile);        ...        ...        initializeList();        getProfData();        lv.setAdapter(adapter); } protected void initializeList(){                lv = (ListView)findViewById(R.id.profilelist);           adapter = new SimpleAdapter(this,list,   R.layout.selectprofile_row,    new String[] {"id","name","sex","year","date"},       new int[]{R.id.profid,R.id.name,R.id.sex,R.id.year,R.id.crdatevalue}    );   list.clear();       }

Here 'selectprofile_row' defines the layout of the list row.

After populating the array list in getProfData() , set adapter to the list view. You can also add listener to the list item , if needed.

Android - Generic declaration of colours

It is very important that we declare background colours and layouts generically. I made this mistake of hardcoding the colours in the individual xml files. It became really hectic every time I wanted to try different colours. Then finally, I decided to declare them generically. Here is how you do it.

Declare mycustomcolors.xml in the values folder. Define all the colour codes here.

<?xml version="1.0" encoding="utf-8"?> <resources> <color name="bgcolor">#F8F8F8</color> <color name="headtxtcolor">#e69b28</color> <color name="othertxtcolor">#000000</color> <color name="headerEnd">#999999</color> <color name="headerStart">#000000</color> <color name="profileEnd">#E69B28</color> <color name="profileStart">#FFAE33</color> <color name="sectionEnd">#FFFFFF</color> <color name="sectionStart">#CCCCCC</color> </resources>

   

The above colour codes can be used in shapes and other layouts. This is for a gradient colour button profile_band.xml in drawable-hdpi. 

<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle"> <gradient     android:startColor="@color/profileStart"     android:endColor="@color/profileEnd"         android:angle="90" />       </shape> Text colours used in an xml..  <TextView         android:id="@+id/profName"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:layout_below="@id/header"         android:paddingLeft="10dp"         android:text="profile name"         android:textColor="@color/othertxtcolor"         android:textSize="14dp"         android:layout_gravity="center_vertical"        />

As mobile apps should have good screen appearance , it is very important that you have the flexibility to try various options.