Technical Library

Dropdown for Android™

A Dropdown List UI element enables users to choose between multiple items in a list. These UI elements have three states: default, pressed, and disabled. The current item is checked and the user is allowed to scroll through the list.

Download UI elements for Android.

Creation

You need to create a new com.att.widgets.lib.dropdown.DropDown object and add it to your view or layout.

Full layout code

<?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:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="This is a sample of 3 Dropdowns"
android:paddingBottom="10dp"
android:textStyle="bold"/>
<LinearLayout android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:paddingBottom="10dp">
<TextView android:layout_width="100dip"
android:layout_height="fill_parent"
android:gravity="center_vertical"
android:text="Andriod Os:"/>
<com.att.widgets.lib.dropdown.DropDown
android:id="@+id/dropdown"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
<LinearLayout android:id="@+id/dropdown_2_view"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:paddingBottom="10dp">
<TextView android:layout_width="100dip"
android:layout_height="fill_parent"
android:gravity="center_vertical"
android:text="Phones:"/>
</LinearLayout>
<TextView android:id="@+id/dropdown_text_1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
<TextView android:id="@+id/dropdown_text_2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
<LinearLayout android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="10dip">
<TextView android:layout_width="100dip"
android:layout_height="fill_parent"
android:gravity="center_vertical"
android:text="Disabled Dropdown:"/>
<com.att.widgets.lib.dropdown.DropDown
android:id="@+id/dropdown_disabled"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
</LinearLayout>

Activity

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.RelativeLayout;
import android.widget.TextView;
import com.att.widgets.lib.dropdown.DropDown;
public class DropDownActivity extends Activity implements OnClickListener {
private String[]array_1 = {"Gingerbread", "Froyo", "Cupcake", "Donut", "Eclair"};
private String[]array_2 = {"Milestone", "Galaxy", "Nexus One", "MotoBlur"};
private DropDown dropDown_1, dropDown_2;
private TextView textView_1, textView_2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ViewGroup v = (ViewGroup)findViewById(R.id.dropdown_2_view);
textView_1 = (TextView)findViewById(R.id.dropdown_text_1);
textView_2 = (TextView)findViewById(R.id.dropdown_text_2);
dropDown_1 = ((DropDown)findViewById(R.id.dropdown));
dropDown_1.setFocusable(true);
dropDown_2 = new DropDown(this);
RelativeLayout.LayoutParams ll = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
dropDown_2.setLayoutParams(ll);
v.addView(dropDown_2);
dropDown_1.setData(array_1);
dropDown_2.setData(array_2);
dropDown_1.setFieldsNumber(4);
dropDown_2.setFieldsNumber(3);
((DropDown)findViewById(R.id.dropdown_disabled)).setEnabled(false);
((DropDown)findViewById(R.id.dropdown_disabled)).setDisplayText("Disabled Dropdown");
//listeners
dropDown_1.setOnClickListener(this);
dropDown_2.setOnClickListener(this);
}
public void onClick(View v) {
if(v == dropDown_1){
textView_1.setText("Selected Android Os: " + dropDown_1.getSelectedText());
}else if(v == dropDown_2){
textView_2.setText("Selected Phone: " +dropDown_2.getSelectedText());
}
}
}

Explanation

The first Dropdown is defined in Xml with the id "dropdown", and focused by code

First Drop Down Layout

<com.att.widgets.lib.dropdown.DropDown
android:id="@+id/dropdown" android:layout_width="fill_parent"
android:layout_height="wrap_content" />

First Drop Down Activity Code

dropDown_1 = ((DropDown)findViewById(R.id.dropdown));
dropDown_1.setFocusable(true);
dropDown_1.setData(array_1);
dropDown_1.setOnClickListener(this);
// Number of fields visible on the drop down list
dropDown_1.setFieldsNumber(4);

Second Drop Down Layout

And the second DropDown is generated from the following code. Only LinearLayout is defined in the xml

 <LinearLayout android:id="@+id/dropdown_2_view"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
</LinearLayout>

Second Drop Down Activity Code

ViewGroup v = (ViewGroup)findViewById(R.id.dropdown_2_view);
dropDown_2 = new DropDown(this);
RelativeLayout.LayoutParams ll = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
dropDown_2.setLayoutParams(ll);
v.addView(dropDown_2);
dropDown_2.setFocusable(true);
dropDown_2.setData(array_2);
dropDown_2.setOnClickListener(this);
//number of fields visible on the drop down list
dropDown_2.setFieldsNumber(3);

You can choose how you want to do it.

Click listeners

You should add a click listener to handle the selection event

dropDown.setOnClickListener(this);

and implement the OnClickListener in the current class. For example:

public class DropDownActivity extends Activity implements OnClickListener
...
public void onClick(View v) {
...
}

Android is a trademark of Google Inc.