// UC.javapackage com.apress.uc;import android.app.Activity;import android.os.Bundle;import android.text.Editable;
import android.text.TextWatcher;import android.view.View;import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;public class UC extends Activity
{private int position = 0;private double[] multipliers ={0.0015625,         // Acres to square miles101325.0,          // Atmospheres to Pascals100000.0,          // Bars to Pascals0,                 // Degrees Celsius to Degrees Fahrenheit (placeholder)0,                 // Degrees Fahrenheit to Degrees Celsius (placeholder)0.00001,           // Dynes to Newtons0.3048,            // Feet/Second to Metres/Second0.0284130625,      // Fluid Ounces (UK) to Litres0.0295735295625,   // Fluid Ounces (US) to Litres746.0,             // Horsepower (electric) to Watts735.499,           // Horsepower (metric) to Watts1/1016.0469088,    // Kilograms to Tons (UK or long)1/907.18474,       // Kilograms to Tons (US or short)1/0.0284130625,    // Litres to Fluid Ounces (UK)1/0.0295735295625, // Litres to Fluid Ounces (US)331.5,             // Mach Number to Metres/Second1/0.3048,          // Metres/Second to Feet/Second1/331.5,           // Metres/Second to Mach Number0.833,             // Miles/Gallon (UK) to Miles/Gallon (US)1/0.833,           // Miles/Gallon (US) to Miles/Gallon (UK)100000.0,          // Newtons to Dynes1/101325.0,        // Pascals to Atmospheres0.00001,           // Pascals to Bars640.0,             // Square Miles to Acres1016.0469088,      // Tons (UK or long) to Kilograms907.18474,         // Tons (US or short) to Kilograms1/746.0,           // Watts to Horsepower (electic)1/735.499          // Watts to Horsepower (metric)
   };@Overridepublic void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.main);final EditText etUnits = (EditText) findViewById(R.id.units);final Spinner spnConversions = (Spinner) findViewById(R.id.conversions);ArrayAdapter<CharSequence> aa;aa = ArrayAdapter.createFromResource(this, R.array.conversions,android.R.layout.simple_spinner_item);aa.setDropDownViewResource(android.R.layout.simple_spinner_item);spnConversions.setAdapter(aa);AdapterView.OnItemSelectedListener oisl;oisl = new AdapterView.OnItemSelectedListener(){@Overridepublic void onItemSelected(AdapterView<?> parent, View view,int position, long id){UC.this.position = position;}@Overridepublic void onNothingSelected(AdapterView<?> parent){System.out.println("nothing");}};spnConversions.setOnItemSelectedListener(oisl);final Button btnClear = (Button) findViewById(R.id.clear);AdapterView.OnClickListener ocl;ocl = new AdapterView.OnClickListener(){@Overridepublic void onClick(View v){etUnits.setText("");}};btnClear.setOnClickListener(ocl);btnClear.setEnabled(false);final Button btnConvert = (Button) findViewById(R.id.convert);ocl = new AdapterView.OnClickListener(){@Overridepublic void onClick(View v){String text = etUnits.getText().toString();double input = Double.parseDouble(text);double result = 0;if (position == 3)result = input*9.0/5.0+32; // Celsius to Fahrenheitelseif (position == 4)result = (input-32)*5.0/9.0; // Fahrenheit to Celsiuselseresult = input*multipliers[position];etUnits.setText(""+result);}};btnConvert.setOnClickListener(ocl);btnConvert.setEnabled(false);Button btnClose = (Button) findViewById(R.id.close);ocl = new AdapterView.OnClickListener(){@Overridepublic void onClick(View v){finish();}};btnClose.setOnClickListener(ocl);TextWatcher tw;tw = new TextWatcher(){@Overridepublic void afterTextChanged(Editable s){}@Overridepublic void beforeTextChanged(CharSequence s, int start, int count,int after){}@Overridepublic void onTextChanged(CharSequence s, int start, int before,int count){if (etUnits.getText().length() == 0){btnClear.setEnabled(false);btnConvert.setEnabled(false);}else{btnClear.setEnabled(true);btnConvert.setEnabled(true);}}};etUnits.addTextChangedListener(tw);}
}

<?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"android:gravity="center_vertical"android:background="@drawable/gradientbg"android:padding="5dip"><LinearLayout android:layout_width="fill_parent"android:layout_height="wrap_content"><TextView android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_marginRight="10dip"android:text="@string/units"android:textColor="#000000"android:textSize="15sp"android:textStyle="bold"/><EditText android:id="@+id/units"android:layout_width="fill_parent"android:layout_height="wrap_content"android:hint="type a number"android:inputType="numberDecimal|numberSigned"android:maxLines="1"/></LinearLayout><Spinner android:id="@+id/conversions"android:layout_width="fill_parent"android:layout_height="wrap_content"android:prompt="@string/prompt"/><LinearLayout android:layout_width="fill_parent"android:layout_height="wrap_content"><Button android:id="@+id/clear"android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1"android:text="@string/clear"/><Button android:id="@+id/convert"android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1"android:text="@string/convert"/><Button android:id="@+id/close"android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1"android:text="@string/close"/></LinearLayout>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources><string name="app_name">Units Converter</string><string name="clear">Clear</string><string name="close">Close</string><string name="convert">Convert</string><string name="prompt">Select a conversion</string><string name="units">Units</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<resources><string-array name="conversions"><item>Acres to Square Miles</item><item>Atmospheres to Pascals</item><item>Bars to Pascals</item><item>Degrees Celsius to Degrees Fahrenheit</item><item>Degrees Fahrenheit to Degrees Celsius</item><item>Dynes to Newtons</item><item>Feet/Second to Metres/Second</item><item>Fluid Ounces (UK) to Litres</item><item>Fluid Ounces (US) to Litres</item><item>Horsepower (electric) to Watts</item><item>Horsepower (metric) to Watts</item><item>Kilograms to Tons (UK or long)</item><item>Kilograms to Tons (US or short)</item><item>Litres to Fluid ounces (UK)</item><item>Litres to Fluid ounces (US)</item><item>Mach Number to Metres/Second</item><item>Metres/Second to Feet/Second</item><item>Metres/Second to Mach Number</item><item>Miles/Gallon (UK) to Miles/Gallon (US)</item><item>Miles/Gallon (US) to Miles/Gallon (UK)</item><item>Newtons to Dynes</item><item>Pascals to Atmospheres</item><item>Pascals to Bars</item><item>Square Miles to Acres</item><item>Tons (UK or long) to Kilograms</item><item>Tons (US or short) to Kilograms</item><item>Watts to Horsepower (electric)</item><item>Watts to Horsepower (metric)</item></string-array>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"><gradient android:startColor="#fccb06" android:endColor="#fd6006"android:angle="270"/><corners android:radius="10dp"/>
</shape>

<menu xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"tools:context="com.apress.uc.UC" >
</menu>