com.androidplot.util

Class Configurator

java.lang.Object

com.androidplot.util.Configurator

public abstract class Configurator
extends Object

Utility class for "configuring" objects via XML config files. Supports the following field types: String Enum int float boolean

Config files should be stored in /res/xml. Given the XML configuration /res/xml/myConfig.xml, one can apply the configuration to an Object instance as follows:

MyObject obj = new MyObject(); Configurator.configure(obj, R.xml.myConfig);

WHAT IT DOES: Given a series of parameters stored in an XML file, Configurator iterates through each parameter, using the name as a map to the field within a given object. For example:

 
 <config car.engine.sparkPlug.condition="poor"/>
 
 

Given a Car instance car and assuming the method setCondition(String) exists within the SparkPlug class, Configurator does the following:

 
 car.getEngine().getSparkPlug().setCondition("poor");
 
 

Now let's pretend that setCondition takes an instance of the Condition enum as it's argument. Configurator then does the following:

car.getEngine().getSparkPlug().setCondition(Condition.valueOf("poor");

Now let's look at how ints are handled. Given the following xml:

would result in: car.getEngine.setMiles(Integer.ParseInt("100000");

That's pretty straight forward. But colors are expressed as ints too in Android but can be defined using hex values or even names of colors. When Configurator attempts to parse a parameter for a method that it knows takes an int as it's argument, Configurator will first attempt to parse the parameter as a color. Only after this attempt fails will Configurator resort to Integer.ParseInt. So:

would result in: car.getHood().getPaint().setColor(Color.parseColor("Red");

Next lets talk about float. Floats can appear in XML a few different ways in Android, especially when it comes to defining dimensions:

Configurator will correctly parse each of these into their corresponding real pixel value expressed as a float.

One last thing to keep in mind when using Configurator: Values for Strings and ints can be assigned to localized values, allowing a cleaner solution for those developing apps to run on multiple form factors or in multiple languages:

Field Summary

Fields

Modifier and Type	Field and Description
protected static String	CFG_ELEMENT_NAME

Constructor Summary

Constructors

Constructor and Description
Configurator()

Method Summary

Modifier and Type	Method and Description
protected static String	argArrToString(Object[] args)
static void	configure(android.content.Context ctx, Object obj, HashMap<String,String> params)
static void	configure(android.content.Context ctx, Object obj, int xmlFileId)
protected static void	configure(android.content.Context ctx, Object obj, String key, String value) Recursively descend into an object using key as the pathway and invoking the corresponding setter if one exists.
protected static Method	getGetter(Class clazz, String fieldId)
protected static Object	getObjectContaining(Object obj, String path) Returns the object containing the field specified by path.
protected static Method	getSetter(Class clazz, String fieldId)
protected static float	parseFloatAttr(android.content.Context ctx, String value) Treats value as a float parameter.
protected static int	parseIntAttr(android.content.Context ctx, String value)
protected static int	parseResId(android.content.Context ctx, String prefix, String value)
protected static String	parseStringAttr(android.content.Context ctx, String value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CFG_ELEMENT_NAME

protected static final String CFG_ELEMENT_NAME

See Also:

Constant Field Values

Constructor Detail

Configurator

public Configurator()

Method Detail

parseResId

protected static int parseResId(android.content.Context ctx,
                                String prefix,
                                String value)

parseIntAttr

protected static int parseIntAttr(android.content.Context ctx,
                                  String value)

parseFloatAttr

protected static float parseFloatAttr(android.content.Context ctx,
                                      String value)

Treats value as a float parameter. First value is tested to see whether it contains a resource identifier. Failing that, it is tested to see whether a dimension suffix (dp, em, mm etc.) exists. Failing that, it is evaluated as a plain old float.

Parameters:

ctx -

value -

Returns:

parseStringAttr

protected static String parseStringAttr(android.content.Context ctx,
                                        String value)

getSetter

protected static Method getSetter(Class clazz,
                                  String fieldId)
                           throws NoSuchMethodException

Throws:

NoSuchMethodException

getGetter

protected static Method getGetter(Class clazz,
                                  String fieldId)
                           throws NoSuchMethodException

Throws:

NoSuchMethodException

getObjectContaining

protected static Object getObjectContaining(Object obj,
                                            String path)
                                     throws InvocationTargetException,
                                            IllegalAccessException,
                                            NoSuchMethodException

Returns the object containing the field specified by path.

Parameters:

obj -

path - Path through member hierarchy to the destination field.

Returns:

null if the object at path cannot be found.

Throws:

InvocationTargetException

IllegalAccessException

NoSuchMethodException

configure

public static void configure(android.content.Context ctx,
                             Object obj,
                             int xmlFileId)

Parameters:

ctx -

obj -

xmlFileId - ID of the XML config file within /res/xml

configure

public static void configure(android.content.Context ctx,
                             Object obj,
                             HashMap<String,String> params)

configure

protected static void configure(android.content.Context ctx,
                                Object obj,
                                String key,
                                String value)
                         throws InvocationTargetException,
                                IllegalAccessException,
                                NoSuchMethodException

Recursively descend into an object using key as the pathway and invoking the corresponding setter if one exists.

Parameters:

key -

value -

Throws:

InvocationTargetException

IllegalAccessException

NoSuchMethodException

argArrToString

protected static String argArrToString(Object[] args)