Android开源代码解读の地图照片应用Panoramio的实现详解（二）
本文分析两个类：程序中用到的数据类PanoramioItem，以及工具类BitmapUtils。
1）Parcelable接口和PanoramioItem类
任何类如果希望自己的实例能够写入到Parcel中或者从Parcel中恢复出来，都必须实现Parcelable接口，实现这个接口的类除了要重写接口中定义的函数，还需要定义一个名为CREATOR的静态域，而CREATOR是实现Parcelable.Creator接口的对象，说了这么多，下面看下Parcelable的代码就一目了然了：
[java]
public interface Parcelable {
/**
* Flag for use with {@link #writeToParcel}: the object being written
* is a return value, that is the result of a function such as
* "<code>Parcelable someFunction()</code>",
* "<code>void someFunction(out Parcelable)</code>", or
* "<code>void someFunction(inout Parcelable)</code>". Some implementations
* may want to release resources at this point.
*/
public static final int PARCELABLE_WRITE_RETURN_VALUE = 0x0001;
/**
* Bit masks for use with {@link #describeContents}: each bit represents a
* kind of object considered to have potential special significance when
* marshalled.
*/
public static final int CONTENTS_FILE_DESCRIPTOR = 0x0001;
/**
* Describe the kinds of special objects contained in this Parcelable's
* marshalled representation.
*
* @return a bitmask indicating the set of special object types marshalled
* by the Parcelable.
*/
public int describeContents();
/**
* Flatten this object in to a Parcel.
*
* @param dest The Parcel in which the object should be written.
* @param flags Additional flags about how the object should be written.
* May be 0 or {@link #PARCELABLE_WRITE_RETURN_VALUE}.
*/
public void writeToParcel(Parcel dest, int flags);
/**
* Interface that must be implemented and provided as a public CREATOR
* field that generates instances of your Parcelable class from a Parcel.
*/
public interface Creator<T> {
/**
* Create a new instance of the Parcelable class, instantiating it
* from the given Parcel whose data had previously been written by
* {@link Parcelable#writeToParcel Parcelable.writeToParcel()}.
*
* @param source The Parcel to read the object's data from.
* @return Returns a new instance of the Parcelable class.
*/
public T createFromParcel(Parcel source);
/**
* Create a new array of the Parcelable class.
*
* @param size Size of the array.
* @return Returns an array of the Parcelable class, with every entry
* initialized to null.
*/
public T[] newArray(int size);
}
}
public interface Parcelable {
/**
* Flag for use with {@link #writeToParcel}: the object being written
* is a return value, that is the result of a function such as
* "<code>Parcelable someFunction()</code>",
* "<code>void someFunction(out Parcelable)</code>", or
* "<code>void someFunction(inout Parcelable)</code>". Some implementations
* may want to release resources at this point.
*/
public static final int PARCELABLE_WRITE_RETURN_VALUE = 0x0001;
/**
* Bit masks for use with {@link #describeContents}: each bit represents a
* kind of object considered to have potential special significance when
* marshalled.
*/
public static final int CONTENTS_FILE_DESCRIPTOR = 0x0001;
/**
* Describe the kinds of special objects contained in this Parcelable's
* marshalled representation.
*
* @return a bitmask indicating the set of special object types marshalled
* by the Parcelable.
*/
public int describeContents();
/**
* Flatten this object in to a Parcel.
*
* @param dest The Parcel in which the object should be written.
* @param flags Additional flags about how the object should be written.
* May be 0 or {@link #PARCELABLE_WRITE_RETURN_VALUE}.
*/
public void writeToParcel(Parcel dest, int flags);
/**
* Interface that must be implemented and provided as a public CREATOR
* field that generates instances of your Parcelable class from a Parcel.
*/
public interface Creator<T> {
/**
* Create a new
补充：移动开发 , Android ,
