MotionEvent.PointerProperties

id

int id

指针ID。 最初设置为INVALID_POINTER_ID （-1）。

toolType

int toolType

指针工具类型。 最初设置为0。

MotionEvent.PointerProperties

MotionEvent.PointerProperties ()

用无效的指针ID创建一个指针属性对象。

MotionEvent.PointerProperties

MotionEvent.PointerProperties (MotionEvent.PointerProperties other)

创建一个指针属性对象作为另一个指针属性对象内容的副本。

clear

void clear ()

将指针属性重置为其初始值。

copyFrom

void copyFrom (MotionEvent.PointerProperties other)

复制另一个指针属性对象的内容。

equals

boolean equals (Object other)

指示其他某个对象是否“等于”这一个。

equals方法在非空对象引用上实现等价关系：

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

类Object的equals方法实现了对象上最可能的等价关系; 也就是说，对于任何非空参考值x和y ，此方法返回true当且仅当x和y引用同一对象（ x == y的值为true ）。

请注意，无论何时重写此方法，通常都必须重写 hashCode方法，以维护 hashCode方法的常规协定，该方法声明相等对象必须具有相同的哈希码。

hashCode

int hashCode ()

返回对象的哈希码值。 为了散列表的好处而支持该方法，例如由HashMap提供的HashMap 。

hashCode的总合同是：

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

尽可能合理实用，类Object定义的hashCode方法确实为不同的对象返回不同的整数。 （这通常通过将对象的内部地址转换为整数来实现，但Java ^TM编程语言不需要此实现技术。）