Class Size2DSyntax

public abstract class Size2DSyntax
extends Object
implements Serializable, Cloneable

Class Size2DSyntax is an abstract base class providing the common implementation of all attributes denoting a size in two dimensions.

A two-dimensional size attribute's value consists of two items, the X dimension and the Y dimension. A two-dimensional size attribute may be constructed by supplying the two values and indicating the units in which the values are measured. Methods are provided to return a two-dimensional size attribute's values, indicating the units in which the values are to be returned. The two most common size units are inches (in) and millimeters (mm), and exported constants INCH and MM are provided for indicating those units.

Once constructed, a two-dimensional size attribute's value is immutable.

Design

A two-dimensional size attribute's X and Y dimension values are stored internally as integers in units of micrometers (µm), where 1 micrometer = 10^-6 meter = 1/1000 millimeter = 1/25400 inch. This permits dimensions to be represented exactly to a precision of 1/1000 mm (= 1 µm) or 1/100 inch (= 254 µm). If fractional inches are expressed in negative powers of two, this permits dimensions to be represented exactly to a precision of 1/8 inch (= 3175 µm) but not 1/16 inch (because 1/16 inch does not equal an integral number of µm).

Storing the dimensions internally in common units of µm lets two size attributes be compared without regard to the units in which they were created; for example, 8.5 in will compare equal to 215.9 mm, as they both are stored as 215900 µm. For example, a lookup service can match resolution attributes based on equality of their serialized representations regardless of the units in which they were created. Using integers for internal storage allows precise equality comparisons to be done, which would not be guaranteed if an internal floating point representation were used. Note that if you're looking for U.S. letter sized media in metric units, you have to search for a media size of 215.9 x 279.4 mm; rounding off to an integral 216 x 279 mm will not match.

The exported constant INCH is actually the conversion factor by which to multiply a value in inches to get the value in µm. Likewise, the exported constant MM is the conversion factor by which to multiply a value in mm to get the value in µm. A client can specify a resolution value in units other than inches or mm by supplying its own conversion factor. However, since the internal units of µm was chosen with supporting only the external units of inch and mm in mind, there is no guarantee that the conversion factor for the client's units will be an exact integer. If the conversion factor isn't an exact integer, resolution values in the client's units won't be stored precisely.

Fields

INCH

public static final int INCH

Value to indicate units of inches (in). It is actually the conversion factor by which to multiply inches to yield µm (25400).

See Also:

Constant Field Values

MM

public static final int MM

Value to indicate units of millimeters (mm). It is actually the conversion factor by which to multiply mm to yield µm (1000).

See Also:

Constant Field Values

Constructors

Size2DSyntax

protected Size2DSyntax(float x,
                       float y,
                       int units)

Construct a new two-dimensional size attribute from the given floating-point values.

Parameters:

x - X dimension.

y - Y dimension.

units - Unit conversion factor, e.g. INCH or MM.

Throws:

IllegalArgumentException - (Unchecked exception) Thrown if x < 0 or y < 0 or units < 1.

Size2DSyntax

protected Size2DSyntax(int x,
                       int y,
                       int units)

Construct a new two-dimensional size attribute from the given integer values.

Parameters:

x - X dimension.

y - Y dimension.

units - Unit conversion factor, e.g. INCH or MM.

Throws:

IllegalArgumentException - (Unchecked exception) Thrown if x < 0 or y < 0 or units < 1.

Methods

getSize

public float[] getSize(int units)

Get this two-dimensional size attribute's dimensions in the given units as floating-point values.

Parameters:

units - Unit conversion factor, e.g. INCH or MM.

Returns:

A two-element array with the X dimension at index 0 and the Y dimension at index 1.

Throws:

IllegalArgumentException - (unchecked exception) Thrown if units < 1.

getX

public float getX(int units)

Returns this two-dimensional size attribute's X dimension in the given units as a floating-point value.

Parameters:

units - Unit conversion factor, e.g. INCH or MM.

Returns:

X dimension.

Throws:

IllegalArgumentException - (unchecked exception) Thrown if units < 1.

getY

public float getY(int units)

Returns this two-dimensional size attribute's Y dimension in the given units as a floating-point value.

Parameters:

units - Unit conversion factor, e.g. INCH or MM.

Returns:

Y dimension.

Throws:

IllegalArgumentException - (unchecked exception) Thrown if units < 1.

toString

public String toString(int units,
                       String unitsName)

Returns a string version of this two-dimensional size attribute in the given units. The string takes the form "XxY U", where X is the X dimension, Y is the Y dimension, and U is the units name. The values are displayed in floating point.

Parameters:

units - Unit conversion factor, e.g. INCH or MM.

unitsName - Units name string, e.g. in or mm. If null, no units name is appended to the result.

Returns:

String version of this two-dimensional size attribute.

Throws:

IllegalArgumentException - (unchecked exception) Thrown if units < 1.

equals

public boolean equals(Object object)

Returns whether this two-dimensional size attribute is equivalent to the passed in object. To be equivalent, all of the following conditions must be true:

1. object is not null.
2. object is an instance of class Size2DSyntax.
3. This attribute's X dimension is equal to object's X dimension.
4. This attribute's Y dimension is equal to object's Y dimension.

Overrides:

equals in class Object

Parameters:

object - Object to compare to.

Returns:

True if object is equivalent to this two-dimensional size attribute, false otherwise.

See Also:

Object.hashCode(), HashMap

hashCode

public int hashCode()

Returns a hash code value for this two-dimensional size attribute.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

toString

public String toString()

Returns a string version of this two-dimensional size attribute. The string takes the form "XxY um", where X is the X dimension and Y is the Y dimension. The values are reported in the internal units of micrometers.

Overrides:

toString in class Object

Returns:

a string representation of the object.

getXMicrometers

protected int getXMicrometers()

Returns this two-dimensional size attribute's X dimension in units of micrometers (µm). (For use in a subclass.)

Returns:

X dimension (µm).

getYMicrometers

protected int getYMicrometers()

Returns this two-dimensional size attribute's Y dimension in units of micrometers (µm). (For use in a subclass.)

Returns:

Y dimension (µm).