org.eclipse.swt.internal

Class Compatibility

java.lang.Object

org.eclipse.swt.internal.Compatibility

public final class Compatibility
extends java.lang.Object

This class is a placeholder for utility methods commonly used on J2SE platforms but not supported on some J2ME profiles.

It is part of our effort to provide support for both J2SE and J2ME platforms.

IMPORTANT: some of the methods have been modified from their J2SE parents. Refer to the description of each method for specific changes.

• Exceptions thrown may differ since J2ME's set of exceptions is a subset of J2SE's one.
• The range of the mathematic functions is subject to change.

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
private static java.util.ResourceBundle	msgs
static double	PI Returns the PI constant as a double.
(package private) static double	toRadians

Constructor Summary

Constructors

Constructor and Description
Compatibility()

Method Summary

Methods

Modifier and Type	Method and Description
static int	ceil(int p, int q) Answers the most negative (i.e. closest to negative infinity) integer value which is greater than the number obtained by dividing the first argument p by the second argument q.
static int	cos(int angle, int length) Answers the length of the side adjacent to the given angle of a right triangle.
static boolean	equalsIgnoreCase(java.lang.String s1, java.lang.String s2) Compares two instances of class String ignoring the case of the characters and answers if they are equal.
static void	exec(java.lang.String prog) Execute a program in a separate platform process if the underlying platform support this.
static void	exec(java.lang.String[] progArray) Execute progArray[0] in a separate platform process if the underlying platform support this.
static void	exec(java.lang.String[] prog, java.lang.String[] envp, java.lang.String workingDir) Execute prog[0] in a separate platform process if the underlying platform supports this.
static boolean	fileExists(java.lang.String parent, java.lang.String child) Answers whether the indicated file exists or not.
static int	floor(int p, int q) Answers the most positive (i.e. closest to positive infinity) integer value which is less than the number obtained by dividing the first argument p by the second argument q.
static java.lang.String	getMessage(java.lang.String key) Returns the NLS'ed message for the given argument.
static java.lang.String	getMessage(java.lang.String key, java.lang.Object[] args)
static void	interrupt() Interrupt the current thread.
static boolean	isLetter(char c) Answers whether the character is a letter.
static boolean	isLetterOrDigit(char c) Answers whether the character is a letter or a digit.
static boolean	isSpaceChar(char c) Answers whether the character is a Unicode space character.
static boolean	isWhitespace(char c) Answers whether the character is a whitespace character.
static java.io.OutputStream	newDeflaterOutputStream(java.io.OutputStream stream, int level) Create a DeflaterOutputStream if such things are supported.
static java.io.InputStream	newFileInputStream(java.lang.String filename) Open a file if such things are supported.
static java.io.OutputStream	newFileOutputStream(java.lang.String filename) Open a file if such things are supported.
static java.io.InputStream	newInflaterInputStream(java.io.InputStream stream) Create an InflaterInputStream if such things are supported.
static int	pow2(int n) Returns 2 raised to the power of the argument.
static int	round(int p, int q) Answers the result of rounding to the closest integer the number obtained by dividing the first argument p by the second argument q.
static int	sin(int angle, int length) Answers the length of the side opposite to the given angle of a right triangle.

Methods inherited from class java.lang.Object

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

Field Detail

PI

public static double PI

Returns the PI constant as a double.

toRadians

static double toRadians

msgs

private static java.util.ResourceBundle msgs

Constructor Detail

Compatibility

public Compatibility()

Method Detail

cos

public static int cos(int angle,
      int length)

Answers the length of the side adjacent to the given angle of a right triangle. In other words, it returns the integer conversion of length * cos (angle).

IMPORTANT: the j2me version has an additional restriction on the argument. length must be between -32767 and 32767 (inclusive).

Parameters:

angle - the angle in degrees

length - the length of the triangle's hypotenuse

Returns:

the integer conversion of length * cos (angle)

sin

public static int sin(int angle,
      int length)

Answers the length of the side opposite to the given angle of a right triangle. In other words, it returns the integer conversion of length * sin (angle).

IMPORTANT: the j2me version has an additional restriction on the argument. length must be between -32767 and 32767 (inclusive).

Parameters:

angle - the angle in degrees

length - the length of the triangle's hypotenuse

Returns:

the integer conversion of length * sin (angle)

ceil

public static int ceil(int p,
       int q)

Answers the most negative (i.e. closest to negative infinity) integer value which is greater than the number obtained by dividing the first argument p by the second argument q.

Parameters:

p - numerator

q - denominator (must be different from zero)

Returns:

the ceiling of the rational number p / q.

fileExists

public static boolean fileExists(java.lang.String parent,
                 java.lang.String child)

Answers whether the indicated file exists or not.

Parameters:

parent - the file's parent directory

child - the file's name

Returns:

true if the file exists

floor

public static int floor(int p,
        int q)

Answers the most positive (i.e. closest to positive infinity) integer value which is less than the number obtained by dividing the first argument p by the second argument q.

Parameters:

p - numerator

q - denominator (must be different from zero)

Returns:

the floor of the rational number p / q.

round

public static int round(int p,
        int q)

Answers the result of rounding to the closest integer the number obtained by dividing the first argument p by the second argument q.

IMPORTANT: the j2me version has an additional restriction on the arguments. p must be within the range 0 - 32767 (inclusive). q must be within the range 1 - 32767 (inclusive).

Parameters:

p - numerator

q - denominator (must be different from zero)

Returns:

the closest integer to the rational number p / q

pow2

public static int pow2(int n)

Returns 2 raised to the power of the argument.

Parameters:

n - an int value between 0 and 30 (inclusive)

Returns:

2 raised to the power of the argument

Throws:

java.lang.IllegalArgumentException -

• ERROR_INVALID_RANGE - if the argument is not between 0 and 30 (inclusive)

newDeflaterOutputStream

public static java.io.OutputStream newDeflaterOutputStream(java.io.OutputStream stream,
                                           int level)
                                                    throws java.io.IOException

Create a DeflaterOutputStream if such things are supported.

Parameters:

stream - the output stream

Returns:

a deflater stream or null

Throws:

java.io.IOException

Since:

3.4

newFileInputStream

public static java.io.InputStream newFileInputStream(java.lang.String filename)
                                              throws java.io.IOException

Open a file if such things are supported.

Parameters:

filename - the name of the file to open

Returns:

a stream on the file if it could be opened.

Throws:

java.io.IOException

newFileOutputStream

public static java.io.OutputStream newFileOutputStream(java.lang.String filename)
                                                throws java.io.IOException

Open a file if such things are supported.

Parameters:

filename - the name of the file to open

Returns:

a stream on the file if it could be opened.

Throws:

java.io.IOException

newInflaterInputStream

public static java.io.InputStream newInflaterInputStream(java.io.InputStream stream)
                                                  throws java.io.IOException

Create an InflaterInputStream if such things are supported.

Parameters:

stream - the input stream

Returns:

a inflater stream or null

Throws:

java.io.IOException

Since:

3.3

isLetter

public static boolean isLetter(char c)

Answers whether the character is a letter.

Parameters:

c - the character

Returns:

true when the character is a letter

isLetterOrDigit

public static boolean isLetterOrDigit(char c)

Answers whether the character is a letter or a digit.

Parameters:

c - the character

Returns:

true when the character is a letter or a digit

isSpaceChar

public static boolean isSpaceChar(char c)

Answers whether the character is a Unicode space character.

Parameters:

c - the character

Returns:

true when the character is a Unicode space character

isWhitespace

public static boolean isWhitespace(char c)

Answers whether the character is a whitespace character.

Parameters:

c - the character to test

Returns:

true if the character is whitespace

exec

public static void exec(java.lang.String prog)
                 throws java.io.IOException

Execute a program in a separate platform process if the underlying platform support this.

The new process inherits the environment of the caller.

Parameters:

prog - the name of the program to execute

Throws:

java.io.IOException - if the program cannot be executed

java.lang.SecurityException - if the current SecurityManager disallows program execution

exec

public static void exec(java.lang.String[] progArray)
                 throws java.io.IOException

Execute progArray[0] in a separate platform process if the underlying platform support this.

The new process inherits the environment of the caller.

Parameters:

progArray - array containing the program to execute and its arguments

Throws:

java.io.IOException - if the program cannot be executed

java.lang.SecurityException - if the current SecurityManager disallows program execution

exec

public static void exec(java.lang.String[] prog,
        java.lang.String[] envp,
        java.lang.String workingDir)
                 throws java.io.IOException

Execute prog[0] in a separate platform process if the underlying platform supports this.

The new process inherits the environment of the caller.

Parameters:

prog - array containing the program to execute and its arguments

envp - array of strings, each element of which has environment variable settings in the format name=value

workingDir - the working directory of the new process, or null if the new process should inherit the working directory of the caller

Throws:

java.io.IOException - if the program cannot be executed

java.lang.SecurityException - if the current SecurityManager disallows program execution

Since:

3.6

getMessage

public static java.lang.String getMessage(java.lang.String key)

Returns the NLS'ed message for the given argument. This is only being called from SWT.

Parameters:

key - the key to look up

Returns:

the message for the given key

See Also:

SWT.getMessage(String)

getMessage

public static java.lang.String getMessage(java.lang.String key,
                          java.lang.Object[] args)

interrupt

public static void interrupt()

Interrupt the current thread.

Note that this is not available on CLDC.

equalsIgnoreCase

public static boolean equalsIgnoreCase(java.lang.String s1,
                       java.lang.String s2)

Compares two instances of class String ignoring the case of the characters and answers if they are equal.

Parameters:

s1 - string

s2 - string

Returns:

true if the two instances of class String are equal