/*******************************************************************************
* Copyright (c) 2000, 2007 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.swt.internal;
import java.io.*;
import java.text.MessageFormat;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.zip.InflaterInputStream;
import java.util.zip.DeflaterOutputStream;
import org.eclipse.swt.SWT;
/**
* This class is a placeholder for utility methods commonly
* used on J2SE platforms but not supported on some J2ME
* profiles.
* <p>
* It is part of our effort to provide support for both J2SE
* and J2ME platforms.
* </p>
* <p>
* IMPORTANT: some of the methods have been modified from their
* J2SE parents. Refer to the description of each method for
* specific changes.
* </p>
* <ul>
* <li>Exceptions thrown may differ since J2ME's set of
* exceptions is a subset of J2SE's one.
* </li>
* <li>The range of the mathematic functions is subject to
* change.
* </li>
* </ul>
*/
public final class Compatibility {
/**
* Returns the PI constant as a double.
*/
public static double PI = Math.PI;
static double toRadians = PI / 180;
/**
* 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).
* <p>
* IMPORTANT: the j2me version has an additional restriction on
* the argument. length must be between -32767 and 32767 (inclusive).
* </p>
*
* @param angle the angle in degrees
* @param length the length of the triangle's hypotenuse
* @return the integer conversion of length * cos (angle)
*/
public static int cos(int angle, int length) {
return (int)(Math.cos(angle * toRadians) * 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).
* <p>
* IMPORTANT: the j2me version has an additional restriction on
* the argument. length must be between -32767 and 32767 (inclusive).
* </p>
*
* @param angle the angle in degrees
* @param length the length of the triangle's hypotenuse
* @return the integer conversion of length * sin (angle)
*/
public static int sin(int angle, int length) {
return (int)(Math.sin(angle * toRadians) * length);
}
/**
* 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.
*
* @param p numerator
* @param q denominator (must be different from zero)
* @return the ceiling of the rational number p / q.
*/
public static int ceil(int p, int q) {
return (int)Math.ceil((float)p / q);
}
/**
* Answers whether the indicated file exists or not.
*
* @param parent the file's parent directory
* @param child the file's name
* @return true if the file exists
*/
public static boolean fileExists(String parent, String child) {
return new File (parent, child).exists();
}
/**
* 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.
*
* @param p numerator
* @param q denominator (must be different from zero)
* @return the floor of the rational number p / q.
*/
public static int floor(int p, int q) {
return (int)Math.floor((double)p / q);
}
/**
* Answers the result of rounding to the closest integer the number obtained
* by dividing the first argument p by the second argument q.
* <p>
* 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).
* </p>
*
* @param p numerator
* @param q denominator (must be different from zero)
* @return the closest integer to the rational number p / q
*/
public static int round(int p, int q) {
return Math.round((float)p / q);
}
/**
* Returns 2 raised to the power of the argument.
*
* @param n an int value between 0 and 30 (inclusive)
* @return 2 raised to the power of the argument
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_INVALID_RANGE - if the argument is not between 0 and 30 (inclusive)</li>
* </ul>
*/
public static int pow2(int n) {
if (n >= 1 && n <= 30)
return 2 << (n - 1);
else if (n != 0) {
SWT.error(SWT.ERROR_INVALID_RANGE);
}
return 1;
}
/**
* Create an DeflaterOutputStream if such things are supported.
*
* @param stream the output stream
* @return a deflater stream or <code>null</code>
* @exception IOException
*
* @since 3.4
*/
public static OutputStream newDeflaterOutputStream(OutputStream stream) throws IOException {
return new DeflaterOutputStream(stream);
}
/**
* Open a file if such things are supported.
*
* @param filename the name of the file to open
* @return a stream on the file if it could be opened.
* @exception IOException
*/
public static InputStream newFileInputStream(String filename) throws IOException {
return new FileInputStream(filename);
}
/**
* Open a file if such things are supported.
*
* @param filename the name of the file to open
* @return a stream on the file if it could be opened.
* @exception IOException
*/
public static OutputStream newFileOutputStream(String filename) throws IOException {
return new FileOutputStream(filename);
}
/**
* Create an InflaterInputStream if such things are supported.
*
* @param stream the input stream
* @return a inflater stream or <code>null</code>
* @exception IOException
*
* @since 3.3
*/
public static InputStream newInflaterInputStream(InputStream stream) throws IOException {
return new BufferedInputStream(new InflaterInputStream(stream));
}
/**
* Answers whether the character is a letter.
*
* @param c the character
* @return true when the character is a letter
*/
public static boolean isLetter(char c) {
return Character.isLetter(c);
}
/**
* Answers whether the character is a letter or a digit.
*
* @param c the character
* @return true when the character is a letter or a digit
*/
public static boolean isLetterOrDigit(char c) {
return Character.isLetterOrDigit(c);
}
/**
* Answers whether the character is a Unicode space character.
*
* @param c the character
* @return true when the character is a Unicode space character
*/
public static boolean isSpaceChar(char c) {
return Character.isSpaceChar(c);
}
/**
* Answers whether the character is a whitespace character.
*
* @param c the character to test
* @return true if the character is whitespace
*/
public static boolean isWhitespace(char c) {
return Character.isWhitespace(c);
}
/**
* Execute a program in a separate platform process if the
* underlying platform support this.
* <p>
* The new process inherits the environment of the caller.
* </p>
*
* @param prog the name of the program to execute
*
* @exception IOException
* if the program cannot be executed
* @exception SecurityException
* if the current SecurityManager disallows program execution
*/
public static void exec(String prog) throws java.io.IOException {
Runtime.getRuntime().exec(prog);
}
/**
* Execute progArray[0] in a separate platform process if the
* underlying platform support this.
* <p>
* The new process inherits the environment of the caller.
* <p>
*
* @param progArray array containing the program to execute and its arguments
*
* @exception IOException
* if the program cannot be executed
* @exception SecurityException
* if the current SecurityManager disallows program execution
*/
public static void exec(String[] progArray) throws java.io.IOException{
Runtime.getRuntime().exec(progArray);
}
private static ResourceBundle msgs = null;
/**
* Returns the NLS'ed message for the given argument. This is only being
* called from SWT.
*
* @param key the key to look up
* @return the message for the given key
*
* @see SWT#getMessage(String)
*/
public static String getMessage(String key) {
String answer = key;
if (key == null) {
SWT.error (SWT.ERROR_NULL_ARGUMENT);
}
if (msgs == null) {
try {
msgs = ResourceBundle.getBundle("org.eclipse.swt.internal.SWTMessages"); //$NON-NLS-1$
} catch (MissingResourceException ex) {
answer = key + " (no resource bundle)"; //$NON-NLS-1$
}
}
if (msgs != null) {
try {
answer = msgs.getString(key);
} catch (MissingResourceException ex2) {}
}
return answer;
}
public static String getMessage(String key, Object[] args) {
String answer = key;
if (key == null || args == null) {
SWT.error (SWT.ERROR_NULL_ARGUMENT);
}
if (msgs == null) {
try {
msgs = ResourceBundle.getBundle("org.eclipse.swt.internal.SWTMessages"); //$NON-NLS-1$
} catch (MissingResourceException ex) {
answer = key + " (no resource bundle)"; //$NON-NLS-1$
}
}
if (msgs != null) {
try {
MessageFormat formatter = new MessageFormat("");
formatter.applyPattern(msgs.getString(key));
answer = formatter.format(args);
} catch (MissingResourceException ex2) {}
}
return answer;
}
/**
* Interrupt the current thread.
* <p>
* Note that this is not available on CLDC.
* </p>
*/
public static void interrupt() {
Thread.currentThread().interrupt();
}
/**
* Compares two instances of class String ignoring the case of the
* characters and answers if they are equal.
*
* @param s1 string
* @param s2 string
* @return true if the two instances of class String are equal
*/
public static boolean equalsIgnoreCase(String s1, String s2) {
return s1.equalsIgnoreCase(s2);
}
}
|