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/*******************************************************************************
* Copyright (c) 2000, 2011 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.*;
import java.util.*;
import org.eclipse.swt.*;
/**
* 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.
*
*
*/
public final class Compatibility {
/**
* Answers the most negative (i.e. closest to negative infinity)
* integer value which is greater than or equal to 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 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).
*
*
* @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
* - ERROR_INVALID_RANGE - if the argument is not between 0 and 30 (inclusive)
*
*/
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;
}
/**
* Execute prog[0] in a separate platform process if the
* underlying platform supports this.
*
* The new process inherits the environment of the caller.
*
*
* @param prog array containing the program to execute and its arguments
* @param envp
* array of strings, each element of which has environment
* variable settings in the format name=value
* @param workingDir
* the working directory of the new process, or null if the new
* process should inherit the working directory of the caller
*
* @exception IOException
* if the program cannot be executed
* @exception SecurityException
* if the current SecurityManager disallows program execution
*
* @since 3.6
*/
public static void exec(String[] prog, String[] envp, String workingDir) throws java.io.IOException{
Runtime.getRuntime().exec(prog, null, workingDir != null ? new File(workingDir) : null);
}
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;
}
}