ecommons/org.eclipse.statet.ecommons.databinding.core/src/org/eclipse/statet/ecommons/databinding/core/validation/DecimalValidator.java

/*=============================================================================#
 # Copyright (c) 2007, 2021 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ecommons.databinding.core.validation;

import java.text.ParsePosition;

import com.ibm.icu.text.NumberFormat;

import org.eclipse.core.databinding.validation.IValidator;
import org.eclipse.core.databinding.validation.ValidationStatus;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;

import org.eclipse.statet.jcommons.lang.NonNullByDefault;


/**
 * Validator for decimals.
 */
@NonNullByDefault
public class DecimalValidator implements IValidator<Object> {
	
	
	private final NumberFormat formatter;
	
	private final boolean allowEmpty;
	private final double min;
	private final double max;
	
	private final String message;
	
	
	public DecimalValidator(final double min, final double max, final boolean allowEmpty,
			final String message) {
		this.allowEmpty= allowEmpty;
		this.min= min;
		this.max= max;
		this.message= message;
		
		this.formatter= NumberFormat.getNumberInstance();
		this.formatter.setParseIntegerOnly(false);
	}
	
	public DecimalValidator(final double min, final double max,
			final String message) {
		this(min, max, false, message);
	}
	
	
	@Override
	public IStatus validate(final Object value) {
		if (value instanceof String) {
			final String s= ((String)value).trim();
			if (this.allowEmpty && s.length() == 0) {
				return Status.OK_STATUS;
			}
			final ParsePosition result= new ParsePosition(0);
			final Number number= this.formatter.parse(s, result);
			if (result.getIndex() == s.length() && result.getErrorIndex() < 0) {
				final double n= number.doubleValue();
				if (n >= this.min && n <= this.max) {
					return Status.OK_STATUS;
				}
				// return range message
			}
		}
		return ValidationStatus.error(this.message);
	}
	
}