numberinputelement.java

ZK 基础介绍 功能操作 模块 结合数据库操作

/* NumberInputElement.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Fri May  4 11:39:46     2007, Created by tomyeh
}}IS_NOTE

Copyright (C) 2007 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
	This program is distributed under GPL Version 2.0 in the hope that
	it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zul.impl;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.text.NumberFormat;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;

import org.zkoss.lang.JVMs;
import org.zkoss.util.Locales;
import org.zkoss.math.RoundingModes;

/**
 * A skeletal implementation for number-type input box.
 *
 * @author tomyeh
 */
abstract public class NumberInputElement extends FormatInputElement {
	/** The rounding mode. */
	private int _rounding = BigDecimal.ROUND_HALF_EVEN;

	/** Sets the rounding mode.
	 * Note: You cannot change the rounding mode unless you are
	 * using Java 6 or later.
	 *
	 * @param mode the rounding mode. Allowed value:
	 * {@link BigDecimal#ROUND_CEILING}, {@link BigDecimal#ROUND_DOWN},
	 * {@link BigDecimal#ROUND_FLOOR}, {@link BigDecimal#ROUND_HALF_DOWN},
	 * {@link BigDecimal#ROUND_HALF_UP}, {@link BigDecimal#ROUND_HALF_EVEN},
	 * {@link BigDecimal#ROUND_UNNECESSARY} and {@link BigDecimal#ROUND_UP}
	 *
	 * @exception UnsupportedOperationException if Java 5 or below
	 */
	public void setRoundingMode(int mode) {
		if (_rounding != mode) {
			if (!JVMs.isJava6())
				throw new UnsupportedOperationException("Java 6 or above is required");
			_rounding = mode;
		}
	}
	/** Sets the rounding mode by the name.
	 * Note: You cannot change the rounding mode unless you are
	 * using Java 6 or later.
	 *
	 * @param name the rounding mode's name. Allowed value:
<dl>
<dt>CEILING</dt>
	<dd>Rounding mode to round towards positive infinity.</dd>
<dt>DOWN</dt>
	<dd>Rounding mode to round towards zero.</dd>
<dt>FLOOR</dt>
	<dd>Rounding mode to round towards negative infinity.</dd>
<dt>HALF_DOWN</dt>
	<dd>Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down.</dd>
<dt>HALF_EVEN</dt>
	<dd>Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor.</dd>
<dt>HALF_UP</dt>
	<dd>Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up.</dd>
<dt>UNNECESSARY</dt>
	<dd>Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary.</dd>
<dt>UP</dt>
	<dd>Rounding mode to round away from zero.</dd>
</dl>
	 * @exception UnsupportedOperationException if Java 5 or below
	 * @see RoundingModes
	 */
	public void setRoundingMode(String name) {
		setRoundingMode(RoundingModes.valueOf(name));
	}
	/** Returns the rounding mode.
	 * <p>Default: {@link BigDecimal#ROUND_HALF_EVEN}.
	 */
	public int getRoundingMode() {
		return _rounding;
	}
	
	//utilities//
	/** Formats a number (Integer, BigDecimal...) into a string.
	 * If null, an empty string is returned.
	 *
	 * <p>A utility to assist the handling of numeric data.
	 *
	 * @see #toNumberOnly
	 * @param defaultFormat used if {@link #getFormat} returns null.
	 * If defaultFormat and {@link #getFormat} are both null,
	 * the system's default format is used.
	 */
	protected String formatNumber(Object value, String defaultFormat) {
		if (value == null) return "";

		final DecimalFormat df = (DecimalFormat)
			NumberFormat.getInstance(Locales.getCurrent());
		if (_rounding != BigDecimal.ROUND_HALF_EVEN)
			df.setRoundingMode(RoundingMode.valueOf(_rounding));

		String fmt = getFormat();
		if (fmt == null) fmt = defaultFormat;
		if (fmt != null) df.applyPattern(fmt);
		return df.format(value);
	}
	/** Filters out non digit characters, such comma and whitespace,
	 * from the specified value.
	 * It is designed to let user enter data in more free style.
	 * They may or may not enter data in the specified format.
	 *
	 * @return a two element array. The first element is the string to
	 * parse with, say, Double.parseDouble. The second element is
	 * an integer to indicate how many digits the result shall be scaled.
	 * For example, if the second element is 2. Then, the result shall be
	 * divided with 10 ^ 2.
	 *
	 * @see #formatNumber
	 */
	protected Object[] toNumberOnly(String val) {
		if (val == null) return new Object[] {null, null};

		final DecimalFormatSymbols symbols =
			new DecimalFormatSymbols(Locales.getCurrent());
		final char GROUPING = symbols.getGroupingSeparator(),
			DECIMAL = symbols.getDecimalSeparator(),
			PERCENT = symbols.getPercent(),
			PER_MILL = symbols.getPerMill(), //1/1000
			//not support yet: INFINITY = symbols.getInfinity(), NAN = symbols.getNaN(),
			MINUS = symbols.getMinusSign();
		final String fmt = getFormat();
		StringBuffer sb = null;
		int divscale = 0; //the second element
		boolean minus = false;
		for (int j = 0, len = val.length(); j < len; ++j) {
			final char cc = val.charAt(j);

			boolean ignore = false;
			//We handle percent and (nnn) specially
			if (cc == PERCENT) {
				divscale += 2;
				ignore = true;
			} else if (cc == PER_MILL) {
				divscale += 3;
				ignore = true;
			} else if (cc == '(') {
				minus = true;
				ignore = true;
			}

			//We don't add if cc shall be ignored (not alphanum but in fmt)
			if (!ignore)
				ignore = (cc < '0' || cc > '9')
				&& cc != DECIMAL && cc != MINUS && cc != '+'
				&& (Character.isWhitespace(cc) || cc == GROUPING || cc == ')'
					|| (fmt != null && fmt.indexOf(cc) >= 0));
			if (ignore) {
				if (sb == null)
					sb = new StringBuffer(len).append(val.substring(0, j));
			} else {
				final char c2 = cc == MINUS ? '-':
					cc == DECIMAL ? '.':  cc;
				if (cc != c2) {
					if (sb == null)
						sb = new StringBuffer(len).append(val.substring(0, j));
					sb.append(c2);
				} else if (sb != null) {
					sb.append(c2);
				}
			}
		}
		if (minus) {
			if (sb == null)
				sb = new StringBuffer(val.length() + 1).append(val);
			if (sb.length() > 0) {
				if (sb.charAt(0) == '-') {
					sb.deleteCharAt(0);
				} else {
					sb.insert(0, '-');
				}
			}
		}
		return new Object[] {
			(sb != null ? sb.toString(): val), new Integer(divscale)};
	}
}