org.eclipse.wb.internal.css.semantics.LengthValue.java Source code

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Here is the source code for org.eclipse.wb.internal.css.semantics.LengthValue.java

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/*******************************************************************************
 * Copyright (c) 2011 Google, Inc.
 * 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:
 *    Google, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.wb.internal.css.semantics;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;

import java.text.NumberFormat;
import java.text.ParsePosition;
import java.util.Locale;

/**
 * Length value, it is used for any length/size properties, for example for
 * margin/padding/border-width.
 * 
 * @author scheglov_ke
 * @coverage CSS.semantics
 */
public final class LengthValue extends AbstractValue {
    private static final NumberFormat VALUE_DECIMAL_FORMAT = NumberFormat.getInstance(Locale.ENGLISH);
    public static final String UNIT_NAMES[] = new String[] { "px", "pt", "in", "cm", "mm", "pc", "em", "ex", "%" };
    public static final String UNIT_TITLES[] = new String[] { "pixels", "points", "in", "cm", "mm", "picas", "ems",
            "exs", "%" };
    private String m_value;
    private String m_unit;

    ////////////////////////////////////////////////////////////////////////////
    //
    // Constructor
    //
    ////////////////////////////////////////////////////////////////////////////
    public LengthValue(AbstractSemanticsComposite composite) {
        super(composite);
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Object
    //
    ////////////////////////////////////////////////////////////////////////////
    @Override
    public String toString() {
        return "{" + ToStringBuilder.reflectionToString(this, ToStringStyle.SIMPLE_STYLE) + "}";
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Assignment
    //
    ////////////////////////////////////////////////////////////////////////////
    /**
     * Sets value of this {@link LengthValue} same as given {@link LengthValue}.
     */
    public void set(LengthValue value) {
        m_value = value.m_value;
        m_unit = value.m_value;
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Access
    //
    ////////////////////////////////////////////////////////////////////////////
    /**
     * Assigns value as string, should be separated if possible on value and unit, or use full string
     * as value without unit.
     */
    @Override
    public void set(String s) {
        // try to find unit
        if (s != null) {
            for (int I = 0; I < UNIT_NAMES.length; I++) {
                String unit = UNIT_NAMES[I];
                if (s.endsWith(unit)) {
                    // check that value is correct number
                    String value = StringUtils.substring(s, 0, -unit.length());
                    try {
                        VALUE_DECIMAL_FORMAT.parse(value);
                    } catch (Throwable e) {
                        continue;
                    }
                    // OK, we have correct value and unit
                    m_value = value;
                    m_unit = unit;
                    notifyListeners();
                    return;
                }
            }
        }
        // no, we can not separate given string on value and unit, so use string itself as value
        m_value = s;
        m_unit = "px";
        notifyListeners();
    }

    @Override
    public String get() {
        String value = m_value;
        if (value != null) {
            value = value.trim();
            if (value.length() == 0) {
                value = null;
            }
        }
        //
        if (value == null) {
            return null;
        }
        if (requiresUnit()) {
            return value + m_unit;
        }
        return value;
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Value
    //
    ////////////////////////////////////////////////////////////////////////////
    public void setValue(String value) {
        if (m_value == value || m_value != null && m_value.equals(value)) {
            return;
        }
        m_value = value;
        notifyListeners();
    }

    public String getValue() {
        return m_value;
    }

    public boolean hasValue() {
        return m_value != null && m_value.trim().length() != 0;
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Unit
    //
    ////////////////////////////////////////////////////////////////////////////
    /**
     * Checks if current value requires unit. We need unit only if value is number.
     */
    public boolean requiresUnit() {
        if (hasValue()) {
            ParsePosition parsePosition = new ParsePosition(0);
            VALUE_DECIMAL_FORMAT.parse(m_value, parsePosition);
            return parsePosition.getIndex() == m_value.length();
        }
        return false;
    }

    public void setUnit(String unit) {
        if (m_unit == unit || m_unit != null && m_unit.equals(unit)) {
            return;
        }
        m_unit = unit;
        notifyListeners();
    }

    public String getUnit() {
        return m_unit;
    }

    public boolean hasUnit() {
        return m_unit != null;
    }
}