CSSDeclaration.java

/**
 * Copyright (C) 2014-2017 Philip Helger (www.helger.com)
 * philip[at]helger[dot]com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.helger.css.decl;

import java.util.Locale;

import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.concurrent.NotThreadSafe;

import com.helger.commons.ValueEnforcer;
import com.helger.commons.annotation.Nonempty;
import com.helger.commons.annotation.ReturnsMutableObject;
import com.helger.commons.hashcode.HashCodeGenerator;
import com.helger.commons.string.ToStringGenerator;
import com.helger.css.CCSS;
import com.helger.css.CSSSourceLocation;
import com.helger.css.ICSSSourceLocationAware;
import com.helger.css.ICSSWriterSettings;
import com.helger.css.property.ECSSProperty;

/**
 * Represents a single element in a CSS style rule. (eg. <code>color:red;</code>
 * or <code>background:uri(a.gif) !important;</code>)<br>
 * Instances of this class are mutable since 3.7.4.
 *
 * @author Philip Helger
 */
@NotThreadSafe
public class CSSDeclaration implements ICSSSourceLocationAware, ICSSPageRuleMember
{
  public static final boolean DEFAULT_IMPORTANT = false;

  private String m_sProperty;
  private CSSExpression m_aExpression;
  private boolean m_bIsImportant;
  private CSSSourceLocation m_aSourceLocation;

  /**
   * Constructor for non-important values.
   *
   * @param sProperty
   *        The name of the property. E.g. "color". May neither be
   *        <code>null</code> nor empty. The property value is automatically
   *        lowercased!
   * @param aExpression
   *        The value of the property. May not be <code>null</code>.
   */
  public CSSDeclaration (@Nonnull @Nonempty final String sProperty, @Nonnull final CSSExpression aExpression)
  {
    this (sProperty, aExpression, DEFAULT_IMPORTANT);
  }

  /**
   * Constructor.
   *
   * @param sProperty
   *        The name of the property. E.g. "color". May neither be
   *        <code>null</code> nor empty. The property value is automatically
   *        lowercased!
   * @param aExpression
   *        The value of the property. May not be <code>null</code>.
   * @param bIsImportant
   *        <code>true</code> if it is important, <code>false</code> if not.
   */
  public CSSDeclaration (@Nonnull @Nonempty final String sProperty,
                         @Nonnull final CSSExpression aExpression,
                         final boolean bIsImportant)
  {
    setProperty (sProperty);
    setExpression (aExpression);
    setImportant (bIsImportant);
  }

  /**
   * @return The property of this declaration (e.g. "color" or "margin-top").
   *         The string is always lowercase. Never <code>null</code>.
   */
  @Nonnull
  @Nonempty
  public String getProperty ()
  {
    return m_sProperty;
  }

  /**
   * Set the property of this CSS value (e.g. <code>background-color</code>).
   *
   * @param sProperty
   *        The CSS property name to set. May neither be <code>null</code> nor
   *        empty. The property value is automatically lowercased!
   * @return this
   * @since 3.7.4
   */
  @Nonnull
  public CSSDeclaration setProperty (@Nonnull @Nonempty final String sProperty)
  {
    m_sProperty = ValueEnforcer.notEmpty (sProperty, "Property").toLowerCase (Locale.US);
    return this;
  }

  /**
   * Set the property of this CSS value (e.g. <code>background-color</code>).
   *
   * @param eProperty
   *        The CSS property to set. May not be <code>null</code>.
   * @return this
   * @since 3.7.4
   */
  @Nonnull
  public CSSDeclaration setProperty (@Nonnull final ECSSProperty eProperty)
  {
    ValueEnforcer.notNull (eProperty, "Property");
    return setProperty (eProperty.getName ());
  }

  /**
   * @return The expression of this declaration (e.g. "red" or "25px" or "25px
   *         10px 25px 9px") as a structured value. Never <code>null</code>.
   */
  @Nonnull
  @ReturnsMutableObject ("design")
  public CSSExpression getExpression ()
  {
    return m_aExpression;
  }

  /**
   * Set the expression (= value) of this declaration.
   *
   * @param aExpression
   *        The value of the property. May not be <code>null</code>.
   * @return this
   * @since 3.7.4
   */
  @Nonnull
  public CSSDeclaration setExpression (@Nonnull final CSSExpression aExpression)
  {
    m_aExpression = ValueEnforcer.notNull (aExpression, "Expression");
    return this;
  }

  /**
   * @return <code>true</code> if this declaration is important (
   *         <code>!important</code>) or <code>false</code> if not.
   */
  public boolean isImportant ()
  {
    return m_bIsImportant;
  }

  /**
   * Set the important flag of this value.
   *
   * @param bIsImportant
   *        <code>true</code> to mark it important, <code>false</code> to remove
   *        it.
   * @return this
   * @since 3.7.4
   */
  @Nonnull
  public CSSDeclaration setImportant (final boolean bIsImportant)
  {
    m_bIsImportant = bIsImportant;
    return this;
  }

  @Nonnull
  @Nonempty
  public String getAsCSSString (@Nonnull final ICSSWriterSettings aSettings, @Nonnegative final int nIndentLevel)
  {
    return m_sProperty +
           CCSS.SEPARATOR_PROPERTY_VALUE +
           m_aExpression.getAsCSSString (aSettings, nIndentLevel) +
           (m_bIsImportant ? CCSS.IMPORTANT_SUFFIX : "");
  }

  public void setSourceLocation (@Nullable final CSSSourceLocation aSourceLocation)
  {
    m_aSourceLocation = aSourceLocation;
  }

  @Nullable
  public CSSSourceLocation getSourceLocation ()
  {
    return m_aSourceLocation;
  }

  @Override
  public boolean equals (final Object o)
  {
    if (o == this)
      return true;
    if (o == null || !getClass ().equals (o.getClass ()))
      return false;
    final CSSDeclaration rhs = (CSSDeclaration) o;
    return m_sProperty.equals (rhs.m_sProperty) &&
           m_aExpression.equals (rhs.m_aExpression) &&
           m_bIsImportant == rhs.m_bIsImportant;
  }

  @Override
  public int hashCode ()
  {
    return new HashCodeGenerator (this).append (m_sProperty)
                                       .append (m_aExpression)
                                       .append (m_bIsImportant)
                                       .getHashCode ();
  }

  @Override
  public String toString ()
  {
    return new ToStringGenerator (this).append ("property", m_sProperty)
                                       .append ("expression", m_aExpression)
                                       .append ("important", m_bIsImportant)
                                       .appendIfNotNull ("sourceLocation", m_aSourceLocation)
                                       .getToString ();
  }
}