Feature/add property rule support

ph-css/src/main/java/com/helger/css/ICSSWriterSettings.java

@@ -128,6 +128,11 @@ public interface ICSSWriterSettings
    */
   boolean isWriteSupportsRules ();
 
+  /**
+   * @return <code>true</code> if {@link CSSPropertyRule @property rules} should be written, <code>false</code> if not
+   */
+  boolean isWritePropertyRules ();
+
   /**
    * @return <code>true</code> if {@link CSSUnknownRule unknown @ rules} should be written, <code>false</code> if not
    */

ph-css/src/main/java/com/helger/css/decl/AbstractHasTopLevelRules.java

@@ -609,6 +609,57 @@ public ICommonsList <CSSSupportsRule> getAllSupportsRules ()
     return m_aRules.getAllMapped (CSSSupportsRule.class::isInstance, CSSSupportsRule.class::cast);
   }
 
+  /**
+   * Check if at least one of the top-level rules is a property rule (implementing
+   * {@link CSSPropertyRule}).
+   *
+   * @return <code>true</code> if at least one <code>@property</code> rule is contained,
+   *         <code>false</code> otherwise.
+   */
+  public boolean hasPropertyRules ()
+  {
+    return m_aRules.containsAny (CSSPropertyRule.class::isInstance);
+  }
+
+  /**
+   * Get the number of top-level rules that are property rules (implementing
+   * {@link CSSPropertyRule}).
+   *
+   * @return The number of contained <code>@supports</code> rules. Always &ge; 0.
+   */
+  @Nonnegative
+  public int getPropertyRuleCount ()
+  {
+    return m_aRules.getCount (CSSPropertyRule.class::isInstance);
+  }
+
+  /**
+   * Get the <code>@property</code> rule at the specified index.
+   *
+   * @param nIndex
+   *        The index to be resolved. Should be &ge; 0 and &lt; {@link #getPropertyRuleCount()}.
+   * @return <code>null</code> if an invalid index was specified.
+   * @since 8.1.2
+   */
+  @Nullable
+  public CSSPropertyRule getPropertyRuleAtIndex (@Nonnegative final int nIndex)
+  {
+    return m_aRules.getAtIndexMapped (CSSPropertyRule.class::isInstance, nIndex, CSSPropertyRule.class::cast);
+  }
+
+  /**
+   * Get a list of all top-level rules that are property rules (implementing
+   * {@link CSSPropertyRule}).
+   *
+   * @return A copy of all contained <code>@property</code> rules. Never <code>null</code>.
+   */
+  @NonNull
+  @ReturnsMutableCopy
+  public ICommonsList <CSSPropertyRule> getAllPropertyRules ()
+  {
+    return m_aRules.getAllMapped (CSSPropertyRule.class::isInstance, CSSPropertyRule.class::cast);
+  }
+
   /**
    * Check if at least one of the top-level rules is an unknown rule (implementing
    * {@link CSSUnknownRule}).

ph-css/src/main/java/com/helger/css/decl/CSSPropertyRule.java

@@ -0,0 +1,211 @@
+/*
+ * Copyright (C) 2014-2026 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 org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+import com.helger.annotation.Nonempty;
+import com.helger.annotation.Nonnegative;
+import com.helger.annotation.style.ReturnsMutableCopy;
+import com.helger.base.enforce.ValueEnforcer;
+import com.helger.base.hashcode.HashCodeGenerator;
+import com.helger.base.state.EChange;
+import com.helger.base.string.StringHelper;
+import com.helger.base.tostring.ToStringGenerator;
+import com.helger.collection.commons.ICommonsList;
+import com.helger.css.CSSSourceLocation;
+import com.helger.css.ICSSSourceLocationAware;
+import com.helger.css.ICSSWriterSettings;
+
+/**
+ * Represents a single <code>@property</code> rule: a list of style rules only valid when a certain
+ * declaration is available. See {@link com.helger.css.ECSSSpecification#CSS3_CONDITIONAL}<br>
+ * Example:<br>
+ * <code>@supports (transition-property: color) {
+  div { color:red; }
+}</code>
+ *
+ * @author Mike Wiedenbauer
+ */
+public class CSSPropertyRule extends AbstractHasTopLevelRules implements ICSSTopLevelRule, ICSSSourceLocationAware
+{ 
+  private final String m_sIdentifier;
+  private final CSSPropertyRuleDeclarationList m_aDeclarations = new CSSPropertyRuleDeclarationList();
+  private CSSSourceLocation m_aSourceLocation;
+
+  public static boolean isValidIdentifier (@NonNull @Nonempty final String sIdentifier)
+  {
+    return StringHelper.startsWith (sIdentifier, "--");
+  }
+
+  public CSSPropertyRule (@NonNull @Nonempty final String sIdentifier)
+  {
+    ValueEnforcer.isTrue (isValidIdentifier (sIdentifier), "Identifier is invalid");
+    m_sIdentifier = sIdentifier;
+  }
+
+  @NonNull
+  @Nonempty
+  public String getIdentifier ()
+  {
+    return m_sIdentifier;
+  }
+
+  @NonNull
+  public CSSPropertyRule addDeclaration (@NonNull final CSSPropertyRuleDeclaration aDeclaration)
+  {
+    ValueEnforcer.notNull (aDeclaration, "PropertyRuleDeclaration");
+
+    m_aDeclarations.addDeclaration (aDeclaration);
+    return this;
+  }
+
+  @NonNull
+  public CSSPropertyRule addDeclaration (@Nonnegative final int nIndex, @NonNull final CSSPropertyRuleDeclaration aDeclaration)
+  {
+    ValueEnforcer.isGE0(nIndex, "Index");
+    ValueEnforcer.notNull (aDeclaration, "PropertyRuleDeclaration");
+
+    m_aDeclarations.addDeclaration (nIndex, aDeclaration);
+    return this;
+  }
+
+  @NonNull
+  public EChange removeDeclaration (@NonNull final CSSPropertyRuleDeclaration aDeclaration)
+  {
+    return m_aDeclarations.removeDeclaration (aDeclaration);
+  }
+
+  @NonNull
+  public EChange removeDeclaration (@Nonnegative final int nIndex)
+  {
+    return m_aDeclarations.removeDeclaration (nIndex);
+  }
+
+  @NonNull
+  public EChange removeAllDeclarations ()
+  {
+    return m_aDeclarations.removeAllDeclarations ();
+  }
+
+  @NonNull
+  @ReturnsMutableCopy
+  public ICommonsList <CSSPropertyRuleDeclaration> getAllDeclarations ()
+  {
+    return m_aDeclarations.getAllDeclarations();
+  }
+
+  @Nullable
+  public CSSPropertyRuleDeclaration getDeclarationAtIndex (@Nonnegative final int nIndex)
+  {
+    return m_aDeclarations.getDeclarationAtIndex (nIndex);
+  }
+
+  @NonNull
+  public CSSPropertyRule setDeclarationAtIndex (@Nonnegative final int nIndex, @NonNull final CSSPropertyRuleDeclaration aNewDeclaration)
+  {
+    m_aDeclarations.setDeclarationAtIndex (nIndex, aNewDeclaration);
+    return this;
+  }
+
+  public boolean hasDeclarations ()
+  {
+    return m_aDeclarations.hasDeclarations ();
+  }
+
+  @Nonnegative
+  public int getDeclarationCount ()
+  {
+    return m_aDeclarations.getDeclarationCount ();
+  }
+
+  @NonNull
+  @Nonempty
+  public String getAsCSSString (@NonNull final ICSSWriterSettings aSettings, @Nonnegative final int nIndentLevel)
+  {
+    // Always ignore Property rules?
+    if (!aSettings.isWritePropertyRules ())
+      return "";
+
+    final boolean bOptimizedOutput = aSettings.isOptimizedOutput ();
+    final int nDeclCount = m_aDeclarations.getDeclarationCount();
+
+    final StringBuilder aSB = new StringBuilder ("@property ").append (m_sIdentifier);
+    if (nDeclCount == 0)
+    {
+      aSB.append (bOptimizedOutput ? "{}" : " {}");
+    }
+    else
+    {
+      if (nDeclCount == 1)
+      {
+        aSB.append (bOptimizedOutput ? "{" : " { ");
+        aSB.append (m_aDeclarations.getAsCSSString (aSettings, nIndentLevel + 1));
+        aSB.append (bOptimizedOutput ? "}" : " }");
+      }
+      else
+      {
+        aSB.append (bOptimizedOutput ? "{" : " {" + aSettings.getNewLineString ());
+        if (!bOptimizedOutput)
+          aSB.append (aSettings.getIndent (nIndentLevel + 1));
+        aSB.append (m_aDeclarations.getAsCSSString (aSettings, nIndentLevel + 1));
+        if (!bOptimizedOutput)
+          aSB.append (aSettings.getNewLineString ()).append (aSettings.getIndent (nIndentLevel));
+        aSB.append ('}');
+      }
+    }
+    return aSB.toString();
+  }
+
+  @Nullable
+  public final CSSSourceLocation getSourceLocation ()
+  {
+    return m_aSourceLocation;
+  }
+
+  public final void setSourceLocation (@Nullable final CSSSourceLocation aSourceLocation)
+  {
+    m_aSourceLocation = aSourceLocation;
+  }
+
+  @Override
+  public boolean equals (final Object o)
+  {
+    if (o == this)
+      return true;
+    if (o == null || !getClass ().equals (o.getClass ()))
+      return false;
+    final CSSPropertyRule rhs = (CSSPropertyRule) o;
+    return m_sIdentifier.equals (rhs.m_sIdentifier) && m_aDeclarations.equals (rhs.m_aDeclarations);
+  }
+
+  @Override
+  public int hashCode ()
+  {
+    return new HashCodeGenerator (this).append (m_sIdentifier).append (m_aDeclarations).getHashCode ();
+  }
+
+  @Override
+  public String toString ()
+  {
+    return new ToStringGenerator (this).append ("identifier", m_sIdentifier)
+                                       .append ("declaration", m_aDeclarations)
+                                       .appendIfNotNull ("SourceLocation", m_aSourceLocation)
+                                       .getToString ();
+  }
+}

ph-css/src/main/java/com/helger/css/decl/CSSPropertyRuleDeclaration.java

@@ -0,0 +1,112 @@
+package com.helger.css.decl;
+
+import java.util.Locale;
+
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+import com.helger.annotation.Nonempty;
+import com.helger.annotation.Nonnegative;
+import com.helger.annotation.style.ReturnsMutableObject;
+import com.helger.base.enforce.ValueEnforcer;
+import com.helger.base.hashcode.HashCodeGenerator;
+import com.helger.base.tostring.ToStringGenerator;
+import com.helger.css.CCSS;
+import com.helger.css.CSSSourceLocation;
+import com.helger.css.ICSSSourceLocationAware;
+import com.helger.css.ICSSWriteable;
+import com.helger.css.ICSSWriterSettings;
+
+public class CSSPropertyRuleDeclaration implements ICSSSourceLocationAware, ICSSWriteable
+{
+  private String m_sDescriptor;
+  private CSSExpression m_aExpression;
+  private CSSSourceLocation m_aSourceLocation;
+
+  public CSSPropertyRuleDeclaration (@NonNull @Nonempty final String sDescriptor, @NonNull final CSSExpression aExpression)
+  {
+    setDescriptor(sDescriptor);
+    setExpression(aExpression);
+  }
+
+  @NonNull
+  @Nonempty
+  public final String getDescriptor ()
+  {
+    return m_sDescriptor;
+  }
+
+  @NonNull
+  public final CSSPropertyRuleDeclaration setDescriptor (@NonNull @Nonempty final String sDescriptor)
+  {
+    ValueEnforcer.notEmpty (sDescriptor, "Descriptor");
+    m_sDescriptor = sDescriptor.toLowerCase (Locale.ROOT);
+    return this;
+  }
+
+  @NonNull
+  @ReturnsMutableObject
+  public final CSSExpression getExpression ()
+  {
+    return m_aExpression;
+  }
+
+  @NonNull
+  public final String getExpressionAsCSSString ()
+  {
+    return m_aExpression.getAsCSSString ();
+  }
+
+  @NonNull
+  public final CSSPropertyRuleDeclaration setExpression (@NonNull final CSSExpression aExpression)
+  {
+    m_aExpression = ValueEnforcer.notNull (aExpression, "Expression");
+    return this;
+  }
+
+  @NonNull
+  @Nonempty
+  public String getAsCSSString (@NonNull final ICSSWriterSettings aSettings, @Nonnegative final int nIndentLevel)
+  {
+    return m_sDescriptor +
+           CCSS.SEPARATOR_PROPERTY_VALUE +
+           m_aExpression.getAsCSSString (aSettings, nIndentLevel);
+  }
+
+  @Nullable
+  public final CSSSourceLocation getSourceLocation ()
+  {
+    return m_aSourceLocation;
+  }
+
+  public final void setSourceLocation (@Nullable final CSSSourceLocation aSourceLocation)
+  {
+    m_aSourceLocation = aSourceLocation;
+  }
+
+  @Override
+  public boolean equals (final Object o)
+  {
+    if (o == this)
+      return true;
+    if (o == null || !getClass ().equals (o.getClass ()))
+      return false;
+    final CSSPropertyRuleDeclaration rhs = (CSSPropertyRuleDeclaration) o;
+    return m_sDescriptor.equals (rhs.m_sDescriptor) && m_aExpression.equals (rhs.m_aExpression);
+  }
+
+  @Override
+  public int hashCode ()
+  {
+    return new HashCodeGenerator (this).append (m_sDescriptor).append (m_aExpression).getHashCode ();
+  }
+
+  @Override
+  public String toString ()
+  {
+    return new ToStringGenerator (this).append ("descriptor", m_sDescriptor)
+                                       .append ("expression", m_aExpression)
+                                       .appendIfNotNull ("SourceLocation", m_aSourceLocation)
+                                       .getToString ();
+  }
+}