Color functions

src/main/antlr3/com/github/sommeri/less4j/core/parser/Less.g

@@ -692,7 +692,7 @@ hexColor
     ;
 
 function
-    : (a=IDENT | a=PERCENT) LPAREN b=functionParameter RPAREN -> ^(TERM_FUNCTION $a $b*)
+    : (a=IDENT | a=PERCENT) LPAREN b=functionParameter? RPAREN -> ^(TERM_FUNCTION $a $b*)
     ;
 
 functionParameter

src/main/java/com/github/sommeri/less4j/core/ast/ASTCssNodeType.java

@@ -1,5 +1,5 @@
 package com.github.sommeri.less4j.core.ast;
 
 public enum ASTCssNodeType {
-  UNKNOWN, CSS_CLASS, DECLARATION, STYLE_SHEET, RULE_SET, SELECTOR, SIMPLE_SELECTOR, PSEUDO_CLASS, PSEUDO_ELEMENT, SELECTOR_ATTRIBUTE, ID_SELECTOR, CHARSET_DECLARATION, FONT_FACE, IDENTIFIER_EXPRESSION, COMPOSED_EXPRESSION, STRING_EXPRESSION, NUMBER, COLOR_EXPRESSION, FUNCTION, MEDIA, COMMENT, DECLARATIONS_BODY, SELECTOR_OPERATOR, SELECTOR_COMBINATOR, EXPRESSION_OPERATOR, NTH, NAMED_EXPRESSION, MEDIA_QUERY, MEDIA_EXPRESSION, MEDIUM, MEDIUM_MODIFIER, MEDIUM_TYPE, MEDIUM_EX_FEATURE, VARIABLE_DECLARATION, VARIABLE, INDIRECT_VARIABLE, PARENTHESES_EXPRESSION, SIGNED_EXPRESSION, ARGUMENT_DECLARATION, MIXIN_REFERENCE, GUARD_CONDITION, COMPARISON_EXPRESSION, GUARD, NESTED_SELECTOR_APPENDER, REUSABLE_STRUCTURE, FAULTY_EXPRESSION, ESCAPED_SELECTOR, ESCAPED_VALUE, INTERPOLABLE_NAME, FIXED_NAME_PART, VARIABLE_NAME_PART, KEYFRAMES, KEYFRAMES_NAME, KEYFRAMES_BODY, REUSABLE_STRUCTURE_NAME, VIEWPORT, GENERAL_BODY, PAGE, NAME, PAGE_MA, PAGE_MARGIN_BOX, IMPORT, FAULTY_NODE
+  UNKNOWN, CSS_CLASS, DECLARATION, STYLE_SHEET, RULE_SET, SELECTOR, SIMPLE_SELECTOR, PSEUDO_CLASS, PSEUDO_ELEMENT, SELECTOR_ATTRIBUTE, ID_SELECTOR, CHARSET_DECLARATION, FONT_FACE, IDENTIFIER_EXPRESSION, COMPOSED_EXPRESSION, STRING_EXPRESSION, NUMBER, COLOR_EXPRESSION, FUNCTION, MEDIA, COMMENT, DECLARATIONS_BODY, SELECTOR_OPERATOR, SELECTOR_COMBINATOR, EXPRESSION_OPERATOR, NTH, NAMED_EXPRESSION, MEDIA_QUERY, MEDIA_EXPRESSION, MEDIUM, MEDIUM_MODIFIER, MEDIUM_TYPE, MEDIUM_EX_FEATURE, VARIABLE_DECLARATION, VARIABLE, INDIRECT_VARIABLE, PARENTHESES_EXPRESSION, SIGNED_EXPRESSION, ARGUMENT_DECLARATION, MIXIN_REFERENCE, GUARD_CONDITION, COMPARISON_EXPRESSION, GUARD, NESTED_SELECTOR_APPENDER, REUSABLE_STRUCTURE, FAULTY_EXPRESSION, ESCAPED_SELECTOR, ESCAPED_VALUE, INTERPOLABLE_NAME, FIXED_NAME_PART, VARIABLE_NAME_PART, KEYFRAMES, KEYFRAMES_NAME, KEYFRAMES_BODY, REUSABLE_STRUCTURE_NAME, VIEWPORT, GENERAL_BODY, PAGE, NAME, PAGE_MA, PAGE_MARGIN_BOX, IMPORT, FAULTY_NODE, ANONYMOUS, EMPTY_EXPRESSION
 }

src/main/java/com/github/sommeri/less4j/core/ast/AnonymousExpression.java

@@ -0,0 +1,37 @@
+package com.github.sommeri.less4j.core.ast;
+
+import java.util.Collections;
+import java.util.List;
+
+import com.github.sommeri.less4j.core.parser.HiddenTokenAwareTree;
+
+public class AnonymousExpression extends Expression {
+
+  private String value;
+
+  public AnonymousExpression(HiddenTokenAwareTree token, String value) {
+    super(token);
+    this.value = value;
+  }
+
+  public String getValue() {
+    return value;
+  }
+
+  @Override
+  public List<? extends ASTCssNode> getChilds() {
+    return Collections.emptyList();
+  }
+
+  @Override
+  public ASTCssNodeType getType() {
+    return ASTCssNodeType.ANONYMOUS;
+  }
+
+  @Override
+  public AnonymousExpression clone() {
+    AnonymousExpression result = (AnonymousExpression) super.clone();
+    return result;
+  }
+
+}

src/main/java/com/github/sommeri/less4j/core/ast/ColorExpression.java

@@ -1,29 +1,34 @@
 package com.github.sommeri.less4j.core.ast;
 
+import java.awt.Color;
 import java.util.Collections;
 import java.util.List;
 
 import com.github.sommeri.less4j.core.parser.HiddenTokenAwareTree;
 
 public class ColorExpression extends Expression {
 
-  private String value;
-  private int red;
-  private int green;
-  private int blue;
+  protected String value;
+  protected double red;
+  protected double green;
+  protected double blue;
 
   public ColorExpression(HiddenTokenAwareTree token, String value) {
     super(token);
     setValue(value);
   }
 
-  public ColorExpression(HiddenTokenAwareTree token, int red, int green, int blue) {
+  public ColorExpression(HiddenTokenAwareTree token, double red, double green, double blue) {
     super(token);
     this.red = red;
     this.green = green;
     this.blue = blue;
     this.value = encode(red, green, blue);
   }
+
+  public ColorExpression(HiddenTokenAwareTree token, Color color) {
+    this(token, color.getRed(), color.getGreen(), color.getBlue());
+  }
 
   public String getValue() {
     return value;
@@ -36,18 +41,22 @@ public void setValue(String value) {
     blue=decode(value, 2);
   }
 
-  public int getRed() {
+  public double getRed() {
     return red;
   }
 
-  public int getGreen() {
+  public double getGreen() {
     return green;
   }
 
-  public int getBlue() {
+  public double getBlue() {
     return blue;
   }
 
+  public double getAlpha() {
+    return 1.0f;
+  }
+
   private int decode(String color, int i) {
     if (color.length()<7) {
       String substring = color.substring(i+1, i+2);
@@ -57,15 +66,15 @@ private int decode(String color, int i) {
     return Integer.parseInt(color.substring(i*2+1, i*2+3), 16);
   }
 
-  private String encode(int red, int green, int blue) {
+  private String encode(double red, double green, double blue) {
     return "#" + toHex(red) + toHex(green) + toHex(blue); 
   }
 
-  private String toHex(int color) {
+  protected String toHex(double color) {
     String prefix = "";
     if (color<16)
       prefix = "0";
-    return prefix + Integer.toHexString(color);
+    return prefix + Integer.toHexString((int) Math.round(color));
   }
 
   @Override
@@ -87,4 +96,52 @@ public String toString() {
   public ColorExpression clone() {
     return (ColorExpression) super.clone();
   }
+
+  public String toARGB() {
+    return "#FF" + toHex(red) + toHex(green) + toHex(blue); 
+  }
+
+  public Color toColor() {
+    return new Color((int)Math.round(this.red), (int)Math.round(this.green), (int)Math.round(this.blue));
+  }
+
+  public static class ColorWithAlphaExpression extends ColorExpression {
+
+    /**
+     * Alpha in the range 0-1.
+     */
+    private double alpha;
+
+    public ColorWithAlphaExpression(HiddenTokenAwareTree token, double red, double green, double blue, double alpha) {
+      super(token, red, green, blue);
+      this.alpha = alpha;
+      if (alpha != 1.0) {
+	this.value = encode(red, green, blue, alpha);
+      }
+    }
+
+    public ColorWithAlphaExpression(HiddenTokenAwareTree token, Color color) {
+      this(token, color.getRed(), color.getGreen(), color.getBlue(), color.getAlpha() / 255.0f);
+    }
+
+    @Override
+    public double getAlpha() {
+      return alpha;
+    }
+
+    protected String encode(double red, double green, double blue, double alpha) {
+      return "rgba(" + Math.round(red) + ", " + Math.round(green) + ", " + Math.round(blue) + ", " + alpha + ")";
+    }
+
+    @Override
+    public String toARGB() {
+      return "#" + toHex(Math.round(alpha * 255)) + toHex(red) + toHex(green) + toHex(blue); 
+    }
+
+    @Override
+    public Color toColor() {
+      return new Color((int)Math.round(this.red), (int)Math.round(this.green), (int)Math.round(this.blue), Math.round(this.alpha * 255));
+    }
+
+  }
 }

src/main/java/com/github/sommeri/less4j/core/ast/Declaration.java

@@ -63,6 +63,10 @@ public List<? extends ASTCssNode> getChilds() {
   public boolean isFontDeclaration() {
     return getName()!=null? getName().toLowerCase().equals("font") : false;
   }
+
+  public boolean isFilterDeclaration() {
+    return getName()!=null? getName().toLowerCase().equals("filter") : false;
+  }
 
   @Override
   public String toString() {

src/main/java/com/github/sommeri/less4j/core/ast/EmptyExpression.java

@@ -0,0 +1,24 @@
+package com.github.sommeri.less4j.core.ast;
+
+import java.util.Collections;
+import java.util.List;
+
+import com.github.sommeri.less4j.core.parser.HiddenTokenAwareTree;
+
+public class EmptyExpression extends Expression {
+
+  public EmptyExpression(HiddenTokenAwareTree token) {
+    super(token);
+  }
+
+  @Override
+  public List<? extends ASTCssNode> getChilds() {
+    return Collections.emptyList();
+  }
+
+  @Override
+  public ASTCssNodeType getType() {
+    return ASTCssNodeType.EMPTY_EXPRESSION;
+  }
+
+}

src/main/java/com/github/sommeri/less4j/core/ast/NumberExpression.java

@@ -1,7 +1,9 @@
 package com.github.sommeri.less4j.core.ast;
 
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import com.github.sommeri.less4j.core.parser.HiddenTokenAwareTree;
 
@@ -94,11 +96,102 @@ public boolean hasOriginalString() {
   public ASTCssNodeType getType() {
     return ASTCssNodeType.NUMBER;
   }
+
+  public NumberExpression convertTo(String targetUnit) {
+    Map<Dimension, String> conversions = new HashMap<Dimension, String>();
+    for (Dimension dim : Dimension.values()) {
+      if (dim.getConversions().containsKey(targetUnit)) {
+	conversions.put(dim, targetUnit);
+      }
+    }
+
+    return convertTo(conversions);
+  }
+
+  public NumberExpression convertTo(Map<Dimension, String> conversions) {
+    double value = getValueAsDouble();
+    String unit = getSuffix();
+    Dimension dimension = getDimension();
+
+    String targetUnit = conversions.get(dimension);
+    if (targetUnit == null) {
+      /* No conversion requested for this type of number */
+      return this;
+    }
+
+    Map<String, Number> group = dimension.getConversions();
+
+    Number multiplier = group.get(unit);
+    Number divisor = group.get(targetUnit);
+
+    if (multiplier != null && divisor != null) {
+      return new NumberExpression(getUnderlyingStructure(), value * multiplier.doubleValue() / divisor.doubleValue(), targetUnit, null, getDimension());
+    } else {
+      throw new IllegalArgumentException("Conversion between " + unit + " and " + targetUnit + " is not supported.");
+    }
+  }
 
   public enum Dimension {
     NUMBER, PERCENTAGE, LENGTH, EMS, EXS, ANGLE, TIME, FREQ, REPEATER, UNKNOWN;
-  }
 
+    private Map<String, Number> conversions;
+
+    public static Dimension forSuffix(String suffix) {
+      if (suffix.equals("%")) {
+        return PERCENTAGE;
+      } else if (suffix.equals("px") || suffix.equals("cm") || suffix.equals("mm") || suffix.equals("in") || suffix.equals("pt") || suffix.equals("pc")) {
+        return LENGTH;
+      } else if (suffix.equals("em")) {
+        return EMS;
+      } else if (suffix.equals("ex")) {
+        return EXS;
+      } else if (suffix.equals("deg") || suffix.equals("rad") || suffix.equals("grad")) {
+        return ANGLE;
+      } else if (suffix.equals("ms") || suffix.equals("s")) {
+        return TIME;
+      } else if (suffix.equals("khz") || suffix.equals("hz")) {
+        return FREQ;
+      } else {
+        return UNKNOWN;
+      }
+    }
+
+    public Map<String, Number> getConversions() {
+      if (conversions != null)
+        return conversions;
+
+      HashMap<String, Number> result = new HashMap<String, Number>();
+      switch (this) {
+      case LENGTH:
+        result.put("m", 1);
+        result.put("cm", 0.01);
+        result.put("mm", 0.001);
+        result.put("in", 0.0254);
+        result.put("pt", 0.0254 / 72);
+        result.put("pc", 0.0254 / 72 * 12);
+        break;
+
+      case TIME:
+        result.put("s", 1);
+        result.put("ms", 0.001);
+        break;
+
+      case ANGLE:
+        result.put("rad", 1.0 / (2 * Math.PI));
+        result.put("deg", 1.0 / 360);
+        result.put("grad", 1.0 / 400);
+        result.put("turn", 1);
+        break;
+
+      default:
+        break;
+      }
+
+      this.conversions = result;
+      return result;
+    }
+  }
+
   @Override
   public String toString() {
     if (originalString != null)

src/main/java/com/github/sommeri/less4j/core/compiler/LessToCssCompiler.java

@@ -142,7 +142,7 @@ private void evaluateExpressions(ASTCssNode node) {
   }
 
   private void evaluateInDeclaration(Declaration node) {
-    if (!node.isFontDeclaration()) {
+    if (!node.isFontDeclaration() && !node.isFilterDeclaration()) {
       evaluateExpressions(node);
       return;
     }

src/main/java/com/github/sommeri/less4j/core/compiler/expressions/AbstractFunction.java

@@ -0,0 +1,24 @@
+package com.github.sommeri.less4j.core.compiler.expressions;
+
+import com.github.sommeri.less4j.core.ast.NumberExpression;
+import com.github.sommeri.less4j.core.ast.NumberExpression.Dimension;
+
+abstract class AbstractFunction implements Function {
+
+  static double scaled(NumberExpression n, int size) {
+    if (n.getDimension() == Dimension.PERCENTAGE) {
+      return n.getValueAsDouble() * size / 100;
+    } else {
+      return number(n);
+    }
+  }
+
+  static double number(NumberExpression n) {
+    if (n.getDimension() == Dimension.PERCENTAGE) {
+      return n.getValueAsDouble() / 100;
+    } else {
+      return n.getValueAsDouble();
+    }
+  }
+
+}