package org.apache.fop.fo;
import org.apache.fop.datatypes.*;
+import org.apache.fop.fo.expr.Numeric;
+import org.apache.fop.fo.expr.PropertyParser;
+import org.apache.fop.fo.expr.PropertyInfo;
+import org.apache.fop.fo.expr.PropertyException;
import org.apache.fop.apps.FOPException;
public class Property {
public static class Maker {
+ private static final String UNKNOWN = "UNKNOWN";
+ private String propName;
+ /**
+ * Return the name of the property whose value is being set.
+ */
+ protected String getPropName() { return propName; }
+
+ /**
+ * Construct an instance of a Property.Maker for the given property.
+ * @param propName The name of the property to be made.
+ */
+ protected Maker(String propName) {
+ this.propName = propName;
+ }
+
+ /**
+ * Construct an instance of a Property.Maker.
+ * Note: the property name is set to "UNKNOWN".
+ */
+ protected Maker() {
+ this.propName = UNKNOWN;
+ }
+
+
+ /**
+ * Default implementation of isInherited.
+ * @return A boolean indicating whether this property is inherited.
+ */
public boolean isInherited() { return false; }
- public Property make(PropertyList propertyList, String value) throws FOPException {
+ /**
+ * Return a boolean indicating whether this property inherits the
+ * "specified" value rather than the "computed" value. The default is
+ * to inherit the "computed" value.
+ * @return If true, property inherits the value specified.
+ */
+ public boolean inheritsSpecified() { return false; }
+
+ /**
+ * Return an object implementing the PercentBase interface.
+ * This is used to handle properties specified as a percentage of
+ * some "base length", such as the content width of their containing
+ * box.
+ * Overridden by subclasses which allow percent specifications. See
+ * the documentation on properties.xsl for details.
+ */
+ public PercentBase getPercentBase(FObj fo, PropertyList pl) {
return null;
}
- public Property make(PropertyList propertyList) throws FOPException { // default
+ /**
+ * Return a Maker object which is used to set the values on components
+ * of compound property types, such as "space".
+ * Overridden by property maker subclasses which handle
+ * compound properties.
+ * @param subprop The name of the component for which a Maker is to
+ * returned, for example "optimum", if the FO attribute is
+ * space.optimum='10pt'.
+ */
+ protected Maker getSubpropMaker(String subprop) {
return null;
}
- public Property compute(PropertyList propertyList) { // compute
+ /**
+ * Return a property value for the given component of a compound
+ * property.
+ * @param p A property value for a compound property type such as
+ * SpaceProperty.
+ * @param subprop The name of the component whose value is to be
+ * returned.
+ * NOTE: this is only to ease porting when calls are made to
+ * PropertyList.get() using a component name of a compound property,
+ * such as get("space.optimum"). The recommended technique is:
+ * get("space").getOptimum().
+ * Overridden by property maker subclasses which handle
+ * compound properties.
+ */
+ public Property getSubpropValue(Property p, String subprop) {
return null;
}
- }
- protected PropertyList propertyList;
-
+
+ /**
+ * Return a property value for a compound property. If the property
+ * value is already partially initialized, this method will modify it.
+ * @param baseProp The Property object representing the compound property,
+ * such as SpaceProperty.
+ * @param partName The name of the component whose value is specified.
+ * @param propertyList The propertyList being built.
+ * @param fo The FO whose properties are being set.
+ * @return A compound property object.
+ */
+ public Property make(Property baseProp, String partName,
+ PropertyList propertyList, String value, FObj fo)
+ throws FOPException
+ {
+ Maker spMaker = getSubpropMaker(partName);
+ if (spMaker != null) {
+ Property p = spMaker.make(propertyList, value, fo);
+ if (p != null) {
+ return setSubprop(baseProp, partName, p);
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Set a component in a compound property and return the modified
+ * compound property object.
+ * This default implementation returns the original base property
+ * without modifying it.
+ * It is overridden by property maker subclasses which handle
+ * compound properties.
+ * @param baseProp The Property object representing the compound property,
+ * such as SpaceProperty.
+ * @param partName The name of the component whose value is specified.
+ * @param subProp A Property object holding the specified value of the
+ * component to be set.
+ * @return The modified compound property object.
+ */
+ protected Property setSubprop(Property baseProp, String partName,
+ Property subProp) {
+ return baseProp;
+ }
+
+
+ /**
+ * Create a Property object from an attribute specification.
+ * @param propertyList The PropertyList object being built for this FO.
+ * @param value The attribute value.
+ * @param fo The current FO whose properties are being set.
+ * @return The initialized Property object.
+ */
+ public Property make(PropertyList propertyList, String value, FObj fo)
+ throws FOPException {
+ // skeleton for all Makers except for Enum properties
+ try {
+ /* Check for keyword shorthand values to be substituted. */
+ Property pret=null;
+ String pvalue = checkValueKeywords(value);
+ // Override parsePropertyValue in each subclass of Property.Maker
+ Property p = PropertyParser.parse(pvalue,
+ new PropertyInfo(this, propertyList, fo));
+ pret = convertProperty(p, propertyList, fo);
+ if (pret != null && inheritsSpecified())
+ pret.setSpecifiedValue(pvalue);
+ return pret;
+ } catch (org.apache.fop.fo.expr.PropertyException propEx) {
+ System.err.println("Error in " + propName + " property value: "
+ + propEx);
+ throw new FOPException("Property error");
+ }
+ }
+
+ /**
+ * Return a String to be parsed if the passed value corresponds to
+ * a keyword which can be parsed and used to initialize the property.
+ * For example, the border-width family of properties can have the
+ * initializers "thin", "medium", or "thick". The foproperties.xml
+ * file specifies a length value equivalent for these keywords,
+ * such as "0.5pt" for "thin". These values are considered parseable,
+ * since the Length object is no longer responsible for parsing
+ * unit expresssions.
+ * @param value The string value of property attribute.
+ * @return A String containging a parseable equivalent or null if
+ * the passed value isn't a keyword initializer for this Property.
+ */
+ protected String checkValueKeywords(String value) {
+ return value;
+ }
+
+ /**
+ * Return a Property object based on the passed Property object.
+ * This method is called if the Property object built by the parser
+ * isn't the right type for this property.
+ * It is overridden by subclasses when the property specification in
+ * foproperties.xml specifies conversion rules.
+ * @param p The Property object return by the expression parser
+ * @param propertyList The PropertyList object being built for this FO.
+ * @param fo The current FO whose properties are being set.
+ * @return A Property of the correct type or null if the parsed value
+ * can't be converted to the correct type.
+ */
+ protected Property convertProperty(Property p,
+ PropertyList propertyList, FObj fo) {
+ return null;
+ }
+
+ protected Property convertPropertyDatatype(Property p,
+ PropertyList propertyList, FObj fo) {
+ return null;
+ }
+
+ /**
+ * Return a Property object representing the initial value.
+ * @param propertyList The PropertyList object being built for this FO.
+ */
+ public Property make(PropertyList propertyList) throws FOPException {
+ return make(propertyList, false);
+ }
+
+ /**
+ * Return a Property object representing the initial value.
+ * @param propertyList The PropertyList object being built for this FO.
+ * @param bForceNew A boolean value indicating whether a new Property
+ * object must be constructed or whether a reference to the
+ * default Property object may be returned.
+ */
+ public Property make(PropertyList propertyList, boolean bForceNew) throws FOPException {
+ return null;
+ }
+
+ /**
+ * Return a Property object representing the value of this property,
+ * based on other property values for this FO.
+ * A special case is properties which inherit the specified value,
+ * rather than the computed value.
+ * @param propertyList The PropertyList for the FO.
+ * @return Property A computed Property value or null if no rules
+ * are specified (in foproperties.xml) to compute the value.
+ */
+ public Property compute(PropertyList propertyList) {
+ if (inheritsSpecified()) {
+ // recalculate based on last specified value
+ // Climb up propertylist and find last spec'd value
+ // NEED PROPNAME!!! get from Maker
+ Property specProp = propertyList.getNearestSpecified(propName);
+ if (specProp != null) {
+ // Only need to do this if the value is relative!!!
+ String specVal = specProp.getSpecifiedValue();
+ if (specVal != null) {
+ // SHOULD HAVE FO!!! get from PropertyList ?
+ try {
+ return make(propertyList, specVal, null);
+ } catch (FOPException e) {
+ System.err.println("Error computing property value for " +
+ propName + " from " + specVal);
+ return null;
+ }
+ }
+ }
+ }
+ return null; // standard
+ }
+
+ } // end of nested Maker class
+
+ // put back for SVG for now: note XSL properties don't set it!!!
+ protected PropertyList propertyList;
+
+ /** The original specified value for properties which inherit
+ * specified values. */
+ private String specVal;
+
+ /**
+ * Set the original value specified for the property attribute.
+ * @param specVal The specified value.
+ */
+ public void setSpecifiedValue(String specVal) {
+ this.specVal = specVal;
+ }
+
+ /**
+ * Return the original value specified for the property attribute.
+ * @return The specified value as a String.
+ */
+ public String getSpecifiedValue() {
+ return specVal;
+ }
+
+ /**
+ * Accessor functions for all possible Property datatypes
+ */
public Length getLength() { return null; }
- public String getString() { return null; }
public ColorType getColorType() { return null; }
+ public LengthRange getLengthRange() { return null; }
+ public Space getSpace() { return null; }
public int getEnum() { return 0; }
- public static double toDouble(String s) {
- double d;
- try {
- d = Double.valueOf(s).doubleValue();
- } catch (NumberFormatException e) {
- d = Double.NaN;
- }
- return d;
+ public Number getNumber() { return null; }
+
+ // Classes used when evaluating property expressions
+ public Numeric getNumeric() { return null; }
+ public String getNCname() { return null; }
+
+ public Object getObject() { return null; }
+
+ public String getString() {
+ Object o = getObject();
+ return (o == null)? null : o.toString();
}
}
projects / xmlgraphics-fop.git / commitdiff