org.jfree.report.demo.helper: public class: FontChangeFunction

org.jfree.report.demo.helper
public class: FontChangeFunction [javadoc | source]

java.lang.Object
   org.jfree.report.function.AbstractExpression
      org.jfree.report.function.AbstractFunction
         org.jfree.report.demo.helper.FontChangeFunction

All Implemented Interfaces:
Serializable, Function, Expression

This is a function used in report4-demo. The function demonstrates how to alter an elements property during the report generation. The elements font is changed base on the data provided in the reports datasource.

For every new item row in the report, the font for that row is changed to the fontname specified in the second column of the report data source.

Parameters:
The function expects the name of a field in the item band in the parameter "element". This functions value will always be null.

author: Thomas - Morgner

Constructor:
public FontChangeFunction() { } DefaultConstructor.

Constructor:

 public FontChangeFunction() {

}

DefaultConstructor.

Method from org.jfree.report.demo.helper.FontChangeFunction Summary:
getElement, getValue, initialize, itemsAdvanced, setElement

Methods from org.jfree.report.function.AbstractFunction:
groupFinished, groupStarted, itemsAdvanced, itemsFinished, itemsStarted, reportDone, reportFinished, reportInitialized, reportStarted

Methods from org.jfree.report.function.AbstractExpression:
clone, getDataRow, getDependencyLevel, getInstance, getName, getReportConfiguration, getResourceBundleFactory, getRuntime, isActive, isDeepTraversing, isPreserve, setActive, setDependencyLevel, setName, setPreserve, setRuntime

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.jfree.report.demo.helper.FontChangeFunction Detail:
public String getElement() { return getProperty("element", ""); } Returns the name of the element that should get the font set. Returns an empty string, if the property is not set.
public Object getValue() { return null; } Returns the value calculated by this function. As this function does not calculate values, this method does always return null.
public void initialize() throws FunctionInitializeException { super.initialize(); if (getProperty("element") == null) { throw new FunctionInitializeException("Element name must be specified"); } } Performs the functions initialisation. The initialisation will fail, if the function has no valid name or the required parameter "element" is missing.
public void itemsAdvanced(ReportEvent event) { // if this is a preparerun, nothing gets printed and so no font change is required. if (event.getState().isPrepareRun()) { return; } // Try to get the name of the font to be set. // If the name is null, return without an excpetion, just do nothing. final String fontname = (String) event.getDataRow().get(1); if (fontname == null) { return; } // Lookup the element by name. If there no element found, the getElement function // returns null, so we have to check this case. final Element e = event.getReport().getItemBand().getElement(getElement()); // set the font if an element was found. if (e != null && (e instanceof TextElement)) { final TextElement tx = (TextElement) e; tx.getStyle().setFontDefinitionProperty( new FontDefinition(new Font(fontname, Font.PLAIN, 10))); } } Before an ItemBand is printed, the report generator will call itemsAdvanced for all functions in the function collection. This is the right place to alter the font of the element defined in the "element" property, so that every ItemBand has the font set, that is defined in the data model.
public void setElement(String name) { setProperty("element", name); } Defines the name of the text element that gets its font altered. If the element does not exist or is no text element, the function will do nothing. This functions property is reachable by using the key "element" on getProperty.

Method from org.jfree.report.demo.helper.FontChangeFunction Detail:

 public String getElement() {
    return getProperty("element", "");
}

Returns the name of the element that should get the font set. Returns an empty string, if the property is not set.

 public Object getValue() {
    return null;
}

Returns the value calculated by this function. As this function does not calculate values, this method does always return null.

 public  void initialize() throws FunctionInitializeException {
    super.initialize();
    if (getProperty("element") == null)
    {
      throw new FunctionInitializeException("Element name must be specified");
    }
}

 public  void itemsAdvanced(ReportEvent event) {
    // if this is a preparerun, nothing gets printed and so no font change is required.
    if (event.getState().isPrepareRun())
    {
      return;
    }
    // Try to get the name of the font to be set.
    // If the name is null, return without an excpetion, just do nothing.
    final String fontname = (String) event.getDataRow().get(1);
    if (fontname == null)
    {
      return;
    }
    // Lookup the element by name. If there no element found, the getElement function
    // returns null, so we have to check this case.
    final Element e = event.getReport().getItemBand().getElement(getElement());
    // set the font if an element was found.
    if (e != null && (e instanceof TextElement))
    {
      final TextElement tx = (TextElement) e;
      tx.getStyle().setFontDefinitionProperty(
          new FontDefinition(new Font(fontname, Font.PLAIN, 10)));
    }
}

Before an ItemBand is printed, the report generator will call itemsAdvanced for all functions in the function collection. This is the right place to alter the font of the element defined in the "element" property, so that every ItemBand has the font set, that is defined in the data model.

 public  void setElement(String name) {
    setProperty("element", name);
}

This functions property is reachable by using the key "element" on getProperty.