iReport Ultimate Guide - Nimsoft Library

iReport Ultimate GuideTable 5-3Other element properties, continuedStretch typeNoStretchRelativeToBandHeightRelativeToTallestObjectPrint repeated valuesRemove line when blankThis attribute defines how to calculate the element height during the print elaboration;the three possible values are as follows:This is the pre-defined stretch type, and it dictates that the element height should bekept equal.The element height is increased proportionally to the increasing size of the band; thisis useful for vertical lines that simulate table borders.The element modifies its height according to the deformation of the nearest element:this option is also used with the element group, which is an element group mechanismnot managed by iReport.This option determines whether to print the element when its value is equal to thatwhich is used in the previous record.This option takes away the vertical space occupied by an object if the object is notvisible; the element visibility is determined by the value of the expression contained inthe Print when expression attribute or in case of textfields by the Blank whennull attribute. Think of the page as a grid where the elements are placed, with a linebeing the space the element occupies. The figure below highlights the element A line;in order to remove this line, all the elements that share a portion of the line have to benull (that is, they will not be printed).Print in first wholebandPrint when detailoverflowsPrint when group changesPrint when expressionProperties expressionsThis option ensures that an element is printed in the next page or column if the bandoverflows the page or column; this type of guarantee is useful when the Printrepeated values attribute is enabled.This option prints the element in the following page or column, if the entire band is notprintable in the present page or column.In this combo box, all report groups are presented. If one of them is selected, theelement will be printed only when the expression associated with the group changes,that is, when a new break of the selected group is created.This is an expression like those described in Chapter 3, and it must return a Booleanobject. Besides being associated with elements, this expression is associated with thebands, as well. If the expression returns true, the element is hidden. An emptyexpression or a null value implicitly identifies an expression like newBoolean(true), which will print the element unconditionally.These are a set of key/value pairs that can be defined for each element.5.1.4 Element Custom PropertiesFor each element it is possible to define a set of custom properties; each property is a pair key/value where both key and valueare simple text strings. The value can be generated using an expression (that will have to return a string, of course).Element custom properties are set by modifying the Properties expressions attribute in the property sheet displayedwhen the element is selected (see Figure 5-11).72