/**
* Merges two dimension values with the given dpi value. If these two dimension values are not in
* the same unit, only dimension values in absolute units and pixels can be merged. The unit of
* the merged result will be according to the first dimension value except its unit is pixel.If
* one of them is null, the other value will be returned.
*
* @param dimension1 the first dimension value to merge
* @param dimension2 the second dimension value to merge
* @param dpi the dpi value
* @return the merged dimension value, or null if these two dimension value cannot be merged or
* both of them are null.
*/
public static DimensionValue mergeDimension(
DimensionValue dimension1, DimensionValue dimension2, int dpi) {
if (dimension1 == null || dimension2 == null) {
if (dimension1 == null) {
return dimension2;
}
return dimension1;
}
String unit = dimension1.getUnits();
String unit2 = dimension2.getUnits();
Double meature = null;
if (unit.equalsIgnoreCase(unit2)) {
meature = dimension1.getMeasure() + dimension2.getMeasure();
} else if (isAbsoluteUnit(unit)) {
if (isAbsoluteUnit(unit2)) {
meature = dimension1.getMeasure() + convertTo(dimension2, null, unit).getMeasure();
} else if (DesignChoiceConstants.UNITS_PX.equalsIgnoreCase(unit2)) {
meature = dimension1.getMeasure() + convertTo(dimension2, null, unit, 0, validateDPI(dpi));
}
} else if (DesignChoiceConstants.UNITS_PX.equalsIgnoreCase(unit) && isAbsoluteUnit(unit2)) {
meature = convertTo(dimension1, null, unit2, 0, validateDPI(dpi)) + dimension2.getMeasure();
unit = unit2;
}
if (meature != null) return new DimensionValue(meature, unit);
return null;
}
/**
* Return if the given unit is a relative unit or not. The following units defined in <code>
* DesignChoiceConstants</code> are considered as relative:
*
* <ul>
* <li>UNITS_EM
* <li>UNITS_EX
* <li>UNITS_PERCENTAGE
* <li>UNITS_PX
* </ul>
*
* @param unit a given unit.
* @return <code>true</code> if the unit is a relative unit like em, ex, % and px. Return <code>
* false</code> if the unit is not a relative unit.( it can be an absolute relative unit like
* "mm", or even an unrecognized unit. )
*/
public static final boolean isRelativeUnit(String unit) {
return DesignChoiceConstants.UNITS_EM.equalsIgnoreCase(unit)
|| DesignChoiceConstants.UNITS_EX.equalsIgnoreCase(unit)
|| DesignChoiceConstants.UNITS_PERCENTAGE.equalsIgnoreCase(unit)
|| DesignChoiceConstants.UNITS_PX.equalsIgnoreCase(unit);
}