16 #ifndef QGSSCALEEXPRESSION_H
17 #define QGSSCALEEXPRESSION_H
56 QgsScaleExpression( Type type,
const QString& baseExpression,
double minValue,
double maxValue,
double minSize,
double maxSize,
double nullSize = 0 );
58 operator bool()
const {
return ! mExpression.isEmpty(); }
64 double size(
double value )
const;
69 double minSize()
const {
return mMinSize; }
74 double maxSize()
const {
return mMaxSize; }
113 static QString createExpression( Type type,
const QString& baseExpr,
double minValue,
double maxValue,
double minSize,
double maxSize,
double nullSize );
Class for parsing and evaluation of expressions (formerly called "search strings").
Class storing parameters of a scale expression, which is a subclass of QgsExpression for expressions ...
double nullSize() const
Returns the size value when expression evaluates to NULL.
double maxValue() const
Returns the maximum value expected by the expression.
QString baseExpression() const
Returns the base expression string (or field reference) used for calculating the values to be mapped ...
Type type() const
Returns the scale expression's type (method used to calculate the size from a value).
double minSize() const
Returns the minimum size calculated by the expression.
double minValue() const
Returns the minimum value expected by the expression.
double maxSize() const
Returns the maximum size calculated by the expression.