Registered Properties

In order for an object property to be displayed in the WIDGET_PROPERTYSHEET interface, which makes it possible for a user to interactively change the value of the property using the mouse and keyboard, the following two conditions must be met:

Registering a Property

To register a property, use the RegisterProperty method of the IDLitComponent class:

where PropertyIdentifier is a string that uniquely identifies the property, TypeCode is an integer between 0 and 9 specifying the property data type, and ATTRIBUTE is a property attribute.

Registering All Available Properties

Some of the classes in the IDL object class library include a mechanism to register all available properties in a single operation. If an object class has a REGISTER_PROPERTIES property, then setting that property to 1 when creating the object automatically registers all properties that can be registered. If a property contains a "Yes" in the Registered box of the property description table, it will be registered automatically if the REGISTER_PROPERTIES property is set when the object is created. (See About Object Property Descriptions for a description of the property description table.)

Registered Property Data Types

Registered properties must be of one of the data types listed in the following table.

Table 4-1: iTools Property Data Types

Table 4-1: iTools Property Data Types
Type Code	Type	Description
0	USERDEF	User Defined properties can contain values of any IDL type, but must also include a string value that will be displayed in the property sheet. See the following discussion for additional information.
1	BOOLEAN	Boolean properties contain either the integer 0 or the integer 1.
2	INTEGER	Integer properties contain an integer value. If a property of integer data type has a VALID_RANGE attribute that includes an increment value, the property is displayed in a property sheet using a slider. If no increment value is supplied, the property sheet allows the user to edit values manually.
3	FLOAT	Float properties contain a double-precision floating-point value. If a property of float data type has a VALID_RANGE attribute that includes an increment value, the property is displayed in a property sheet using a slider. If no increment value is supplied, the property sheet allows the user to edit values manually.
4	STRING	String properties contain a scalar string value
5	COLOR	Color properties contain an RGB color triplet
6	LINESTYLE	Linestyle properties contain an integer value between 0 and 6, corresponding to the following IDL line styles: 0 = Solid 1 = Dotted 2 = Dashed 3 = Dash Dot 4 = Dash Dot Dot 5 = Long Dashes 6 = No Line See Property Controls for a visual example of the available line styles.
7	SYMBOL	Symbol properties contain an integer value between 0 and 8, corresponding to the following IDL symbol types: 0 = No symbol 1 = Plus sign 2 = Asterisk 3 = Period (Dot) 4 = Diamond 5 = Triangle 6 = Square 7 = X 8 = "Greater-than" Arrow Head (`>`) 9 = "Less-than" Arrow Head (`<`) See Property Controls for a visual example of the available symbols.
8	THICKNESS	Thickness properties contain an integer value between 1 and 10, corresponding to the thickness (in points) of the line.
9	ENUMLIST	Enumerated List properties contain an array of string values defined when the property is registered. The GetProperty method returns the zero-based index of the selected item.

User Defined Property Types

The User Defined property type lets you create a custom interface that allow users of your iTool to select data of types other than the predefined iTool property types. Creating a user defined property type entails the following: