All about Forms 6i

System Variables
SYSTEM.DATE_THRESHOLD : Represents the database date requery threshold.
Default : 01:00 (Synchronization occurs after one minute of elapsed time.) This does not mean that Form Builder polls the RDBMS once every minute. It means that whenever Form Builder needs to generate the value for the system variables $$DBDATE$$, $$DBDATETIME$$, $$DBTIME$$, or SYSTEM.EFFECTIVE_DATE, it updates the effective date by adding the amount of elapsed time (as measured by the local operating system) to the most previously queried RDBMS value. If the amount of elapsed time exceeds the date threshold, then a new query is executed to retrieve the RDBMS time and the elapsed counter is reset.

SYSTEM.EFFECTIVE_DATE: Represents the effective database date. The variable value must always be in the following format: DD-MON-YYYY HH24:MI:SS
Default: RDBMS date.
SYSTEM.FORM_STATUS represents the status of the current form. The value can be one of three character strings: NEW, QUERY, CHANGED
SYSTEM.SUPPRESS_WORKING suppresses the "Working..." message in Runform, in order to prevent the screen update usually caused by the display of the "Working..." message. The value of the variable is one of the following two CHAR values: TRUE, FALSE
SYSTEM.TRIGGER_RECORD represents the number of the record that Form Builder is processing. This number represents the record's current physical order in the block's list of records. The value is always a character string.
SYSTEM.MODE indicates whether the form is in Normal, Enter Query, or Fetch Processing mode. The value is always a character string. NORMAL, ENTER-QUERY, Enter Query mode.
SYSTEM.FORM_STATUS represents the status of the current form. The value can be one of three character strings: CHANGED, NEW , QUERY.
SYSTEM.MESSAGE_LEVEL stores one of the following message severity levels: 0, 5, 10, 15, 20, or 25. The default value is 0.
PARAMETERS:
When you create a parameter, you specify its name, data type, length, and default value.
To create a parameter:
1. In the Object Navigator, create a parameter.
To create a parameter, select the Parameters node in the Object Navigator and then choose Navigator Create.
2. In the Property Palette, set the desired parameter properties:
In PL/SQL, you can reference and set the values of form parameters using bind variable syntax.
To reference a parameter: Preface the parameter name with the reserved word PARAMETER, as shown in the following examples:
:PARAMETER.parameter_name := 'TOKYO'; OR
:block.item := :PARAMETER.parameter_name;
Canvas Types :
1 Content
2 Stacked
3 Tab
4 Horizontal Toolbar
5 Vertical Toolbar

Visual Attributes :
Visual attributes are the font, color, and pattern properties that you set for form and menu objects that appear in your application's interface. Visual attributes can include the following properties:
1 Font properties: Font Name, Font Size, Font Style, Font Width, Font Weight
2 Color and pattern properties: Foreground Color, Background Color, Fill Pattern, Charmode Logical Attribute, White on Black

Every interface object has a Visual Attribute Group property that determines how the object's individual visual attribute settings (Font Size, Foreground Color, etc.) are derived. The Visual Attribute Group property can be set to Default, NULL, or the name of a named visual attribute defined in the same module.
There are several ways to set the visual attributes of objects:
1 In the Property Palette, set the Visual Attribute Group property as desired, then set the individual attributes (Font Name, Foreground Color, etc.) to the desired settings.
2 In the Layout Editor, select an item or a canvas and then choose the desired font, color, and pattern attributes from the Font dialog and Fill Color and Text Color palettes.
3 Define a named visual attribute object with the appropriate font, color, and pattern settings and then apply it to one or more objects in the same module. You can programmatically change an object's named visual attribute setting to change the font, color, and pattern of the object at runtime.
4 Subclass a visual attribute that includes visual attribute properties and then base objects on it that inherit those properties.
5 Create a property class that includes visual attribute properties and then base objects on it that inherit those properties.
About named visual attributes: Setting the Visual Attribute Group property to a named visual attribute defined in the same module specifies that the object should use the attribute settings defined for the named visual attribute. A named visual attribute is a separate object in a form or menu module that defines a collection of visual attribute properties. Once you create a named visual attribute, you can apply it to any object in the same module, much like styles in a word processing program.
Applies to canvas, tab page, item, radio button

Property Classes :
A property class is a named object that contains a list of properties and their settings. Once you create a property class you can base other objects on it. An object based on a property class can inherit the setting of any property in the class that makes sense for that object.
Property class inheritance is an instance of subclassing. Conceptually, you can consider a property class as a universal subclassing parent.
There can be any number of properties in a property class, and the properties in a class can apply to different types of objects. For example, a property class might contain some properties that are common to all types of items, some that apply only to text items, and some that apply only to check boxes.
When you base an object on a property class, you have complete control over which properties the object should inherit from the class, and which should be overridden locally.
Property classes are separate objects, and, as such, can be copied between modules as needed. Perhaps more importantly, property classes can be subclassed in any number of modules.
Menu Item Types
Separator Menu Item :
A separator menu item is displayed as a horizontal line (or other platform-specific visual element), and is useful for visually grouping related items on the same menu. For example, you could use a separator to isolate the radio items of one radio group from other menu items. You must set a separator item's Command Type property to Null. End users cannot select a separator menu item.
Magic Menu Item :
Magic items provide a way to quickly create menu items for standard functions available in most GUI applications. Form Builder provides the following magic item types: About, Copy, Clear, Cut, Paste, Help, Quit, Undo, Window.
Plain Menu Item : Default menu item.
Radio Menu Item
Check Menu Item