Generic widget properties

Abstract

The properties described in this document are similar for all widgets. We shall discuss here several generic property pages reflecting different aspects of widget appearance and behaviour.

Basic property page

Overview

Basic properties control the visual appearance of the widget.

Basic properties

Title

Type: string
Dynamic: yes
Static: yes
Description: It is the text appearing somewhere in the widget, for example, button label. This property may have very different representation depending on the widget type. Note also, that this property is meaningless for some widgets.

Size and position

Type: integer
Dynamic: yes
Static: yes
Description: A group of properties specifying the position and size of the widget on the form. Position is measured relative to the top left corner of the form. Measurement unit is pixel.

State property page

Overview

This property page controls visibility of the widget, whether the user input is enabled in it and whether the widget properties will be synchronized during form updates.

State properties

Is visible

Type: boolean
Multiple values: allowed
Values concatenation: boolean conjunction ("and" operation)
Dynamic: yes
Static: no
Description: A boolean expression or a set of boolean expressions to determine whether the widget is visible on the screen.

Is enabled

Type: boolean
Multiple values: allowed
Values concatenation: boolean conjunction ("and" operation)
Dynamic: yes
Static: no
Description: A boolean expression or a set of boolean expressions to determine whether the user may input data into the widget.

Auto update

Type: boolean
Dynamic: no
Static: yes
Description: A flag specifying whether to update the widget contents and dynamic properties when the form is being updated. The form is updated whenever the user changes contents or selection in one of the widgets. If you have several widgets bound to the same target, it is good to set this flag for all of them.

Check property page

Overview

Validation allows you to reject an invalid user input and warn the user of his mistakes.

Validation properties

Expressions

Type: boolean
Multiple values: allowed
Values concatenation: boolean conjunction ("and" operation)
Dynamic: yes
Static: no
Description: Boolean expression or a set of boolean expressions to check that the user input is valid.

Validation message

Type: boolean
Dynamic: yes
Static: yes
Description: A flag whether to display validation error message.

Message

Type: string
Dynamic: yes
Static: yes
Description: A message which is displayed when the validation fails.

Beep

Type: boolean
Dynamic: yes
Static: yes
Description: A flag whether to perform beep when the validation fails.

On change event

You may sometimes need to perform some actions when the user alters the content or the selection in the widget. It is the On change event that is used in this case. The property page has a droppable treeview, where you can put procedures to be invoked to handle the event.


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Last updated: 2005/02/02 11:51:10