Event-driven Natural uses the following basic terminology:
A property of a dialog or a dialog element which can assume specific values.
Example: If the HAS-STATUS-BAR
attribute is set to TRUE for a dialog, then the dialog contains a
status bar.
The following operations may be made on attributes:
| Operation | Result |
|---|---|
| Query | In event handler code, you can query an attribute's value at
runtime. Example:
#L:= #DLG$WINDOW.HAS-STATUS-BAR |
| Set | In event handler code, you can set an attribute to a value in
the global attribute list before you create a dialog element dynamically.
Example:
#PUSH.STYLE:= 'O' PROCESS GUI ACTION ADD WITH #W PUSHBUTTON #PUSH |
| Modify | In event handler code, you can modify an attribute value of an
existing dialog element at runtime. Example:
#PUSH.STYLE:= 'C' |
This is the main dialog of an application. It is started from the command line or via the object list. When this dialog is closed, all other dialogs of the application are closed as well.
A type of dialog element. Examples: edit area control, push button control, list box control.
A Natural object similar to a map or a program that represents a window
in an event-driven application, plus all event handlers and attributes directly
attached to the window. It can be a window, a modal window, a dialog box, an
MDI child window, and an MDI frame window. The window as such is identified by
its handle, the whole dialog is represented by the value of the system variable
*DIALOG-ID.
A special kind of dialog that is exclusively processed in an
application. While this dialog is active, all other dialogs of the application
are disabled and do not accept any user input. If a dialog invokes a dialog box
with an OPEN DIALOG
statement, the dialog returns from the OPEN DIALOG statement only
after the dialog box is closed. This allows the application to return
parameters from the dialog box to the dialog.
The Natural editor with which you create and maintain dialogs.
Dialog elements are (in most cases) graphical elements inside a window that enable the end user to interact with the event-driven application. After a dialog has been created, and its attributes have been set, the programmer places the dialog elements inside the window; usually, this comprises a menu control, possibly a toolbar, and other elements, such as push button controls and input field controls. There are two types of elements: controls and items.
Occurs when a user interacts with a dialog element. An event may also be
sent from within a piece of code (user-defined event). Example: a click event
occurs when the user uses the mouse to click on a push button control for which
a piece of click event handler code has been specified. The system variable
*EVENT
contains the event name.
Programming code that is connected with a dialog element, and is triggered when a particular type of event occurs.
Identifies a dialog element in code and is stored in handle variables.
Example: #PB-1.
A type of dialog element that is part of a control. Example: selection box item, which is part of a selection box control.
Allows an application to manage several different documents or several views of the same document within the main application window (MDI frame window). These views or documents are displayed in separate MDI child windows.
Displays a view of a document within the MDI frame window of an MDI application.
The parent window to all other child (document) windows in an MDI application.
Similar to a dialog box, except that if a dialog invokes a modal window
with an OPEN DIALOG
statement, the dialog returns from the OPEN DIALOG statement
immediately after the modal window has completed opening.
As opposed to MDI applications, SDI applications do not have an MDI frame window that contains the document windows. Only a single view of a single document is displayed.
A dialog with style "Popup" is modeless and can be moved anywhere on the desktop.
The basic type of window.
