mdi

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Determines if a form conforms to the Multiple Document Interface (MDI) standard.

Property of

Form

Description

MDI is a Windows specification for opening multiple document windows within the application window. Most word processors are MDI applications. In dBASE Plus, all windows are forms. MDI forms have the following characteristics:

Like application windows, they are moveable and sizeable.

They are listed on the Windows menu of the application.

They have a title bar, and in that title bar are the system menu, minimize, maximize, and close icons.

When one MDI form is maximized, all other MDI forms in the same application are maximized.

When they are active, their menus replace the menus in the main menu bar.

They cannot be modal.

The shortcut keystroke to close the form is Ctrl+F4.

The opposite of MDI is SDI (Single Document Interface), where each document is in its own application window. The Windows Explorer is an SDI application. SDI forms have the following features:

They each have complete control over their appearance; whether they are movable, sizeable, have a title bar, or any control icons enabled.

Each form is listed separately in the Windows Taskbar.

Their menus appear in the form.

They can be modeless or modal.

They can be set to always display on top of other windows, or appear as palette windows.

The shortcut keystroke to close the form is Alt+F4.

A form’s mdi property determines whether a form is MDI or SDI. When mdi is true, the following properties are ignored:

maximize

minimize

moveable

sizeable

smallTitle

sysMenu

topMost

Those properties default to the corresponding values for an MDI form.

Because an MDI form cannot be modal, you cannot open an MDI form with the readModal( ) method.