BS ISO/IEC 15852:1999

1 General
1.1 Scope
1.2 Relation to Environment
1.3 Windows, Elements and Choices
1.4 Displays
1.5 Events
1.6 Attributes
1.7 Drawing
1.8 Parents and Children
2 Normative Reference
3 Attributes
3.1 Manipulating Attributes
3.2 Attribute Definitions
3.3 Attribute Value Domains
4 Displays
4.1 Display Attributes
5 Windows
5.1 Window Types
5.2 Window Components
5.3 Window Repainting
5.4 Window Attributes
6 Elements
6.1 Gadgets
6.2 Menus
6.3 Timers
6.4 Element Attributes
6.5 Choice Attributes
7 Drawing
7.1 Draw Command Numbers
7.2 Draw Commands
8 Events
8.1 Event Types
8.2 Event Specification Attributes
8.3 Processing Events
8.4 Event Commands
8.5 Event Information
9 Additional Functions and Special Variables
9.1 Functions
9.2 Special Variables
10 Error Handling
10.1 Error Information
10.2 Errors
11 Conformance
11.1 Implementations
Index
TABLES:
Window Attributes
Element Attributes
Choice Attributes
Events
Event Information
Implementation Definition
Implementation-Specific Features
Portability Limits
Unimplemented Features

Defines the M Windowing API (MWAPI) which extends the M programming technology with the addition of capabilities for developing and operating graphical user interface (GUI) applications.

The M Windowing API (MWAPI) extends the M programming technology with the addition of capabilities for developing and operating graphical user interface (GUI) applications. For the purposes of this International Standard, an application is defined as a collection of one or more Mroutines using MWAPI capabilities and a user is a person utilizing such an application. 1.2 Relation to Environment The MWAPI may, but is not required to, operate in conjunction with an underlying windowing platform. The MWAPI does not provide a detailed specification of look and feel for applications. Rather, if an underlying windowing platform is present, it is intended that the MWAPI adhere to the platform\'s look and feel to the extent practicable. If no underlying windowing platform is present, the MWAPI implementation determines look and feel characteristics and carries out actions that would otherwise be carried out by the underlying windowing platform. 1.3 Windows, Elements and Choices The primary mechanism for communicating with a user is a window. Windows provide a general mechanism for displaying text and graphics, typically enclosed by a border. Associated with windows, elements perform specialized tasks. Elements include gadgets, menus, and timers. Gadgets are used for specialized input and output. For instance, there are gadgets designed for text input and gadgets that enable users to select from a list of items. Menus are used to enable users to select actions to be performed. Timers provide a means for notification of an application when a specified period of time has elapsed. Menus and certain gadgets contain a list of choices. For instance, a list box has a list of items that a user can select. An entity is a window, element, or choice. 1.4 Displays Windows are shown to the user via a display, a logical surface on which windows are placed. Each M process has its own display(s); displays are not shared, although physical devices may be shared. There is not necessarily a one-to-one correspondence between a display and the hardware device on which it appears. Multiple displays may appear on the same device and may overlap. A single display may span multiple devices. Each display has associated input devices, typically a keyboard with alphanumeric, function and other keys, and a pointer such as a mouse. 1.5 Events Applications are made aware of actions taken by users, such as pressing a key or selecting a menu item, or of other occurrences via events. Applications specify the events about which they wish to be notified and the code to execute when an event occurs. 1.6 Attributes The characteristics of windows, elements, and choices are specified through attributes in the structured system variable∧$WINDOW. The characteristics of displays are specified through attributes in the structured system variable∧$DISPLAY. The characteristics of events that occur are specified through attributes in the structured system variable∧$EVENT. 1.7Drawing Within one type of gadget, the generic box, the MW API provides facilities for drawing geometric figures, text, and other graphical objects. 1.8Parents and Children Each window and element has a single parent. A window’s parent is either the display on which it appears or another window. An element’s parent is a window. If P is the parent of C, then C is a child of P. A is an ancestor of C and C is a descendant of A if A is the parent of C, or there exist one or more windows (B1 ... Bn) such that A is the parent of B1, Bn is the parent of C, and, for X equal to B1 through Bn-1, Bx is the parent of Bx+1. A window or element inherits default values for certain attributes from its parent. A window or element cannot be created before its parent is created. A window or element can be created by the same M command that creates its parent. P is a parent menu of S and S is a submenu of P if S is displayed when a choice in P is activated.