Programming Guide

Appendix H. Glossary

This glossary defines many of the terms used in this book. It includes terms and definitions from the IBM Dictionary of Computing, as well as terms specific to the OS/2 operating system and the Presentation Manager. It is not a complete glossary for the entire OS/2 operating system; nor is it a complete dictionary of computer terms.

Other primary sources for these definitions are:

Glossary Listing

0-9

A

abstract class
A class used only to derive other classes. An abstract class is never instantiated. Contrast with concrete class.

accelerator
In SAA Common User Access architecture, a key or combination of keys that invokes an application-defined function.

accelerator table
A table used to define which key strokes are treated as accelerators and the commands they are translated into.

action
One of a set of defined tasks that a computer performs. Users request the application to perform an action in several ways, such as typing a command, pressing a function key, or selecting the action name from a menu bar or menu.

action data
Information stored in the undo object's action history that allows a part to reverse the effects of an undoable action.

action history
The cumulative set of reversible actions available at any one time, maintained by the undo object.

action subhistory
A subset of action data added to the undo object's action history by a part in a modal state. The part can then remove the subhistory from the action history without affecting earlier actions.

action type
A constant that defines whether an undoable action is a single-stage action (such as a cut) or part of a two-stage action (such as a drag-move).

activate
(1) For a part, to make ready to receive the selection focus. A frame is activated when a mouse-down event occurs within it. (2) For a window, to bring it to the front by passing the cursor over it.

active frame
The frame that has the selection focus and usually the keyboard focus. Editing takes place in the active frame; the selection or insertion point is displayed within the frame. The active frame usually has the keystroke and menu focuses, also.

active part
The part displayed in the active frame. The active part controls the part-specific palettes and menus, and its content contains the selection or insertion point. The active part can be displayed in one or more frames, only one of which is the active frame.

active program
A program currently running on the computer. An active program can be interactive (running and receiving input from the user) or noninteractive (running but not receiving input from the user). See also interactive program and noninteractive program.

active shape
A shape that describes the portion of a facet within which a part expects to receive user events. If, for example, an embedded part's used shape and active shape are identical, the containing part both draws and accepts events in the unused areas within the embedded part's frame.

active window
The window with which the user is currently interacting.

address space
(1) The range of addresses available to a program. (A)   (2) The area of virtual storage available for a particular job.

American National Standard Code for Information Interchange
The standard code, using a coded character set consisting of 7-bit coded characters (8 bits including parity check), that is used for information interchange among data processing systems, data communication systems, and associated equipment. The ASCII set consists of control characters and graphic characters. (A)

Note:

IBM has defined an extension to ASCII code (characters 128-255).

ancestor
See superclass.

anchor
On the OS/2 platform,a window procedure that handles Presentation Manager* message conversions between an icon procedure and an application.

annotation
A property in a part's storage unit that is separate from the part's contents.

ANSI
American National Standards Institute.

APA
All points addressable.

API
Application programming interface.

application
A collection of software components used to perform specific types of user-oriented work on a computer; for example, a payroll application, an airline reservation application, a network application. See also conventional application.

application-modal
Pertaining to a message box or dialog box for which processing must be completed before further interaction with any other window owned by the same application may take place.

application object
In SAA Advanced Common User Access architecture, a form that an application provides for a user; for example, a spreadsheet form. Contrast with user object.

application programming interface (API)
A functional interface supplied by the operating system or by a separately orderable licensed program that allows an application program written in a high-level language to use specific data or functions of the operating system or the licensed program.

application result handler
A result handler that is associated with a particular application. Contrast with system result handler.

arbitrator
An OpenDoc object that manages negotiation among parts about ownership of shared resources. Examples of such resources are the menu focus, selection focus, keystroke focus, and the serial ports.

area
In computer graphics, a filled shape such as a solid rectangle.

ASCII
American National Standard Code for Information Interchange.

ASCIIZ
A string of ASCII characters that is terminated with a byte containing the value 0.

aspect ratio
In computer graphics, the width-to-height ratio of an area, symbol, or shape.

ASYNC
Asynchronous.

asynchronous (ASYNC)
(1) Pertaining to two or more processes that do not depend upon the occurrence of specific events such as common timing signals. (T)   (2) Without regular time relationship; unexpected or unpredictable with respect to the execution of program instructions. See also synchronous.

atom
A constant that represents a string. As soon as a string has been defined as an atom, the atom can be used in place of the string to save space. Strings are associated with their respective atoms in an atom table. See integer atom.

atom table
A table used to relate atoms with the strings that they represent. Also in the table is the mechanism by which the presence of a string can be checked.

attribute
A characteristic or property that can be controlled, usually to obtain a required appearance; for example, the color of a line. See also graphics attributes and segment attributes.

automatic link
In Information Presentation Facility (IPF), a link that begins a chain reaction at the primary window. When the user selects the primary window, an automatic link is activated to display secondary windows.

auxiliary storage unit
An extra storage unit that a part uses to store its contents. Contrast with main storage unit.

B

background
(1) In multiprogramming, the conditions under which low-priority programs are executed. Contrast with foreground. (2) An active session that is not currently displayed on the screen.

background color
The color in which the background of a graphic primitive is drawn.

base class
See superclass.

base draft
The original draft of a document. Every OpenDoc document has a base draft, from which all subsequent drafts are ultimately derived. See also current draft.

base menu bar
The menu bar that contains the menus shared by all parts in a document. The document shell installs the base menu bar; parts add their own menus and items.

base object
The object whose interface is extended by an extension object.

Bento
A container suite that implements OpenDoc storage on OS/2, Windows, AIX, and some other platforms.

bias transform
A transform that is applied to measurements in a part's coordinate system to change them into platform-normal coordinates.

binding
(1) In programming, an association between a variable and a value for that variable that holds within a defined scope. The scope may be that of a rule, a function call or a procedure invocation. (2) In OpenDoc, the process of selecting an executable code module based on type information. (3) In SOM, a file enabling a compiler to match a method implementation with its declaration. Also called a header file.

bit map
A representation in memory of the data displayed on an APA device, usually the screen.

block
(1) A string of data elements recorded or transmitted as a unit. The elements may be characters, words, or logical records. (T)   (2) To record data in a block. (3) A collection of contiguous records recorded as a unit. Blocks are separated by interblock gaps and each block may contain one or more records. (A)  

block device
A storage device that performs I/O operations on blocks of data called sectors. Data on block devices can be randomly accessed. Block devices are designated by a drive letter (for example, C:).

border
(1) A visual indication (for example, a separator line or a background color) of the boundaries of a window. (2) For OpenDoc, see frame border.

breakpoint
(1) A point in a computer program where execution may be halted. A breakpoint is usually at the beginning of an instruction where halts, caused by external intervention, are convenient for resuming execution. (T)   (2) A place in a program, specified by a command or a condition, where the system halts execution and gives control to the workstation user or to a specified program.

buffer
(1) A portion of storage used to hold input or output data temporarily. (2) To allocate and schedule the use of buffers. (A)  

bundled frame
A frame whose contents do not respond to user events. For example, a mouse click within a bundled frame selects but does not activate the frame.

button
A mechanism used to request or initiate an action. See also barrel buttons, bezel buttons, mouse button, push button, and radio button.

byte stream
Data that consists of an unbroken stream of bytes.

C

cache
A high-speed buffer storage that contains frequently accessed instructions and data; it is used to reduce access time.

cached micro presentation space
On the OS/2 platform, a presentation space from a Presentation-Manager-owned store of micro presentation spaces. It can be used for drawing to a window only, and must be returned to the store when the task is complete.

call
(1) The action of bringing a computer program, a routine, or a subroutine into effect, usually by specifying the entry conditions and jumping to an entry point. (I)  (A)   (2) To transfer control to a procedure, program, routine, or subroutine.

calling sequence
A sequence of instructions together with any associated data necessary to execute a call. (T)  

Cancel
An action that removes the current window or menu without processing it, and returns the previous window.

canvas
The platform-specific drawing environment on which frames are laid out. Each printing device has one drawing canvas. See also static canvas, dynamic canvas, and drawing canvas.

canvas coordinate space
The coordinate space of the canvas upon which a part's content is drawn. It may or may not be equal to window coordinate space.

cascaded menu
A menu that appears when the arrow to the right of a cascading choice is selected. It contains a set of choices that are related to the cascading choice. Cascaded menus are used to reduce the length of a menu. See also cascading choice.

CASE statement
In PM programming, provides the body of a window procedure. There is usually one CASE statement for each message type supported by an application.

category
See part category.

chained list
A list in which the data elements may be dispersed but in which each data element contains information for locating the next. (T)  Synonymous with linked list.

change ID
(1) A number used to identify a particular instance of clipboard contents. (2) A number used to identify a particular instance of link source data.

character
A letter, digit, or other symbol.

character box
In computer graphics, the boundary that defines, in world coordinates, the horizontal and vertical space occupied by a single character from a character set. See also character mode. Contrast with character cell.

character cell
The physical, rectangular space in which any single character is displayed on a screen or printer device. Position is addressed by row and column coordinates. Contrast with character box.

character code
The means of addressing a character in a character set, sometimes called code point.

character device
A device that performs I/O operations on one character at a time. Because character devices view data as a stream of bytes, character-device data cannot be randomly accessed. Character devices include the keyboard, mouse, and printer, and are referred to by name.

character mode
A mode that, in conjunction with the font type, determines the extent to which graphics characters are affected by the character box, shear, and angle attributes.

character set
(1) An ordered set of unique representations called characters; for example, the 26 letters of English alphabet, Boolean 0 and 1, the set of symbols in the Morse code, and the 128 ASCII characters. (A)   (2) All the valid characters for a programming language or for a computer system. (3) A group of characters used for a specific reason; for example, the set of characters a printer can print.

check box
A square box with associated text that represents a choice. When a user selects a choice, a check mark (&check.) appears in the check box to indicate that the choice is in effect. The user can clear the check box by selecting the choice again. Contrast with radio button.

check mark
(1) A check mark (&check.) symbol that shows that a choice is currently in effect. (2) The symbol that is used to indicate a selected item on a pull-down menu.

child class
See subclass.

child process
A process started by another process, which is called the parent process. Contrast with parent process.

child window
A window that appears within the border of its parent window (either a primary window or another child window). When the parent window is resized, moved, or destroyed, the child window also is resized, moved, or destroyed; however, the child window can be moved or resized independently from the parent window, within the boundaries of the parent window. Contrast with parent window.

choice
An option that can be selected. The choice can be presented as text, as a symbol (number or letter), or as an icon (a pictorial symbol).

CI Labs
Component Integration Laboratories.

circular link
A configuration of links in which changes to a lin's destination directly or indirectly affect its source.

class
In object-oriented design or programming, a group of objects that share a common definition and that therefore share common properties, operations, and behavior. Members of the group are called instances of the class.

class hierarchy
The structure by which classes are related through inheritance.

class method
In System Object Model, an action that can be performed on a class object. Synonymous with factory method.

class object
In System Object Model, the run-time implementation of a class.

class style
The set of properties that apply to every window in a window class.

client
(1) A functional unit that receives shared services from a server. (T)   (2) A user, as in a client process that uses a named pipe or queue that is created and owned by a server process.

client area
The part of the window, inside the border, that is below the menu bar. It is the user's work space, where a user types information and selects choices from selection fields. In primary windows, it is where an application programmer presents the objects that a user works on.

client program
An application that creates and manipulates instances of classes.

client window
The window in which the application displays output and receives input. This window is located inside the frame window, under the window title bar and any menu bar, and within any scroll bars.

clip limits
The area of the paper that can be reached by a printer or plotter.

clip shape
A shape that defines the limits of drawing within a facet.

clipboard
In SAA Common User Access architecture, an area of computer memory, or storage, that temporarily holds data. Data in the clipboard is available to other applications.

clipboard focus
In OpenDoc, a designation of ownership of access to the clipboard. The part with the clipboard focus can read from and write to the clipboard.

clipping
In computer graphics, removing those parts of a display image that lie outside a given boundary.  (I)  (A)

clipping area
The area in which the window can paint.

clipping path
A clipping boundary in world-coordinate space.

clone
To copy an object and all its referenced objects. When you clone an object, that object plus all other objects to which there is a strong persistent reference in the cloned object are copied.

close
For a frame, to remove from memory but not from storage. A closed frame is not permanently removed from its document. Contrast with remove.

code page
An assignment of graphic characters and control-function meanings to all code points.

code point
(1) Synonym for character code. (2) A 1-byte code representing one of 256 potential characters.

code segment
An executable section of programming code within a load module.

command
The name and parameters associated with an action that a program can perform.

command area
An area composed of a command field prompt and a command entry field.

command entry field
An entry field in which users type commands.

command ID
A position-independent identifier for a menu command. See also synthetic command ID.

command line
On a display screen, a display line, sometimes at the bottom of the screen, in which only commands can be entered.

command mode
A state of a system or device in which the user can enter commands.

command prompt
A field prompt showing the location of the command entry field in a panel.

Common Object Request Broker Architecture (CORBA)
A standard promulgated by the Object Management Group industry consortium for defining interactions among objects.

Common User Access (CUA) architecture
Guidelines for the dialog between a human and a workstation or terminal. One of the three SAA architectural areas. See also Common Programming Interface.

compile
To translate a program written in a higher-level

component
(1) Hardware or software that is part of a functional unit. A functional part of an operating system; for example, the scheduler or supervisor. (2) A set of modules that performs a major function within a system; for example, a compiler or a master scheduler. (3) A software product that functions in the OpenDoc environment. Part editors, part viewers, and services are examples of components. See also application component, service component.

Component Integration Laboratories (CI Labs)
A consortium of platform and application vendors that oversees the development and distribution of OpenDoc technology.

composite window
A window composed of other windows (such as a frame window, frame-control windows, and a client window) that are kept together as a unit and that interact with each other.

compound document
A single document containing multiple, heterogeneous data types, each created, presented and edited by its own software. A compound document is made up of parts.

concrete class
A class designed to be instantiated. Contrast with abstract class.

connect or reconnect
For a frame object, to reestablish its connection to the part it displays. Reconnecting a frame may involve recreating it from storage.

connectable part
A part that can report events.

container
(1) An object that holds other objects. A folder is an example of a container object. (2) A holder of persistent data (documents); part of the OpenDoc container suite. (3) A container is specified in an object specifier record by a keyword-specified descriptor record with the keyword keyAEContainer. The keyword-specified descriptor record is usually another object specifier record. It can also be a null descriptor record. The objects a container contains can be either elements or properties.

container part
A part that can embed other parts within its content. A container part is capable of being a containing part. Contrast with simple part and noncontainer part. See also container application.

containing frame
The display frame of an embedded frame's containing part. Each embedded frame has one containing frame; each containing frame has one or more embedded frames.

containing part
The part that immediately contains an embedded part. Each embedded part has one containing part; each containing part has one or more embedded parts.

container suite
A document storage architecture, built on top of a platform's native file system, that allows for the creation, storage, and retrieval of compound documents. A container suite is implemented as a set of OpenDoc classes: containers, documents, drafts, and storage units. See also Bento.

containment
A relationship between objects wherein an object of one class contains a reference to an object of another class. Contrast with inheritance.

content
See part content.

content area
The potentially visible area of a part as viewed in a frame or window. If the content area is greater than the area of the frame or window, only a portion of the part can be viewed at a time.

content coordinate space
The coordinate space defined by applying the internal transform of a frame to a point in frame coordinate space.

content element
A data item that can be seen by the user and is presented by a part's content model. Content elements can be manipulated through the graphical interface to a part.

content extent
The vertical dimension of the content area of a part in a frame. Content extent is used to calculate bias transforms.

content model
The specification of a part's contents (the data types of its content elements) and its content operations (the actions that can be performed on it and the interactions among its content elements).

content operation
A user action that manipulates a content element.

content property
A visual or behavioral characteristic of a containing part, such as its text font, that it makes available for embedded parts to adopt. Embedded parts can adopt the content properties of their containing parts, thus giving a more uniform appearance to a set of parts. Contrast with property and Info property.

content storage unit
The main storage unit of the Clipboard, drag-and-drop object, link source object, or link object.

content transform
The composite transform that converts from a part's content coordinates to its canvas coordinates.

content view type
See frame view type.

contiguous
Touching or joining at a common edge or boundary, for example, an unbroken consecutive series of storage locations.

control
A a component of the user interface that allows a user to select choices or type information; for example, a check box, an entry field, a radio button.

control area
A storage area used by a computer program to hold control information. (I)  (A)  

Control Program
(1) The basic functions of the operating system, including DOS emulation and the support for keyboard, mouse, and video input/output. (2) On the OS/2 platform, a computer program designed to schedule and to supervise the execution of programs of a computer system.  (I)  (A)

control window
A window that is used as part of a composite window to perform simple input and output tasks. Radio buttons and check boxes are examples.

control word
An instruction within a document that identifies its parts or indicates how to format the document.

conventional application
An application that directly handles events, opens documents, and is wholly responsible for manipulating, storing, and retrieving all of the data in its documents. Contrast with application component.

coordinate bias
The difference between a given coordinate system and platform-normal coordinates. Coordinate bias typically involves both a change in axis polarity and an offset.

coordinate space
A two-dimensional set of points used to generate output on a video display of printer.

Copy
A choice that places onto the clipboard, a copy of what the user has selected. See also Cut and Paste.

CORBA
See Common Object Request Broker Architecture.

correlation
The action of determining which element or object within a picture is at a given position on the display. This follows a pick operation.

CUA architecture
Common User Access architecture.

current draft
The most recent draft of an OpenDoc document. Only the current draft can be edited.

current frame
During drawing, the frame that is being drawn or within which editing is occurring.

current position
In computer graphics, the position, in user coordinates, that becomes the starting point for the next graphics routine, if that routine does not explicitly specify a starting point.

cursor
A symbol displayed on the screen and associated with an input device. The cursor indicates where input from the device will be placed. Types of cursors include text cursors, graphics cursors, and selection cursors. Contrast with pointer and input focus.

Cut
In SAA Common User Access architecture, a choice that removes a selected object, or a part of an object, to the clipboard, usually compressing the space it occupied in a window. See also Copy and Paste.

D

data structure
The syntactic structure of symbolic expressions and their storage-allocation characteristics. (T)  

data transfer
The movement of data from one object to another by way of the clipboard or by direct manipulation.

DBCS
Double-byte character set.

DDE
Dynamic data exchange.

debug
To detect, diagnose, and eliminate errors in programs. (T)  

default container
The outermost container in an application's container hierarchy; usually the application itself. See also container hierarchy.

default editor for kind
A user-specified choice of part editor to use with parts whose preferred editor is not present.

default object accessors
Object accessors provided by OpenDoc that can be used to resolve content objects or properties of parts that do not themselves support scripting. Default accessors can return tokens representing an embedded frame, a standard Info property of a part, or a context switch (swap token).

default procedure
On the OS/2 platform, a function provided by the Presentation Manager Interface and a function of the Windows platform, that may be used to process standard messages from dialogs or windows.

default value
A value assumed when no value has been specified. Synonymous with assumed value. For example, in the graphics programming interface, the default line-type is 'solid'.

definition list
A type of list that pairs a term and its description.

delta
An application-defined threshold, or number of container items, from either end of the list.

derived class
See subclass.

descendant
See child process and subclass.

descriptive text
Text used in addition to a field prompt to give more information about a field.

descriptor list
A descriptor record of data type AEDescList whose data handle refers to a list of descriptor records.

descriptor type
An identifier for the type of data referred to by the handle in a descriptor record.

Deselect all
A choice that cancels the selection of all of the objects that have been selected in that window.

desktop window
The window, corresponding to the physical device, against which all other types of windows are established.

destination content
The content at the destination of a link. It is a copy of the source content.

destination part
For a link, the part that displays the information copied from the source of the link. Contrast with source part.

device context
A logical description of a data destination such as memory, metafile, display, printer, or plotter. See also direct device context, information device context, memory device context, metafile device context, queued device context, and screen device context.

device driver
A file that contains the code needed to attach and use a device such as a display, printer, or plotter.

device space
(1) On the OS/2 platform, coordinate space in which graphics are assembled after all GPI transformations have been applied. Device space is defined in device-specific units. (2) In computer graphics, a space defined by the complete set of addressable points of a display device. (A)  

dialog
The interchange of information between a computer and its user through a sequence of requests by the user and the presentation of responses by the computer.

dialog box
In SAA Advanced Common User Access architecture, a movable window, fixed in size, containing controls that a user uses to provide information required by an application so that it can continue to process a user request. See also message box, primary window, secondary window. Also known as a pop-up window.

Dialog Box Editor
On the OS/2 platform, a WYSIWYG editor that creates dialog boxes for communicating with the application user.

dialog item
A component (for example, a menu or a button) of a dialog box. Dialog items are also used when creating dialog templates.

dialog procedure
A dialog window that is controlled by a window procedure. It is responsible for responding to all messages sent to the dialog window.

dialog template
The definition of a dialog box, which contains details of its position, appearance, and window ID, and the window ID of each of its child windows.

direct device context
A logical description of a data destination that is a device other than the screen (for example, a printer or plotter), and where the output is not to go through the spooler. Its purpose is to satisfy queries. See also device context.

direct manipulation
The user's ability to interact with an object by using the mouse, typically by dragging an object around on the Desktop and dropping it on other objects.

direct memory access (DMA)
A technique for moving data directly between main storage and peripheral equipment without requiring processing of the data by the processing unit.(T)  

directory
A type of file containing the names and controlling information for other files or other directories.

dispatch module
An OpenDoc object used by the dispatcher to dispatch events of a certain type to part editors.

display frame
A frame in which a part is displayed. A part's display frames are created by and embedded in its containing part. Contrast with embedded frame.

display-frames list
A part's list of all the frames in which it is displayed. If a part is displayed in only one frame, it has only one element in this list.

display point
Synonym for pel.

display property
A visual characteristic of a containing part, such as its text font, that it makes available for embedded parts to adopt. Embedded parts can adopt the display characteristics of their containing parts that they understand, thus giving a more uniform appearance to a set of parts. Display properties are stored as properties in a storage unit passed from containing part to embedded part.

Distributed SOM (DSOM)
Distributed System Object Model. A version of SOM that provides remote access to SOM objects in a transparent way that insulates client programmers from having to know the location or platform type where a target object will be instantiated. DSOM allows programmers to use the same object model independently of whether the objects they access are in the same process, in another process on the same machine, or across distributed networks.

DMA
Direct memory access.

document
In OpenDoc, a user-organized collection of parts, all stored together.

document part
See part.

document process
A thread of execution that runs the document shell program. The document process provides the interface between the operating system and part editors. It accepts events from the operating system, provides the address space into which parts are loaded, and provides access to the window system and other features.

document shell
A program that provides an environment for all the parts in a document. The shell maintains the major document global databases: storage, window state, arbitrator, and dispatcher. This code also provides basic document behavior such as document creation, opening, saving, printing, and closing. OpenDoc provides a default document shell for each platform.

document window
A window that displays an OpenDoc document. The edges of the content area of the window represent the frame border of the document's root part. The OpenDoc document shell manages opening and closing of document windows. Contrast with part window.

double-byte character set (DBCS)
A set of characters in which each character is represented by two bytes. Languages such as Japanese, Chinese, and Korean, which contain more characters than can be represented by 256 code points, require double-byte character sets. Since each character requires two bytes, the entering, displaying, and printing of DBCS characters requires hardware and software that can support DBCS.

draft
A configuration of a document, defined at a certain point in time by the user. A document is made up of a set of drafts.

draft key
A number that identifies a specific cloning transaction.

draft permissions
A specification of the class of read/write access that a part editor has to a draft.

drag
In SAA Common User Access, to use a pointing device to move an object; for example, clicking on a window border, and dragging it to make the window larger.

drag and drop
A facility of OpenDoc that allows users to move or copy data through direct manipulation.

drag-copy
A drag-and-drop operation in which the dragged data remains at the source, and a copy is inserted at the destination.

drag-move
A drag-and-drop operation in which the dragged data is deleted from the source and inserted at the destination.

dragging
(1) In computer graphics, moving an object on the display screen as if it were attached to the pointer. (2) In computer graphics, moving one or more segments on a display surface by translating.  (I)  (A)

drawing canvas
The platform-specific drawing environment on which frames are laid out. See also canvas, static canvas, and dynamic canvas.

drawing chain
See segment chain.

drop
To fix the position of an object that is being dragged, by releasing the select button of the pointing device. See also drag.

DSOM
Distributed System Object Model. A version of SOM that works transparently over a network.

dynamic canvas
A drawing canvas that can potentially be changed, such as a window, that can be scrolled or paged to display different portions of a part's data. Contrast with static canvas.

dynamic data exchange (DDE)
On the OS/2 platform, a message protocol used to communicate between applications that share data. The protocol uses shared memory as the means of exchanging data between applications.

dynamic data formatting
A formatting procedure that enables you to incorporate text, bit maps or metafiles in an IPF window at execution time.

dynamic link library
A collection of executable programming code and data that is bound to an application at load time or run time, rather than during linking. The programming code and data in a dynamic link library can be shared by several applications simultaneously.

dynamic linking
The process of resolving external references in a program module at load time or run time rather than during linking.

dynamic segments
Graphics segments drawn in exclusive-or mix mode so that they can be moved from one screen position to another without affecting the rest of the displayed picture.

dynamic storage
(1) A device that stores data in a manner that permits the data to move or vary with time such that the specified data is not always available for recovery. (A)   (2) A storage in which the cells require repetitive application of control signals in order to retain stored data. Such repetitive application of the control signals is called a refresh operation. A dynamic storage may use static addressing or sensing circuits. (A)   (3) See also static storage.

dynamic time slicing
Varies the size of the time slice depending on system load and paging activity.

dynamic-link module
A module that is linked at load time or run time.

E

editor of last resort
The part editor that displays any part for which there is no available part editor on the system. The editor of last resort typically displays a gray rectangle representing the part's frame.

editor properties
A notebook, accessed through the Edit menu, in which the user can view and change properties for the part editor of the currently active part.

embed
To display one part in a frame within another part. The embedded part retains its identity as a separate part from the containing part. Contrast with incorporate.

embedded content
Content displayed in an embedded frame. A containing part editor does not directly manipulate embedded content. Contrast with intrinsic content.

embedded frame
A frame that displays an embedded part. The embedded frame itself is considered intrinsic content of the containing part; the part displayed within the frame is not.

embedded-frames list
A containing part's private list of all the frames embedded within it.

embedded part
A part displayed in an embedded frame. The data for an embedded part is stored within the same draft as its containing part. An embedded part is copied during a duplication of its containing part. An embedded part may itself be a containing part, unless it is a noncontainer part.

embedding part
A part that is capable of embedding other parts within its content; that is, it is capable of being a containing part. See also container part. Contrast with nonembedding part.

EMS
Expanded memory specification.

entry field
In SAA Common User Access architecture, an area where a user types information. Its boundaries are usually indicated. See also selection field.

entry-field control
The component of a user interface that provides the means by which the application receives data entered by the user in an entry field. When it has the input focus, the entry field displays a flashing pointer at the position where the next typed character will go.

entry panel
A defined panel type containing one or more entry fields and protected information such as headings, prompts, and explanatory text.

environment parameter
A parameter used by all methods of SOM objects to pass exceptions.

environment segment
The list of environment variables and their values for a process.

environment strings
ASCII text strings that define the value of environment variables.

environment variables
On the OS/2 platform, variables that describe the execution environment of a process. These variables are named by the operating system or by the application. Environment variables named by the operating system are PATH, DPATH, INCLUDE, INIT, LIB, PROMPT, and TEMP. The values of environment variables are defined by the user in the CONFIG.SYS file, or by using the SET command at the OS/2 command prompt.

error message
An indication that an error has been detected. (A)  

event
See user event.

event consumer
The receiver of an event notification.

event handler
(1) A routine that executes in response to receiving a user event. (2) See semantic-event handler.

event-info structure
A data structure that carries information about an OpenDoc user event in addition to that provided by the event structure.

Event Manager
The collection of routines that an application can use to receive information about actions performed by the user, to receive notice of changes in the processing status of the application, and to communicate with other applications.

event semaphore
A semaphore that enables a thread to signal a waiting thread or threads that an event has occurred or that a task has been completed. The waiting threads can then perform an action that is dependent on the completion of the signaled event.

event source
The sender of an event notification, must be a connectable part.

event structure
A platform-specific structure that carries information about an OpenDoc user event.

exception
In programming languages, an abnormal situation that may arise during execution, that may cause a deviation from the normal execution sequence, and for which facilities exist in a programming language to define, raise, recognize, ignore, and handle it.

exclusive focus
A focus that can be owned by only one frame at a time. The selection focus, for example, is exclusive; the user can edit within only one frame at a time. Contrast with non-exclusive focus.

exclusive system semaphore
A system semaphore that can be modified only by threads within the same process.

executable file
(1) A file that contains programs or commands that perform operations or actions to be taken. (2) A collection of related data records that execute programs.

exit
To execute an instruction within a portion of a computer program in order to terminate the execution of that portion. Such portions of computer programs include loops, subroutines, modules, and so on. (T)   Repeated exit requests return the user to the point from which all functions provided to the system are accessible. Contrast with cancel.

expanded memory specification (EMS)
On the OS/2 platform, enables DOS applications to access memory above the 1MB re al mode addressing limit.

extended attribute
On the OS/2 platform, an additional piece of information about a file object, such as its data format or category. It consists of a name and a value. A file object may have more than one extended attribute associated with it.

extended-choice selection
A mode that allows the user to select more than one item from a window. Not all windows allow extended choice selection.

extension
An OpenDoc object that extends the programming interface of another OpenDoc object. Part editors, for example, can provide additional interfaces through extensions. An object class that duplicates all the characteristics of an object class of the same name and adds some of its own. Like a word in a dictionary, a single object class ID can have several related definitions.

extent
Continuous space on a disk or diskette that is occupied by or reserved for a particular data set, data space, or file.

external link
On the OS/2 platform, in Information Presentation Facility, a link that connects external online document files.

external transform
A transform that is applied to a facet to position, scale, or otherwise transform the facet and the image drawn within it. The external transform loates the facet in the coordinate space of the frame's containing part. Contrast with internal transform.

externalize
For a part or other OpenDoc object, to transform its in-memory representation into a persistent form in a storage unit. See also write. Contrast with internalize.

extracted draft
A draft that is extracted from a document into a new document.

F

facet
An object that describes where a frame is displayed on a canvas.

factory method
A method in one class that creates an instance of another class.

fidelity
The faithfulness of translation attained (or attainable) between data of different part kinds. For a given part kind, other part kinds are ranked in fidelity by the level at which their editors can translate its data without loss.

file
A named set of records stored or processed as a unit. (T)  

file specification
The full identifier for a file, which includes its drive designation, path, file name, and extension.

file system
The combination of software and hardware that supports storing information on a storage device.

flag
(1) An indicator or parameter that shows the setting of a switch. (2) A character that signals the occurrence of some condition, such as the end of a word. (A)   (3) A characteristic of a file or directory that enables it to be used in certain ways. and read-only flag.

focus
A designation of ownership of a shared resource such as menus, selection, keystrokes, and serial ports. The part that owns a focus has use of that shared resource.

focus module
An OpenDoc object used by the arbitrator to assign an owner or owners to a given focus type.

focus set
A group of focuses requested as a unit.

folder
A container used to organize objects.

font
A particular size and style of typeface that contains definitions of character sets, marker sets, and pattern sets.

frame
(1) The part of a window that can contain several different visual elements specified by the application, but drawn and controlled by the operating system. (2) In OpenDoc, a bounded portion of the content area of a part, defining the location of an embedded part. The edge of a frame marks the boundary between intrinsic content and embedded content. A frame can be a rectangle or any other, even irregular, shape.

frame border
A visual indication of the boundary of a frame. The appearance of the frame border indicates the state of the frame (active, inactive, or selected). The frame border is drawn and manipulated by the containing part or by OpenDoc, not by the part within the frame.

frame coordinate space
The coordinate space in which a part's frame shape, used shape, active shape, and clip shape are defined. Contrast with content coordinate space. See also window coordinate space, canvas coordinate space.

frame group
A set of embedded frames that a containing part designates as related, for purposes such as flowing content from one frame to another. Each frame group has its own group ID; frames within a frame group have a frame sequence.

frame negotiation
The process of adjusting the size and shape of an embedded frame. Embedded parts can request changes to their frames, but the containing parts control the changes that occur.

frame sequence
The order of frames in a frame group.

frame shape
A shape that defines a frame and its border, expressed in terms of the frame's local coordinate space.

frame styles
On the OS/2 platform, standard window layouts provided by the Presentation Manager.

frame transform
The composite transform that converts from a part's frame coordinates to its canvas coordinates

frame view type
A view type in which all or a portion of a part's contents is displayed within a frame, the border of which is visible when the part is active or selected. Other possible view types for displaying a part include large icon, small icon, and thumbnail. Frame view type is sometimes called content view type.

function
(1) In a programming language, a block, with or without formal parameters, whose execution is invoked by means of a call. (2) A set of related control statements that cause one or more programs to be performed.

function key
A key that causes a specified sequence of operations to be performed when it is pressed, for example, F1 and Alt-K.

function key area
The area at the bottom of a window that contains function key assignments such as F1=Help.

G

GPI
On the OS/2 platform, Graphics programming interface.

graphic primitive
In computer graphics, a basic element, such as an arc or a line, that is not made up of smaller parts and that is used to create diagrams and pictures. See also graphics segment.

graphics
(1) A picture defined in terms of graphic primitives and graphics attributes. (2) The making of charts and pictures. (3) Pertaining to charts, tables, and their creation. (4) See computer graphics, coordinate graphics, fixed-image graphics, interactive graphics, passive graphics, raster graphics.

graphics attributes
Attributes that apply to graphic primitives. Examples are color, line type, and shading-pattern definition. See also segment attributes.

graphics field
The clipping boundary that defines the visible part of the presentation-page contents.

graphics mode
One of several states of a display. The mode determines the resolution and color content of the screen.

graphics model space
On the OS/2 platform, the conceptual coordinate space in which a picture is constructed after any model transforms have been applied. Also known as model space.

Graphics programming interface
On the OS/2 platform, the formally defined programming language that is between an IBM graphics program and the user of the program.

graphics segment
On the OS/2 platform, a sequence of related graphic primitives and graphics attributes. See also graphic primitive.

graphics system
A specific drawing architecture. Some graphics systems (such as Display PostScript) are available on more than one platform; some platforms support more than one graphics system.

group
A collection of logically connected controls. For example, the buttons controlling paper size for a printer could be called a group. See also program group.

group ID
In OpenDoc, a number that identifies a frame group, assigned by the group's containing part.

H

handle
(1) An identifier that represents an object, such as a device or window, to the Presentation Interface. (2) In the Advanced DOS and OS/2 operating systems, a binary value created by the system that identifies a drive, directory, and file so that the file can be found and opened.

header
(1) System-defined control information that precedes user data. (2) The portion of a message that contains control information for the message, such as one or more destination fields, name of the originating station, input sequence number, character string indicating the type of message, and priority level for the message.

heap
An area of free storage available for dynamic allocation by an application. Its size varies according to the storage requirements of the application.

help function
(1) A function that provides information about a specific field, an application panel, or information about the help facility. (2) One or more display images that describe how to use application software or how to do a system operation.

Help index
On the OS/2 platform, a help action that provides an index of the help information available for an application.

help panel
A panel with information to assist users that is displayed in response to a help request from the user.

help window
On the OS/2 platform, a secondary window that displays information when the user requests help.

hierarchical inheritance
The relationship between parent and child classes. An object that is lower in the inheritance hierarchy than another object, inherits all the characteristics and behaviors of the objects above it in the hierarchy.

hierarchy
A tree of segments beginning with the root segment and proceeding downward to dependent segment types.

hit testing
The means of identifying which window is associated with which input device event.

hook
A point in a system-defined function where an application can supply additional code that the system processes as though it were part of the function.

hook chain
A sequence of hook procedures that are "chained" together so that each event is passed, in turn, to each procedure in the chain.

hot part
A part, such as a control, that performs an action rather than activating itself, when it receives a mouse click.

hot spot
The part of the pointer that must touch an object before it can be selected. This is usually the tip of the pointer.

I

I/O operation
An input operation to, or output operation from a device attached to a computer.

IAC
Interapplication communication

icon
(1) A graphical representation of an object, consisting of an image, image background, and a label. Icons can represent items (such as a document file) that the user wants to work on, and actions that the user wants to perform. On the OS/2 platform, in the Presentation Manager, icons are used for data objects, system actions, and minimized programs. (2) In OpenDoc, a small, type-specific picture with a name. Possible iconic view types for displaying a part include as a (standard) large icon, small icon, or thumbnail; the other possible view type is in a frame.

icon area
On the OS/2 platform, in the Presentation Manager, the area at the bottom of the screen that is normally used to display the icons for minimized programs.

Icon Editor
On the OS/2 platform, the Presentation Manager-provided tool for creating icons.

identity transform
A transform that has no effect on points to which it is applied.

IDL
Interface Definition Language.

inactive frame
A frame that does not have the selection focus.

inactive part
A part that has no active display frames.

incorporate
To merge the data from one part into the contents of another part so that the merged data retains no separate identity as a part. Contrast with embed.

Information Presentation Facility (IPF)
A facility provided by the OS/2 operating system, by which application developers can produce online documentation and context-sensitive online help panels for their applications.

inheritance
The passing of class resources or attributes from a parent class downstream in the class hierarchy to a child class. The new class inherits all the data and methods of the parent class without having to redefine them.

in-place editing
User manipulation of data in an embedded part without leaving the context of the document in which the part is displayed (for example, without opening a new window for the part).

input focus
(1) The area of a window where user interaction is possible using an input device, such as a mouse or the keyboard. (2) The position in the active window where a user's normal interaction with the keyboard will appear.

input/output control
A device-specific command that requests a function of a device driver.

inside-out activation
A mode of user interaction in which a mouse click anywhere in a document activates the smallest possible enclosing frame and performs the appropriate selection action on the content element at the click location. OpenDoc uses inside-out selection. Contrast with outside-in activation.

inside-out selection
A mode of user interaction in which a mouse click anywhere in a document activates the smallest possible enclosing frame and performs the appropriate selection action on the content element at the click location. OpenDoc uses inside-out selection. Contrast with outside-in selection.

instance
A single occurrence of an object class that has a particular behavior. See also object.

instantiate
(1) To make an instance of; to replicate. (2) In object-oriented programming, to represent a class abstraction with a concrete instance of the class.

instruction pointer
A pointer that provides addressability for a machine interface instruction in a program.

integer atom
An atom that represents a predefined system constant and carries no storage overhead. For example, names of window classes provided by Presentation Manager are expressed as integer atoms.

interactive graphics
Graphics that can be moved or manipulated by a user at a terminal.

interactive program
(1) A program that is running (active) and is ready to receive (or is receiving) input from a user. (2) A running program that can receive input from the keyboard or another input device. Contrast with active program and noninteractive program.

Also known as a foreground program.

interapplication communication (IAC) architecture
A standard and extensible mechanism for communication among applications.

interchange file
A file containing data that can be sent from one application to another.

Interface Definition Language (IDL)
Language-neutral syntax created by IBM to describe the interface of classes that can be compiled by the SOM compiler.

internal transform
A transform that positions, scales, or otherwise transforms the image of a part drawn within a frame. Contrast with external transform.

internalize
For a part or other OpenDoc object, to transform its persistent form in a storage unit into an appropriate in-memory representation. Contrast with externalize. See also read.

interoperability
Access to an OpenDoc part or document from different platforms or with different software systems.

intrinsic content
The content elements native to a particular part, as opposed to other parts embedded in it. Contrast with embedded content.

invalid shape
The area of a frame, facet, or canvas that needs redrawing. Update events cause redrawing of the invalid area.

invalidate
To mark an area of a canvas (or facet, or frame) as in need of redrawing.

invariant
An aspect of the internal state of an object that must be maintained for the object to behave properly according to its design.

IPF
On the OS/2 platform, Information Presentation Facility.

IPF compiler
On the OS/2 platform, a text compiler that interpret tags in a source file and converts the information into the specified format.

IPF tag language
On the OS/2 platform, a markup language that provides the instructions for displaying online information.

ISO string
A null-terminated 7-bit ASCII string.

item
A data object that can be passed in a DDE transaction.

iterator
A class or object that provides sequential access to a collection of objects of another class. A part's embedded-frames iterator, for example, provides access to all of the part's embedded frames.

J

K

kerning
The design of graphics characters so that their character boxes overlap. Used to space text proportionally.

keyboard accelerator
A keystroke that generates a command message for an application.

keyboard augmentation
A function that enables a user to press a keyboard key while pressing a mouse button.

keyboard focus
A temporary attribute of a window. The window that has a keyboard focus receives all keyboard input until the focus changes to a different window.

keystroke focus
A designation of ownership of keystroke events. The part whose frame has the keystroke focus receives keystroke events. See also selection focus.

keystroke focus frame
The frame to which keystroke events are to be sent.

keyword
A four-character code that uniquely identifies a descriptor record inside another descriptor record.

kind
See part kind.

L

label
In a graphics segment, an identifier of one or more elements that is used when editing the segment.

LAN
local area network.

large icon view type
On the OS/2 platform, a view type in which a part is represented by a 32 by 32-pixel bitmap image. Other possible view types for displaying a part include small icon, thumbnail, and frame.

layout
The process of arranging frames and content elements in a document for drawing.

lazy instantiation
The process of creating objects (such as embedded frames) in memory only when they are needed for display, such as when the user scrolls them into view. Lazy instantiation can help minimize the memory requirements of your parts.

LDT
Local Descriptor Table.

link
(1) A persistent reference to a part or to a set of content elements of a part. (2) An OpenDoc object that represents a link destination.

link destination
The portion of a part's content area that represents the destination of a link.

link key
A number that identifies a specific transaction to access a link object or link-source object.

link manager
An OpenDoc object that coordinates cross-document links.

link source
The portion of a part's content area that represents the source of a link.

link specification
An object, placed on the clipboard or in a drag-and-drop object, from which the source part (the part that placed the data) can construct a link if necessary.

link status
The link-related state (in a link source, in a link destination, or not in a link) of a frame.

linked list
Synonym for chained list.

linked part
A part (or a portion of a part's content data) that appears to the user to be embedded in one part, but it is actually embedded in a different part. Linked data is not copied when the link's containing part is duplicated; a new link is created instead.

list box
A control that contains scrollable choices from which a user can select one choice.

Note:

In CUA architecture, this is a programmer term.
The end user term is selection list.

list button
A button labeled with an underlined down-arrow that presents a list of valid objects or choices that can be selected for that field.

load
For a part editor, to transform the persistent form of a part in a draft into an appropriate in-memory representation, which can be a representation of the complete part or only a subset, depending on the current display requirements of the document. Contrast with save.

Local Descriptor Table (LDT)
On the OS/2 platform, defines code and data segments specific to a single task.

lock
A serialization mechanism by means of which a resource is restricted for use by the holder of the lock.

M

main storage unit
The storage unit that holds the contents property (kODPropContents) of a part. A part's main storage unit, plus possibly other auxiliary storage units referenced from it, holds all of a part's content.

map
(1) A set of values having a defined correspondence with the quantities or values of another set.  (I)  (A) (2) To establish a set of values having a defined correspondence with the quantities or values of another set.  (I)

maximize
To enlarge a window to its largest possible size.

memory block
Part memory within a heap.

memory management
A feature of the operating system for allocating, sharing, and freeing main storage.

memory object
Logical unit of memory requested by an application, which forms the granular unit of memory manipulation from the application viewpoint.

menu
An extension of the menu bar that displays a list of choices available for a selected choice in the menu bar. After a user selects a choice in menu bar, the corresponding menu appears. Additional pop-up windows can appear from menu choices.

menu bar
The area near the top of a window, below the title bar and above the rest of the window, that contains choices that provide access to other menus.

menu button
The button on a pointing device that a user presses to view a pop-up menu associated with an object.

message
(1) On the OS/2 platform, in the Presentation Manager, a packet of data used for communication between the Presentation Manager interface and Presentation Manager applications (2) In a user interface, information not requested by users but presented to users by the computer in response to a user action or internal process.

message block
A byte stream that an open application uses to send data to and receive data from another open application (which can be located on the same computer or across a network).

message box
(1) A dialog window predefined by the system and used as a simple interface for applications, without the necessity of creating dialog-template resources or dialog procedures. (2) On the OS/2 platform, a type of window that shows messages to users. See also dialog box, primary window, secondary window.

message filter
The means of selecting which messages from a specific window will be handled by the application.

message queue
A sequenced collection of messages to be read by the application.

message stream mode
A method of operation in which data is treated as a stream of messages. Contrast with byte stream.

metaclass
The conjunction of an object and its class information; that is, the information pertaining to the class as a whole, rather than to a single instance of the class. Each class is itself an object, which is an instance of the metaclass.

metafile
A file containing a series of attributes that set color, shape and size, usually of a picture or a drawing. Using a program that can interpret these attributes, a user can view the assembled image.

metafile device context
A logical description of a data destination that is a metafile, which is used for graphics interchange. See also device context.

method
A function that manipulates the data of a particular class of objects.

method override
The replacement, by a child class, of the implementation of a method inherited from a parent and an ancestor class.

minimize
To remove from the screen all windows associated with an application and replace them with an icon that represents the application.

modal dialog box
In SAA Advanced Common User Access architecture, a type of movable window, fixed in size, that requires a user to enter information before continuing to work in the application window from which it was displayed. Contrast with modeless dialog box. Also known as a serial dialog box. Contrast with parallel dialog box.

Note:

In CUA architecture, this is a programmer term.
The end user term is pop-up window.

modal focus
A designation of ownership of the right to display modal dialog boxes. A part displaying a modal dialog must first acquire the modal focus, so that other parts cannot do the same until the first part is finished.

modeless dialog box
In SAA Advanced Common User Access architecture, a type of movable window, fixed in size, that allows users to continue their dialog with the application without entering information in the dialog box. Also known as a parallel dialog box. Contrast with modal dialog box.

Note:

In CUA architecture, this is a programmer term.
The end user term is pop-up window.

module definition file
On the OS/2 platform, a file that describes the code segments within a load module. For example, it indicates whether a code segment is loadable before module execution begins (preload), or loadable only when referred to at run time (load-on-call).

monitor
A special use of a dispatch module, in which it is installed in order to be notified of events, but does not dispatch them.

monolithic application
See conventional application.

mouse
A device that a user moves on a flat surface to position a pointer on the screen. It allows a user to select a choice o function to be performed or to perform operations on the screen, such as dragging or drawing lines from one position to another.

mouse region
An area (by default a size of 1 pixel square) within which the user can move the mouse pointer without triggering an event.

multitasking
The concurrent processing of applications or parts of applications. A running application and its data are protected from other concurrently running applications.

N

name space
An object consisting of a set of text strings used to identify kinds of objects or classes of behavior, for registration purposes. For example, OpenDoc uses name spaces to identify part kinds and categories for binding.

name-space manager
An OpenDoc object that creates and deletes name spaces.

named pipe
A named buffer that provides client-to-server, server-to-client, or full duplex communication between unrelated processes. Contrast with unnamed pipe.

noncontainer part
A part that cannot itself contain embedded parts. A noncontainer part can never be a containing part. Contrast with container part.

nonpersistent frame
A frame that exists as an object in memory, but has no storage unit and is not stored persistently.

NUL
Null character.

null character (NUL)
(1) Character-device name reserved for a nonexistent (dummy) device. (2) A control character that is used to accomplish media-fill or time-fill and that may be inserted into or removed from a sequence of characters without affecting the meaning of the sequence; however, the control of equipment or the format may be affected by this character. (I)  (A)  

null descriptor record
A descriptor record whose descriptor type is typeNull and whose data handle is NIL.

null-terminated string
A string of (n+1) characters where the (n+1)th character is the 'null' character (0x00) Also known as 'zero-terminated' string and 'ASCIIZ' string.

O

object
A programming entity, existing in memory at run time, that is an individual instantiation of a particular class.

object accessor
A function called by the name resolver to resolve semantic-event object specifiers.

Object Linking and Embedding (OLE)
An application protocol developed by Microsoft Corporation that allows objects created by one application to be linked to or embedded in objects created by another application.

Object Management Group (OMG)
An industry consortium that promulgates standards for object programming.

ODF
OpenDoc Development Framework

OLE
Object Linking and Embedding.

OLE interoperability
A technology that enables seamless interoperability between OpenDoc and Microsoft Corporation's Object Linking and Embedding (OLE) technology for interapplication communication. It allows OLE objects to function automatically as parts in OpenDoc documents, and OpenDoc parts to function automatically as OLE objects in OLE containers.

OMG
Object Management Group.

OpenDoc
A multiplatform technology, implemented as a set of shared libraries, that uses component software to facilitate the construction and sharing of compound documents.

OpenDoc Development Framework (ODF)
A part-editor framework that facilitates creation of OpenDoc parts.

ordered list
Vertical arrangements of items, with each item in the list preceded by a number or letter.

outside-in activation
A mode of user interaction in which a mouse click anywhere in a document activates the largest possible enclosing frame that is not already active. Contrast with inside-out activation.

outside-in selection
A mode of user interaction in which a mouse click anywhere in a document activates the largest possible enclosing frame that is not already active. Contrast with inside-out selection.

override
To replace a method belonging to a superclass with a method of the same name in a subclass, in order to modify its behavior.

owner
For a canvas, the part that created the canvas and attached it to a facet. The owner is responsible for transferring the results of drawing on the canvas to its parent canvas.

ownership
The determination of how windows communicate using messages.

P

page
(1) A 4KB segment of contiguous physical memory. (2) A defined unit of space on a storage medium.

paint
(1) The action of drawing or redrawing the contents of a window. (2) In computer graphics, to shade an area of a display image; for example, with crosshatching or color.

panel
In SAA Basic Common User Access architecture, a particular arrangement of information that is presented in a window or pop-up. If some of the information is not visible, a user can scroll through the information.

panel area
An area within a panel that contains related information. The three major Common User Access-defined panel areas are the action bar, the function key area, and the panel body.

panel area separator
In SAA Basic Common User Access architecture, a solid, dashed, or blank line that provides a visual distinction between two adjacent areas of a panel.

parent canvas
The canvas closest above a canvas in the facet hierarchy. If, for example, there is a single offscreen canvas attached to an embedded facet in a window, the window canvas (attached to the root facet) is the parent of the offscreen canvas.

parent class
See superclass.

parent process
A process that creates other processes. Contrast with child process.

parent window
A window that creates a child window. The child window is drawn within the parent window. If the parent window is moved, resized, or destroyed, the child window also will be moved, resized, or destroyed. However, the child window can be moved and resized independently from the parent window, within the boundaries of the parent window. Contrast with child window.

part
A portion of a compound document. It consists of document content, plus, at run time, a part editor that manipulates that content. The content is data of a given structure or type, such as text, graphics, or video. The code is a part editor. In programming terms, a part is an object, an instantiation of a subclass of the class ODPart. To a user, a part is a single set of information displayed and manipulated in one or more frames or windows. Synonymous with document part.

part category
A general classification of the format of data handled by a part editor. Categories are broad classes of data format, meaningful to end-users, such as "text", "graphics", or "table". Contrast with part kind.

part container
See container part.

part content
The portion of a part that describes its data. In programming terms, the part content is represented by the instance variables of the part object; it is the state of the part and is the portion of it that is stored persistently. To the user, there is no distinction between part and part content; the user considers both the part content alone, and the content plus its part editor, as a part. Contrast with part editorand part. See also intrinsic content and embedded content.

part editor
An application component that can display and change the data of a part. It is the executable code that provides the behavior for the part. Contrast with part content, part viewer.

part ID
An identifier that uniquely names a part within the context of a document. This ID represents a storage unit ID within a particular draft of a document.

part info
(1) Part-specific data, of any type or size, used by a part editor to identify what should be displayed in a particular frame or facet and how it should be displayed. (2) Information about a given part that can be seen by the user and is displayed in the Part Info dialog box.

part kind
A specific classification of the format of data handled by a part editor. A kind specifies the specific data format handled by, and possibly native to, a part editor. Kinds are meaningful to end-users and have designations such as such as "MyEditor 2.0" or "MyEditor 1.0". Contrast with part category.

part property
A user-accessible characteristic of a part or a portion of its content. The user can modify some properties, such as the name of a part; the user cannot modify some other properties, such as its part category. See also property.

part registry
The mechanism by which the document shell maps parts to part editors according to their part kind.

part table
A list of all the parts contained within a document and a list of associated data.

part viewer
An application component that can display, but not change, the data of a part. Contrast with part editor.

part window
A window that displays an embedded part by itself, for easier viewing or editing. Any part that is embedded in another part can be opened up into its own part window. The part window is separate from and has a slightly different appearance than the document window that displays the entire document in which the part is embedded.

part-wrapper object
A private OpenDoc object that is used to reference a part.

partition
(1) A fixed-size division of storage. (2) On an IBM personal computer fixed disk, one of four possible storage areas of variable size; one may be accessed by DOS, and each of the others may be assigned to another operating system.

Paste
A choice in the Edit pull-down that a user selects to move the contents of the clipboard into a preselected location. See also Copy and Cut.

Paste As
A choice in the Edit pull-down that a user selects to move the contents of the clipboard into a preselected location by means of a dialog box allowing the user to specify the format of the data. See also Copy and Cut.

path
The route used to locate files; the storage location of a file. A fully qualified path lists the drive identifier, directory name, subdirectory name (if any), and file name with the associated extension.

pel
(1) The smallest area of a display screen capable of being addressed and switched between visible and invisible states. Synonym for display point, pixel, and picture element. (2) Picture element.

persistence
The quality of an entity such as a part, link, or object, that allows it to span separate document launches and transport to different computers. For example, a part unloaded to persistent storage is typically written to a hard disk.

persistent object
An object whose instance data and state are preserved between system shutdown and system startup.

persistent reference
A number, stored somewhere within a storage unit, that refers to another storage unit in the same document. Persistent references permit complex runtime object relationships to be stored externally, and later reconstructed.

pick
To select part of a displayed object using the pointer.

pixel
(1) Synonym for pel. (2) Picture element.

platform
The operating system environment in which a program runs. For example, OpenDoc is implemented on the OS/2, Windows, AIX, and the Macintosh platforms.

platform-normal coordinates
The native coordinate system for a particular platform. OpenDoc performs all layout and drawing in platform-normal coordinates; to convert from another coordinate system to platform- normal coordinates requires application of a bias transform.

PM
Presentation Manager.

pointer
(1) The symbol displayed on the screen that is moved by a pointing device, such as a mouse. The pointer is used to point at items that users can select. Contrast with cursor. (2) A data element that indicates the location of another data element. (T)  

pointing device
In SAA Advanced Common User Access architecture, an instrument, such as a mouse, trackball, or joystick, used to move a pointer on the screen.

polygon
One or more closed figures that can be drawn filled, outlined, or filled and outlined.

polyline
A sequence of adjoining lines.

pop
To retrieve an item from a last-in-first-out stack of items. Contrast with push.

pop-up menu
A menu that lists the actions that a user can perform on an object. The contents of the pop-up menu can vary depending on the context, or state, of the object.

pop-up window
(1) A window that appears on top of another window in a dialog. Each pop-up window must be completed before returning to the underlying window. (2) In SAA Advanced Common User Access architecture, a movable window, fixed in size, in which a user provides information required by an application so that it can continue to process a user request.

port
(1) A connection between the CPU and main memory or a device (such as a terminal) for transferring data. (2) A socket on the back panel of a computer where you plug in a cable for connection to a network or a peripheral device.

position code
A parameter (to a storage unit's Focus method) with which you specify the desired property or value to access.

preferences
The mechanism through which the user assigns a part editor to a given part kind.

preferred editor
The part editor that last edited a part, or for whom the part's data was just translated. If a part's preferred editor is not present, OpenDoc attempts to bind the part to the user's default editor for kind or default editor for category.

preferred kind
The part kind that a part specifies as its highest-fidelity, preferred format for editing. It is the part kind stored as the first value in the contents property of the part's storage unit, unless the storage unit also contains a property of type kODPropPreferredKind specifying another value as the preferred kind.

presentation
A particular style of display for a part's content. For example, an outline or expanded style for text, or a wire-frame or solid style for graphic objects. A part can have multiple presentations, each with its own rendering, layout, and user-interface behavior. Contrast with view type.

presentation drivers
On the OS/2 platform, special purpose I/O routines that handle field device-independent I/O requests from the PM and its applications.

Presentation Manager (PM)
The interface of the OS/2 operating system that presents, in windows a graphics-based interface to applications and files installed and running under the OS/2 operating system.

presentation page
The coordinate space in which a picture is assembled for display.

presentation space (PS)
(1) On the OS/2 platform, contains the device-independent definition of a picture. (2) The display space on a display device.

print job
The result of sending a document or picture to be printed.

privilege level
A protection level imposed by the hardware architecture of the IBM personal computer. There are four privilege levels (number 0 through 3). Only certain types of programs are allowed to execute at each privilege level. See also IOPL code segment.

process
An instance of an executing application and the resources it is using.

program
A sequence of instructions that a computer can interpret and execute.

program details
On the OS/2 platform, information about a program that is specified in the Program Manager window and is used when the program is started.

program group
On the OS/2 platform, in the Presentation Manager, several programs that can be acted upon as a single entity.

program name
The full file specification of a program. Contrast with program title.

program title
On the OS/2 platform, the name of a program as it is listed in the Program Manager window. Contrast with program name.

promise
A specification of data to be transferred at a future time. If a data transfer involves a very large amount of data, the source part can choose to put out a promise instead of actually writing the data to a storage unit.

prompt
A displayed symbol or message that requests input from the user or gives operational information; for example, on the display screen of an IBM personal computer, the DOS A> prompt. The user must respond to the prompt in order to proceed.

Properties notebook
A control window that is used to display the properties for a part and to enable the user to change them.

property
In the OpenDoc storage subsystem, a component of a storage unit. A property defines a kind of information (such as "name" or "contents") and contains one or more data streams, called values, that consist of information of that kind. Properties in a stored part are accessible without the assistance of a part editor. Contrast with content property and Info property. See also display property, and user property,.

protocol
(1) A set of semantic and syntactic rules that determines the behavior of functional units in achieving communication. (I)   (2) The programming interface through which a specific task or set of related tasks is performed. The drag-and-drop protocol, for example, is the set of calls that a part editor makes (and responds to) in order to support the dragging of items into or out of its content.

proxy
A special type of content element in a containing part, a proxy is the site of an embedded part. A proxy holds a frame that has a reference to an embedded part or linked part.

proxy content
Data, associated with a single embedded frame written to the Clipboard (or drag-and-drop object or link-source object), that the frame's original containing part wanted associated with the frame, such as a drop shadow or other visual adornment. Proxy content is absent if intrinsic content as well as an embedded frame was written.

PS
Presentation space.

pull-down
(1) An action bar extension that displays a list of choices available for a selected action bar choice. After users select an action bar choice, the pull-down appears with the list of choices. Additional pop-up windows may appear from pull-down choices to further extend the actions available to users. (2) In SAA Common User Access architecture, pertaining to a choice in an action bar pull-down.

purge
To free noncritical memory, usually by writing or releasing cached data. In low-memory situations, OpenDoc can ask a part editor or other objects to purge memory.

push
To add an item to a last-in-first-out stack of items. Contrast with pop.

push button
A rectangle with text inside. Push buttons are used in windows for actions that occur immediately when the push button is selected.

Q

R

radio button
(1) A control window, shaped like a round button on the screen, that can be in a checked or unchecked state. It is used to select a single item from a list. Contrast with check box. (2) A circle with text beside it. Radio buttons are combined to show a user a fixed set of choices from which only one can be selected. The circle is partially filled when a choice is selected.

read-only file
A file that can be read from but not written to.

realize
To cause the system to ensure, wherever possible, that the physical color table of a device is set to the closest possible match in the logical color table.

reentrant
The attribute of a program or routine that allows the same copy of the program or routine to be used concurrently by two or more tasks.

reference
A pointer to (or other representation of) an object, used to gain access to the object when needed.

reference count
The number of references to an object. Objects that are reference-counted, such as windows and parts, cannot be deleted from memory unless their reference counts are zero.

reference counted object
An object that maintains a reference count. All classes descended from ODRefCntObject are reference-counted.

reference phrase
(1) A word or phrase that is emphasized in a device-dependent manner to inform the user that additional information for the word or phrase is available. (2) In hypertext, text that is highlighted and preceded by a single-character input field used to signify the existence of a hypertext link.

reference phrase help
On the OS/2 platform, highlighted words or phrases within help information that a user selects to get additional information.

refresh
To update a window, with changed information, to its current status.

region
A clipping boundary in device space.

register
A part of internal storage having a specified storage capacity and usually intended for a specific purpose. (T)  

registry
A dictionary that lists executable code modules and associated data by which they can be selected. Examples of a registry are part registry and scripting component registry.

release
To delete a reference to an object. For a reference-counted object, releasing it decrements its reference count.

remote file system
A file-system driver that gains access to a remote system without a block device driver.

remove
To delete an object (such as a frame) permanently from its draft, as well as from memory. Contrast with close.

resource
On the OS/2 platform and on the Windows platform, the means of providing extra information used in the definition of a window. A resource can contain definitions of fonts, templates, accelerators, and mnemonics; the definitions are held in a resource file.

resource file
On the OS/2 platform and on the Windows platform, a file containing information used in the definition of a window. Definitions can be of fonts, templates, accelerators, and mnemonics.

restore
To return a window to its original size or position following a sizing or moving action.

return code
(1) A value returned to a program to indicate the results of an operation requested by that program. (2) A code used to influence the execution of succeeding instructions.(A)

revert
To return a draft to the state it had just after its last save.

RGB
(1) Color coding in which the brightness of the additive primary colors of light, red, green, and blue, are specified as three distinct values of white light. (2) Pertaining to a color display that accepts signals representing red, green, and blue.

roman
Relating to a type style with upright characters.

root facet
The facet that displays the root frame in a document window.

root frame
The frame in which the root part of a document is displayed. The root frame shape is the same as the content area of the document window.

root part
The part that forms the base of a document and establishes its basic editing, embedding, and printing behavior. A document has only one root part, which can contain content elements and perhaps other, embedded parts. Any part can be a root part.

root segment
In a hierarchical database, the highest segment in the tree structure.

root storage unit
See content storage unit.

root window
See document window.

run time
(1) Any instant at which the execution of a particular computer program takes place. (T)   (2) The amount of time needed for the execution of a particular computer program. (T)   (3) The time during which an instruction in an instruction register is decoded and performed. Synonym for execution time.

S

SAA
See Systems Application Architecture.

save
To write all the data of all parts of a document (draft) to persistent storage.

SBCS
Single-byte character set.

scope
The range of a cloning operation, limiting which objects are to be copied. Scope is expressed in terms of a frame object or its storage unit.

screen
The physical surface of a display device upon which information is shown to a user.

screen device context
A logical description of a data destination that is a particular window on the screen. See also device context.

scripting language
A logic used for OpenDoc direct scripting as opposed to the logic used for programming languages such as C and C++.

scroll bar
a part of a window, associated with a scrollable area, that a user interacts with to see information that is not currently allows visible.

scrollable entry field
An entry field larger than the visible field.

scrollable selection field
A selection field that contains more choices than are visible.

scrolling
Moving a display image vertically or horizontally in a manner such that new data appears at one edge, as existing data disappears at the opposite edge.

secondary window
A window that contains information that is dependent on information in a primary window and is used to supplement the interaction in the primary window.

segment
See graphics segment.

segment attributes
Attributes that apply to the segment as an entity, as opposed to the individual primitives within the segment. For example, the visibility or detectability of a segment.

segment chain
All segments in a graphics presentation space that are defined with the 'chained' attribute. Synonym for picture chain.

segment priority
The order in which segments are drawn.

segment store
An area in a normal graphics presentation space where retained graphics segments are stored.

select
(1) To mark or choose an item. Note that select means to mark or type in a choice on the screen; enter means to send all selected choices to the computer for processing. (2) In OpenDoc, to designate as the focus of subsequent editing operations. If the user selects an embedded part, that part's frame border takes on an appearance that designates it as selected. The embedded part's container is activated.

selection cursor
A visual indication that a user has selected a choice. It is represented by outlining the choice with a dotted box. See also text cursor.

selection field
(1) On the OS/2 platform, a set of related choices. See also entry field. (2) An area of a panel that cannot be scrolled and contains a fixed number of choices.

selection focus
The location of editing activity. The part whose frame has the selection focus is the active part, and has the selection or insertion point. See also keystroke focus.

semaphore
An object used by applications for signalling purposes and for controlling access to serially reusable resources.

separator
A line or color boundary that provides a visual distinction between two adjacent areas.

sequence number
A number that defines the position of a frame in its frame group.

serial dialog box
See modal dialog box.

service
An OpenDoc component that, unlike a part editor, is not primarily concerned with editing and displaying parts. Instead, it provides a service to parts or documents, using the OpenDoc extension mechanism. Spelling checkers or database-access tools, for example, can be implemented as services.

session
(1) A routing mechanism for user interaction via the console; a complete environment that determines how an application runs and how users interact with the application. OS/2 can manage more than one session at a time, and more than one process can run in a session. Each session has its own set of environment variables that determine where OS/2 looks for dynamic-link libraries and other important files. (2) In the OS/2 operating system, one instance of a started program or command prompt. Each session is separate from all other sessions that might be running on the computer. The operating system is responsible for coordinating the resources that each session uses, such as computer memory, allocation of processor time, and windows on the screen. (3) A logical connection between two entities (such as an OS/2 program and a database server) that facilitates the transmission of information between the two entities. An application has the option to accept or reject a session request. Authentication of the requesting user may be required before a session can commence. See also authentication, message block, port.

session ID
A number that uniquely identifies a session.

Settings dialog box
A dialog box, accessible through the Part Info dialog box, that displays part-specific, custom Info properties.

settings extension
An OpenDoc extension class that you can use to implement a Properties notebook.

shadow
An object that refers to another object. A shadow is not a copy of another object, but is another representation of the object.

shape
A description of a geometric area of a drawing canvas.

shared data
Data that is used by two or more programs.

shared memory
In the OS/2 operating system, a segment that can be used by more than one program.

shared resource
A facility used by multiple parts. Examples of shared resources are the menu focus, selection focus, keystroke focus, and serial ports. See also arbitrator.

shear
In computer graphics, the forward or backward slant of a graphics symbol or string of such symbols relative to a line perpendicular to the baseline of the symbol.

shell
(1) A software interface between a user and the operating system of a computer. Shell programs interpret commands and user interactions on devices such as keyboards, pointing devices, and touch-sensitive screens, and communicate them to the operating system. (2) Software that allows a kernel program to run under different operating-system environments.

shell plug-in
A shared library that modifies or extends the functions of the document shell.

sibling
A frame or facet at the same level of embedding as another frame or facet within the same containing frame or facet. Sibling frames and facets are z-ordered to allow for overlapping.

sibling processes
Child processes that have the same parent process.

sibling windows
Child windows that have the same parent window.

signature
The aspect of a method defined by its return type and parameter list.

simple list
A list of like values; for example, a list of user names.

simple part
A part that cannot itself contain embedded parts. Contrast container part.

small icon view type
A view type in which a part is represented by a 16 by 16-pixel bitmap image. Other possible view types for displaying a part include large icon, thumbnail, and frame.

SOM
System Object Model.

SOM object
An object or class created according to the system object model.

source content
The content at the source of a link. It is copied into the link and then into the destination content.

source data
Statements in a scripting language that constitute an uncompiled script.

source file
A file that contains source statements for items such as high-level language programs and data description specifications.

source frame
(1) An embedded frame whose part that has been opened up into its own part window. (2) The frame to which other synchronized frames are attached.

source part
(1) In data transfer, the part that provides the data that is transferred. (2) For a link, the part that contains the original information that is copied and displayed at the destination of the link. Contrast with destination part.

source statement
A statement written in a programming language.

spin button
A type of entry field that shows a scrollable ring of choices from which a user can select a choice. After the last choice is displayed, the first choice is displayed again. A user can also type a choice from the scrollable ring into the entry field without interacting with the spin button.

split-frame view
A display technique for windows or frames, in which two or more facets of a frame display different scrolled portions of a part's content.

stack
A list constructed and maintained so that the next data element to be retrieved is the most recently stored. This method is characterized as last-in-first-out (LIFO).

static canvas
A drawing canvas that cannot be changed after it has been rendered, such as a printer page. Contrast with dynamic canvas.

static control
The means by which the application presents descriptive information (for example, headings and descriptors) to the user. The user cannot change this information.

static storage
(1) A read/write storage unit in which data is retained in the absence of control signals. (A)   Static storage may use dynamic addressing or sensing circuits. (2) Storage other than dynamic storage. (A)  

stationery
A part that opens by copying itself and opening the copy into a window, leaving the original stationery part unchanged.

storage system
The OpenDoc mechanism for providing persistent storage for documents and parts. The storage system object must provide unique identifiers for parts as well as cross-document links. It stores parts as a set of standard properties plus type-specific content data.

storage unit
In the OpenDoc storage subsystem, an object that represents the basic unit of persistent storage. Each storage unit has a list of properties, and each property contains one or more data streams called values.

storage-unit cursor
A preset storage unit/ property/value designation, created to allow swift focusing on frequently accessed data.

storage-unit ID
A unique identifier of a storage unit within a draft.

storage-unit view
A storage unit prefocused on a given property and value. A storage-unit view provides thread-safe access to a storage unit.

strong persistent reference
A persistent reference that, when the storage unit containing the reference is cloned, causes the referenced storage unit to be copied also. Contrast with weak persistent reference.

style
See window style.

subclass
An object class that inherits properties and element classes from another object class, its superclass. A subclass can also include properties and element classes that are not inherited from its superclass. Every object class, with the exception of cObject, is a subclass of another object class.

subdirectory
A file referred to in a root directory that contains the names of other files stored on the diskette or fixed disk.

subframe
A frame that is both an embedded frame in, and a display frame of, a part. A part can create an embedded frame, make it a subframe of its own frame, and then display itself in that subframe.

subsystem
A broad subdivision of the interface and capabilities of OpenDoc, involving one or more protocols (for example, OpenDoc subsystems include shell, storage, drawing, user events).

superclass
A class from which another class (its subclass) is derived. Also called ancestor, base class, or parent class. It is the object class from which a subclass inherits properties and elements.

swapping
(1) A process that interchanges the contents of an area of real storage with the contents of an area in auxiliary storage. (I)  (A)   (2) In a system with virtual storage, a paging technique that writes the active pages of a job to auxiliary storage and reads pages of another job from auxiliary storage into real storage. (3) The process of temporarily removing an active job from main storage, saving it on disk, and processing another job in the area of main storage formerly occupied by the first job.

switch
(1) To move the cursor from one point of interest to another; for example, to move from one screen or window to another or from a place within a displayed image to another place on the same displayed image. (2) In a computer program, a conditional instruction and an indicator to be interrogated by that instruction. (3) A device or programming technique for making a selection, for example, a toggle, a conditional jump.

switch list
See Task List.

symbols
On the OS/2 platform, in Information Presentation Facility, a document element used to produce characters that cannot be entered from the keyboard.

synchronized frames
Separate frames that display the same representation of the same part, and should therefore be updated together. In general, if an embedded part has two or more editable display frames of the same presentation, those frames (and all their embedded frames) should be synchronized.

synchronous
Pertaining to two or more processes that depend upon the occurrence of specific events such as common timing signals. (T)   See also asynchronous.

synthetic command ID
A command ID created by OpenDoc for a menu command that had not previously been registered with the menu bar object.

Systems Application Architecture.
A set of IBM software interfaces, conventions, and protocols that provide a framework for designing and developing applications that are consistent across systems.

system coercion dispatch table
See coercion handler dispatch table.

System Menu
On the OS/2 platform, the pull-down in the top left corner of a window that allows it to be moved and sized with the keyboard.

system object accessor dispatch table
See object accessor dispatch table.

System Object Model (SOM)
A mechanism for language-neutral, object-oriented programming.

system queue
The master queue for all pointer device or keyboard events.

system result handler
A result handler that is available to all applications that use the system. Contrast with application result handler.

system-defined messages
Messages that control the operations of applications and provides input an other information for applications to process.

Systems Application Architecture (SAA)
A set of IBM software interfaces, conventions, and protocols that provide a framework for designing and developing applications that are consistent across systems.

T

text
Characters or symbols.

thread
A unit of execution within a process. It uses the resources of the process.

thread-safe
Said of an activity, or access to data, that can be safely undertaken in a multitasking environment.

thumbnail view type
A view type in which a part is represented by a large (64-by-64 pixels) bitmap image that is typically a miniature representation of the layout of the part content. Other possible view types for displaying a part include large icon, small icon, and frame.

title bar
The area at the top of each window that contains the window title and system menu icon. When appropriate, it also contains the minimize, maximize, and restore icons. Contrast with panel title.

TLB
Translation lookaside buffer.

token
A short, codified representation of a string. The session object creates tokens for ISO strings.

token disposal function
An object callback function that disposes of a token.

transform
(1) The action of modifying a picture by scaling, shearing, reflecting, rotating, or translating. (2) The object that performs or defines such a modification; also referred to as a transformation.

translation
The conversion of one type of data to another type of data. Specifically, the conversion of data of one part kind to data of another part kind. Note that translation can involve loss of fidelity.

Translation lookaside buffer (TLB)
A hardware-based address caching mechanism for paging information.

Tree
On the OS/2 platform, in the Presentation Manager, the window in the File Manager that shows the organization of drives and directories.

U

undo
To rescind a command, negating its results. OpenDoc provides the ability to undo events by utilizing a command history.

update ID
(1) In OpenDoc, a number used to identify a particular instance of Clipboard contents. (2) A number used to identify a particular instance of link source data.

used shape
A shape that describes the portion of a frame that a part actually uses for drawing; that is, the part of the frame that the containing part should not draw over.

user event
A message, sent to a part by the dispatcher, that pertains only to the state of the part's graphical user interface, not directly to its contents. User events include mouse clicks and keystrokes, and they deliver information about, among other things, window locations and scroll bar positions.

user interface
Hardware, software, or both that allows a user to interact with and perform operations on a system, program, or device.

user-interface part
A part without content elements, representing a unit of a document's user interface. Buttons and dialog boxes, for example, can be user-interface parts.

user property
One of a set of user-accessible characteristics of a part or its frame. The user can modify some user properties, such as the name of a part; the user cannot modify some other user properties, such as part category. Each user property defined by OpenDoc is stored as a distinct property in the storage unit of the part or its frame.

utility program
(1) A computer program in general support of computer processes; for example, a diagnostic program, a trace program, a sort program. (T)   (2) A program designed to perform an everyday task such as copying data from one storage device to another. (A)  

V

validate
To mark a portion of a canvas (or facet, or frame) as no longer in need of redrawing. Contrast with invalidate.

value
In the OpenDoc storage subsystem, a data stream associated with a property in a storage unit. Each property has a set of values, and there can be only one value of a given data type for each property.

value set control
A visual component that enables a user to select one choice from a group of mutually exclusive choices.

view
A way of looking at an object's information.

view type
The basic visual representation of a part. Supported view types include frame, icon, small icon, and thumbnail.

viewer
See part viewer.

viewing pipeline
The series of transformations applied to a graphic object to map the object to the device on which it is to be presented.

viewing window
A clipping boundary that defines the visible part of model space.

VIO
Video Input/Output.

visible region
A window's presentation space, clipped to the boundary of the window and the boundaries of any overlying window.

W

weak persistent reference
A persistent reference that, when the storage unit containing the reference is cloned, is ignored; the referenced storage unit is not copied. Contrast with strong persistent reference.

wildcard character
Synonymous with global file-name character.

window
(1) A portion of a display surface in which display images pertaining to a particular application can be presented. Different applications can be displayed simultaneously in different windows. (A)   (2) An area of the screen with visible boundaries within which information is displayed. A window can be smaller than or the same size as the screen. Windows can appear to overlap on the screen. (3) A division of a screen in which one of several programs being executed concurrently can display information.

window canvas
The canvas attached to the root facet of a window. Every window has a window canvas.

window class
The grouping of windows whose processing needs conform to the services provided by one window procedure.

window-content transform
The composite transform that converts from a part's content coordinates to its window coordinates.

window coordinate space
The coordinate space of the window in which a part's content is drawn. It may or may not be equal to the canvas coordinate space.

window coordinates
A set of coordinates by which a window position or size is defined; measured in device units, or pels.

window-frame transform
The composite transform that converts from a part's frame coordinates to its window coordinates.

window handle
Unique identifier of a window, generated by the operating system when the window is created, and used by applications to direct messages to the window.

window procedure
Code that is activated in response to a message. The procedure controls the appearance and behavior of its associated windows.

window rectangle
The means by which the size and position of a window is described in relation to the desktop window.

window resource
On the OS/2 platform and the Windows platform a read-only data segment stored in the .EXE file of an application or the .DLL file of a dynamic link library.

window state
An object that lists the set of windows that are open at a given time. Part editors can alter the window state, and the window state can be persistently stored.

window style
The set of properties that influence how events related to a particular window will be processed.

Workplace Shell
The OS/2 object-oriented, graphical user interface.

world-coordinate space
Coordinate space in which graphics are defined before transformations are applied.

wrapper
An object (or class) that exists to provide an object-oriented interface to a non-object- oriented or system-specific structure. The OpenDoc class ODWindow, for example, is a wrapper for a system-specific window structure.

WYSIWYG
What-You-See-Is-What-You-Get. A capability of a text editor to continually display pages exactly as they will be printed.

Z

z-order
The order in which sibling windows are presented. The topmost sibling window obscures any portion of the siblings that it overlaps; the same effect occurs down through the order of lower sibling windows.

z-ordering
The front-to-back ordering of sibling frames used to determine clipping and event handling when frames overlap.

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