Glossary(IM: O)

Inside Macintosh: Overview /

Glossary
A5 world An area of memory in an application's partition that contains the QuickDraw global variables, the application global variables, the application parameters, and the jump table--all of which are accessed through the A5 register.
action procedure A procedure that performs an action in response to the user holding the mouse button down while the cursor is in a control.
activate event An event indicating that a window is becoming active or inactive. Each activate event specifies the window to be changed and the direction of the change (that is, whether it's becoming active or becoming inactive).
active application The application currently interacting with the user. Its icon appears on the right side of the menu bar. See also current process, foreground process.
active control A control in which the Control Manager responds to a user's mouse actions by providing visual feedback.
active window The frontmost window on the desktop, the one in which the user is currently working. The active window is designated by racing stripes in the title bar, active controls, and highlighted selections.
address A number that specifies the location of a byte in memory.
alert An alert sound, an alert box, or both. Alerts warn the user of an unusual or potentially undesirable situation occurring within an application. See also alert box.
alert box A window that an application displays on the screen to warn the user or to report an error to the user. An alert box typically consists of text describing the situation and buttons that require the user to acknowledge or rectify the problem. An alert box may or may not be accompanied by an alert sound.
alert resource A resource (of type 'ALRT') that specifies alert sounds, a display rectangle, and an item list for an alert box.
alert sound An audible signal from the Macintosh speaker that warns the user of an unusual or potentially undesirable situation occurring within an application. An alert sound may or may not be accompanied by an alert box.
Alias Manager The part of the Operating System that helps you to locate specified files, directories, or volumes at a later time. The Alias Manager creates and resolves alias records.
alias record A data structure created by the Alias Manager to identify a file, directory, or volume.
allocate To assign an area of memory for use.
Apple event A high-level event whose structure and interpretation are determined by the Apple Event Interprocess Messaging Protocol.
Apple Event Manager The part of the Macintosh system software that allows applications to send and respond to Apple events.
Apple Menu Items folder A directory located in the System Folder for storing desk accessories, applications, folders, and aliases that the user wants to display in and access from the Apple menu.
application global variables A set of variables stored in the application's A5 world that are global to the application.
application heap An area of memory in the application heap zone in which memory is dynamically allocated and released on demand. The heap contains the application's 'CODE' segment 1, data structures, resource map, and other code segments as needed.
application parameters Thirty-two bytes of memory in the application partition that are reserved for system use. The first long word is the address of the first QuickDraw global variable.
application partition A partition of memory reserved for use by an application. The application partition consists of free space, the application heap, the application's stack, and the application's A5 world.
auto-key event An event indicating that a key is still down after a certain amount of time has elapsed.
background-only application An application that does not have a user interface.
background process A process that isn't currently interacting with the user. Compare foreground process.
bitmap A set of bits that represents the positions and states of a corresponding set of items, such as pixels.
block See memory block.
button A control that appears on the screen as a rounded rectangle with a title centered inside. When the user clicks a button, the application performs the action described by the button's title. Button actions are usually performed instantaneously. Examples include completing operations defined by a dialog box and acknowledging an error message in an alert box.
checkbox A control that appears onscreen as a small square with an accompanying title. A checkbox displays one of two settings: on (indicated by an X inside the box) or off. When the user clicks a checkbox, the application reverses its setting. See also radio button.
close box The small white box on the left side of the title bar of an active window. Clicking it closes the window.
Command-key equivalent Refers specifically to a keyboard equivalent that the user invokes by holding down the Command key and pressing another key (other than a modifier key) at the same time.
Communications Toolbox A part of the Macintosh system software that you can use to provide your application with basic networking and communications services.
compact See heap compaction.
compatibility The ability of an application to execute properly in different operating environments.
content region The part of a window in which the contents of a document, the size box, and the window controls (including the scroll bars) are displayed.
context The information about a process maintained by the Process Manager. This information includes the current state of the process, the address and size of its partition, its type, its creator, a copy of its low-memory globals, information about its 'SIZE' resource, and a process serial number.
context switch A major or minor switch.
control An onscreen object that the user can manipulate with the mouse. By manipulating a control, the user can take an immediate action or change a setting to modify a future action.
control definition function A function that defines the appearance and behavior of a control. A control definition function, for example, draws the control. See also standard control definition functions.
control definition ID A number passed to control-creation routines to indicate the type of control. It consists of the control definition function's resource ID and a variation code.
control list A series of entries pointing to the descriptions of the controls associated with the window.
Control Manager A collection of routines that applications use to create and manipulate controls, especially those in windows.
control record A data structure of type ControlRecord, which the Control Manager uses to store all the information it needs for its operations on a control.
cooperative multitasking environment A multitasking environment in which applications explicitly cooperate to share the available system resources. See also multitasking environment.
current directory The directory whose contents are listed in the dialog box displayed by the Standard File Package. See also default directory.
current menu list A data structure that contains handles to the menu records of all menus in the current menu bar and the menu records of any submenus or pop-up menus that an application inserts into the list.
current process The process that is currently executing and whose A5 world is valid; this process can be in the background or the foreground.
cursor Any 256-bit image, defined by a 16-by-16-bit square. The mouse driver displays the current cursor and maps the movement of the mouse to relative locations on the screen as the user moves the mouse.
dangling pointer A copy of a master pointer that no longer points to the correct memory address.
data fork The part of a file that contains data accessed using the File Manager. The data usually corresponds to data entered by the user; the application creating a file can store and interpret the data in the data fork in whatever manner is appropriate.
default button In an alert box or a dialog box, the button whose action is invoked when the user presses the Return key or the Enter key. The Dialog Manager automatically draws a bold outline around the default button in alert boxes; applications should draw a bold outline around the default button in dialog boxes. The default button should invoke the preferred action which, whenever possible, should be a "safe" action--that is, one that doesn't cause loss of data.
default directory The directory used in File Manager routines whenever you don't explicitly specify some directory. See also current directory.
default volume The volume that contains the default directory.
desk accessory A "mini-application" that is available from the Apple menu regardless of which application you're using--for example, the Calculator, Note Pad, Alarm Clock, Puzzle, Scrapbook, Key Caps, and Chooser.
desktop The working environment displayed on the Macintosh computer: the gray background area on the screen.
Device Manager The part of the Macintosh Operating System that supports device I/O.
dialog box A window that's used for some special or limited purpose, such as to solicit information from the user before the application carries out the user's command. See also modal dialog box, modeless dialog box, and movable modal dialog box.
Dialog Manager The part of the Macintosh Toolbox that provides routines for creating and manipulating alerts and dialog boxes.
dialog record A data structure of type DialogRecord that the Dialog Manager uses to create dialog boxes and alerts.
dialog resource A resource (of type 'DLOG') that specifies the window type, display rectangle, and item list for a dialog box.
directory A subdivision of a volume, available in the hierarchical file system. A directory can contain files and other directories (known as subdirectories).
disabled item In an alert box or a dialog box, an item for which the Dialog Manager does not report user events. An example of a disabled item is static text, which typically does not respond to clicks.
disk A physical medium capable of storing information.
disk initialization The process of making a disk usable by the Macintosh Operating System.
Disk Initialization Manager The part of the Macintosh Operating System that manages the process of initializing disks.
disk-inserted event An event indicating that a disk has been inserted into a disk drive.
display rectangle A rectangle that defines the size and location of an item in an alert box or a dialog box. The display rectangle is specified in an item list and uses coordinates local to the alert box or a dialog box.
disposed handle A handle whose associated relocatable block has been disposed of.
divider A gray line used in menus to separate groups of menu items.
document (1) A file that a user can create and edit. A document is usually associated with a single application, which the user expects to be able to open by double-clicking the document's icon in the Finder. (2) Any collection of information that is displayed in a document window.
document record An application-defined data structure that contains information about the window, any controls in the window (such as scroll bars), and the file (if any) whose contents are displayed in the window.
document window A window in which the user enters text, draws graphics, or otherwise enters or manipulates data.
double indirection The means by which the Memory Manager or an application accesses the data associated with a handle variable.
drag region The area occupied by a window's title bar, except for the close box and zoom box. The user can move a window on the desktop by dragging the drag region.
edition The data written to an edition container by a publisher. A publisher writes data to an edition whenever a user saves a document that contains a publisher, and subscribers in other documents may read the data from the edition whenever it is updated.
Edition Manager The part of the Macintosh system software that allows applications to automate copy and paste operations between applications, so that data can be shared dynamically.
empty handle A handle whose master pointer has the value NIL (possibly indicating that the underlying relocatable block has been purged).
enabled item In an alert box or a dialog box, an item for which the Dialog Manager reports user events. For example, the Dialog Manager reports clicks in an enabled OK button.
event The means by which the Event Manager communicates information about user actions, changes in the processing status of the application, and other occurrences that require a response from the application.
event-driven programming A way of structuring an application so that it is guided by events reporting a user's actions and other occurrences in the computer.
event filter function An application-defined routine that supplements the Dialog Manager's ability to handle events--for example, an event filter function can test for disk-inserted events and can allow background applications to receive update events.
event loop A section of code that repetitively retrieves events from the Event Manager and dispatches to the appropriate event-handler.
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 priority The order in which an event of a particular type is returned to an application.
event record A data structure of type EventRecord that your application uses when retrieving information about an event. The Event Manager returns, in an event record, information about what type of event occurred (a mouse click or keypress, for example) and additional information associated with the event.
extension See system extension.
Extensions folder A directory located in the System Folder for storing system extension files such as printer and network drivers and files of types 'INIT', 'scri', and 'appe'.
file A named, ordered sequence of bytes stored on a Macintosh volume, divided into a data fork and a resource fork.
file fork One of the two parts of a file. See also data fork and resource fork.
File Manager The part of the Macintosh Operating System that manages the organization, reading, and writing of data located on physical data storage devices such as disk drives.
file system A method of organizing files and directories on a volume.
Finder An application that works with the system software to keep track of files and manage the user's desktop display.
Finder Interface A set of routines, data structures, and resources that you can use to coordinate your application with the Finder.
folder A directory. See directory.
Fonts folder A directory located in the System Folder for storing fonts.
foreground process The process currently interacting with the user; it appears to the user as the active application. The foreground process displays its menu bar, and its windows are in front of the windows of other applications. Compare background process.
fork See file fork.
fragmentation See heap fragmentation.
frame The part of a window drawn automatically by the Window Manager, namely, the title bar, including the close box and zoom box, and the window's outline.
free block A memory block containing space available for allocation.
global coordinate system The coordinate system that represents all potential QuickDraw drawing space. The origin of the global coordinate system--that is, the point (0,0)--is at the upper-left corner of the main screen. Compare local coordinate system.
global variables See application global variables, system global variables, and QuickDraw global variables.
glue routine A routine, usually written in assembly-language, that allows a high-level language to call a low-level routine. Also, any short special-purpose assembly-language routine.
graphics port A complete, individual drawing environment with an independent coordinate system. Each window is drawn in a graphics port.
handle A variable containing the address of a master pointer, used to access a relocatable block. See also pointer.
heap An area of memory in which space is dynamically allocated and released on demand, using the Memory Manager. See also application heap.
heap compaction The process of moving allocated blocks within a heap to collect the free space into a single block.
heap fragmentation The state of a heap when the available free space is scattered throughout the heap in numerous unused blocks.
help balloon A rounded-rectangle window that contains explanatory information for the user. With tips pointing at the objects they annotate, help balloons look like bubbles used for dialog in comic strips. Help balloons are turned on by the user from the Help menu; when Balloon Help assistance is on, a help balloon appears whenever the user moves the cursor over an area that is associated with it.
hierarchical menu A menu to which a submenu is attached.
high-level event An event sent from one application to another requesting transfer of information or performance of some action.
high-level event queue A separate queue that the Event Manager maintains to store high-level events transmitted to an application. The Event Manager maintains a high-level event queue for each open application capable of receiving high-level events.
icon An image that represents an object, a concept, or a message.
inactive control A control that has no meaning or effect in the current context--for example, the scroll bars in an empty window. The Control Manager dims inactive controls or otherwise visually indicates their inactive state.
inactive window A window in which the user is not working.
interapplication communications (IAC) architecture A standard and extensible mechanism for communicating among Macintosh applications.
item list A resource (of type 'DITL') that specifies the items--such as buttons and static text--to display in an alert box or a dialog box.
item number An integer that identifies an item in either a menu or dialog box. Menu items are assigned item numbers starting with 1 for the first menu item in the menu, 2 for the second menu item in the menu, and so on, up to the number of the last menu item in the menu. Dialog items are assigned numbers that correspond to the item's position in its item list. For example, the first item listed in a dialog item list is item number 1.
jump table An area of memory in an application's A5 world that contains one entry for every externally referenced routine in every code segment of the application. The jump table is the means by which the loading and unloading of segments is implemented.
keyboard equivalent A keyboard combination of one or more modifier keys and another key that invokes a corresponding menu command when pressed by the user. See also Command-key equivalent.
key-down event An event indicating that the user pressed a key on the keyboard.
key-up event An event indicating that the user released a key on the keyboard.
local coordinate system The coordinate system defined by the port rectangle of a graphics port. When the window manager creates a window, it places the origin of the local coordinate system at the upper-left corner of the window's port rectangle. Compare global coordinate system.
localization The process of adapting an application to a specific language, culture, and region.
lock To temporarily prevent a relocatable block from being moved during heap compaction.
low-level events The type of event returned by the Event Manager to report very low level hardware and software occurrences. Low-level events report actions by the user, changes in windows on the screen, and that the Event Manager has no other events to report. Compare high-level events, operating-system events.
low-memory system global variables See system global variables.
Macintosh Operating System The part of Macintosh system software that manages basic low-level operations such as file reading and writing, memory allocation and deallocation, process execution, and interrupt handling.
Macintosh script management system The Script Manager, script-aware parts of other text managers, the WorldScript extensions, and one or more script systems.
Macintosh system software A collection of routines that you can use to simplify your development of Macintosh applications. See also Macintosh Toolbox and Macintosh Operating System.
Macintosh Toolbox The part of the Macintosh system software that allows you to implement the standard Macintosh user interface in your application.
Macintosh User Interface Toolbox See Macintosh Toolbox.
major switch A change of the foreground process. The Process Manager switches the context of the foreground process with the context of a background process (including the A5 worlds and low-memory globals) and brings the background process to the front, sending the previous foreground process to the background. See also context, minor switch.
manager A part of the Macintosh system software.
master pointer A pointer to a relocatable block, maintained by the Memory Manager and updated whenever the block is moved, purged, or reallocated. All handles to a relocatable block refer to it by double indirection through the master pointer.
master pointer block A nonrelocatable block of memory that contains master pointers. A master pointer block in your application heap contains 64 master pointers, and a master pointer block in the system heap contains 32 master pointers.
memory block An area of contiguous memory within a heap.
Memory Manager The part of the Operating System that dynamically allocates and releases memory space in the heap.
menu A user interface element you can use in your application to allow the user to view or choose an item from a list of choices and commands that your application provides. See also hierarchical menu, pull-down menu, pop-up menu, and submenu.
menu bar A white rectangle that is tall enough to display menu titles in the height of the system font and system font size, and with a black lower border that is one pixel tall. The menu bar extends across the top of the startup screen and contains the title of each available pull-down menu.
menu bar definition function A function that draws the menu bar and performs most of the drawing activities related to the display of menus when the user moves the cursor between menus. This function, in conjunction with the menu definition procedure, defines the general appearance and behavior of menus.
menu bar resource A resource (of type 'MBAR') that specifies the order and resource ID of each menu in a menu bar.
menu definition procedure A procedure that performs all the drawing of menu items within a specific menu. This procedure, in conjunction with the menu bar definition function, defines the general appearance and behavior of menus.
menu ID A number that you assign to a menu in your application. Each menu in your application must have a unique menu ID.
menu item In a menu, a rectangle with text and other characteristics identifying a command that the user can choose.
menu list A data structure that contains handles to the menu records of one or more menus (although a menu list can be empty). Compare current menu list.
Menu Manager The collection of routines that an application can use to create, display, and manage its menus.
menu record A data structure of type MenuInfo that the Menu Manager uses to maintain information about a menu.
menu resource A resource (of type 'MENU') that specifies the menu title and the individual characteristics of items in a menu.
menu title The word or icon in the menu bar or in a window that shows the location of a menu.
minimum partition size The actual partition size limit below which an application cannot run.
minor switch A change in the context of a process. The Process Manager switches the context of a process to give time to a background process without bringing the background process to the front. See also context, major switch.
modal dialog box A dialog box that puts the user in the state or "mode" of being able to work only inside the dialog box. A modal dialog box resembles an alert box. The user cannot move a modal dialog box and can dismiss it only by clicking its buttons. See also modeless dialog box and movable modal dialog box.
modal dialog filter function An application-defined function that filters events passed from the Event Manager to your application when one of its modal dialog boxes is being displayed.
modeless dialog box A dialog box that looks like a document window without a size box or scroll bars. The user can move a modeless dialog box, make it inactive and active again, and close it like any document window. See also modal dialog box and movable modal dialog box.
modifier keys The Shift, Option, Command, Control, and Caps Lock keys.
mouse-down event An event indicating that the user pressed the mouse button.
mouse location The location of the cursor at the time an event occurred.
mouse-moved event An event indicating that the cursor is outside of a specified region.
mouse-up event An event indicating that the user released the mouse button.
movable modal dialog box A modal dialog box that has a title bar (with no close box) by which the user can drag the dialog box. See also dialog box, modal dialog box, and modeless dialog box.
multitasking environment An environment in which several independent applications or other processes can be open at once. See also cooperative multitasking environment.
nonrelocatable block A block whose location in the heap is fixed. This block can't be moved during heap compaction or other memory operations.
null event An event indicating that no events of the requested types exist in the application's event stream.
open application An application that is loaded into memory.
Operating System See Macintosh Operating System.
operating-system event An event returned by the Event Manager to communicate information about changes in the operating status of applications (suspend and resume events) and to report that the user has moved the mouse outside of an area specified by the application (mouse-moved events). Compare low-level events, high-level events.
Operating System Event Manager The collection of low-level routines that manage the Operating System event queue.
Operating System event queue A queue that the Operating System Event Manager creates and maintains. The Operating System Event Manager detects and reports low-level hardware-related events such as mouse clicks, keypresses, and disk insertions and places these events in the Operating System event queue.
package A collection of system software routines that's stored as a resource and brought into memory only when needed. See also manager.
part code An integer between 1 and 253 that stands for a particular part of a control. The FindControl and TrackControl functions return a part code to indicate the location of the cursor when the user presses the mouse button.
partition A contiguous block of memory reserved for use by the Operating System or by an application. See also application partition and system partition.
patch To replace a piece of ROM code with other RAM-based code (by storing a new entry into the trap dispatch table). Also, a resource that contains the new code.
pixel The smallest dot you can draw on the screen.
point The intersection of a horizontal grid line and a vertical grid line in the coordinate plane. Defined by the Point data type.
pointer A variable containing the address of a byte in memory. See also handle.
pop-up menu A menu that appears elsewhere than the menu bar. The Control Manager provides a control definition function for applications to use when implementing pop-up menus.
PPC Toolbox See Program-to-Program Communications (PPC) Toolbox.
preferences file A file, usually located in the Preferences folder, that records a user's configuration settings for an application.
Preferences folder A directory located in the System Folder for holding files that record users' configuration settings for applications on a particular Macintosh computer.
preferred partition size The partition size at which an application can run most effectively. The Operating System attempts to secure this partition size upon launch of the application.
process An open application, or, in some cases, an open desk accessory. (Only desk accessories that are not opened in the context of another application are considered processes.)
Process Manager The part of the Macintosh Operating System that provides a cooperative multitasking environment by controlling access to shared resources and managing the scheduling, execution, and termination of applications.
process serial number A number assigned by the Process Manager to identify a particular instance of an application during a single boot of the local machine.
Program-to-Program Communications (PPC) Toolbox The part of the Macintosh system software that allows applications to exchange blocks of data with each other by reading and writing low-level message blocks.
pull-down menu A menu that is identified by a menu title (a word or an icon) in the menu bar.
purge To remove a relocatable block from the heap, leaving its master pointer allocated but set to NIL.
purgeable block A relocatable block that can be purged from the heap.
QuickDraw The part of the Macintosh Toolbox that performs all graphics operations on the Macintosh screen.
QuickDraw global variables A set of variables stored in the application's A5 world that contain information used by QuickDraw.
QuickTime A collection of managers and other system software components that allow your application to control time-based data.
radio button A control that appears on screen as a small circle. A radio button displays one of two settings: on (indicated by a black dot inside the circle) or off. A radio button is always a part of a group of related radio buttons in which only one button can be on at a time. When the user clicks an unmarked radio button, the application turns that button on and turns the other buttons in its group off.
RAM See random-access memory.
RAM disk A portion of the available RAM reserved for use as a temporary storage device. A user can configure a RAM disk or disable it altogether using controls in the Memory control panel.
random-access memory (RAM) Memory whose contents can be changed. The RAM in a Macintosh computer contains exception vectors, buffers used by hardware devices, the system and application heaps, the stack, and other information used by applications.
read-only memory (ROM) Memory whose contents are permanent. The ROM in a Macintosh computer contains routines for the Toolbox and the Operating System, and the various system traps.
reallocate To allocate new space in the heap for a purged block and to update the block's master pointer to point to its new location.
rectangle The area picked by intersecting the grid lines of any two points in the coordinate plane.
release (1) To free an allocated area of memory, making it available for reuse. (2) To allow a previously held range of pages to be movable in physical memory.
relocatable block A block that can be moved within the heap during compaction.
resource Any data stored according to a defined structure in a resource fork of a file; the data in a resource is interpreted according to its resource type.
resource file The resource fork of a file.
resource fork The part of a file that contains the files' resources. A resource fork consists of a resource map and resources.
resource ID A number that identifies a specific resource of a given resource type.
resource map In a resource file, data that is read into memory when the file is opened and that, given a resource specification, leads to the corresponding resource data.
resource name A string that, together with the resource type, identifies a resource in a resource file. A resource may or may not have a name.
resource specification A resource type and either a resource ID or a resource name.
resource type A sequence of four characters that uniquely identifies a specific type of resource.
resume event An event indicating that an application has been switched back into the foreground and can resume interacting with the user. See also suspend event.
return receipt A high-level event that indicates whether the other application accepted the high-level event sent to it by your application.
ROM See read-only memory.
script A writing system for a human language.
Script Manager The part of the Macintosh system software that manages script systems.
script system A collection of software facilities that provides for the representation of a specific writing system. It consists of keyboard resources, a set of international resources, one or more fonts, and possibly a script system extension.
segment One of several logical divisions of the code of an application. Not all segments need to be in memory at the same time.
Segment Manager The part of the Macintosh Operating System that loads and unloads your application's code segments into and out of memory.
signature A resource whose type is defined by a four-character sequence that uniquely identifies an application to the Finder. A signature is located in an application's resource fork.
size box A box in the lower-right corner of windows that can be resized. Dragging the size box resizes the window.
size region The area occupied by a window's size box. See size box.
size resource A resource (of type 'SIZE') that specifies the operating characteristics, minimum partition size, and preferred partition size of an application.
stack An area of memory in the application partition that is used to store temporary variables.
stack frame The area of the stack used by a routine for its parameters, return address, local variables, and temporary storage.
Standard File Package The part of system software that allows you to present the standard user interface when a file is to be saved or opened.
stationery pad A document that a user creates to serve as a template for other documents. The Finder tags a document as a stationery pad by setting the isStationery bit in the Finder flags field of the file's file information record. An application that is asked to open a stationery pad should copy the template's contents into a new document and open the document in an untitled window.
submenu A menu that is attached to another menu.
suspend event An event indicating that the execution of your application is about to be suspended as the result of either a major or minor switch. The application is suspended at the application's next call to WaitNextEvent or EventAvail. See also resume event.
switch See major switch and minor switch.
system extension A file of type 'INIT' that contains executable code. System extensions are loaded into memory at system startup time.
System file A file, located in the System Folder, that contains the basic system software plus some system resources, such as sound and keyboard resources.The System file behaves like a folder in this regard: although it looks like a suitcase icon, double-clicking it opens a window that reveals movable resource files (such as sounds, keyboard layouts, and script system resource collections) stored in the System file.
System Folder A directory containing the software that Macintosh computers use to start up. The System Folder includes a set of folders for storing related files, such as preferences files that an application might need when starting up.
system global variables A collection of global variables stored in the system partition.
system heap An area of memory in the system partition reserved for use by the Operating System.
system partition A partition of memory reserved for use by the Operating System.
system resource A resource in the system resource file.
terminate To end the execution of a process. A process can terminate by crashing, by quitting, or by being killed by some other process.
Text Services Manager The part of the system software that manages the interactions between applications that request text services and text service components that provide them.
Time Manager The part of the Macintosh Operating System that lets you schedule the execution of a routine after a certain time has elapsed.
title bar The bar at the top of a window that displays the window name, contains the close and zoom boxes, and indicates whether the window is active.
Toolbox Event Manager See Event Manager.
transfer mode A specification of which Boolean operation QuickDraw should perform when drawing or when transferring a bit image from one bitmap to another.
unlock To allow a relocatable block to be moved during heap compaction.
unpurgeable block A relocatable block that can't be purged from the heap.
update event An event indicating that the contents of a window need updating.
update region A region maintained by the Window Manager that includes the parts of a window's content region that need updating. The Event Manager generates update events as necessary, based on the contents of the update region, telling your application to update a window.
user items Items in a dialog box that are managed largely by an application, not by the Dialog Manager. These items are designated by the constant userItem.
user state The size and location that the user has established for a window.
Vertical Retrace Manager The part of the Operating System that schedules and executes tasks during a vertical retrace interrupt.
visible region The part of a window's graphics port that's actually visible on the screen--that is, the part that's not covered by other windows.
volume A portion of a storage device that is formatted to contain files.
window An area on the screen that displays information, including user documents as well as communications such as alert boxes and dialog boxes. The user can open or close a window; move it around on the desktop; and sometimes change its size, scroll through it, and edit its contents.
window definition function A function that defines the general appearance and behavior of a window. The Window Manager calls the window definition function to draw the window's frame, determine what region of the window the cursor is in, draw the window's size box, draw the window's zoom box, move and resize the window, and calculate the window's structure and content regions.
window definition ID An integer that specifies the resource ID of a window definition function in the upper 12 bits and an optional variation code in the lower 4 bits. When creating a new window, your application supplies a window definition ID either as a field in the 'WIND' resource or as a parameter to the NewWindow or NewCWindow function.
window list A list maintained by the Window Manager of all windows on the desktop. The frontmost window is first in the window list, and the remaining windows appear in the order in which they are layered on the desktop.
Window Manager The part of the Macintosh Toolbox that provides routines for creating and manipulating windows.
Window Manager port A graphics port that represents the desktop area on the main monitor--that is, a rounded-corner rectangle that occupies all of the main monitor except for the area occupied by the title bar.
window record A data structure of type WindowRecord (or CWindowRecord) in which the Window Manager stores a window's characteristics, including the window's graphics port, title, visibility status, and control list.
window type A collection of characteristics--such as the shape of the window's frame and the features of its title bar--that describe a window.
zoom box A box in the right side of a window's title bar that the user can click to alternate between two different window sizes (the user state and the standard state).