t

T

Date & Time control panel: A control panel that allows the user to set the current date and time and to specify formatting preferences for both.

Table of Contents Register (RTOC): A processor register that points to the table of contents of the fragment containing the code currently being executed. On the PowerPC processor, the general-purpose register 2 is dedicated to serve as the RTOC.

table of contents (TOC): An area of static data in a fragment that contains a pointer to each routine or data item that is imported from some other fragment, as well as pointers to the fragment's own static data.

tab control: A control that appears as a row of folder tabs on top of a pane. It allows multiple panes to appear in the same window.

tag

See: attribute value tag

tag byte: The first byte of a block header.

tag list: A property of many QuickDraw GX objects. It is an array of references to tag objects associated with the object.

tag list position: The position of an item in a list of items with the same collection tag.

tag object: A QuickDraw GX object whose purpose, structure, and content are entirely controlled by the application creating it. Tag objects exist to allow custom information and behavior to be attached to standard QuickDraw GX objects. Tag objects are classified by tag type; objects reference their tag objects through a tag list.

tag type: A longword data type (equivalent to OSType) that can be represented by four 1-byte characters, such as 'appl'. Tag types specify the formats of tag objects, such as synonyms.

tail patch: A patch that invokes the next patch in the patch daisy chain as a subroutine, guaranteeing that the tail patch regains control after the execution of all subsequent patches

See also: head patch

Talk: An ADB command that requests a specific device to send the contents of a specific device register across the bus

See also: Flush, Listen, SendReset

tangents array: An array that determines the scaling and orientation of the characters or glyphs in the shape. It contains one entry for each character or glyph in the shape.

target

See: alias target

target address: An application signature, a process serial number, a session ID, a target ID record, or some other application-defined type that identifies the target of an Apple event.

target application: The application addressed to rec eive an Apple event. Typically, an Apple event client sends an Apple event requesting a service from a server application; in this case, the server is the target application of the Apple event. The server application may return a different Apple event as a reply; in this case, the client is the target of the reply Apple event.

target device: A SCSI device that responds to commands from an initiator.

target format: A value that specifies what format the TransliterateText function is to convert text into.

target modifier: A value that provides formatting information beyond that specified in the target format, for use by the TransliterateText function.

TCP

See: Transmission Control Protocol (TCP)

TCP/IP

See: Transmission Control Protocol/Internet Protocol (TCP/IP)

tearing: The effect you obtain if you redraw the screen from the buffer while the buffer is only half updated, so that you get one half of one image and one half of another on a single raster scan.

template

See: AOCE template

temporal compression: Image compression that is performed between frames in a sequence. This compression technique takes advantage of redundancy between adjacent frames in a sequence to reduce the amount of data that is required to accurately represent each frame in the sequence. Sequences that have been temporally compressed typically contain key frames at regular intervals

See also: spatial compression

Temporary Items folder: A directory located at the root level of a volume for storing temporary buffer files created by applications. The Temporary Items folder is invisible to the user.

temporary memory: Memory allocated outside an application partition that may be available for occasional short-term use.

terminate: To end the execution of a process. A process can terminate by crashing, by quitting, or by being killed by some other process.

termination routine: A function contained in a fragment that is executed just before the fragment is unloaded

text: The written representation of language. Text is a sequence of symbols that conveys meaning to its reader. The set of symbols used, and the most basic rules for their presentation, constitute the writing system of the text. The lexical, grammatical, and semantic significance of combinations of the symbols constitute the language of the text.

text area: The space on the display device within which the text should fit.

text attributes: The set of flags that allow you to specify how QuickDraw GX alters glyph outlines or chooses the proper metrics for horizontal or vertical text.

Text control panel: A control panel, available on non-U.S. versions of system software, that allows the user to set aspects of the text behavior of any enabled script system.

text direction: The direction in which reading proceeds. Roman text has a left-to-right direction; Hebrew and Arabic have a (predominantly) right-to-left direction; Chinese and Japanese can have a vertical direction.

text face: (1) A style object property. It is the text face"the constructed stylistic variation from plain text"to apply when drawing the text of a shape. (2) An algorithmic way for your application to produce typestyles.

text object: An object of type JMTextRef used to encapsulate strings passed by JManager functions. In addition to the actual text, a text object also contains text encoding information and the length of the string.

text rendering: The process of preparing characters that are stored in memory for display as glyphs.

text run: A complete unit of text, made up of character codes or glyph codes.

text segment: For text layout, the portion of a style run (it may be the entire style run) that falls on a single text line. Most text measuring and drawing routines work on a single text segment at a time.

text service: A text-entry or text-processing function provided by a text service component. Inline input is one example of a text service.

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.

text service component: A software module that is a registered component with the Component Manager, and that is used for entry, processing, or formatting of text. Text service components use the Text Services Manager to request action from and send information to client applications.

text service component type: A specification of the function associated with a particular kind of text service component; part of its component description record. Currently, only one text service component type is defined: 'inpm', specifying an inline input method.

text shape: A type of QuickDraw GX shape. The geometry of a text shape contains a string of characters to be drawn in a single font and style

See also: glyph shape, layout shape, typographic shape

text size: A style object property. It is the size, in typographic points (72 per inch), to draw the text of a shape.

text string: An array of characters referenced by a pointer and a length word. A text string may contain up to 32,767 bytes of character data

See also: Pascal string

text style

See: style

text style table: In an item color table resource, a specification for the typeface, font style, font size, and color of text in an editable text item or a static text item.

text width: The area between the margins; it is the length available for displaying a line of text.

text-done callback procedure: An application-defined procedure that is executed when the Speech Manager has finished processing (although not necessarily speaking) a buffer of input text.

text-encoding specification: Information within a text object that identifies the text-encoding system used for text within the object.

text-encoding system: A computer representation for one or more character sets used by one or more languages and regions. For instance, Unicode is a 16-bit text-encoding system that provides a code for every character in every major writing system.

text-to-speech

See: synthesized speech

theme: A user-editable combination of a given appearance with a system font, desktop picture or pattern, and highlight color

See also: appearance

thread: (1) A path of execution. For example, one thread in a program might handle user interactions, another might perform calculations, and a third might perform I/O. (2) An independent event loop in the Java virtual machine. Multiple threads can run concurrently in a Java virtual machine. A thread is also called a lightweight process. (3) To design software with more than one path of execution.

thumbnail picture: A picture that can be created from an existing image that is stored as a pixel map, a picture, or a picture file. A thumbnail picture is useful for creating small representative images of a source image and in previews for files that contain image data.

TIB

See: transfer instruction block (TIB)

TIB instructions: Commands that control the SCSI Manager data transfer routines.

TIB pseudoprogram: A sequence of TIB instructions.

tick: A unit of time equal to one sixtieth of a second.

tick marks: Indicator marks on a slider which provide a scale against which relative movement of the slider indicator can be measured

See also: indicator, slider

tiled highlighting: A highlighting mechanism whereby the highlighted area corresponding to every character in a line of text is unique, without gaps or overlaps.

timbre: The tone of a sound, which can range from clear to buzzing.

timeout interval: The interval of time the system waits for the startup drive to respond while the computer is booting.

time base: A set of values that define the time basis for an entity, such as a QuickTime movie. A time base consists of a time coordinate system (that is, a time scale and a duration) along with a rate value. The rate value specifies the speed with which time passes for the time base.

time coordinate system: A set of values that defines the context for a time base. A time coordinate system consists of a time scale and a duration. Together, these values define the coordinate system in which a time value or a time base has meaning.

Time Manager: The part of the Mac OS that lets you schedule the execution of a routine after a certain time has elapsed.

Time Manager queue: A list of all installed Time Manager tasks.

Time Manager task record: A data structure that contains information about a Time Manager task. Defined by the TMTask data type.

time scale: The number of time units that pass per second in a time coordinate system. A time coordinate system that measures time in sixtieths of a second, for example, has a time scale of 60.

time unit: The basic unit of measure for time in a time coordinate system. The value of the time unit for a time coordinate system is represented by the formula (1/time scale) seconds. A time coordinate system that has a time scale of 60 measures time in terms of sixtieths of a second.

time value: A value that specifies a number of time units in a time coordinate system. A time value may contain information about a point in time or about a duration.

tint: The area ratio of dot color to background color that describes the tint color in a halftone.

tint color: The actual resultant color produced by a halftone; it is a mixture of the dot color and the background color, in proportions specified by the tint ratio.

tint space: The color space used by a halftone.

tint type: The calculation method, such as luminance tint or color mixture tint, used to determine the tint color and the tint in a halftone.

tiny: Used to describe a number whose magnitude is smaller than the smallest positive normalized number in the format of the number.

tip: At the side of a help balloon, the point that indicates what object or area is explained in the help balloon

See also: help balloon, variation code

title bar: The bar at the top of a window that displays the window name; contains the proxy icon, close box, collapse box, and zoom box; and indicates whether the window is active.

title bar region: The entire area occupied by a window's title bar, including the title text region

See also: title bar, title text region

title text region: That portion of a window's title bar that is occupied by the name of the window

See also: title bar

TLAP

See: TokenTalk Link-Access Protocol (TLAP)

TOC

See: table of contents (TOC)

token: (1) An abstract category of text element that stands for a name, symbol, punctuation, quoted literal, or other sequence of characters. (2) A descriptor record returned by an object accessor function that identifies a requested Apple event object in a specified container.

tokenization: A function provided by the Script Manager and individual script systems. Tokenization identifies the different lexical elements in an arbitrary string of text by using localized information from the tokens resource ('itl4'), and converts the string to a series of tokens.

tokens resource: An international resource of type 'itl4'. The tokens resource contains information needed to convert text in a particular language into a series of tokens. Each installed script system has one or more tokens resources.

TokenTalk: The data link that allows an AppleTalk network to be connected by token ring cables.

TokenTalk Link-Access Protocol (TLAP): The AppleTalk link-access protocol used in a TokenTalk network. TLAP is built on top of the standard token ring data-link layer.

token block record: A parameter block used by the IntlTokenize function. The token block record contains, among other information, a pointer to a list of token records.

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

token record: A data structure, used by the IntlTokenize function, that describes an individual token.

tolerance: For hit-testing, a value that specifies how close to a shape part a hit point must be for the hit-test to be considered successful.

tolerant color: A color that accepts"within a specified range"the value that the Color Manager determines is the closest match available in the color table. If there is no match within the specified range, the Palette Manager loads the required color

See also: courteous color

tool

See: application extension

Toolbox Event Manager

See: Event Manager

Toolbox trap: An exception that is caused by an A-line instruction that executes a Mac OS routine.

Toolbox trap dispatch table: A table in RAM that contains addresses to Toolbox routines.

top-side bearing: The white space between the top of the glyph and the visible beginning of the glyph.

total override: An implementation of a printing message override that does not forward the message to other message handlers.

To recipient: A principal recipient of a message

See also: original recipient

TPrint record: A data structure of type TPrint. A TPrint record contains fields that specify the Printing Manager version, information about the printer (such as its resolution in dpi), and the dimensions of the paper rectangle.

TPrJob record: A data structure of type TPrJob. The TPrJob job record contains information about a particular print job; for instance, the first and last pages to be printed, the number of copies, and the printing method (either draft-quality or deferred).

track: A Movie Toolbox data structure that represents a single data stream in a QuickTime movie. A movie may contain one or more tracks. Each track is independent of other tracks in the movie and represents its own data stream. Each track has a corresponding media. The media describes the data for the track.

tracking: Kerning between all glyphs in the shape, not just the kerning pairs already defined by the font. You can increase or decrease interglyph spacing by using a track number

See also: kerning

track boundary region: A region that describes the area occupied by a track in the track's coordinate system. The Movie Toolbox obtains this region by applying the track clipping region and the track matte to the visual image contained in the track rectangle.

track clipping region: The clipping region of a track in the track's coordinate system. The Movie Toolbox applies the track's clipping region and the track matte to the image contained in the track rectangle to obtain the track boundary region. Only that portion of the track that lies in the track boundary region is then transformed into an image in the movie coordinate system.

track height: The height, in pixels, of the track rectangle.

track matte: A pixel map that defines the blending of track visual data. The value of each pixel in the pixel map governs the relative intensity of the track data for the corresponding pixel in the result image. The Movie Toolbox applies the track matte, along with the track clipping region, to the image contained in the track rectangle to obtain the track boundary region.

track movie boundary region: A region that describes the area occupied by a track in the movie coordinate system, before the movie has been clipped by the movie clipping region. The movie boundary region is built up from the track movie boundary regions for each of the movie's tracks.

track offset: The blank space that represents the intervening time between the beginning of a movie and the beginning of a track's data. In an audio track, the blank space translates to silence; in a video track, the blank space generates no visual image. All of the tracks in a movie use the movie's time coordinate system. That is, the movie's time scale defines the basic time unit for each of the movie's tracks. Each track begins at the beginning of the movie, but the track's data might not begin until some time value other than 0.

track rectangle: A rectangle that completely encloses the visual representation of a track in a QuickTime movie. The width of this rectangle in pixels is referred to as the track width; the height, as the track height.

track setting: A value that specifies the relative tightness or looseness of interglyph spacing.

track width: The width, in pixels, of the track rectangle.

trailing edge: The edge of a glyph that is encountered last when reading text of that glyph's language. For glyphs of left-to-right text, the trailing edge is the right edge; for glyphs of right-to-left text, the trailing edge is the left edge

See also: leading edge

trailing spaces: White space characters occurring at the end of the last style run in a line of text.

transaction: (1) A task that can be performed over a network, such as sending or receiving data. (2) A sequence of Apple events sent back and forth between the client and server applications, beginning with the client's initial request for a service. All Apple events that are part of one transaction must have the same transaction ID. (3) The exchange of data between two ATP client applications in which the requester application sends a request to the responder application to perform. The exchange of data is limited to the request-response interaction, and the response data is bound to the request data by a transaction ID.

transaction bitmap: The bitmap/sequence number field of the header, when the ATP packet is a request packet. The transaction bitmap identifies the number of buffers that a requester application has reserved for the response data.

transaction-based protocol: A communications protocol in which one socket client transmits a request for some action and the other socket client carries out the action and transmits a response.

transcendental functions: Functions that can be used as building blocks in numerical functions. All of the functions contained in the PowerPC Numerics library are transcendental functions.

transcription: The representation of sound sequences in phonetic symbols.

transfer instruction block (TIB): A data structure used to pass instructions to the SCSI Manager data transfer routines.

transfer mode: (1) A specification, either Boolean or arithmetic, of how QuickDraw should draw or copy images into a bitmap or pixel map. In drawing text, QuickDraw uses transfer mode, along with foreground and background color, to determine how the text to be drawn (called the source) interacts with anything already drawn in the current graphics port, called the destination. See arithmetic transfer mode, Boolean transfer mode. (2) A QuickDraw GX data structure"also a property of an ink object"that controls the interaction between the color of a shape and the colors of the background at the location where the shape is drawn.

transfer mode type: A specification of the kind of transfer mode"such as copy mode or XOR mode"to apply when drawing a shape or pixel. In QuickDraw GX, same as component mode.

transform: (1) A mode you can specify with some Icon Utilities routines that draw icons. Specifying transforms with these routines alters the appearance of the icons in standard ways that are analogous to Finder states for icons. For example, you can specify the transform ttSelected to draw an icon so that it is highlighted as if it were selected in the Finder. (2) A QuickDraw GX object associated with a shape object. A transform object contains information that affects the visual appearance of a shape when it is drawn and specifies how the associated shape objects' geometries will be represented in a view port.

transformation matrix: A 3-by-3 matrix that defines how to map points from one coordinate space into another coordinate space.

transform concatenation: The process by which QuickDraw GX combines the clips and mappings of transform objects at different levels of a picture hierarchy when drawing a picture shape.

transition: An AppleTalk event, such as an AppleTalk driver being opened or closed, that can affect an AppleTalk application.

transition event handler routine: A developer-supplied rou tine that the LAP Manager calls to handle a transition event. Entries in the AppleTalk Transition Queue contain a field that holds a pointer to the transition event handler routine.

transition vector: In the PowerPC runtime architecture, an 8-byte data structure that describes the entry point and base register address of a routine. In the CFM-68K runtime environment, a structure that contains the entry point address of a function and the value to be placed in the A5 register when the function executes. A CFM-68K transition vector may be 12-bytes long or 8-bytes long depending on whether it is created for an application or a shared library

See also: application transition vector, shared library transition vector

translate: To move an item. A mapping can be used to translate, or move, a shape by a given amount or to a given location.

translation extension: A component called by Macintosh Easy Open to identify and translate files or scraps

See also: application translation extension

translation file type: The type of a file relevant for translation purposes

See also: catalog type

translation group: A collection of source and destination file types; within each translation group, each source file type can be translated into any destination file type.

Translation Manager: A collection of routines that provide data conversion services (such as implicit translation) for applications on Macintosh computers. You can use the Translation Manager to implement explicit translation.

translation options: The use of one or more constants to translate QuickDraw data to QuickDraw GX shapes.

translation system: A translation extension, with or without external translators, that is able to recognize and translate files or scraps.

translation table: A data structure used by the GetPhysical function to indicate which physical blocks correspond to a given logical block. This parameter block is defined by the LogicalToPhysicalTable data type.

translator: (1) A piece of software called by translation extensions or by applications to convert documents or scraps from one format to another. (2) A set of functions that convert QuickDraw data into QuickDraw GX shapes or pictures. The translation approximates the intent of the original QuickDraw images; it does not provide a pixel-by-pixel mapping of the image.

transliteration: For the Macintosh script management system, the conversion of characters that are phonetic representations of the same sound sequence between subscripts within a script. In the Roman script system, this means case conversion. For Japanese, Chinese, and Korean, transliteration refers to the conversion, without linguistic or semantic considerations, of characters from one subscript to another subscript within a script. Examples include the transliteration of Japanese Hiragana to Katakana, and the transliteration of Korean Jamo to Hangul.

transliteration resource: An international resource of type 'trsl'. The transliteration resource provides rules for converting text phonetically from one subscript to another within a script system. The transliteration resource is optional; it is used only by 2-byte script systems.

Transmission Control Protocol (TCP): The Internet protocol that permits two computers to set up a connection.

Transmission Control Protocol/Internet Protocol (TCP/IP): The major transport protocol and the network layer protocol typically used in communicating messages over the Internet.

transport protocol: A protocol that includes services that determine how data is to be transferred across an AppleTalk internet.

transport (XPT): The part of SCSI Manager 4.3 that accepts I/O requests and passes them to the appropriate SCSI interface module (SIM).

trap: Any of a large set of Macintosh system software routines accessed via A-line instructions

See also: split trap

trap dispatcher: The exception handler that deals with the occurrence of A-line instructions, providing the subroutine linkage between the A-line instruction and Macintosh system code.

trap dispatch table: A table of entry points to Macintosh system routines that are invoked with A-line instructions

See also: Operating System trap dispatch table, Toolbox trap dispatch table

Trap Manager: The part of the Mac OS that provides the subroutine linkage to most Macintosh system software routines.

trap number: The bits of a trap word (bits 0_7 for an Operating System routine, bits 0_9 for a Toolbox routine) that serve as an index into the trap dispatch tables.

trap patch

See: patch

trap word

See: A-line instruction

Trash folder: A directory at the root level of a volume for storing files that the user has moved to the Trash icon. After opening the Trash icon, the user sees the collection of all items that the user has moved to the Trash icon"that is, the union of appropriate Trash directories from all mounted volumes. A Macintosh computer set up to share files among users in a network environment maintains separate Trash subdirectories for remote users within its shared Trash directory. The Finder empties a Trash directory (or, in the case of a file server, a Trash subdirectory) only when the user of that directory chooses the Empty Trash command.

trigonometric functions: Functions that perform trigonometric operations, such as cosine, sine, and tangent.

tristimulus values: An hypothetical set of primaries, XYZ, set up by the CIE that correspond to the way the eye's retina behaves. The term tristimulus comes from the fact that color perception results from the retina of the eye responding to three types of stimuli. After experimentation, the CIE set up a hypothetical set of primaries, XYZ, that correspond to the way the eye's retina behaves.

true inside: The right side of a clockwise contour or the left side of a counterclockwise contour.

truncate: To chop off the fractional part of a real number so that only the integer part remains. For example, if the real number 1.99999999999 is truncated, the truncated value is 1.

TSM document: A private data structure maintained by the Text Services Manager that relates one or more text service components to a particular application window.

TSM-aware application: An application that makes calls to the Text Services Manager. A TSM-aware application can use a variety of text services such as inline input.

tuple: The NBP name and internet socket address pair that an entity provides to register itself with NBP. NBP adds the tuple as a names table entry to its names table.

two's complement encoding: A system for digitally encoding sound that stores the amplitude values as a signed number"silence is represented by a sample with a value of 0. For example, with 8-bit sound samples, two's complement values would range from _128 to 127, with 0 meaning silence. The Audio Interchange File Format (AIFF) used by the Sound Manager stores samples in two's complement form

See also: offset-binary encoding

type: (1) The field of an NBP entity name that is used to identify the type of service that the entity provides. Entities of the same type can find potential partners by looking up addresses of other entities that are registered with NBP based on the type portion of the name

See also: shape type

typestyle: A variant version of glyphs in the same font family. Typical typestyles available on the Macintosh computer include bold, italic, underline, outline, shadow, condensed, and extended.

type conversion: The process of changing a shape from one shape type to another. Often the geometry of the shape is significantly affected during this process.

type selection: The ability to select an item from a list of items by typing the first character or characters of the item's name.

type validation: A QuickDraw GX validation level that confirms that references to object types are valid

See also: all object validation, structure validation

typographic bounding rectangle: The smallest rectangle that encloses the full span of the glyphs from the ascent line to the descent line.

typographic point: A unit of measurement describing the size of glyphs in a font. There are 72.27 typographic points per inch, as opposed to 72 points per inch in QuickDraw GX.

typographic shape: Any QuickDraw GX shape that has one of the following shape types: text, glyph, layout.

'trsl' resource

See: transliteration resource