A class that's defined solely so that other classes can inherit from it. Programs don't use instances of an abstract class, only of its subclasses.
In the Application Kit, a message sent by an object (such as an NSButton or NSSlider) in response to a user action (such as clicking the button or dragging the slider's knob). The message translates the user's action into a specific instruction for the application. In WebObjects, a message sent by a dynamic element object (such as a WOSubmitButton or WOHyperlink) in response to a use action (such as clicking the button or hyperlink). The message translates the user's action into a specific instruction for the response component. See also target.
The application currently associated with keyboard events. Menus are shown for the active application only, and only the active application can have the current key window and main window.
In Enterprise Objects Framework, the software that mediates between an application built with Enterprise Objects Framework and the database server to which the application connects, providing a uniform, server-independent interface for working with database systems. In WebObjects, software that mediates between an application built with WebObjects and the HTTP server used to transmit requests between the web browser on the client and the application.
The value that indicates the coverage of a pixel in an image, ranging from 0.0 for a transparent pixel (no coverage) to 1.0 for an opaque pixel (full coverage). Also, the value set by the setalpha operator for the coverage parameter in the current graphics state. See also color value.
In the Application Kit, a view is said to be the ancestor of all the views below it in the view hierarchy, including its subviews. Compare descendant .
When the user drags to define a range, the position of the cursor when the mouse button is pressed. Compare end point .
A high-level operating-system event that conforms to the Apple Event Interprocess Messaging Protocol (AEIMP). An Apple event typically consists of a message from an application to itself or to another application.
A program with a graphical user interface that the user can run from the workspace, such as TextEdit, FaxReader, or Preferences.
The APIs available for implementing the Yellow Box window-based user interface in an application. The Application Kit provides a basic program structure for applications that draw on the screen and respond to events.
The process of preserving a data structure, especially an object, for later use. An archived data structure is usually stored in a file, but it can also be written to memory, copied to the pasteboard, or sent to another application. Archiving involves writing data to a special kind of data stream, called a typed stream. See also typed stream .
One of the four keys with arrows on them. They move the insertion point in the indicated direction.
In Enterprise Objects Framework, an object that mediates between enterprise objects and the user interface object that displays it.
To choose a menu command that controls a submenu, causing the submenu to appear next to the supermenu (the menu with the controlling command). Moving or closing a supermenu also moves or closes its attached submenu; choosing the controlling command a second time detaches and hides the submenu.
A panel that demands the user's attention. Until the user acts to dismiss the panel from the screen, no other action within the application is possible. Attention panels permit the user to rescind a command (such as Close), ask the user to complete a command (such as Save As), and give warnings that the user must acknowledge. See also panel .
In Enterprise Objects Framework, the description of one of the properties of an entity; loosely, associates a database column with an instance variable of an enterprise object.
In the Application Kit, the color that fills the content area of a window and provides a background for all the drawing done within the window, or the color that fills a view as a background for any drawing the view or its subviews do.
The part of a slider or a scroller that holds the moveable knob. See also knob .
The reference coordinate system for a window. The origin is in the window's lower-left corner of the window, outside the border and resize bar if it has them. The positive x-axis extends to the right and the positive y-axis extends upward; the length of a unit on either axis is one screen pixel.
A remote message that returns immediately, without waiting for the application that receives the message to respond. The sending application and the receiving application act independently, and are therefore not "in sync." Compare synchronous message .
On PowerPC-based computers only, the part of Rhapsody's architecture designed to support a full version of the Mac OS, hosted on a modern kernel. The Blue Box is not an emulator for backward compatibility; it is the same source code as the Mac OS. bounds rectangle
In the Application Kit, the smallest rectangle in a view's coordinate system that completely encloses its frame rectangle. Unless the view's coordinate axes have been rotated, the bounds rectangle (stated in the view's own coordinates) and its frame rectangle (stated in its superview's coordinates) enclose exactly the same area onscreen.
A window with an input buffer that also acts as a backup buffer for screen pixel values. All images are first rendered in the buffer, then flushed from the buffer to the screen.
A directory in the file system that groups code and resources that can be used in a program. Bundles are managed by NSBundle objects, which dynamically load code and find localized and nonlocalized bundle resources. Applications, palettes, and frameworks are types of bundles.
The cursor image (a spinning disk) that indicates that an application is busy.
In the Objective-C language, a set of method definitions that is segregated from the rest of the class definition. Categories can be used to split a class definition into parts, or to add methods to an existing class. Java has no facility that is directly equivalent to categories in Objective-C.
The code that identifies a character in a given character set; an index into the character set's encoding vector.
The keys that transmit characters to the computer. This includes not only the usual letters, numbers, and symbols, but also Return, Delete, Tab, Esc, and the arrow keys.
The set of characters for a particular font or fonts; for example, the Macintosh character set (an extension of ASCII) or Symbol.
In the Java and Objective-C languages, a prototype for a particular kind of object. A class definition declares instance variables and defines methods for all members of the class. Objects that have the same types of instance variables and have access to the same methods belong to the same class. See also class object .
In the Objective-C language, a method that is declared and implemented by the class object and is not available to instances of the class. In the Java language, methods that are statically declared in a class are also sometimes referred to as "class methods" since they are bound to the class itself. However, unlike Objective-C, Java does not allow class methods to be inherited or overridden by a subclass. Compare instance method .
In the Java and Objective-C languages, an object that represents a class and knows how to create new instances of the class. Class objects are created by the compiler and lack instance variables, although they can have static variables. Otherwise, class objects behave like all other objects. As the receiver in a message expression, a class object is represented by the class name.
To press and release a mouse button while the cursor is positioned over an object onscreen. Clicking an object may select it or cause it to act in some way. Users can also click to select a particular location (for the insertion point, for example).
In the PostScript language, a path enclosing the area where drawing can take place. Areas not within the clipping path aren't affected by PostScript painting operators such as stroke and fill .
The button that can appear at the far left in a window's title bar. Clicking the button closes the window (removes it from the workspace).
One of the parameters that make up a color specification. For grayscale, there's a single component. A color that's specified by red, green, and blue (RGB) parameters has three components.
The value that indicates the color of a pixel; each color component is assigned a separate value ranging from 0.0 to 1.0. Also, the current value of the color parameter of the graphics state, as set by setgray , setrgbcolor , or another similar operator. See also alpha value .
In WebObjects, a dynamic HTML page. A component is made up of an HTML template, a code or script file, and a declarations file, which binds variables and methods in the code to elements in the HTML template.
A method of accumulating separately rendered images into a final image. It encompasses simple copying as well as more sophisticated operations that take advantage of transparency.
A type of variable provided by the C-thread functions to help synchronize the threads in a task.
A special window that displays system log messages, as well as output written to the standard error and standard output streams by applications launched from the Workspace Manager.
The area within a window that's available for the application to use. It excludes only the window's border, title bar, and resize bar.
A rectangle surrounding a window's content area, expressed in the screen coordinate system. See also frame rectangle .
In the NSWindow class, an NSView that's exactly the same size as a window's content area and has all the views that draw within the content area as its subviews and descendants; every NSWindow object has a content view. In the NSScrollView class, the NSClipView object that encloses the visible portion of a document and provides basic scrolling behavior. Compare document view; frame view .
An integer assigned by the Window Server to identify the PostScript execution context for an application. In the Application Kit, the context number is used to distinguish among running applications.
A graphical object--such as a button, slider, text field, or scroller--that the user can operate to give instructions to an application.
An object in an application that, in the Model-View-Controller programming paradigm, acts as a mediator between view and model objects. It performs tasks specific to the application and hence tends not to be reusable.
In image representation, how much background shows through a pixel; passed to PostScript operators as a value from 0.0 for no coverage (transparent) to 1.0 for full coverage (opaque). See also alpha value .
The coordinate system reflected in the current transformation matrix (CTM) of an application's current graphics state. It's usually the coordinate system of the NSView object that's about to draw.
The window that's the current device of a particular PostScript context's current graphics state. The current window receives all drawing directed to the window device of a context's current graphics state. The PostScript operators windowdeviceround and currentwindow set and return the current graphics state's current window.
In the Rhapsody user interface, the small image (usually an arrow) that moves on the screen correspondingly as you move the mouse.
A tracking rectangle that's associated with a particular image for the cursor.
An organized collection of data. In the Enterprise Objects Framework, often used informally to refer to a database server or a database management system (DBMS), including not only the data but also the server processes that allow access to it, or the language used to state commands or queries, such as SQL.
An object that acts on behalf of another object. NSWindow, NSApplication, NSText, NSListener, NSBrowser, NSImage, and other objects can be assigned delegates.
An operating-system facility that causes pages of data to be brought from disk into physical memory only as they're needed.
In the Application Kit, a view is said to be the descendant of all the views above it in the view hierarchy, including its superview. Compare ancestor .
In Objective-C, the init... method that has primary responsibility for initializing new instances of a class. Each class defines or inherits its own designated initializer. Through messages to self , other init... methods in the same class directly or indirectly invoke the designated initializer, and the designated initializer, through a message to super , invokes the designated initializer of its superclass.
One of the two images that are combined when compositing. The composite replaces the destination image. Compare source image .
In Objective-C, the table used to implement runtime messaging programs. Each class has a dispatch table that associates method selectors with the addresses of method implementations.
An NSView object representing an entire document. An NSClipView object contains a document view as its subview. The NSClipView translates and clips this subview to allow the user to view a portion of a large document. Compare content view; frame view .
A window that displays the contents of a user-created file.
To press and release a mouse button twice in succession while the cursor is positioned over an object onscreen. To count as a double-click rather than as two separate clicks, the mouse cannot move and the mouse button must be pressed the second time within a short interval of the first. The interval can be adjusted by the user.
To move the mouse (and the cursor on screen) while a mouse button is held down.
Binding a method to a message--that is, finding the method implementation to invoke in response to the message--at runtime, rather than at compile time.
The drawing that an application does to provide feedback during user actions--for example, highlighting objects that are clicked or pressed, and moving objects that are dragged.
In WebObjects, an HTML element whose contents are defined at runtime.
Discovering the class of an object at runtime rather than at compile time. In the Objective-C language, all objects of type id are dynamically typed. See also dynamic binding .
An array that maps character codes to the corresponding characters in a given character set.
When the user drags to define a range, the position of the cursor when the mouse button is released. Compare anchor point .
In Enterprise Objects Framework, the description of one of the database's collections of data (loosely speaking, the name and description of a table in the database) and how that collection is mapped to enterprise objects.
A high-speed local area network technology. Ethernet is an industry standard because of its reliability and capacity to rapidly transfer large amount of information.
The direct or indirect report of a user's action on the keyboard or mouse. See also event queue .
The part of the Window Server that accepts user input such as keyboard and mouse actions and decides which window to assign it to.
A long integer associated with a window. It controls which types of events will be associated with the window and passed to the application that owns the window. A 1 in the bit corresponding to a particular event type means the window accepts that type of event.
In the Application Kit, a message to perform a method named after an event. Event messages are used to dispatch events to the objects that will respond to them. See also action message .
In the Window Server process, PostScript procedures that the Window Server calls to process events in windows.
A ring buffer that temporarily stores event records that an application receives from the Window Server.
The color that's shown in a new area of a window, before any drawing is done in the area.
A collection of related information stored on a disk, such as a document, report, letter, or application.
A directory that the Workspace Manager presents as a file, allowing the user to manipulate a group of files as if they were one file. A file package for an application executable should have the same name as the executable file, plus a ".app" extension. File packages for documents should bear the same extension as the one assigned to the application's document files.
The collection of all the files the user can access through the computer.
In the Application Kit, the object that has the first chance to respond to keyboard event messages, mouse-moved event messages, and action messages with user-selected targets. Each NSWindow object has its own first responder, which it changes in response to mouse-down events.
An event that occurs when the user presses the Shift, Control, Option, or Command key, or turns Caps Lock on or off.
A panel, such as a palette, that stays in front of standard windows and other panels. See also tiers .
To empty a buffer in which information has accumulated and send the information on to its destination.
In the Objective-C language, a protocol that's declared with the @protocol directive. Classes can adopt formal protocols, objects can respond at runtime when asked if they conform to a formal protocol, and instances can be typed by the formal protocols they conform to. The Java equivalent of a formal protocol is an interface.
In the Application Kit, the rectangle that defines the location and size of a graphical object, particularly NSWindow, NSView, and NSCell objects. An NSWindow's frame rectangle is stated in the screen coordinate system, an NSView's frame rectangle is specified in its superview's coordinate system, and an NSCell's frame rectangle is specified in the containing NSView's coordinate system.
In the Application Kit, the NSView object that fills the window's frame rectangle and draws its border, title bar, and resize bar. This is a private view; it has the content view as its one public subview. Compare content view; document view .
A color value that represents a shade of gray, ranging from 0.0 for black to 1.0 for white.
A pixel pattern that the PostScript interpreter uses to approximate a specified color in an area if each of the pixels in the area can't be assigned that exact color.
The computer that's running (is host to) a particular program. The term is usually used to refer to a computer on a network.
The point in the cursor image whose location on the screen is reported as the cursor's location. The cursor is said to be "over" the location at its hot spot.
In the Objective-C language, the general type for any kind of object regardless of class. id is defined as a pointer to an object data structure. It can be used for both class objects and instances of a class.
In the Objective-C language, a protocol declared as a category, usually as a category of the NSObject class. The language gives explicit support to formal protocols, but not to informal ones.
In object-oriented programming, the ability of a superclass to pass its characteristics (methods and instance variables) on to its subclasses.
In object-oriented programming, the hierarchy of classes that's defined by the arrangement of superclasses and subclasses. Every class (except NSObject, which is at the root of the hierarchy) has a superclass, and any class may have an unlimited number of subclasses. Through its superclass, each class inherits from those above it in the hierarchy.
The point where whatever the user types or pastes in an application will be inserted. In text, it's typically marked by a blinking vertical bar.
In the Java and Objective-C languages, an object that belongs to (is a member of) a particular class. Instances are created at runtime according to the specification in the class definition.
In the Window Server, temporary drawing done within a window.
In the Java and Objective-C languages, any method that can be used by an instance of a class rather than by the class object. Compare class method .
In the Java and Objective-C languages, any variable that's part of the internal data structure of an instance. Instance variables are declared in a class definition and become part of all objects that are members of or inherit from the class.
A tool that lets you graphically specify your application's user interface. It sets up interface objects for you and makes it easy for you to establish connections between these objects and your own code where needed.
The design or modification of a software product, including online help and documentation, to facilitate localization. Internationalization of software typically involves writing or modifying code to make use of locale-aware operating-system services for appropriate localized text input, display, formatting, and manipulation. See also localization .
When applied to two given rectangles, the area that both have in common. If the two rectangles are expressed in the same coordinate system, their intersection is also a rectangle. See also union .
The ability of an object to reveal information about itself as an object--such as its class and superclass, the messages it can respond to, and the protocols it conforms to.
Input/output; the sending and retrieving of information into the memory of a program, usually to and from a file or a peripheral device through an I/O port.
A port used to represent a task or thread in Mach function calls. Also known as a task port or thread port.
A way of using the keyboard, rather than the mouse, to choose a menu command, operate a button in a panel, or pick an item from a pop-up or pull-down list. While holding a modifier key down, the user types a character associated with the command, button, or item. See also key equivalent .
A hardware-dependent code that indicates the position of a key on the keyboard.
An event that occurs when the user generates a character by pressing a key. Holding the key down generates subsequent key-down events at regular intervals.
In the Application Kit, the character that can be used as the keyboard alternative for a given object.
An event that occurs when the user releases any key except Shift, Control, Option, or Command.
The window in the active application that receives keyboard events. The title bar of the key window is highlighted in black.
An event that occurs when the user moves, resizes, or reorders a window or activates or deactivates an application. It includes the window-moved, window-exposed, window-resized, screen-changed, application-activate, and application-deactivate subevents.
The part of a slider or scroller that the user can drag. See also bar .
A programming philosophy stating that high-overhead operations should be deferred until absolutely necessary. Even then, only the portion of the operation that's unavoidable should be performed.
The adaptation of a software product, including online help and documentation, for use in one or more regions of the world, in addition to the region for which the original product was created. Localization of software can include translation of user-interface text, resizing of text-related graphical elements, and replacement or modification of user-interface images and sound. See also internationalization . .
The kernel used by Rhapsody. Mach is compatible with BSD 4.4 but adds additional features.
A measurement of how busy the system is. Unlike the UNIX load average, higher Mach factors mean that the system is less busy.
A task that provides services to clients, using a MiG-generated RPC interface.
The principal control loop for applications that are driven by events. From the time it's launched until the moment it's terminated, an application gets one event after another from the Window Server and responds to them, waiting between events if the next event isn't ready. In the Application Kit, the NSApplication object runs the main event loop.
The principal menu in an application, usually identified by the name of the application in its title bar. The main menu lacks a close button and cannot be made the submenu of another menu.
The screen where the key window is located, or, if there is no key window, the screen where the menu bar is located, or, if there's neither a key window nor a menu bar onscreen, the screen that has the origin of the screen coordinate system at its lower-left corner.
The standard window that's affected by actions in a panel and certain menu commands. If the main window isn't also the key window, its title bar is highlighted in dark gray.
A specification file used by the program make to build an executable version of an application. A makefile details the files, dependencies, and rules by which the application is built.
A Mach facility that maps virtual memory onto a physical file. Thereafter, any reference to that part of virtual memory causes the corresponding page of the physical file to be brought into memory.
The horizontal strip at the top of the main screen that contains menu titles, which can be text or icons. The title bar may also contain information such as the time of day.
In object-oriented programming, the method selector (name) and accompanying arguments that tell the receiving object in a message expression what to do.
In object-oriented programming, an expression that sends a message to an object. In the Objective-C language, message expressions are enclosed within square brackets and consist of a receiver followed by a message (method selector and arguments). In the Java language, message expressions use a "dot notation," where the receiver and the message are separated by the period character.
In object-oriented programming, a procedure that can be executed by an object.
Mach's message interface generator. MiG provides a procedure call interface to Mach's system of interprocess messaging.
A temporary event loop that's set up to get events directly from the event queue, bypassing the main event loop. Typically, a mouse-down event initiates the modal loop and the following mouse-up event ends it. The loop gets mouse-dragged events (or mouse-entered and mouse-exited events) to track the cursor's movement while the user holds the mouse button down.
A period of time when the user's actions are interpreted in a special way.
In the Model-View-Controller programming paradigm, a model is an object in an application that represents special knowledge and expertise. Model objects typically hold a special set of data and define logic that manipulates that data. They communicate with controller objects and are generally reusable.
In Enterprise Objects Framework, a description of the data available from a database as it will be seen and used by a database application; loosely speaking, a database-to-objects mapping. The model is produced by the EOModeler application. The model resides in a file package having the extension ".eomodeld", in one of several designated directories, so that Interface Builder's Enterprise Objects Framework palette is automatically aware of the models available to it.
Keys that change the meaning of other keys or of the user's actions with the mouse; the Shift, Option, Command, and Control keys.
An event that occurs when the user presses a button on the mouse. There's one type of mouse-down event for the left (or only) mouse button and one for the right button.
An event that occurs when the user moves the mouse while holding down a mouse button. There's one type of mouse-dragged event for when the mouse is moved with the left (or only) mouse button down, or with both buttons down, and another type for when it's moved with the right button down.
An event that occurs when the cursor enters a tracking rectangle. Depending on instructions given when the rectangle was created, the event may be generated only while one or both of the mouse buttons is being held down.
An event that occurs when the cursor leaves a tracking rectangle. Depending on instructions given when the rectangle was created, the event may be generated only while one or both of the mouse buttons is being held down.
An event that occurs when the user moves the mouse without holding down a mouse button.
The responsiveness of the cursor to movements of the mouse. Usually, the faster the mouse is moved, the farther the cursor travels.
An event that occurs when the user releases a mouse button. There's one type of mouse-up event for the left (or only) mouse button and one for the right button.
Describes an operating system that allows the concurrent execution of multiple programs. Rhapsody includes a multitasking operating system.
Mutual exclusion variable; a type of variable provided by the C-thread functions to help protect critical regions in a multiple-thread task.
A group of hosts that can directly communicate with each other.
In the Application Kit, the object that will be sent event and action messages that the intended receiver can't handle. See also responder chain .
Network File System; an NFS file server allows users on the network to share files as if they were on their own local disk.
A file (actually a file package) that stores the specifications for all or part of an application's interface. These files can contain archived objects, information about connections between objects, and sound and image data. You use Interface Builder to create nib files.
In the Objective-C language, an object id with a value of 0.
Nonmaskable interrupt; the interrupt produced by a particular keyboard sequence.
A window without a backup buffer for screen pixel values.
A programming unit that groups together a data structure (instance variables) and the operations (methods) that can use or affect that data. Objects are the principal building blocks of object-oriented programs.
In Enterprise Objects Framework, setting the outer-join property of a relationship means that all values of the primary key are represented in the return, even when some of the related records have no matching value for the foreign key. For example, if the relationship links "account code" to "salesperson for account," the return includes those that have no assigned salesperson. .
An instance variable that points to another object. Outlet instance variables are a way for an object to keep track of the other objects to which it may need to send messages.
In the Window Server process, a set of PostScript procedures, shared by all applications, that the Window Server calls to perform various tasks for applications.
A window that holds objects that control what happens in other windows (such as a Font panel) or in the application generally (such as a Preferences panel), or a window that presents information about the application to the user (such as an information panel). See also attention panel .
The smallest unit that can be assigned a color or coverage value for showing images on the screen or printed page.
A window with no border, title bar, or resize bar.
In object-oriented programming, the ability of different objects to respond, each in its own way, to the same message.
A menu-like list of items that appears over (or next to) an onscreen button when the button is pressed. The user can choose an item by dragging to it and releasing the mouse button. When the mouse button is released, the pop-up list disappears.
An indication to the Window Server of which window or windows an event should be sent to.
To press a mouse button and keep it down for a period of time while the cursor is positioned over an object onscreen. Pressing an onscreen object (such as a scroll button) may cause it to take repeated action, or may produce another object (such as a pop-up list) that the user can drag into.
A program that is at some stage of execution. In Mach, a task containing a single thread of execution is equivalent to a process.
process identifier, or
process ID
A number that uniquely identifies a process.
A tool that lets you create and maintain your application's project and source file hierarchy. Project Builder provides a user interface for building your application from its source files, as well as connections with other Rhapsody developer applications for interactive debugging.
A set of attributes that describes the form a project takes and what results from building the project. For example, a project type determines whether the resulting binary code is executable or loadable and whether it can be linked against. A project type specifies such things as default extension, makefiles, source code templates, and allowable resources.
In Enterprise Objects Framework, a general term for any attribute or relationship of an entity.
In the Objective-C language, the declaration of a group of methods not associated with any particular class. The Java equivalent of an Objective-C formal protocol is an interface. See also formal protocol; informal protocol .
A program that creates a C function corresponding to a sequence of PostScript code. When this function is called, a binary-encoded version of the PostScript code is sent to the Window Server.
A menu-like list that appears under an onscreen button when the button is pressed. The user can drag into the list to choose an action from it. When the mouse button is released, the pull-down list disappears.
In Enterprise Objects Framework, an expression that filters the enterprise objects to be retrieved by testing the truth of a proposition, retaining those for which the proposition is true and excluding the rest. In SQL, a clause preceded by "where", as in "name, department, salary where salary > 50000."
The fixed amount of time a thread can run before being preempted.
Random-access memory; memory that a microprocessor can either read or write to.
A concept of time when using a computer. If the user defines or initiates an event and the event occurs instantaneously, the computer is said to be operating in real time.
In object-oriented programming, the object that is sent a message.
An area that's defined by a point, (x, y), and an extent (width and height).
In Enterprise Objects Framework, a property constructed by matching records having the same value for an attribute in one entity with those having the same value for a corresponding attribute in another entity.
A message sent from one application to an object in another application.
An object in another application, one that's a potential receiver for a remote message.
In WebObjects, the typical application processing loop. A cycle of the request-response loop begins when the application receives a request from the HTTP server and ends when the application returns a response to the server in the form of an HTML page.
The bar, located along the bottom of a window, that the user can grab and drag to resize the window.
The number of pixels per unit distance along the vertical and horizontal coordinate axes. The greater the resolution in each direction, the more precise an image can be.
In the Application Kit, a linked list of NSResponder objects that's formed by initializing each object's next responder with the id of another object. If an NSResponder can't handle an event message or untargeted action message that it receives, the message is passed to its next responder.
A window with a backup buffer for screen pixel values. Images are rendered into the buffer for any portions of the window that aren't visible onscreen.
The code name for Apple's next generation operating system and development platform. Rhapsody is composed of an operating system that is hosted on PowerPC-based and Intel-based computers, as well as a development platform, the Yellow Box, that is hosted on Rhapsody for Power Macintosh, Rhapsody for PC Compatibles, Windows 95/98, Windows NT, and eventually on the Mac OS.
Read-only memory; memory that a microprocessor can read but not write to.
The class in a class hierarchy that does not inherit from any other class, yet from which all other classes in the hierarchy inherit behavior and attributes, directly or indirectly. The primary Yellow Box root class is NSObject.
A transformation that rotates the origin of the resulting coordinate system relative to the original coordinates.
Remote procedure call; in Mach, RPC is implemented using MiG-generated messages.
The coordinate system used to locate windows on the screen. The origin is in the lower-left corner of the screen, the positive x-axis extends to the right, and the positive y-axis extends upward. The length of a unit on either axis is one screen pixel. When the Window Server can display to more than one screen, all screens share the same screen coordinate system; only one of the screens has the coordinate origin at its lower-left corner.
A list maintained by the Window Server that orders windows from front to back, with the frontmost window at the top of the list. If a window isn't on the list, it won't be displayed on the screen.
Any of the buttons that the user can press to scroll a display, such as the buttons in a scroller. Each scroll button is labeled by a small triangular arrow indicating the direction of scrolling.
In the Objective-C language, the name of a method when it's used in a source-code message to an object, or the unique identifier that replaces the name when the source code is compiled. Compiled selectors are of type SEL.
In WebObjects, a period of time during which a user is accessing a WebObjects application. Because users on different clients may be accessing your application at the same time, an application may have more than one session accessing it at a time.
One of the two images that are combined when compositing. Compare destination image .
Structured Query Language; the industry-standard language for accessing and manipulating relational databases. The abbreviation is pronounced "sequel" or as individual English letters. SQL-92 is an international standard, defined in ISO/IEC 9075:1992 (E), "Information Technology--Database Languages--SQL" and in ANSI X3.135-1992, "Database Language SQL."
The principal windows of an application; the windows where its primary work is done. All windows are standard windows, except those with specialized functions (menus, panels, pop-up, and pull-down lists).
Giving the compiler information about what kind of object an instance is. In the Objective-C language, you might statically type a variable as a pointer to a particular class rather than type it as id . In the Java language, you must statically type variables; there's no equivalent to Objective-C's id type.
In the Application Kit, the appearance of a window's border, title bar, and resize bar.
In object-oriented programming, any class that's one step below another class in the inheritance hierarchy. Occasionally used more generally to mean any class that inherits from another class, and sometimes also used as a verb to mean the process of defining a subclass of another class.
Any menu that can be brought to the screen through a command in another menu. See also attach; main menu; supermenu .
In the Application Kit, any view that's located within the coordinate system of another view, its superview. See also view hierarchy .
In object-oriented programming, a class that's one step above another class in the inheritance hierarchy; the class through which a subclass inherits methods and instance variables.
A menu containing a command that controls another menu, its submenu.
In the Application Kit, any view that has subviews--other views that are located within its coordinate system. See also view hierarchy .
A remote message that doesn't return until the receiving application finishes responding to the message. Because the application that sends the message waits for an acknowledgment or return information from the receiving application, the two applications are kept "in sync." Compare asynchronous message .
The keys that control the computer's basic functions; the Power, brightness, and volume keys.
An event that occurs when the user requests a system shutdown.
In the Rhapsody user interface, what the user selects to be acted on by a menu command or a control within a panel--for example, text that's to be deleted by the Cut command. In the Application Kit, the object that receives action messages from an NSControl object.
In Mach, a paged virtual address space along with protected access to ports, virtual memory, and system processors. A task itself performs no computation; rather, it's a framework for running threads. See also thread .
Transmission Control Protocol/Internet Protocol. The protocols used to deliver messages between computers over the network.
To drag an attached submenu away from its supermenu. Tearing off a submenu detaches it from its supermenu and gives it an independent life onscreen. Torn-off menus are the only menus with close buttons.
In Mach, the basic unit of program execution. A thread consists of a program counter, a set of registers, and a stack pointer. See also task .
Describes code that can be used safely by several threads simultaneously.
The sections of the screen list. Each tier is occupied by a different type of window, with attention panels in the frontmost tier, menus in the next two tiers, docked icons in the tier below menus, and floating panels below docked icons. All other windows are in the bottom tier.
A function that you specify to be called repeatedly at a given time interval.
The strip above the content area of a window that users can grab to drag the window to a new location. The title bar holds the window's title, if it has one, and may contain buttons to miniaturize and close the window.
The miniaturize and close buttons that are located in a window's title bar.
A window with a border and title bar (and possibly a resize bar). The title bar can be empty.
A rectangle that an application can set to track the cursor. The application is notified when the cursor enters or leaves the rectangle. Depending on instructions given when the rectangle is created, the application may be notified only when the left or the right (or both) mouse buttons are held down. See also mouse-entered event; mouse-exited event .
A procedure that the PostScript interpreter uses to correct color values to compensate for nonlinear response in an output device and the human eye.
An alteration to a coordinate system that defines a new coordinate system. Standard transformations include rotation, scaling, and translation. A transformation is represented by a matrix.
To press and release a mouse button three times in succession while the cursor is positioned over an object onscreen. The mouse button must be pressed the second time within a short interval of the first, and the third time within a short interval of the second.
A specialized data stream used for archiving. When a typed stream is used, the type of the data is archived along with the data and an object's class hierarchy and version are archived with the object. See also archiving .
When applied to a set of rectangles, the smallest rectangle that completely encloses them all. See also intersection .
In the Model-View-Controller programming paradigm, a view object is an object in the user interface that displays data given it by a controller object and communicates the user's intentions to the controller object. View objects are highly reusable (the Application Kit provides most of the view objects an application usually needs).
In the Application Kit, the arrangement of NSView objects within a window. Each view has a superview and may have any number of subviews. Subviews are located within the coordinate systems of their superviews.
In the Application Kit, the smallest rectangle in a view's coordinate system that completely covers the visible part of the view--the part falling within all the view's ancestors in the view hierarchy. If the entire area enclosed by a view's frame rectangle is also enclosed by the frame rectangles of each of its ancestors, all of the view is visible and the visible rectangle is identical to the bounds rectangle. If not, the visible rectangle is a portion of the bounds rectangle, or null.
The APIs available for implementing a web-based user interface in an application.
In the Window Server, an integer assigned to identify a window; it's never negative or 0. In the Application Kit, a user object that's mapped to the number assigned by the Window Server. The window number used by the Application Kit is said to be "local" to the application; the number assigned by the Window Server is "global."
A process that dispatches user events to applications and renders PostScript code on behalf of applications.
Page-like rectangular areas where applications can draw onscreen. Windows can be moved and reordered front to back.
The window that fills the entire workspace on the screen and provides the dark gray background for other windows.
The development platform provided by Rhapsody. The Yellow Box is a set of object-oriented frameworks that are accessible through a set of APIs based on the integration of OPENSTEP, Apple technologies, and Java.
A particular region of dynamic memory. Zones are set up in program code and are passed to allocation methods and functions to specify that the allocated memory should come from a particular zone. Allocating related data structures from the same zone can improve locality of reference and overall system performance. For example, all the views that are displayed in the same window might be clustered in the same zone.