c

callback

A function that represents a connection between a contact and the rest of an application program. A contact calls a callback function in order to report the results of the user interface component that it represents.

children

First-level subwindows of a window.

class event

Event translations that belong to all instances of a contact class. A class event translations translation is created by the defevent macro.

class resources

Resources defined for each instance of a contact class. Also see constraint resources.

click

A :button-press event followed immediately by a :button-release event for the same button, with no intervening change in pointer position or modifier key state.

client

An application program connects to the window system server by some interprocess communication (IPC) path, such as a TCP connection or a shared memory buffer. This program is referred to as a client of the window system server. More precisely, the client is the IPC path itself. A program with multiple paths open to the server is viewed as multiple clients by the protocol. Resource lifetimes are controlled by connection lifetimes, not by program lifetimes.

clipping regions

In a graphics context, a bitmap or list of rectangles can be specified to restrict output to a particular region of the window. The image defined by the bitmap or rectangles is called a clipping region.

colormap

A set of entries defining color values. The colormap associated with a window is used to display the contents of the window. Each pixel value indexes the colormap to produce RGB values that drive the guns of a monitor. Depending on hardware limitations, one or more colormaps can be installed at one time, such that windows associated with those maps display with correct colors.

composite

A subclass of contact representing contacts that are the parents of other contacts. A composite provides geometry management and input focus management services for the contacts that are its children.

complete resource class

A list of symbols containing the class of the contact, the class of the contact's parent (and so on), and the class of the contact-display to which the contact belongs. The complete resource class is one of the two items used as a key by a CLUE application in order to access a contact resource value in a resource database.

complete resource name

A list of symbols containing the name of the contact, the name of the contact's parent (and so on), and the name of the contact-display to which the contact belongs. The complete resource name is one of the two items used as a key by a CLUE application in order to access a contact resource value in a resource database.

connection

The IPC path between the server and client program. A client program typically has one connection to the server over which requests and events are sent.

constraint resources

Resources defined for each child belonging to a member of a composite class. Constraint resources are typically used to control the parent's geometry management policy. Also see class resources.

contact

The basic CLUE object for programming a user interface.

contact-display

The CLUE object type that represents a connection to an X server and that supports an event loop for application input.

contact initialization

The process of collecting initial values for all contact attributes. No server resources (windows and so on) are actually allocated until contact realization.

contact realization

The process of allocating contact resources. This process completes contact creation.

containment

A window contains the pointer if the window is viewable and the hot spot of the cursor is within a visible region of the window or a visible region of one of its inferiors. The border of the window is included as part of the window for containment. The pointer is in a window if the window contains the pointer but no inferior contains the pointer.

content

The single child of a shell. The basic geometry management policy implemented by the shell class constrains a shell and its content to have the same width and height; size changes to one are automatically applied to the other.

coordinate system

The coordinate system has x horizontal and y vertical, with the origin [0, 0] at the upper left. Coordinates are discrete and are in terms of pixels. Each window and pixmap has its own coordinate system. For a window, the origin is at the inside upper left, inside the border.

cursor

The visible shape of the pointer on a screen. It consists of a hot-spot, a source bitmap, a shape bitmap, and a pair of colors. The cursor defined for a window controls the visible appearance when the pointer is in that window.