There are many components in XView—here is a list of some of them, with a brief description of each.
CANVAS: drawing canvas, use Xlib calls
CMS: color management
CURSOR: manipulate cursor images
DRAGDROP: set up active sites to receive drag and drop objects
FILE_CHOOSER: standard open/save file dialog
FONT: allocate fonts
FRAME: set up top-level frames
FULLSCREEN: set up full-screen grabs
ICON: manage X icons
MENU, MENU_ITEM: set up menu buttons and menu items
NOTICE: popup messages
NOTIFIER: handles X events, timers, interrupts, etc.
PANEL: control panel container for other panel items
PANEL_ITEM: generic item on a control panel
PANEL_BUTTON: standard action button
PANEL_CHOICE: multiple choice component (many arrangements)
PANEL_CHECK_BOX: another style of multiple choice components
PANEL_GAUGE: numeric indicator (thermometer-style)
PANEL_LIST: scrolling list box, text and glyphs
PANEL_MESSAGE: read-only labels
PANEL_MULTILINE_TEXT: editable text component (with scroll-bar)
PANEL_NUMERIC_TEXT: editable numbers-only text (with up/down arrows)
PANEL_SLIDER: numeric entry via slider, with many options for appearence
PANEL_TEXT: standard text entry component
SCROLLBAR: component typically used by other components
SELECTION: standard X selections
SERVER: maintain connection to X server
TEXTSW: text edit window with scrollbar (allows multiple views)
TTYSW: standard terminal emulation window, connected to a shell