Next Prev Up Top Contents Index

13.3.1 The Text Cursor Protocol

Many streams that maintain a text cursor also display some visible indication of it. The object that represents this display is (somewhat confusingly) also called a cursor.

cursor [Protocol Class]	

Summary: The protocol class that corresponds to cursors. If you want to create a new class that behaves like cursor, it should be a subclass of cursor . Subclasses of cursor must obey the cursor protocol. Members of this class are mutable.

cursorp [Function]	

Arguments: object

Summary: Returns t if object is a cursor; otherwise, it returns nil .

:sheet

Summary: The :sheet initarg is used to specify the sheet with which the cursor is associated.

standard-text-cursor

Summary: The instantiable class that implements a text cursor. Typically, ports will further specialize this class.

cursor-sheet [Generic Function]

Arguments: cursor

Summary: Returns the sheet with which the cursor cursor is associated.

cursor-position [Generic Function]

Arguments: cursor

Summary: Returns the x and y position of the cursor cursor as two values.

(setf* cursor-position) [Generic Function]

Arguments: x y cursor

Summary: Sets the x and y position of the cursor cursor to the specified position. For the details of setf* , see C.4, Multiple-Value Setf

cursor-visibility [Generic Function]

Arguments: cursor

(setf cursor-visibility) [Generic Function]

Arguments: visibility cursor

Summary: Returns (or sets) the visibility of the cursor cursor . The visibility is one of :on (the cursor will be visible at its current position), :off (the cursor is active, but not visible at its current position), or nil (the cursor is to be deactivated).

display-cursor [Generic Function]

Arguments: cursor state

Summary: This draws or erases the cursor cursor . If state is :draw , the cursor will be drawn. If the state is :erase , the cursor will be erased.


CommonLisp Interface Manager 2.0 User's Guide - 8 Aug 2003

Next Prev Up Top Contents Index