A Cursor.T is a screen-independent specification of a cursor shape. The call VBT.SetCursor(v, cs) sets the cursor of v to be cs.
The locking level is LL.sup <= VBT.mu for all of the procedures in this interface.
INTERFACE Cursor; IMPORT Pixmap, Point; TYPE T = RECORD cs: INTEGER END; Predefined = [0..2]; CONST DontCare = T{0}; TextPointer = T{1}; NotReady = T{2};
You should set Cursor.DontCare when you don't care about the cursor shape; Cursor.TextPointer when the cursor is to be used for editing text, and Cursor.NotReady to indicate that the application is not receptive to user input.
TYPE Raw = RECORD plane1, plane2: Pixmap.Raw; hotspot: Point.T; color1, color2, color3: RGB; END; BW = {UseBg, UseFg, UseIntensity}; RGB = RECORD r, g, b: REAL; gray := -1.0; bw := BW.UseIntensity END;
A Raw represents a cursor with explicit offset, bitmaps, and colors.
The plane1 and plane2 are depth-1 pixmaps. They must have the same bounding rectangle, and the hotspot must lie within the bounding rectangle or on its east or south edge. If the hotspot is illegal, it will be moved to the closest legal position.
The cursor's hotspot is kept on top of the mouse's location on the screen. The cursor's image tracks the mouse relative to the hotspot. For example, if the hotspot is (0, 0), the (0, 0) bit of the cursor's image will be located over the mouse's location. The remainder of the cursor will appear to the south and east.
The color of each pixel in the cursor's image is determined from the corresponding bits in plane1 and plane2 (p1 and p2):
p1 = 0, p2 = 0 => transparent p1 = 0, p2 = 1 => color1 p1 = 1, p2 = 0 => color2 p1 = 1, p2 = 1 => color3
The colors for the cursor are matched as closely as possible to the selection of cursor colors that the screentype supports. If the screentype allows only two colors for the cursor, then the pixels that would have been color3 will be color1. The gray and bw values control the color on gray-scale and monochrome displays, according to the same rule used in PaintOp.FromRGB.
PROCEDURE FromRaw(READONLY r: Raw): T;
If the screentype does not support r's colors or size, FromRaw will clip or convert colors as necessary. On a screentype that does not allow user-defined cursors, the cursor returned by FromRaw will behave like DontCare.
PROCEDURE FromName(READONLY names: ARRAY OF TEXT): T;
Return the first available cursor of those named in the array names.
The entries of names are cursor names as specified in the ScrnCursor interface, possibly containing wild card characters. On any particular screentype, FromName(names) iterates through names in order and returns an arbitrary match from the first name that matches anything. If no name has any matches, it returns DontCare.
Standard X screentypes support the cursors named in X Window System by Scheifler et. al. [XSpec] Appendix B. Therefore, for example,
FromName(ARRAY OF TEXT{"XC_arrow"})
returns a cursor that behaves like the X arrow cursor on X screentypes, and like DontCare on screentypes that have no cursor named XC_arrow.
END Cursor.
Return a cursor that looks like r on all screens.