oldType = ShowCursor([type] [, screenid][, mouseid])
The optional ‘mouseid’ allows to select which mouse cursor shall
be redisplayed or changed in visual appearance. This only makes sense
if you have multiple visible mouse cursors and is a Linux only feature.
The return value ‘oldType’ is always zero, as this query mechanism is not
supported with PTB-3. Just returned for backwards-compatibility.
OSX, WINDOWS, LINUX: ______________________________________________________
Cursor shape can be selected. These types are defined by name:
‘Arrow’ = Standard mouse-pointer arrow.
‘CrossHair’ = A cross-hair cursor.
‘Hand’ = A hand symbol.
‘SandClock’ = Some sort of sand clock/hour-glass (not available on OSX).
‘TextCursor’ = A text selection/caret placement cursor (AKA I Beam).
Apart from that names, you can pass integral numbers for type to select
further shapes. The mapping of numbers to shapes is operating system
dependent, therefore not portable across different platforms. On
MS-Windows, you can select between number 0 to 8. On Linux/X11 you can
select from a wide range of numbers from 0 up to (at least) 152, maybe
more, depending on your setup. See the C header file “X11/cursorfont.h”
for a mapping of numbers to shapes. Passing invalid numbers can create
errors. On Linux with Wayland backend, you can pass custom additional
namestrings as ‘type’.
Linux allows for display and handling of multiple mouse cursors if your
X-Server is of version 1.7 or later, or if you use the Wayland display
backend on a modern Wayland server.
If provided, the optional “type” argument changes the cursor shape to:
4: I Beam