>Psychtoolbox>PsychBasic

oldType = ShowCursor([type][, screenidOrWindow=0][, mouseid])

ShowCursor redisplays the mouse pointer after a previous call to HideCursor.

If the optional ‘type’ is specified, it also allows to alter the shape of the
cursor. Note that this function may not have any effect if the cursor location
is not on top of an open onscreen window, as cursor visibility or shape may not
be under Psychtoolbox control while the cursor interacts with other desktop
items.

‘screenidOrWindow’ allows to specify the screen or onscreen window to which
the function should apply. Although optional, it is strongly recommended to
provide this parameter for cross-platform compatibility across operating systems.

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 it is a Linux/X11 only feature.

The return value ‘oldType’ is always zero, as this query mechanism is not
supported with PTB-3. Just returned for backwards-compatibility.

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 those names, you can pass integral numbers for ‘type’ to select
further shapes. The mapping of numbers to shapes is operating system
dependent, and therefore not portable across different platforms. On
MS-Windows, you can select between number 0 to 13. 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: ____________________________________________________________________

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.

OSX: ______________________________________________________________________

If provided, an optional numeric ‘type’ argument changes the cursor shape to:

0: Arrow = like ‘Arrow’
4: I Beam = like ‘TextCursor’
5: Cross = like ‘CrossHair’
10: Hand = like ‘Hand’

Better use the names for cross platform portability!

Windows: __________________________________________________________________

If provided, an optional numeric ‘type’ argument changes the cursor shape to:

0: Arrow (IDC_ARROW)
1: Crosshair (IDC_CROSS)
2: Hand (IDC_HAND)
3: Four-pointed arrow pointing north, south, east, and west (IDC_SIZEALL)
4: Double-pointed arrow pointing north and south (IDC_SIZENS)
5: Double-pointed arrow pointing west and east (IDC_SIZEWE)
6: Hourglass (IDC_WAIT)
7: Slashed circle (IDC_NO)
8: I-beam (IDC_IBEAM)
9: Double-pointed arrow pointing northeast and southwest (IDC_SIZENESW)
10: Double-pointed arrow pointing northwest and southeast (IDC_SIZENWSE)
11: Standard arrow and small hourglass (IDC_APPSTARTING)
12: Arrow and question mark (IDC_HELP)
13: Vertical arrow (IDC_UPARROW)
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