Version 7 Cursor for Locators
- To: mathgroup at smc.vnet.net
- Subject: [mg93858] Version 7 Cursor for Locators
- From: "David Park" <djmpark at comcast.net>
- Date: Thu, 27 Nov 2008 05:31:02 -0500 (EST)
Version 7 has introduced a new cursor type in graphics (at least) that I
will call a 'movable' cursor. It consists of a regular arrow outline with
the addition of a set of very small up/down/left/right arrows near the tail.
I don't know if the documentation gives any information on this but I
surmise that the purpose is to show when the cursor is over a movable
Locator object. That is pretty useful, but I think there is a problem with
it.
The 'movable' cursor doesn't show if the graphics consists of nothing but a
single Locator. It shows when we have a Locator plus any other graphical
element(s).
The following contains two Locators, a Line between them, and a midpoint.
The 'movable' cursor displays only over the Locators and not over the Line
or Point. This must be the intended and proper behavior.
DynamicModule[{pt1 = {-4, -4}, pt2 = {4, 4}},
Graphics[
{Dynamic@
{Line[{pt1, pt2}],
AbsolutePointSize[5],
Point[(pt1 + pt2)/2]},
Locator[Dynamic[pt1]],
Locator[Dynamic[pt2]]},
PlotRange -> 10,
Frame -> True,
ImageSize -> 200]
]
But if we Deploy the Graphics display, by any of the available methods, the
'movable' cursor no longer works properly, but displays over ALL graphical
elements.
DynamicModule[{pt1 = {-4, -4}, pt2 = {4, 4}},
Deploy@Graphics[
{Dynamic@
{Line[{pt1, pt2}],
AbsolutePointSize[5],
Point[(pt1 + pt2)/2]},
Locator[Dynamic[pt1]],
Locator[Dynamic[pt2]]},
PlotRange -> 10,
Frame -> True,
ImageSize -> 200]
]
This is unfortunate because the 'movable' cursor type is a feature that
conveys useful information, and it is also a nice technique to Deploy
dynamic displays.
David Park
djmpark at comcast.net
<http://home.comcast.net/~djmpark> http://home.comcast.net/~djmpark