ENVIView::ClearSnailTrail

The ClearSnailTrail method clears all data in the overview's snail trail and resets the snail trail. These tasks are performed regardless of whether the overview or snail trail is displayed.

Example

; Launch the application

e = ENVI()

; Open ENVIRaster

file = FILEPATH('qb_boulder_msi', ROOT_DIR=e.ROOT_DIR, $

  SUBDIRECTORY = ['data'])

raster = e.OpenRaster(file)

; Create the first view and layer

view1 = e.GetView()

layer1 = view1.CreateLayer(raster)

view1.SHOW_OVERVIEW = 1

view1.SHOW_SNAIL_TRAIL = 1

; Create the second view and layer

view2 = e.CreateView()

layer2 = view2.CreateLayer(raster, /CIR)

view2.SHOW_OVERVIEW = 1

view2.SHOW_SNAIL_TRAIL = 0

; After playing around with the view1 overview,

; clear the snail trail

view1.ClearSnailTrail

Syntax

ENVIView.ClearSnailTrail [, ERROR=variable]

Keywords

ERROR

Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.

When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.

See Manage Errors for more information on error handling in ENVI programming.

Version History

ENVI 5

Introduced

API Version

4.3