Hello Scott,
If i right understand you - all what you need - read the MapBasic
Manual's Chapter - "WinChangedHandler procedure"
------------------------------------------------------------------
Purpose
A reserved procedure, called automatically when a Map window is panned or zoomed, or
whenever a map layer is added or removed.
Syntax
Declare Sub WinChangedHandler
Sub WinChangedHandler
statement_list
End Sub
statement_list is a list of statements to execute when the map is panned or zoomed
Description
WinChangedHandler is a special-purpose MapBasic procedure name. If the user runs an
application containing a procedure named WinChangedHandler, the application "goes to
sleep" when the Main procedure runs out of statements to execute. As long as the
sleeping application remains in memory, MapBasic calls WinChangedHandler whenever a
Map window's extents are modified (e.g. the Map is scrolled, zoomed or re-sized).
Within the WinChangedHandler procedure, call CommandInfo(�) to determine the Integer
window ID of the affected window.
Multiple MapBasic applications can be "sleeping" at the same time. When a Map window
changes, MapBasic automatically calls all sleeping WinChangedHandler procedures, one
after another.
Under some circumstances, MapBasic may call a WinChangedHandler procedure as a result
of an event which did not affect the map extents. For example, drawing a new object
may trigger the WinChangedHandler procedure.
To halt a sleeping application and remove it from memory, use End Program.
Auto-scrolling Map Windows
MapInfo 4.0 automatically scrolls the Map window if the user clicks with the mouse and
then drags to the edge of the window. If the user auto-scrolls a Map window, MapInfo
calls WinChangedHandler after the tool action is completed or canceled.
For example, if you use MapInfo's Ruler tool and you autoscroll the window during each
segment, MapInfo calls WinChangedHandler once, after you double-click to complete the
measurement (or after you press Esc to cancel the Ruler tool). If the user
auto-scrolls while using a custom MapBasic tool, MapInfo calls the tool's handler
procedure, and then calls WinChangedHandler.
MapInfo will not call WinChangedHandler if the user auto-scrolls but then returns to
the original location before completing the operation or pressing Esc.
To disable the autoscroll feature, use the Set Window statement.
Example
For an example of using a WinChangedHandler procedure, see the OverView sample program.
See Also
System event handlers
------------------------------------------------------------------
--
Best regards,
Vladimir Lashin
MBBuilder COD mailto:[EMAIL PROTECTED]
microOLAP Technologies LLC
http://www.microolap.com/gis/ - GIS related products
---------------------------------------------------------------------
List hosting provided by Directions Magazine | www.directionsmag.com |
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Message number: 2231
