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From: minow@ranger.enet.dec.com (Martin Minow)
Newsgroups: comp.sys.mac.programmer
Subject: Re: List Mgr with TCL
Message-ID: <22938@shlump.lkg.dec.com>
Date: 28 May 91 16:18:39 GMT
Sender: newsdaemon@shlump.lkg.dec.com
Distribution: usa
Organization: Digital Equipment Corporation
Lines: 30


In article <25064@well.sf.ca.us>, mjf@well.sf.ca.us (Marty Fried) asks
about using the ListManger with TCL.

I tried that and, eventually, gave up chasing small bugs (scrolling
worked in one direction only...) It turned out to be simpler (and
more flexible) to build that has, roughly, the following organization:

-- ListPanorama -- this is a CSelector sub-class with three extra
	instance variables: aCommandBase, aDoubleClickCmd, and aBoxHeight.
	It creates a CScrollPane that encloses a CBorder that, in turn,
	encloses the CSelector.
	aCommandBase is passed to CSelector::ISelector.
	aBoxHeight is used to set the CScrollPane vertical scale.
	aDoubleClickCmd will be passed to the ListPanorama's supervisor
	by a DoDoubleClick method.
	The Selector also requires you to override Draw, DrawItem, HiliteItem,
	FindItem, and FindItemBox methods.
-- ListSelector -- this is a CList subclass that has an an InstallSelector
	method. InstallSelector links the ListSelector to its associated
	ListPanorama.  There is also an AdjustSelector method that is
	called whenever the number of items changes.  I also implemented
	GetSelection, ChangeSelection, Append, Remove, Prepend, InsertAfter,
	and InsertAt methods.

Linking the ListPanorama and ListSelector allows each class hierarchy
to work independently, but cooperatively.

Martin Minow
minow@ranger.enet.dec.com