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From: aarsten@idt.unit.no (Amund Aarsten)
Newsgroups: comp.human-factors
Subject: Re: modes in object-oriented graphics packages
Message-ID: <1991Jun30.144313.22086@ugle.unit.no>
Date: 30 Jun 91 14:43:13 GMT
References: <1991Jun24.172022.15695@cpsc.ucalgary.ca>
Sender: news@ugle.unit.no
Reply-To: aarsten@idt.unit.no (Amund Aarsten)
Organization: Div. of CS & Telematics, Norwegian Institute of Technology
Lines: 15

As a part of a larger project (system development environment) I once
hacked a simple graph editor where the same (left) mouse button was
used for both insertion, selection and moves. The idea was that if you
click on an extisting object, you probably want to select it; if you
drag while having a selection you probably want to move it; if you click
outside exsisting objects you probably want to insert a new one (the tool
palette could be on another mouse button).

This worked great except for the arcs in the graph (which are drawn between
the nodes; you drag a line from one node to another). If the above scheme
is used the tool would assume you wanted to select the node when you started
to draw the arc. I can't remember how I worked around it but it wasn't
totally satisfactory (involving shift-buttonpresses etc.).

Amund