<?xml version="1.0" ?>
<!-- $Id$ -->
<notes>
The following sequence diagram demonstrates the use of the frame and comment elements.
<h2>Diagram</h2>
<img src="GUI-DB.gif" alt="Database GUI interface" />
<h2>Diagram Source Code</h2>
<fmtcode ext="pic">
# usage-example for the comment extensions to the
# Written by Sebastian Setzer

.PS
copy "sequence.pic";

# Define the objects
actor(U, "");
object(G,"g:GUI");
placeholder_object(Dummy1); # more space
placeholder_object(D);
step();

# Message sequences
active(G);
step();

create_message(G,D,"db:DB");
active(D);
step();
inactive(D);

async(); # use asynchrone messages (not-filled arrowheads)

comment(D,C,down 1 right, wid 1 ht 0.7 "waiting for" "condition" "dbMailbox")

message(U,G,"openBrowser");
message(G,D,"query()"); active(D);
message(D,G,"result"); inactive(D);

connect_to_comment(D,C)

message(U,G,"scroll");
message(G,D,"query()"); active(D);
message(D,G,"result"); inactive(D);

connect_to_comment(D,C)

message(U,G,"Exit");
step();
begin_frame(G,F,"OnExit");
message(G,D,"shutdown()"); inactive(G); active(D);
comment(G,C,down .2 right .2, wid 2 ht 0.25 "wait for cond. dbShutdown")
step();
comment(D,C,right, wid 2 ht 1 \
	"all queries preceeding the" \
        "shutdown in the mailbox" \
	"are answered already." \
	"DbQuery-Objects can" \
	"be destroyed")
message(D,G,"done"); inactive(D); active(G);

sync();
destroy_message(G,D,"");

step();
end_frame(D,F);

step();
inactive(G);

# Complete the lifelines
step();
complete(G);
complete(U);
.PE
</fmtcode>
</notes>
