%%---------------------------------------------------------------------
%% This is added as a test because it was giving a false positive
%% (function move/4 will never be called) due to the strange use of
%% self-recursive fun construction in placex/3.
%%
%% The analysis was getting confused that the foldl call will never
%% terminate (due to a wrong hard-coded type for foldl) and inferred
%% that the remaining calls in the body of placex/3 will not be
%% reached. Fixed 11 March 2005.
%%---------------------------------------------------------------------
-module(appmon_place).
-export([place/2]).
place(DG, Root) ->
case appmon_dg:get(data, DG, Root) of
false -> [0];
_Other ->
placey(DG, Root, 1),
placex(DG, Root, [])
end.
placey(DG, V, Y) ->
appmon_dg:set(y, DG, V, Y),
Y1 = Y+1,
lists:foreach(fun(C) -> placey(DG, C, Y1) end, appmon_dg:get(out, DG, V)).
placex(DG, V, LastX) ->
Ch = appmon_dg:get(out, DG, V),
ChLX = lists:foldl(fun(C, Accu) -> placex(DG, C, Accu) end,
tll(LastX),
Ch),
Width = appmon_dg:get(w, DG, V),
MyX = calc_mid(DG, Width, Ch),
DeltaX = calc_delta(MyX, hdd(LastX)+20),
appmon_dg:set(x, DG, V, MyX),
move(DG, V, [MyX+Width | ChLX], DeltaX).
move(_DG, _L, LastX, 0) -> LastX;
move(DG, V, LastX, DeltaX) -> move2(DG, V, LastX, DeltaX).
move2(DG, V, LastX, DeltaX) ->
NewX = appmon_dg:get(x, DG, V)+DeltaX,
appmon_dg:set(x, DG, V, NewX),
ChLX = lists:foldl(fun(C, LX) -> move2(DG, C, LX, DeltaX) end,
tll(LastX),
appmon_dg:get(out, DG, V)),
[max(NewX+appmon_dg:get(w, DG, V), hdd(LastX)) | ChLX].
max(A, B) when A>B -> A;
max(_, B) -> B.
calc_mid(_DG, _Width, []) -> 0;
calc_mid(DG, Width, ChList) ->
LeftMostX = appmon_dg:get(x, DG, hd(ChList)),
Z2 = lists:last(ChList),
RightMostX = appmon_dg:get(x, DG, Z2)+appmon_dg:get(w, DG, Z2),
trunc((LeftMostX+RightMostX)/2)-trunc(Width/2).
calc_delta(Mid, Right) ->
if Right>Mid -> Right-Mid;
true -> 0
end.
%% Special head and tail
%% Handles empty list in a non-standard way
tll([]) -> [];
tll([_|T]) -> T.
hdd([]) -> 0;
hdd([H|_]) -> H.
