%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2011-2013. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
-module(observer_app_wx).
-export([start_link/2]).
%% wx_object callbacks
-export([init/1, handle_info/2, terminate/2, code_change/3, handle_call/3,
handle_event/2, handle_sync_event/3, handle_cast/2]).
-behaviour(wx_object).
-include_lib("wx/include/wx.hrl").
-include("observer_defs.hrl").
%% Import drawing wrappers
-import(observer_perf_wx, [haveGC/0,
setPen/2, setFont/3, setBrush/2,
strokeLine/5, strokeLines/2, drawRoundedRectangle/6,
drawText/4, getTextExtent/2]).
-record(state,
{
parent,
panel,
apps_w,
app_w,
paint,
current,
app,
sel,
appmon,
usegc = false
}).
-record(paint, {font, pen, brush, sel, links}).
-record(app, {ptree, n2p, links, dim}).
-record(box, {x,y, w,h, s1}).
-record(str, {x,y,text,pid}).
-define(BX_E, 10). %% Empty width between text and box
-define(BX_HE, (?BX_E div 2)).
-define(BY_E, 10). %% Empty height between text and box
-define(BY_HE, (?BY_E div 2)).
-define(BB_X, 16). %% Empty width between boxes
-define(BB_Y, 12). %% Empty height between boxes
-define(DRAWAREA, 5).
-define(ID_PROC_INFO, 101).
-define(ID_PROC_MSG, 102).
-define(ID_PROC_KILL, 103).
-define(ID_TRACE_PID, 104).
-define(ID_TRACE_NAME, 105).
-define(ID_TRACE_TREE_PIDS, 106).
-define(ID_TRACE_TREE_NAMES, 107).
-define(wxGC, wxGraphicsContext).
start_link(Notebook, Parent) ->
wx_object:start_link(?MODULE, [Notebook, Parent], []).
init([Notebook, Parent]) ->
Panel = wxPanel:new(Notebook, [{size, wxWindow:getClientSize(Notebook)},
{winid, 1}
]),
Main = wxBoxSizer:new(?wxHORIZONTAL),
Splitter = wxSplitterWindow:new(Panel, [{size, wxWindow:getClientSize(Panel)},
{style, ?wxSP_LIVE_UPDATE},
{id, 2}
]),
Apps = wxListBox:new(Splitter, 3, []),
%% Need extra panel and sizer to get correct size updates
%% in draw area for some reason
P2 = wxPanel:new(Splitter, [{winid, 4}]),
Extra = wxBoxSizer:new(?wxVERTICAL),
DrawingArea = wxScrolledWindow:new(P2, [{winid, ?DRAWAREA},
{style,?wxFULL_REPAINT_ON_RESIZE}]),
wxWindow:setBackgroundColour(DrawingArea, ?wxWHITE),
wxWindow:setVirtualSize(DrawingArea, 800, 800),
wxSplitterWindow:setMinimumPaneSize(Splitter,50),
wxSizer:add(Extra, DrawingArea, [{flag, ?wxEXPAND},{proportion, 1}]),
wxWindow:setSizer(P2, Extra),
wxSplitterWindow:splitVertically(Splitter, Apps, P2, [{sashPosition, 150}]),
wxWindow:setSizer(Panel, Main),
wxSizer:add(Main, Splitter, [{flag, ?wxEXPAND bor ?wxALL},
{proportion, 1}, {border, 5}]),
wxWindow:setSizer(Panel, Main),
wxListBox:connect(Apps, command_listbox_selected),
wxPanel:connect(DrawingArea, paint, [callback]),
wxPanel:connect(DrawingArea, size, [{skip, true}]),
wxPanel:connect(DrawingArea, left_up),
wxPanel:connect(DrawingArea, left_dclick),
wxPanel:connect(DrawingArea, right_down),
case os:type() of
{win32, _} -> %% Ignore erase on windows
wxPanel:connect(DrawingArea, erase_background, [{callback, fun(_,_) -> ok end}]);
_ -> ok
end,
UseGC = haveGC(),
Version28 = ?wxMAJOR_VERSION =:= 2 andalso ?wxMINOR_VERSION =:= 8,
Font = case os:type() of
{unix,_} when UseGC, Version28 ->
wxFont:new(12,?wxFONTFAMILY_DECORATIVE,?wxFONTSTYLE_NORMAL,?wxFONTWEIGHT_NORMAL);
_ ->
wxSystemSettings:getFont(?wxSYS_DEFAULT_GUI_FONT)
end,
SelCol = wxSystemSettings:getColour(?wxSYS_COLOUR_HIGHLIGHT),
GreyBrush = wxBrush:new({230,230,240}),
SelBrush = wxBrush:new(SelCol),
LinkPen = wxPen:new(SelCol, [{width, 2}]),
process_flag(trap_exit, true),
{Panel, #state{parent=Parent,
panel =Panel,
apps_w=Apps,
app_w =DrawingArea,
usegc = UseGC,
paint=#paint{font = Font,
pen = wxPen:new({80,80,80}, [{width, 2}]),
brush= GreyBrush,
sel = SelBrush,
links= LinkPen
}
}}.
setup_scrollbar(AppWin, App) ->
setup_scrollbar(wxWindow:getClientSize(AppWin), AppWin, App).
setup_scrollbar({CW, CH}, AppWin, #app{dim={W0,H0}}) ->
W = max(W0,CW),
H = max(H0,CH),
PPC = 20,
if W0 =< CW, H0 =< CH ->
wxScrolledWindow:setScrollbars(AppWin, W, H, 0, 0);
H0 =< CH ->
wxScrolledWindow:setScrollbars(AppWin, PPC, H, W div PPC+1, 0);
W0 =< CW ->
wxScrolledWindow:setScrollbars(AppWin, W, PPC, 0, H div PPC+1);
true ->
wxScrolledWindow:setScrollbars(AppWin, PPC, PPC, W div PPC+1, H div PPC+1)
end;
setup_scrollbar(_, _, undefined) -> ok.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
handle_event(#wx{event=#wxCommand{type=command_listbox_selected, cmdString=AppStr}},
State = #state{appmon=AppMon, current=Prev}) ->
case AppStr of
[] ->
{noreply, State};
_ ->
App = list_to_atom(AppStr),
(Prev =/= undefined) andalso appmon_info:app(AppMon, Prev, false, []),
appmon_info:app(AppMon, App, true, []),
{noreply, State#state{current=App}}
end;
handle_event(#wx{id=Id, event=_Sz=#wxSize{size=Size}},
State=#state{app=App, app_w=AppWin}) ->
Id =:= ?DRAWAREA andalso setup_scrollbar(Size,AppWin,App),
{noreply, State};
handle_event(#wx{event=#wxMouse{type=Type, x=X0, y=Y0}},
S0=#state{app=App, app_w=AppWin}) ->
case App of
#app{ptree=Tree} ->
{X,Y} = wxScrolledWindow:calcUnscrolledPosition(AppWin, X0, Y0),
Hit = locate_node(X,Y, [Tree]),
State = handle_mouse_click(Hit, Type, S0),
{noreply, State};
_ ->
{noreply, S0}
end;
handle_event(#wx{event=#wxCommand{type=command_menu_selected}},
State = #state{sel=undefined}) ->
observer_lib:display_info_dialog("Select process first"),
{noreply, State};
handle_event(#wx{id=?ID_PROC_INFO, event=#wxCommand{type=command_menu_selected}},
State = #state{sel={#box{s1=#str{pid=Pid}},_}}) ->
observer ! {open_link, Pid},
{noreply, State};
handle_event(#wx{id=?ID_PROC_MSG, event=#wxCommand{type=command_menu_selected}},
State = #state{panel=Panel, sel={#box{s1=#str{pid=Pid}},_}}) ->
case observer_lib:user_term(Panel, "Enter message", "") of
cancel -> ok;
{ok, Term} -> Pid ! Term;
{error, Error} -> observer_lib:display_info_dialog(Error)
end,
{noreply, State};
handle_event(#wx{id=?ID_PROC_KILL, event=#wxCommand{type=command_menu_selected}},
State = #state{panel=Panel, sel={#box{s1=#str{pid=Pid}},_}}) ->
case observer_lib:user_term(Panel, "Enter Exit Reason", "kill") of
cancel -> ok;
{ok, Term} -> exit(Pid, Term);
{error, Error} -> observer_lib:display_info_dialog(Error)
end,
{noreply, State};
%%% Trace api
handle_event(#wx{id=?ID_TRACE_PID, event=#wxCommand{type=command_menu_selected}},
State = #state{sel={Box,_}}) ->
observer_trace_wx:add_processes(observer_wx:get_tracer(), [box_to_pid(Box)]),
{noreply, State};
handle_event(#wx{id=?ID_TRACE_NAME, event=#wxCommand{type=command_menu_selected}},
State = #state{sel={Box,_}}) ->
observer_trace_wx:add_processes(observer_wx:get_tracer(), [box_to_reg(Box)]),
{noreply, State};
handle_event(#wx{id=?ID_TRACE_TREE_PIDS, event=#wxCommand{type=command_menu_selected}},
State = #state{sel=Sel}) ->
Get = fun(Box) -> box_to_pid(Box) end,
observer_trace_wx:add_processes(observer_wx:get_tracer(), tree_map(Sel, Get)),
{noreply, State};
handle_event(#wx{id=?ID_TRACE_TREE_NAMES, event=#wxCommand{type=command_menu_selected}},
State = #state{sel=Sel}) ->
Get = fun(Box) -> box_to_reg(Box) end,
observer_trace_wx:add_processes(observer_wx:get_tracer(), tree_map(Sel, Get)),
{noreply, State};
handle_event(Event, _State) ->
error({unhandled_event, Event}).
%%%%%%%%%%
handle_sync_event(#wx{event = #wxPaint{}},_,
#state{app_w=DA, app=App, sel=Sel, paint=Paint, usegc=UseGC}) ->
%% PaintDC must be created in a callback to work on windows.
IsWindows = element(1, os:type()) =:= win32,
%% Avoid Windows flickering hack
DC = if IsWindows -> wx:typeCast(wxBufferedPaintDC:new(DA), wxPaintDC);
true -> wxPaintDC:new(DA)
end,
IsWindows andalso wxDC:clear(DC),
GC = case UseGC of
true ->
GC0 = ?wxGC:create(DC),
%% Argh must handle scrolling when using ?wxGC
{Sx,Sy} = wxScrolledWindow:calcScrolledPosition(DA, {0,0}),
?wxGC:translate(GC0, Sx,Sy),
GC0;
false ->
wxScrolledWindow:doPrepareDC(DA,DC),
DC
end,
%% Nothing is drawn until wxPaintDC is destroyed.
draw({UseGC, GC}, App, Sel, Paint),
UseGC andalso ?wxGC:destroy(GC),
wxPaintDC:destroy(DC),
ok.
%%%%%%%%%%
handle_call(Event, From, _State) ->
error({unhandled_call, Event, From}).
handle_cast(Event, _State) ->
error({unhandled_cast, Event}).
%%%%%%%%%%
handle_info({active, Node}, State = #state{parent=Parent, current=Curr, appmon=Appmon}) ->
create_menus(Parent, []),
Pid = try
Node = node(Appmon),
Appmon
catch _:_ ->
{ok, P} = appmon_info:start_link(Node, self(), []),
P
end,
appmon_info:app_ctrl(Pid, Node, true, []),
(Curr =/= undefined) andalso appmon_info:app(Pid, Curr, true, []),
{noreply, State#state{appmon=Pid}};
handle_info(not_active, State = #state{appmon=AppMon}) ->
appmon_info:app_ctrl(AppMon, node(AppMon), false, []),
lists:member(node(AppMon), nodes()) andalso exit(AppMon, normal),
observer_wx:set_status(""),
{noreply, State#state{appmon=undefined}};
handle_info({delivery, Pid, app_ctrl, _, Apps0},
State = #state{appmon=Pid, apps_w=LBox, current=Curr0}) ->
Apps = [atom_to_list(App) || {_, App, {_, _, _}} <- Apps0],
wxListBox:clear(LBox),
wxListBox:appendStrings(LBox, [App || App <- lists:sort(Apps)]),
case Apps of
[App|_] when Curr0 =:= undefined ->
Curr = list_to_atom(App),
appmon_info:app(Pid, Curr, true, []),
{noreply, State#state{current=Curr}};
_ ->
{noreply, State}
end;
handle_info({delivery, _Pid, app, _Curr, {[], [], [], []}},
State = #state{panel=Panel}) ->
wxWindow:refresh(Panel),
{noreply, State#state{app=undefined, sel=undefined}};
handle_info({delivery, Pid, app, Curr, AppData},
State = #state{panel=Panel, appmon=Pid, current=Curr, usegc=UseGC,
app_w=AppWin, paint=#paint{font=Font}}) ->
GC = if UseGC -> ?wxGC:create(AppWin);
true -> wxWindowDC:new(AppWin)
end,
FontW = {UseGC, GC},
setFont(FontW, Font, {0,0,0}),
App = build_tree(AppData, FontW),
if UseGC -> ?wxGC:destroy(GC);
true -> wxWindowDC:destroy(GC)
end,
setup_scrollbar(AppWin, App),
wxWindow:refresh(Panel),
wxWindow:layout(Panel),
{noreply, State#state{app=App, sel=undefined}};
handle_info({'EXIT', _, noconnection}, State) ->
{noreply, State};
handle_info({'EXIT', _, normal}, State) ->
{noreply, State};
handle_info(_Event, State) ->
%% io:format("~p:~p: ~p~n",[?MODULE,?LINE,_Event]),
{noreply, State}.
%%%%%%%%%%
terminate(_Event, _State) ->
ok.
code_change(_, _, State) ->
State.
handle_mouse_click(Node = {#box{s1=#str{pid=Pid}},_}, Type,
State=#state{app_w=AppWin,panel=Panel}) ->
case Type of
left_dclick -> observer ! {open_link, Pid};
right_down -> popup_menu(Panel);
_ -> ok
end,
observer_wx:set_status(io_lib:format("Pid: ~p", [Pid])),
wxWindow:refresh(AppWin),
State#state{sel=Node};
handle_mouse_click(_, _, State = #state{sel=undefined}) ->
State;
handle_mouse_click(_, right_down, State=#state{panel=Panel}) ->
popup_menu(Panel),
State;
handle_mouse_click(_, _, State=#state{app_w=AppWin}) ->
observer_wx:set_status(""),
wxWindow:refresh(AppWin),
State#state{sel=undefined}.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
create_menus(Parent, _) ->
MenuEntries =
[{"File",
[#create_menu{id=?ID_PROC_INFO, text="Process info"},
#create_menu{id=?ID_PROC_MSG, text="Send Msg"},
#create_menu{id=?ID_PROC_KILL, text="Kill process"}
]},
{"Trace",
[#create_menu{id=?ID_TRACE_PID, text="Trace process"},
#create_menu{id=?ID_TRACE_NAME, text="Trace named process"},
#create_menu{id=?ID_TRACE_TREE_PIDS, text="Trace process tree"},
#create_menu{id=?ID_TRACE_TREE_NAMES, text="Trace named process tree"}
]}],
observer_wx:create_menus(Parent, MenuEntries).
popup_menu(Panel) ->
Menu = wxMenu:new(),
wxMenu:append(Menu, ?ID_PROC_INFO, "Process info"),
wxMenu:append(Menu, ?ID_TRACE_PID, "Trace process"),
wxMenu:append(Menu, ?ID_TRACE_NAME, "Trace named process"),
wxMenu:append(Menu, ?ID_TRACE_TREE_PIDS, "Trace process tree"),
wxMenu:append(Menu, ?ID_TRACE_TREE_NAMES, "Trace named process tree"),
wxMenu:append(Menu, ?ID_PROC_MSG, "Send Msg"),
wxMenu:append(Menu, ?ID_PROC_KILL, "Kill process"),
wxWindow:popupMenu(Panel, Menu),
wxMenu:destroy(Menu).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
locate_node(X, _Y, [{Box=#box{x=BX}, _Chs}|_Rest])
when X < BX ->
{left, Box};
locate_node(X,Y, [Node={Box=#box{x=BX,y=BY,w=BW,h=BH}, _Chs}|Rest])
when X =< (BX+BW)->
if
Y < BY -> {above, Box}; %% Above
Y =< (BY+BH) -> Node;
true -> locate_node(X,Y,Rest)
end;
locate_node(X,Y, [{_, Chs}|Rest]) ->
case locate_node(X,Y,Chs) of
Node = {#box{},_} -> Node;
_Miss ->
locate_node(X,Y,Rest)
end;
locate_node(_, _, []) -> false.
locate_box(From, [{Box=#box{s1=#str{pid=From}},_}|_]) -> Box;
locate_box(From, [{_,Chs}|Rest]) ->
case locate_box(From, Chs) of
Box = #box{} -> Box;
_ -> locate_box(From, Rest)
end;
locate_box(From, []) -> {false, From}.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
build_tree({Root, P2Name, Links, XLinks0}, FontW) ->
Fam = sofs:relation_to_family(sofs:relation(Links)),
Name2P = gb_trees:from_orddict(lists:sort([{Name,Pid} || {Pid,Name} <- P2Name])),
Lookup = gb_trees:from_orddict(sofs:to_external(Fam)),
{_, Tree0} = build_tree2(Root, Lookup, Name2P, FontW),
{Tree, Dim} = calc_tree_size(Tree0),
Fetch = fun({From, To}, Acc) ->
try {value, ToPid} = gb_trees:lookup(To, Name2P),
FromPid = gb_trees:get(From, Name2P),
[{locate_box(FromPid, [Tree]),locate_box(ToPid, [Tree])}|Acc]
catch _:_ ->
Acc
end
end,
XLinks = lists:foldl(Fetch, [], XLinks0),
#app{ptree=Tree, dim=Dim, links=XLinks}.
build_tree2(Root, Tree0, N2P, FontW) ->
case gb_trees:lookup(Root, Tree0) of
none -> {Tree0, {box(Root, N2P, FontW), []}};
{value, Children} ->
Tree1 = gb_trees:delete(Root, Tree0),
{Tree, CHs} = lists:foldr(fun("port " ++_, Acc) ->
Acc; %% Skip ports
(Child,{T0, Acc}) ->
{T, C} = build_tree2(Child, T0, N2P, FontW),
{T, [C|Acc]}
end, {Tree1, []}, Children),
{Tree, {box(Root, N2P, FontW), CHs}}
end.
calc_tree_size(Tree) ->
Cols = calc_col_start(Tree, [0]),
{Boxes,{W,Hs}} = calc_tree_size(Tree, Cols, ?BB_X, [?BB_Y]),
{Boxes, {W,lists:max(Hs)}}.
calc_col_start({#box{w=W}, Chs}, [Max|Acc0]) ->
Acc = if Acc0 == [] -> [0]; true -> Acc0 end,
Depth = lists:foldl(fun(Child, MDepth) -> calc_col_start(Child, MDepth) end,
Acc, Chs),
[max(W,Max)|Depth].
calc_tree_size({Box=#box{w=W,h=H}, []}, _, X, [Y|Ys]) ->
{{Box#box{x=X,y=Y}, []}, {X+W+?BB_X,[Y+H+?BB_Y|Ys]}};
calc_tree_size({Box, Children}, [Col|Cols], X, [H0|Hs0]) ->
Hs1 = calc_row_start(Children, H0, Hs0),
StartX = X+Col+?BB_X,
{Boxes, {W,Hs}} = calc_tree_sizes(Children, Cols, StartX, StartX, Hs1, []),
Y = middle(Boxes, H0),
H = Y+Box#box.h+?BB_Y,
{{Box#box{x=X,y=Y}, Boxes}, {W,[H|Hs]}}.
calc_tree_sizes([Child|Chs], Cols, X0, W0, Hs0, Acc) ->
{Tree, {W,Hs}} = calc_tree_size(Child, Cols, X0, Hs0),
calc_tree_sizes(Chs, Cols, X0, max(W,W0), Hs, [Tree|Acc]);
calc_tree_sizes([], _, _, W,Hs, Acc) ->
{lists:reverse(Acc), {W,Hs}}.
calc_row_start(Chs = [{#box{h=H},_}|_], Start, Hs0) ->
NChs = length(Chs),
Wanted = (H*NChs + ?BB_Y*(NChs-1)) div 2 - H div 2,
case Hs0 of
[] -> [max(?BB_Y, Start - Wanted)];
[Next|Hs] ->
[max(Next, Start - Wanted)|Hs]
end.
middle([], Y) -> Y;
middle([{#box{y=Y}, _}], _) -> Y;
middle([{#box{y=Y0},_}|List], _) ->
{#box{y=Y1},_} = lists:last(List),
(Y0+Y1) div 2.
box(Str0, N2P, FontW) ->
Pid = gb_trees:get(Str0, N2P),
Str = if hd(Str0) =:= $< -> lists:append(io_lib:format("~w", [Pid]));
true -> Str0
end,
{TW,TH} = getTextExtent(FontW, Str),
Data = #str{text=Str, x=?BX_HE, y=?BY_HE, pid=Pid},
%% Add pid
#box{w=round(TW)+?BX_E, h=round(TH)+?BY_E, s1=Data}.
box_to_pid(#box{s1=#str{pid=Pid}}) -> Pid.
box_to_reg(#box{s1=#str{text=[$<|_], pid=Pid}}) -> Pid;
box_to_reg(#box{s1=#str{text=Name}}) -> list_to_atom(Name).
tree_map({Box, Chs}, Fun) ->
tree_map(Chs, Fun, [Fun(Box)]).
tree_map([{Box, Chs}|Rest], Fun, Acc0) ->
Acc = tree_map(Chs, Fun, [Fun(Box)|Acc0]),
tree_map(Rest, Fun, Acc);
tree_map([], _ , Acc) -> Acc.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
draw(_DC, undefined, _, _) ->
ok;
draw(DC, #app{dim={_W,_H}, ptree=Tree, links=Links}, Sel,
#paint{font=Font, pen=Pen, brush=Brush, links=LPen, sel=SelBrush}) ->
setPen(DC, LPen),
[draw_xlink(Link, DC) || Link <- Links],
setPen(DC, Pen),
%% ?wxGC:drawRectangle(DC, 2,2, _W-2,_H-2), %% DEBUG
setBrush(DC, Brush),
setFont(DC, Font, {0,0,0}),
draw_tree(Tree, root, DC),
case Sel of
undefined -> ok;
{#box{x=X,y=Y,w=W,h=H,s1=Str1}, _} ->
setBrush(DC, SelBrush),
drawRoundedRectangle(DC, X-1,Y-1, W+2,H+2, 8.0),
draw_str(DC, Str1, X, Y)
end.
draw_tree({Box=#box{x=X,y=Y,w=W,h=H,s1=Str1}, Chs}, Parent, DC) ->
drawRoundedRectangle(DC, X,Y, W,H, 8.0),
draw_str(DC, Str1, X, Y),
Dot = case Chs of
[] -> ok;
[{#box{x=CX0},_}|_] ->
CY = Y+(H div 2),
CX = CX0-(?BB_X div 2),
strokeLine(DC, X+W, CY, CX, CY),
{CX, CY}
end,
draw_link(Parent, Box, DC),
[draw_tree(Child, Dot, DC) || Child <- Chs].
draw_link({CX,CY}, #box{x=X,y=Y0,h=H}, DC) ->
Y = Y0+(H div 2),
case Y =:= CY of
true ->
strokeLine(DC, CX, CY, X, CY);
false ->
strokeLines(DC, [{CX, CY}, {CX, Y}, {X,Y}])
end;
draw_link(_, _, _) -> ok.
draw_xlink({#box{x=X0, y=Y0, h=BH}, #box{x=X1, y=Y1}}, DC)
when X0 =:= X1 ->
draw_xlink(X0,Y0,X1,Y1,BH,DC);
draw_xlink({#box{x=X0, y=Y0, h=BH, w=BW}, #box{x=X1, y=Y1}}, DC)
when X0 < X1 ->
draw_xlink(X0+BW,Y0,X1,Y1,BH,DC);
draw_xlink({#box{x=X0, y=Y0, h=BH}, #box{x=X1, w=BW, y=Y1}}, DC)
when X0 > X1 ->
draw_xlink(X1+BW,Y1,X0,Y0,BH,DC);
draw_xlink({_From, _To}, _DC) ->
ignore.
draw_xlink(X0, Y00, X1, Y11, BH, DC) ->
{Y0,Y1} = if Y00 < Y11 -> {Y00+BH-6, Y11+6};
true -> {Y00+6, Y11+BH-6}
end,
strokeLines(DC, [{X0,Y0}, {X0+5,Y0}, {X1-5,Y1}, {X1,Y1}]).
draw_str(DC, #str{x=Sx,y=Sy, text=Text}, X, Y) ->
drawText(DC, Text, X+Sx,Y+Sy);
draw_str(_, _, _, _) -> ok.
