Merge branch 'dgud/observer/perf-mon/OTP-9891' into maint

1 files changed, 575 insertions, 0 deletions

diff --git a/lib/observer/src/observer_perf_wx.erl b/lib/observer/src/observer_perf_wx.erl
new file mode 100644
index 0000000000..0de9785fb9
--- /dev/null
+++ b/lib/observer/src/observer_perf_wx.erl
@@ -0,0 +1,575 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2012. 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_perf_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]).
+
+%% Drawing wrappers for DC and GC areas
+-export([haveGC/1,
+	 setPen/2, setFont/3, setBrush/2,
+	 strokeLine/5, strokeLines/2, drawRoundedRectangle/6,
+	 drawText/4, getTextExtent/2]).
+
+-behaviour(wx_object).
+-include_lib("wx/include/wx.hrl").
+-include("observer_defs.hrl").
+
+-record(state,
+	{
+	  offset = 0.0,
+	  active = false,
+	  parent,
+	  windows,
+	  data = {0, queue:new()},
+	  panel,
+	  paint,
+	  appmon,
+	  usegc = false
+	}).
+
+-define(wxGC, wxGraphicsContext).
+
+-record(paint, {font, small, pen, pen2, pens}).
+
+-define(RQ_W,  1).
+-define(MEM_W, 2).
+-define(IO_W,  3).
+
+start_link(Notebook, Parent) ->
+    wx_object:start_link(?MODULE, [Notebook, Parent], []).
+
+init([Notebook, Parent]) ->
+ try
+    Panel = wxPanel:new(Notebook),
+    Main  = wxBoxSizer:new(?wxVERTICAL),
+    Style = ?wxFULL_REPAINT_ON_RESIZE bor ?wxCLIP_CHILDREN,
+    CPU = wxPanel:new(Panel, [{winid, ?RQ_W}, {style,Style}]),
+    wxWindow:setBackgroundColour(CPU, ?wxWHITE),
+    wxSizer:add(Main, CPU, [{flag, ?wxEXPAND bor ?wxALL},
+				 {proportion, 1}, {border, 5}]),
+    MemIO = wxBoxSizer:new(?wxHORIZONTAL),
+    MEM = wxPanel:new(Panel, [{winid, ?MEM_W}, {style,Style}]),
+    wxWindow:setBackgroundColour(MEM, ?wxWHITE),
+    IO  = wxPanel:new(Panel, [{winid, ?IO_W}, {style,Style}]),
+    wxWindow:setBackgroundColour(IO, ?wxWHITE),
+    wxSizer:add(MemIO, MEM, [{flag, ?wxEXPAND bor ?wxLEFT},
+			     {proportion, 1}, {border, 5}]),
+    wxSizer:add(MemIO, IO,  [{flag, ?wxEXPAND bor ?wxLEFT bor ?wxRIGHT},
+			     {proportion, 1}, {border, 5}]),
+    wxSizer:add(Main, MemIO, [{flag, ?wxEXPAND bor ?wxDOWN},
+			      {proportion, 1}, {border, 5}]),
+    wxWindow:setSizer(Panel, Main),
+
+    wxPanel:connect(CPU, paint, [callback]),
+    wxPanel:connect(IO, paint, [callback]),
+    wxPanel:connect(MEM, paint, [callback]),
+    case os:type() of
+	{win32, _} -> %% Ignore erase on windows
+	    wxPanel:connect(CPU, erase_background, [{callback, fun(_,_) -> ok end}]),
+	    wxPanel:connect(IO,  erase_background, [{callback, fun(_,_) -> ok end}]),
+	    wxPanel:connect(MEM, erase_background, [{callback, fun(_,_) -> ok end}]);
+	_ -> ok
+    end,
+
+    UseGC = haveGC(Panel),
+    {Font, SmallFont}
+	= case os:type() of
+	      {unix, _} when UseGC ->
+		  %% Def font is really small when using Graphics contexts for some reason
+		  %% Hardcode it
+		  F = wxFont:new(12,?wxFONTFAMILY_DECORATIVE,?wxFONTSTYLE_NORMAL,?wxFONTWEIGHT_BOLD),
+		  SF = wxFont:new(10, ?wxFONTFAMILY_DECORATIVE, ?wxFONTSTYLE_NORMAL, ?wxFONTWEIGHT_NORMAL),
+		  {F, SF};
+	      _ ->
+		  DefFont = wxSystemSettings:getFont(?wxSYS_DEFAULT_GUI_FONT),
+		  DefSize = wxFont:getPointSize(DefFont),
+		  DefFamily = wxFont:getFamily(DefFont),
+		  F = wxFont:new(DefSize, DefFamily, ?wxFONTSTYLE_NORMAL, ?wxFONTWEIGHT_BOLD),
+		  SF = wxFont:new(DefSize-1, DefFamily, ?wxFONTSTYLE_NORMAL, ?wxFONTWEIGHT_NORMAL),
+		  {F, SF}
+	  end,
+    BlackPen = wxPen:new({0,0,0}, [{width, 2}]),
+    Pens = [wxPen:new(Col, [{width, 2}]) || Col <- tuple_to_list(colors())],
+    process_flag(trap_exit, true),
+    {Panel, #state{parent=Parent,
+		   panel =Panel,
+		   windows = {CPU, MEM, IO},
+		   usegc=UseGC,
+		   paint=#paint{font = Font,
+				small = SmallFont,
+				pen  = ?wxGREY_PEN,
+				pen2 = BlackPen,
+				pens = list_to_tuple(Pens)
+			       }
+		  }}
+   catch _:Err ->
+	   io:format("~p crashed ~p: ~p~n",[?MODULE, Err, erlang:get_stacktrace()]),
+	   {error, Err}
+   end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+handle_event(#wx{event=#wxCommand{type=command_menu_selected}},
+	     State = #state{}) ->
+    {noreply, State};
+
+handle_event(Event, _State) ->
+    error({unhandled_event, Event}).
+
+%%%%%%%%%%
+handle_sync_event(#wx{obj=Panel, event = #wxPaint{}},_,
+		  #state{active=Active, offset=Offset, paint=Paint,
+			 windows=Windows, data=Data, usegc=UseGC}) ->
+    %% PaintDC must be created in a callback to work on windows.
+    %% Sigh workaround bug on MacOSX (Id in paint event is always 0)
+    %% Panel = element(Id, Windows),
+    Id = if Panel =:= element(?RQ_W, Windows)  -> ?RQ_W;
+	    Panel =:= element(?MEM_W, Windows) -> ?MEM_W;
+	    Panel =:= element(?IO_W, Windows)  -> ?IO_W
+	 end,
+    IsWindows = element(1, os:type()) =:= win32,
+
+    DC = if IsWindows -> 
+		 %% Ugly hack to aviod flickering on windows, works on windows only
+		 %% But the other platforms are doublebuffered by default
+		 wx:typeCast(wxBufferedPaintDC:new(Panel), wxPaintDC);
+	    true -> 
+		 wxPaintDC:new(Panel)
+	 end,
+    IsWindows andalso wxDC:clear(DC),
+    GC = if UseGC -> ?wxGC:create(DC);
+	    true -> DC
+	 end,
+    %% Nothing is drawn until wxPaintDC is destroyed.
+    try
+	draw(Offset, Id, {UseGC, GC}, Panel, Paint, Data, Active)
+    catch _:Err ->
+	    io:format("Internal error ~p ~p~n",[Err, erlang:get_stacktrace()])
+    end,
+    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(Stats = {stats, 1, _, _, _},
+	    State = #state{panel=Panel, data=Data, active=Active}) ->
+    if Active ->
+	    wxWindow:refresh(Panel),
+	    Freq = 6,
+	    erlang:send_after(trunc(1000 / Freq), self(), {refresh, 1, Freq});
+       true -> ignore
+    end,
+    {noreply, State#state{offset=0.0, data = add_data(Stats, Data)}};
+
+handle_info({refresh, Seq, Freq}, State = #state{panel=Panel, offset=Prev}) ->
+    wxWindow:refresh(Panel),
+    Next = Seq+1,
+    if Seq > 1, Prev =:= 0.0 ->
+	    %% We didn't have time to handle the refresh
+	    {noreply, State};
+       Next < Freq ->
+	    erlang:send_after(trunc(1000 / Freq), self(), {refresh, Next, Freq}),
+	    {noreply, State#state{offset=Seq/Freq}};
+       true ->
+	    {noreply, State#state{offset=Seq/Freq}}
+    end;
+
+handle_info({active, Node}, State = #state{parent=Parent, panel=Panel, appmon=Old}) ->
+    create_menus(Parent, []),
+    try
+	Node = node(Old),
+	wxWindow:refresh(Panel),
+	{noreply, State#state{active=true}}
+    catch _:_ ->
+	    catch Old ! exit,
+	    Me = self(),
+	    Pid = spawn_link(Node, observer_backend, fetch_stats, [Me, 1000]),
+	    wxWindow:refresh(Panel),
+	    {noreply, State#state{active=true, appmon=Pid, data={0, queue:new()}}}
+    end;
+
+handle_info(not_active, State = #state{appmon=_Pid}) ->
+    %% Pid ! exit,
+    {noreply, State#state{active=false}};
+
+handle_info({'EXIT', Old, _}, State = #state{appmon=Old}) ->
+    {noreply, State#state{active=false, appmon=undefined}};
+
+handle_info(_Event, State) ->
+    %% io:format("~p:~p: ~p~n",[?MODULE,?LINE,_Event]),
+    {noreply, State}.
+
+%%%%%%%%%%
+terminate(_Event, #state{appmon=Pid}) ->
+    catch Pid ! exit,
+    ok.
+code_change(_, _, State) ->
+    State.
+
+add_data(Stats, {N, Q}) when N > 60 ->
+    {N, queue:drop(queue:in(Stats, Q))};
+add_data(Stats, {N, Q}) ->
+    {N+1, queue:in(Stats, Q)}.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+create_menus(Parent, _) ->
+    MenuEntries =
+	[{"File",
+	  [
+	  ]}
+	],
+    observer_wx:create_menus(Parent, MenuEntries).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+collect_data(?RQ_W, {N, Q}) ->
+    case queue:to_list(Q) of
+	[] ->  {0, 0, []};
+	[_] ->  {0, 0, []};
+	[{stats, _Ver, Init0, _IO, _Mem}|Data0] ->
+	    Init = lists:sort(Init0),
+	    [_|Data=[First|_]] = lists:foldl(fun({stats, _, T0, _, _}, [Prev|Acc]) ->
+					   TN = lists:sort(T0),
+					   Delta = calc_delta(TN, Prev),
+					   [TN, list_to_tuple(Delta)|Acc]
+				   end, [Init], Data0),
+	    {N, lmax(Data), lists:reverse([First|Data])}
+    end;
+collect_data(?MEM_W, {N, Q}) ->
+    MemT = mem_types(),
+    Data = [list_to_tuple([Value || {Type,Value} <- MemInfo,
+				    lists:member(Type, MemT)])
+	    || {stats, _Ver, _RQ, _IO, MemInfo} <- queue:to_list(Q)],
+    {N, lmax(Data), Data};
+collect_data(?IO_W, {N, Q}) ->
+    case queue:to_list(Q) of
+	[] ->  {0, 0, []};
+	[_] -> {0, 0, []};
+	[{stats, _Ver, _RQ, {{_,In0}, {_,Out0}}, _Mem}|Data0] ->
+	    [_,_|Data=[First|_]] =
+		lists:foldl(fun({stats, _, _, {{_,In}, {_,Out}}, _}, [PIn,Pout|Acc]) ->
+				    [In,Out,{In-PIn,Out-Pout}|Acc]
+			    end, [In0,Out0], Data0),
+	    {N, lmax(Data), lists:reverse([First|Data])}
+    end.
+
+mem_types() ->
+    [total, processes, system, atom, binary, code, ets].
+
+lmax([]) -> 0;
+lmax(List) ->
+    lists:max([lists:max(tuple_to_list(T)) || T <- List]).
+
+calc_delta([{Id, WN, TN}|Ss], [{Id, WP, TP}|Ps]) ->
+    [100*(WN-WP) div (TN-TP)|calc_delta(Ss, Ps)];
+calc_delta([], []) -> [].
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+draw(Offset, Id, DC, Panel, Paint=#paint{pens=Pens, small=Small}, Data, Active) ->
+    %% This can be optimized a lot by collecting data once
+    %% and draw to memory and then blit memory and only draw new entries in new memory
+    %% area.  Hmm now rewritten to use ?wxGC I don't now if it is feasable.
+    {Len, Max0, Hs} = collect_data(Id, Data),
+    Max = calc_max(Max0),
+    NoGraphs = try tuple_size(hd(Hs)) catch _:_ -> 0 end,
+    Size = wxWindow:getClientSize(Panel),
+    {X0,Y0,WS,HS} = draw_borders(Id, NoGraphs, DC, Size, Max, Paint),
+    Last = 60*WS+X0-1,
+    Start = max(61-Len, 0)*WS+X0 - Offset*WS,
+    case Hs of
+	[] -> ignore;
+	[_] -> ignore;
+	_ ->
+	    Draw = fun(N) ->
+			   Lines = make_lines(Hs, Start, N, {X0,Max*HS,Last}, Y0, WS, HS),
+			   setPen(DC, element(1+ ((N-1) rem tuple_size(Pens)), Pens)),
+			   strokeLines(DC, Lines),
+			   N+1
+		   end,
+	    [Draw(I) || I <- lists:seq(NoGraphs, 1, -1)]
+    end,
+    case Active of
+	false ->
+	    NotActive = "Service not available",
+	    setFont(DC, Small, {0,0,0}),
+	    drawText(DC, NotActive, X0 + 100, element(2,Size) div 2);
+	true ->
+	    ignore
+    end,
+    ok.
+
+make_lines(Ds = [Data|_], PX, N, Clip, ZeroY, WS, HS) ->
+    Y = element(N,Data),
+    make_lines(Ds, PX, N, Clip, ZeroY, WS, HS, Y, []).
+
+make_lines([D1 | Ds = [D2|Rest]], PX, N, Clip={Cx,Cy, _}, ZeroY, WS, HS, Y0, Acc0) ->
+    Y1 = element(N,D1),
+    Y2 = element(N,D2),
+    Y3 = case Rest of
+	     [D3|_] -> element(N,D3);
+	     [] -> Y2
+	 end,
+    This = {max(Cx, PX),ZeroY-min(Cy,Y1*HS)},
+    Acc = if (abs(Y1-Y2) * HS) < 3.0 -> [This|Acc0];
+	     WS < 3.0 -> [This|Acc0];
+	     PX < Cx ->
+		  make_splines(Y0,Y1,Y2,Y3,PX,Clip,ZeroY,WS,HS,Acc0);
+	     true ->
+		  make_splines(Y0,Y1,Y2,Y3,PX,Clip,ZeroY,WS,HS,[This|Acc0])
+	  end,
+    make_lines(Ds, PX+WS, N, Clip, ZeroY, WS, HS, Y1, Acc);
+make_lines([D1],  _PX, N, {_,Cy,Last}, ZeroY, _WS, HS, _Y0, Acc) ->
+    Y1 = element(N,D1),
+    [{Last,ZeroY-min(Cy, Y1*HS)}|Acc].
+
+make_splines(Y00,Y10,Y20,Y30,PX,Clip,ZeroY,WS,HS,Acc) ->
+    Y1 = Y10*HS,
+    Y2 = Y20*HS,
+    Steps = min(abs(Y1-Y2), WS),
+    if Steps > 2 ->
+	    Y0 = Y00*HS,
+	    Y3 = Y30*HS,
+	    Tan = spline_tan(Y0,Y1,Y2,Y3),
+	    Delta = 1/Steps,
+	    splines(Steps-1, 0.0, Delta, Tan, Y1,Y2, PX, Clip,ZeroY, Delta*WS, Acc);
+       true ->
+	    Acc
+    end.
+
+splines(N, XD, XD0, Tan, Y1,Y2, PX0, Clip={Cx,Cy,_},ZeroY, WS, Acc) when N > 0 ->
+    PX = PX0+WS,
+    Delta = XD+XD0,
+    if PX < Cx ->
+	    splines(N-1, Delta, XD0, Tan, Y1, Y2, PX, Clip,ZeroY, WS, Acc);
+       true ->
+	    Y = min(Cy, max(0,spline(Delta, Tan, Y1,Y2))),
+	    splines(N-1, Delta, XD0, Tan, Y1, Y2, PX, Clip,ZeroY, WS,
+		    [{PX, ZeroY-Y}|Acc])
+    end;
+splines(_N, _XD, _XD0, _Tan, _Y1,_Y2, _PX, _Clip,_ZeroY, _WS, Acc) -> Acc.
+
+spline(T, {M1, M2}, Y1, Y2) ->
+    %% Hermite Basis Funcs
+    T2 = T*T,  T3 = T*T*T,
+    H1 = 2*T3-3*T2+1,
+    H2 = -2*T3+3*T2,
+    H3 = T3-2*T2+T,
+    H4 = T3-T2,
+    %% Result
+    M1*H3 + Y1*H1 + Y2*H2 + M2*H4.
+
+spline_tan(Y0, Y1, Y2, Y3) ->
+    S = 1.0,
+    C = 0.5,
+    %% Calc tangent values
+    M1 = S*C*(Y2-Y0),
+    M2 = S*C*(Y3-Y1),
+    {M1,M2}.
+
+-define(BW, 5).
+-define(BH, 5).
+
+draw_borders(Type, NoGraphs, DC, {W,H}, Max,
+	     #paint{pen=Pen, pen2=Pen2, font=Font, small=Small}) ->
+    {Unit, MaxUnit} = bytes(Type, Max),
+    Str1 = observer_lib:to_str(MaxUnit),
+    Str2 = observer_lib:to_str(MaxUnit div 2),
+    Str3 = observer_lib:to_str(0),
+
+    setFont(DC, Font, {0,0,0}),
+    {TW,TH} = getTextExtent(DC, Str1),
+    {SpaceW, _} = getTextExtent(DC, "W"),
+
+    GraphX0 = ?BW+TW+?BW,
+    GraphX1 = W-?BW*4,
+    TopTextX = ?BW+TW+?BW,
+    MaxTextY = ?BH+TH+?BH,
+    BottomTextY = H-?BH-TH,
+    SecondsY = BottomTextY - ?BH - TH,
+    GraphY0 = MaxTextY + (TH / 2),
+    GraphY1 = SecondsY - ?BH,
+    GraphW = GraphX1-GraphX0-1,
+    GraphH = GraphY1-GraphY0-1,
+    GraphY25 = GraphY0 + (GraphY1 - GraphY0) / 4,
+    GraphY50 = GraphY0 + (GraphY1 - GraphY0) / 2,
+    GraphY75 = GraphY0 + 3*(GraphY1 - GraphY0) / 4,
+    ScaleW = GraphW / 60,
+    ScaleH = GraphH / Max,
+
+    setFont(DC, Small, {0,0,0}),
+    Align = fun(Str, Y) ->
+		    {StrW, _} = getTextExtent(DC, Str),
+		    drawText(DC, Str, GraphX0 - StrW - ?BW, Y)
+	    end,
+    Align(Str1, MaxTextY),
+    Align(Str2, GraphY50 - (TH / 2)),
+    Align(Str3, GraphY1 - (TH / 2) + 1),
+
+    setPen(DC, Pen),
+    DrawSecs = fun(Secs, Pos) ->
+		       Str = [observer_lib:to_str(Secs)|" s"],
+		       X = GraphX0+Pos,
+		       drawText(DC, Str,  X-SpaceW, SecondsY),
+		       strokeLine(DC, X, GraphY0, X, GraphY1+5),
+		       Pos + 10*ScaleW
+	       end,
+    lists:foldl(DrawSecs, 0, lists:seq(60,0, -10)),
+
+    strokeLine(DC, GraphX0-3, GraphY25, GraphX1, GraphY25),
+    strokeLine(DC, GraphX0-3, GraphY50, GraphX1, GraphY50),
+    strokeLine(DC, GraphX0-3, GraphY75, GraphX1, GraphY75),
+
+    setPen(DC, Pen2),
+    strokeLines(DC, [{GraphX0, GraphY0-1}, {GraphX0, GraphY1+1},
+		     {GraphX1, GraphY1+1}, {GraphX1, GraphY0-1},
+		     {GraphX0, GraphY0-1}]),
+
+    setFont(DC, Font, {0,0,0}),
+    case Type of
+	?RQ_W ->  drawText(DC, "Scheduler Utilization (%) ", TopTextX,?BH);
+	?MEM_W -> drawText(DC, "Memory Usage " ++ Unit, TopTextX,?BH);
+	?IO_W ->  drawText(DC, "IO Usage " ++ Unit, TopTextX,?BH)
+    end,
+
+    Text = fun(X,Y, Str, PenId) ->
+		   if PenId == 0 ->
+			   setFont(DC, Font, {0,0,0});
+		      PenId > 0 ->
+			   Id = 1 + ((PenId-1) rem tuple_size(colors())),
+			   setFont(DC, Font, element(Id, colors()))
+		   end,
+		   drawText(DC, Str, X, Y),
+		   {StrW, _} = getTextExtent(DC, Str),
+		   StrW + X + SpaceW
+	   end,
+    case Type of
+	?RQ_W ->
+	    TN0 = Text(?BW, BottomTextY, "Scheduler: ", 0),
+	    lists:foldl(fun(Id, Pos0) ->
+				Text(Pos0, BottomTextY, integer_to_list(Id), Id)
+			end, TN0, lists:seq(1, NoGraphs));
+	?MEM_W ->
+	    lists:foldl(fun(MType, {PenId, Pos0}) ->
+				Str = uppercase(atom_to_list(MType)),
+				Pos = Text(Pos0, BottomTextY, Str, PenId),
+				{PenId+1, Pos}
+			end, {1, ?BW}, mem_types());
+	?IO_W ->
+	    TN0 = Text(?BW, BottomTextY, "Input", 1),
+	    Text(TN0, BottomTextY, "Output", 2)
+    end,
+    {GraphX0+1, GraphY1, ScaleW, ScaleH}.
+
+uppercase([C|Rest]) ->
+    [C-$a+$A|Rest].
+
+calc_max(Max) when Max < 10 -> 10;
+calc_max(Max) -> calc_max1(Max).
+
+calc_max1(Max) ->
+    case Max div 10 of
+	X when X < 10 ->
+	    case Max rem 10 of
+		0 -> Max;
+		_ ->
+		    (X+1)*10
+	    end;
+	X ->
+	    10*calc_max1(X)
+    end.
+
+bytes(?RQ_W, Val) -> {"", Val};
+bytes(_, B) ->
+    KB = B div 1024,
+    MB = KB div 1024,
+    GB = MB div 1024,
+    if
+	GB > 10 -> {"(GB)", GB};
+	MB > 10 -> {"(MB)", MB};
+	KB >  0 -> {"(KB)", KB};
+	true    -> {"(B)", B}
+    end.
+
+colors() ->
+    {{200, 50, 50}, {50, 200, 50}, {50, 50, 200},
+     {255, 110, 0}, {50, 200, 200}, {200, 50, 200},
+     {240, 200, 80}, {140, 2, 140},
+     {100, 200, 240}, {100, 240, 100}
+    }.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% wxDC and ?wxGC wrappers
+
+haveGC(Win) ->
+    try
+	GC = ?wxGC:create(Win),
+	?wxGC:destroy(GC),
+	true
+    catch _:_  -> false
+    end.
+
+setPen({false, DC}, Pen) ->
+    wxDC:setPen(DC, Pen);
+setPen({true, GC}, Pen) ->
+    ?wxGC:setPen(GC, Pen).
+
+setFont({false, DC}, Font, Color) ->
+    wxDC:setTextForeground(DC, Color),
+    wxDC:setFont(DC, Font);
+setFont({true, GC}, Font, Color) ->
+    ?wxGC:setFont(GC, Font, Color).
+
+setBrush({false, DC}, Brush) ->
+    wxDC:setBrush(DC, Brush);
+setBrush({true, GC}, Brush) ->
+    ?wxGC:setBrush(GC, Brush).
+
+strokeLine({false, DC}, X0, Y0, X1, Y1) ->
+    wxDC:drawLine(DC, {round(X0), round(Y0)}, {round(X1), round(Y1)});
+strokeLine({true, GC}, X0, Y0, X1, Y1) ->
+    ?wxGC:strokeLine(GC, X0, Y0, X1, Y1).
+
+strokeLines({false, DC}, Lines) ->
+    wxDC:drawLines(DC, [{round(X), round(Y)} || {X,Y} <- Lines]);
+strokeLines({true, GC}, Lines) ->
+    ?wxGC:strokeLines(GC, Lines).
+
+drawRoundedRectangle({false, DC}, X0, Y0, X1, Y1, R) ->
+    wxDC:drawRoundedRectangle(DC, {round(X0), round(Y0)}, {round(X1), round(Y1)}, round(R));
+drawRoundedRectangle({true, GC}, X0, Y0, X1, Y1, R) ->
+    ?wxGC:drawRoundedRectangle(GC, X0, Y0, X1, Y1, R).
+
+drawText({false, DC}, Str, X, Y) ->
+    wxDC:drawText(DC, Str, {round(X),round(Y)});
+drawText({true, GC}, Str, X, Y) ->
+    ?wxGC:drawText(GC, Str, X, Y).
+
+getTextExtent({false, DC}, Str) ->
+    wxDC:getTextExtent(DC, Str);
+getTextExtent({true, GC}, Str) ->
+    {W,H,_,_} = ?wxGC:getTextExtent(GC, Str),
+    {W,H}.