%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%
%% ------------------------------------------------------------
%% distrib_draw
%% Shows one way of making two nodes draw on the same
%% area.
%%
%% ------------------------------------------------------------
%% HOW TO USE:
%% 1) start up two nodes with same cookie.
%% They can be on any machines.
%%
%% sid.ericsson.se> erl -cookie kaka -name hans
%%
%% ozzy.ericsson.se> erl -cookie kaka -name greta
%%
%%
%% 2) Make them aware of each other.
%% <[email protected]> net:ping('[email protected]').
%%
%% 3) Start up distrib_draw from either node.
%% <[email protected]> distrib_draw('[email protected]',
%% '[email protected]').
%%
-module(distrib_draw).
-compile([{nowarn_deprecated_function,{gs,canvas,3}},
{nowarn_deprecated_function,{gs,config,2}},
{nowarn_deprecated_function,{gs,line,2}},
{nowarn_deprecated_function,{gs,start,0}},
{nowarn_deprecated_function,{gs,window,3}}]).
-export([start/2,init/0]).
start(Node1,Node2) ->
Pid1=spawn(Node1,distrib_draw,init,[]),
Pid2=spawn(Node2,distrib_draw,init,[]),
Pid1 ! {connect,red,Pid2},
Pid2 ! {connect,green,Pid1}.
init() ->
process_flag(trap_exit,true),
S=gs:start(),
receive
{connect,Color,Pid} ->
link(Pid),
gs:window(win,S,[{buttonpress,true},{buttonrelease,true},
{configure,true},{title,Color},{map,true}]),
gs:canvas(canvas,win,[{bg,grey},{width,300},{height,200}]),
draw0(0,0,Color,Pid)
after
3000 -> exit(timeout)
end.
%% not drawing state
draw0(X0,Y0,Color,Pid) ->
receive
{gs,_,buttonpress,_,[1,X,Y|_]} ->
gs:config(win,{motion,true}),
draw1(X,Y,Color,Pid);
{draw,Coords,Col2} ->
gs:line(canvas,[{coords,Coords},{width,2},{fg,Col2}]),
draw0(X0,Y0,Color,Pid);
{gs,_,configure,_,[300,200|_]} ->
draw0(X0,Y0,Color,Pid);
{gs,_,configure,_,_} ->
gs:config(win,[{width,300},{height,200}]),
draw0(X0,Y0,Color,Pid);
{gs,_,destroy,_,_} ->
exit(normal);
{'EXIT',_,_} ->
exit(normal);
_X -> draw1(X0,Y0,Color,Pid)
end.
%% i'm now drawing
draw1(X0,Y0,Color,Pid) ->
receive
{gs,_,motion,_,[X,Y|_]} ->
Pid ! {draw,[{X0,Y0},{X,Y}],Color},
gs:line(canvas,[{coords,[{X0,Y0},{X,Y}]},{width,2},{fg,Color}]),
draw1(X,Y,Color,Pid);
{draw,Coords,Col2} ->
gs:line(canvas,[{coords,Coords},{width,2},{fg,Col2}]),
draw1(X0,Y0,Color,Pid);
{gs,_,buttonrelease,_,[1,X,Y|_]} ->
gs:config(win,{motion,false}),
draw0(X,Y,Color,Pid);
{gs,_,configure,_,[300,200|_]} ->
draw0(X0,Y0,Color,Pid);
{gs,_,configure,_,_} ->
gs:config(win,[{width,300},{height,200}]),
draw0(X0,Y0,Color,Pid);
{gs,_,destroy,_,_} ->
exit(normal);
{'EXIT',_,_} ->
exit(normal);
_X -> draw1(X0,Y0,Color,Pid)
end.
%% ------------------------------------------------------------
%% end of 'distrib_draw'
