Observer plugins

lib/observer/doc/src/observer_ug.xml

@@ -355,4 +355,143 @@
     in application STDLIB.
     </p>
   </section>
+
+  <section>
+    <title>Plugins</title>
+    <p>Other third party graphical user interfaces can be added to Observer menu.
+       If any declared, a menu entry 'Plugins' is shown, otherwise not.
+    </p>
+    <p>Plugins have to be declared in <c>observer</c> application configuration,
+       as a list of tuple <c>{NameString, StartMFA}</c> under a key <c>plugins</c>.
+       Plugin names will be sorted in alphabetic order in menu, and a maximum of ten plugins
+       kept. If more are declared only first ten (sorted) ones will be available.
+    </p>
+    <p>
+       <c>NameString</c> is the name of application to display in Plugins menu.
+       <c>StartMFA</c> is the start command MFA , as a 3 or 4 elements tuple.
+       Atom 'node' as fourth tuple element will add the current node observed by Observer as last argument of start command.
+    </p>
+    <list type="bulleted">
+       <item><c>{M, F, []}</c> Start without any argument.</item>
+       <item><c>{M, F, A}</c> Start with argument list A.</item>
+       <item><c>{M, F, A, node}</c> Start with current observed node as last argument of list A.</item>
+    </list>
+    <p>
+    Start command must return a <c>wx_object()</c> like <c>wx:new/0</c>.
+    </p>
+    <p>Configuration example :</p>
+       <code type="none"><![CDATA[
+       [
+         {observer, [ {plugins, [
+                                    { "My app",      {myapp_gui, start, [], node}},
+                                    { "Another app", {another, gui, []}},
+                                    { "A third app", {acme, start, [debug, verbose]}},
+                                    { "A funny app", {funny, ui, [{log_level, 3}], node}}
+                                ]}
+                    ]}
+       ].]]></code>
+    <p>Example of a minimalist plugin restarting applications on observed node.
+       Note that <c>init:restart/0</c> on local node will close Observer,
+       so better using this on a remote observed node.
+    </p>
+    <warning>
+         <p>To prevent the observer from being closed, please do not call
+  	 <c>wx:destroy()</c> from your plugins.</p>
+    </warning>
+    <code type="none"><![CDATA[
+         -module(opdemo).
+
+         -include_lib("wx/include/wx.hrl").
+
+         -behaviour(wx_object).
+
+         -export([start/0, start/1, start_link/0, start_link/1]).
+
+         -export([init/1, handle_call/3, handle_event/2,
+               handle_info/2, handle_cast/2, code_change/3, terminate/2]).
+
+         -record(state,
+            {frame
+            ,node
+            }).
+
+         start() ->
+            start([]).
+
+         start(Args) ->
+            wx_object:start(?MODULE, Args, []).
+
+         start_link() ->
+            start_link([]).
+
+         start_link(Args) ->
+            wx_object:start_link(?MODULE, Args, []).
+
+         init(Node) ->
+            TNode = case Node of
+                        X when is_atom(X) -> X;
+                        _  -> erlang:node() % default to current node
+                     end,
+            Parent = wx:new(),
+            process_flag(trap_exit, true),
+
+            Text = atom_to_list(?MODULE),
+            MiniFrame = wxMiniFrame:new(Parent, ?wxID_ANY, Text, [{style,
+                                    ?wxDEFAULT_FRAME_STYLE bor
+                                    ?wxFRAME_FLOAT_ON_PARENT}]),
+            Panel = wxPanel:new(MiniFrame, []),
+
+            % Add a button to  restart all application of given node
+            Sz = wxBoxSizer:new(?wxVERTICAL),
+            ButtSz = wxStaticBoxSizer:new(?wxHORIZONTAL, Panel,
+                     [{label, atom_to_list(TNode)}]),
+            SzFlags = [{proportion, 0}, {border, 4}, {flag, ?wxALL}],
+            B  = wxButton:new(Panel, 10, [{label,"Restart applications"}]),
+            wxSizer:add(ButtSz, B, SzFlags),
+
+            wxMiniFrame:setSize(MiniFrame, {150,100}),
+            wxMiniFrame:center(MiniFrame),
+            wxMiniFrame:show(MiniFrame),
+            wxWindow:connect(Panel, command_button_clicked),
+            wxWindow:setSizer(Panel, Sz),
+            wxSizer:layout(Sz),
+            wxWindow:refresh(Panel),
+            {MiniFrame, #state{frame=MiniFrame ,node = TNode}}.
+
+         %%%%%%%%%%%%
+         %% Callbacks
+
+         handle_info({'EXIT',_, wx_deleted}, State) ->
+            {noreply,State};
+         handle_info({'EXIT',_, shutdown}, State) ->
+            {noreply,State};
+         handle_info({'EXIT',_, normal}, State) ->
+            {noreply,State};
+         handle_info(_, State) ->
+            {noreply,State}.
+
+         handle_call(_, _From, State) ->
+            {reply,ok,State}.
+
+         handle_cast(_, State) ->
+            {noreply,State}.
+
+         handle_event({wx,10, _, _,
+                     {wxCommand,command_button_clicked,_,_,_}}, State) ->
+            % Restart applications on node
+            Res = rpc:call(State#state.node, init, restart, []),
+            io:format("restarting application on ~p : ~p~n", [State#state.node, Res]),
+            {noreply,State};
+         handle_event(Ev,State) ->
+            io:format("~p Got uncaught event ~p ~n",[?MODULE, Ev]),
+            {noreply, State}.
+
+         code_change(_, _, State) ->
+            {stop, not_yet_implemented, State}.
+
+         terminate(_Reason, _State = #state{frame=Frame}) ->
+            wxMiniFrame:destroy(Frame),
+            ok.
+       .]]></code>
+  </section>
 </chapter>

lib/observer/src/observer_wx.erl

@@ -39,6 +39,8 @@
 -define(ID_NOTEBOOK, 3).
 -define(ID_CDV,      4).
 -define(ID_LOGVIEW, 5).
+-define(FIRST_PLUGINS_MENU_ID, 10).
+-define(LAST_PLUGINS_MENU_ID, 20).
 
 -define(FIRST_NODES_MENU_ID, 1000).
 -define(LAST_NODES_MENU_ID,  2000).
@@ -61,7 +63,8 @@
 	 prev_node="",
 	 log = false,
 	 reply_to=false,
-         config
+	 config,
+	 plugins
 	}).
 
 start() ->
@@ -119,7 +122,8 @@ setup(#state{frame = Frame} = State) ->
     MenuBar = wxMenuBar:new(),
 
     {Nodes, NodeMenus} = get_nodes(),
-    DefMenus = default_menus(NodeMenus),
+    {Plugins, PluginsMenus} = get_plugins(),
+    DefMenus = default_menus(NodeMenus, PluginsMenus),
     observer_lib:create_menus(DefMenus, MenuBar, default),
 
     wxFrame:setMenuBar(Frame, MenuBar),
@@ -209,7 +213,8 @@ setup(#state{frame = Frame} = State) ->
 			   active_tab = SysPid,
                            panels = Panels,
 			   node  = node(),
-			   nodes = Nodes
+			   nodes = Nodes,
+			   plugins = Plugins
 			  },
     %% Create resources which we don't want to duplicate
     SysFont = wxSystemSettings:getFont(?wxSYS_SYSTEM_FIXED_FONT),
@@ -367,6 +372,37 @@ handle_event(#wx{id = Id, event = #wxCommand{type = command_menu_selected}},
              end,
     {noreply, change_node_view(Node, LState)};
 
+handle_event(#wx{id = Id, event = #wxCommand{type = command_menu_selected}},
+	     #state{plugins= Ns} = State)
+  when Id > ?FIRST_PLUGINS_MENU_ID, Id =< ?LAST_PLUGINS_MENU_ID ->
+    {N, {M, F, A}} = case lists:nth(Id - ?FIRST_PLUGINS_MENU_ID, Ns) of
+                        {N0, {M0, F0, [], node}} -> {N0, {M0, F0, [State#state.node]}};
+                        {N0, {M0, F0, A0, node}} -> {N0, {M0, F0, A0 ++ [State#state.node]}};
+                        {N0, {M0, F0, A0}} -> {N0, {M0, F0, A0}}
+                     end,
+    Env = wx:get_env(),
+    spawn(fun() ->
+           wx:set_env(Env),
+           WO = try
+		   erlang:apply(M, F, A)
+		catch
+		   throw:T1 -> T1
+		end,
+           Pid = try
+		   wx_object:get_pid(WO)
+		 catch
+		   throw:T2 -> T2
+		 end,
+           case Pid of
+               Pid when is_pid(Pid) ->
+                       erlang:monitor(process, Pid),
+                       set_status("Plugin started : " ++ N);
+               _  -> io:format("~ts : ~p~n", [N, WO]),
+                       set_status(io_lib:format("Plugin ~ts : start error", [N]))
+           end
+        end),
+    {noreply, State};
+
 handle_event(Event, #state{active_tab=Pid} = State) ->
     Pid ! Event,
     {noreply, State}.
@@ -656,7 +692,7 @@ create_connect_dialog(connect, #state{frame = Frame}) ->
 	    cancel
     end.
 
-default_menus(NodesMenuItems) ->
+default_menus(NodesMenuItems, PluginsMenu) ->
     CDV   = #create_menu{id = ?ID_CDV, text = "Examine Crashdump"},
     Quit  = #create_menu{id = ?wxID_EXIT, text = "Quit"},
     About = #create_menu{id = ?wxID_ABOUT, text = "About"},
@@ -673,7 +709,7 @@ default_menus(NodesMenuItems) ->
 	false ->
 	    FileMenu = {"File", [CDV, Quit]},
 	    HelpMenu = {"Help", [About,Help]},
-	    [FileMenu, NodeMenu, LogMenu, HelpMenu];
+	    lists:flatten([FileMenu, NodeMenu, LogMenu, PluginsMenu, HelpMenu]);
 	true ->
 	    %% On Mac quit and about will be moved to the "default' place
 	    %% automagicly, so just add them to a menu that always exist.
@@ -806,7 +842,7 @@ is_rb_compatible(Node) ->
 
 is_rb_server_running(Node, LogState) ->
    %% If already started, somebody else may use it.
-   %% We can not use it too, as far log file would be overriden. Not fair.
+   %% We cannot use it too, as far log file would be overriden. Not fair.
    case rpc:block_call(Node, erlang, whereis, [rb_server]) of
        Pid when is_pid(Pid), (LogState == false) ->
 	   throw("Error: rb_server is already started and maybe used by someone.");
@@ -815,3 +851,22 @@ is_rb_server_running(Node, LogState) ->
        undefined ->
 	   ok
    end.
+
+get_plugins() ->
+   %% Returns optional plugins to add to menu, otherwise []
+   application:load(observer),
+   case application:get_env(observer, plugins) of
+      undefined -> {[], []};
+      {ok, P}  -> % Add only valid parameters
+            F = lists:filter(fun(X) -> case X of
+                                          {_N, {_M, _F, _A}} -> true;
+                                          {_N, {_M, _F, _A, node}} -> true;
+                                          _ -> io:format("~p~n",[{invalid, X}]), false end end , P),
+            {Plugins, _} = lists:split((?LAST_PLUGINS_MENU_ID - ?FIRST_PLUGINS_MENU_ID), lists:usort(F)),
+            {_, PMenues} = lists:foldl(fun({N, _}, {Id, Acc}) when Id =< ?LAST_PLUGINS_MENU_ID ->
+                                       {Id + 1, [#create_menu{id=Id + ?FIRST_PLUGINS_MENU_ID,
+                                                              text=N} | Acc]}
+                                       end, {1, []}, Plugins),
+         {Plugins, {"Plugins",lists:reverse(PMenues)}}
+   end.
+