Appending Text to SWT Textbox from multiple threads.

[Sharad Gupta]

Hi All,

I am trying to update a text box from another thread but it has 
me stumped right now.

What I am trying to achieve is that the user can Initiate 
multiple pipeShell and the output from each of those should go 
into its own Textbox in parallel.

I tried creating the SWT UI Controls inside as well as outside my 
spawn but since they get added to a single parent Control its 
getting maddeningly frustrating.

Here is the Code:

     int nextIndex = 1;
     Text[int] statusItems;

     public int addStatus(string title, string process = "", int 
waitFor = 0)
     {
         int idx = nextIndex;
         nextIndex++;
         Tid id = spawn(&addStatusImpl, idx, title, process, 
waitFor);

// tabStatuses = new TabFolder(canvas,SWT.TOP);
         auto statusItem = new Text(tabStatuses);
         auto tabItem = new TabItem(tabStatuses, SWT.NONE);
         send(id, statusItem, tabItem);

         std.concurrency.register(title, id);

         //auto msg = receiveOnly!(int, Text)();
         //statusItems[idx] = msg[1];
         //return msg[0];
         return idx;
     }

     static private void addStatusImpl(int idx, string title, 
string process = "", int waitFor = 0)
     {
         auto msg = receiveOnly!(Text, TabItem)();
         Text item = msg[0];

         //send(idx, item);

         TabItem tabItem = msg[1];
         tabItem.setText(title);
         tabItem.setControl(item);

         if(process.length != 0)
         {
             Text b = statusItems.get(waitFor, null);
             Tid id;
             if(b is null)
                 addProcess(item, process, null, null);
             else
                 addProcess(item, process, b.processPipe.pid(), 
b.title);
         }
     }

static public void addProcess(Text txtStatus, string command, Pid 
waitFor, string waitForTitle)
{
     if(waitFor !is null)
     {
         auto blocker = tryWait(waitFor);
         if(!blocker.terminated)
         {
             txtStatus.append("Waiting for " ~ waitForTitle ~ 
"...\n");
             wait(waitFor);
         }
         if(blocker.status != 0)
         {
             txtStatus.append("ERROR: Process " ~ waitForTitle ~ " 
did not finish properly. Terminating Self.\n");
             return;
         }
     }

     string finalCommand = escapeShellCommand(command);
     auto pipes = pipeShell(finalCommand, Redirect.all, null, 
std.process.Config.suppressConsole);
     scope(exit) wait(pipes.pid);

     foreach(str; pipes.stdout.byLine)
     {
         string s = to!string(str);
         txtStatus.append(s);
     }

     foreach(str; pipes.stderr.byLine)
     {
         string s = to!string(str);
         txtStatus.append(s);
     }
}

Can someone please help me with a solution. I am new to D (long 
term c/c++ programmer) and am probably missing something.

Also any tips to do stuff the "D" way would also be appreciated 
as you can see that my mind set is still C-style coding.

Thank you all.