HackStudio: Add TerminalWrapper::on_command_exit

Author: https://github.com/bugaevc
Commit: cd11a8597a
Pull-request: https://github.com/SerenityOS/serenity/pull/779

DevTools/HackStudio/TerminalWrapper.cpp

@@ -47,6 +47,9 @@ void TerminalWrapper::run_command(const String& command)
         }
         m_process_state_widget->set_tty_fd(-1);
         m_pid = -1;
+
+        if (on_command_exit)
+            on_command_exit();
     };
 
     m_pid = fork();

DevTools/HackStudio/TerminalWrapper.h

@@ -12,6 +12,8 @@ public:
 
     void run_command(const String&);
 
+    Function<void()> on_command_exit;
+
 private:
     explicit TerminalWrapper(GWidget* parent);