Remove Tab 1/2 differences from UDP interface

The UDP "Free  text" message comamnd should  not expose implementation
differences between tab one and tab two. The "send next" capability is
not available on  tab two so use  of it has been removed  from the UDP
interface.

The ability  to trigger  the immediate  (or in next  Tx period  if the
current period  is Rx) sending  of the  current free text  message has
been added to the UDP interface. This is done by sending a "Free text"
UDP message containing an empty text message with the "Send" flag set.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@5725 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

MessageAggregator.cpp

@@ -222,7 +222,7 @@ public:
         Q_EMIT do_free_text (id_, text, false);
       });
     connect (message_line_edit_, &QLineEdit::editingFinished, [this] () {
-        Q_EMIT do_free_text (id_, message_line_edit_->text (), !message_line_edit_->text ().isEmpty ());
+        Q_EMIT do_free_text (id_, message_line_edit_->text (), true);
       });
     control_layout->addLayout (form_layout);
     control_layout->addWidget (auto_off_button_);

NetworkMessage.hpp

@@ -199,14 +199,29 @@
  *                         Send                   bool
  *
  *			This message  allows the server  to set the current  free text
- *			message content. Sending this  message is equivalent to typing
+ *			message content. Sending this  message with a non-empty "Text"
- *			a new  message (old contents  are discarded) in to  the WSJT-X
+ *			field is equivalent to typing  a new message (old contents are
- *			free text message field or  "Tx5" field (both are updated) and
+ *			discarded) in to  the WSJT-X free text message  field or "Tx5"
- *			if the Send  flag is set then clicking the  "Now" radio button
+ *			field (both  are updated) and if  the "Send" flag is  set then
- *			for the  "Tx5" field  if tab  one is  current or  clicking the
+ *			clicking the "Now" radio button for the "Tx5" field if tab one
- *			"Free msg"  radio button  if tab  two is  current.  It  is the
+ *			is current or clicking the "Free  msg" radio button if tab two
- *			responsibility  of  the sender  to  limit  the length  of  the
+ *			is current.
- *			message text and to limit it to legal message characters.
+ *
+ *			It is the responsibility of the  sender to limit the length of
+ *			the  message   text  and   to  limit   it  to   legal  message
+ *			characters. Despite this,  it may be difficult  for the sender
+ *			to determine the maximum message length without reimplementing
+ *			the complete message encoding protocol. Because of this is may
+ *			be better  to allow any  reasonable message length and  to let
+ *			the WSJT-X application encode and possibly truncate the actual
+ *			on-air message.
+ *
+ *			If the  message text is  empty the  meaning of the  message is
+ *			refined  to send  the  current free  text  unchanged when  the
+ *			"Send" flag is set or to  clear the current free text when the
+ *			"Send" flag is  unset.  Note that this API does  not include a
+ *			command to  determine the  contents of  the current  free text
+ *			message.
  */
 
 #include <QDataStream>

mainwindow.cpp

@@ -202,17 +202,29 @@ MainWindow::MainWindow(bool multiple, QSettings * settings, QSharedMemory *shdme
   connect (m_messageClient, &MessageClient::error, this, &MainWindow::networkError);
   connect (m_messageClient, &MessageClient::free_text, [this] (QString const& text, bool send) {
       if (m_config.accept_udp_requests ()) {
+        // send + non-empty text means set and send the free text
+        // message, !send + non-empty text means set the current free
+        // text message, send + empty text means send the current free
+        // text message without change, !send + empty text means clear
+        // the current free text message
+        qDebug () << "Free text UDP message - text:" << text << "send:" << send << "text empty:" << text.isEmpty ();
         if (0 == ui->tabWidget->currentIndex ()) {
+          if (!text.isEmpty ()) {
             ui->tx5->setCurrentText (text);
+          }
           if (send) {
             ui->txb5->click ();
-        } else {
+          } else if (text.isEmpty ()) {
-          ui->txrb5->click ();
+            ui->tx5->setCurrentText (text);
           }
         } else if (1 == ui->tabWidget->currentIndex ()) {
+          if (!text.isEmpty ()) {
             ui->freeTextMsg->setCurrentText (text);
+          }
           if (send) {
             ui->rbFreeText->click ();
+          } else if (text.isEmpty ()) {
+            ui->freeTextMsg->setCurrentText (text);
           }
         }
       }