Fix #2091

companion/src/wizarddialog.cpp

@@ -181,6 +181,16 @@ int StandardPage::nextFreeChannel(int channel)
   return -1;
 }
 
+int StandardPage::totalChannelsAvailable()
+{
+  int c = 0;
+  for(int i=0; i<WIZ_MAX_CHANNELS; i++)
+    if (wizDlg->mix.channel[i].page == Page_None)
+      c++;
+
+  return c;
+}
+
 void StandardPage::populateCB(QComboBox *cb, int preferred)
 {
   cb->clear();
@@ -708,11 +718,13 @@ TailPage::TailPage(WizardDialog *dlg, QString image, QString title, QString text
   elevatorCB = new QComboBox();
   rudderCB = new QComboBox();
 
-  QLayout *l = layout();
+  l = layout();
   l->addWidget(new QLabel(tr("Rudder Channel:")));
   l->addWidget(rudderCB);
   l->addWidget(new QLabel(tr("Elevator Channel:")));
   l->addWidget(elevatorCB);
+
+  errorMessage = NULL;
 }
 
 void TailPage::initializePage()
@@ -720,6 +732,13 @@ void TailPage::initializePage()
   populateCB(elevatorCB, getDefaultChannel(ELEVATOR_INPUT));
   populateCB(rudderCB, getDefaultChannel(RUDDER_INPUT));
   StandardPage::initializePage();
+
+  if (totalChannelsAvailable() < 2) {
+    errorMessage = new QLabel(tr("Only one channel still available!<br>"
+      "You probably should configure your model without using the wizard."));
+    errorMessage->setStyleSheet("QLabel { color : red; }");
+    l->addWidget(errorMessage);
+  }
 }
 
 bool TailPage::validatePage()
@@ -729,6 +748,17 @@ bool TailPage::validatePage()
     bookChannel(rudderCB, RUDDER_INPUT,   100));
 }
 
+void TailPage::cleanupPage()
+{
+  if (errorMessage)
+  {
+    l->removeWidget(errorMessage);
+    delete errorMessage;
+    errorMessage = NULL;
+  }
+  StandardPage::cleanupPage();
+}
+
 SimpleTailPage::SimpleTailPage(WizardDialog *dlg, QString image, QString title, QString text, int nextPage)
   : StandardPage(Page_Simpletail, dlg, image, title, text, nextPage)
 {

companion/src/wizarddialog.h

@@ -55,6 +55,7 @@ class  StandardPage: public QWizardPage
     int nextFreeChannel(int channel = 0);
     void populateCB(QComboBox * cb, int preferred=-1);
     bool bookChannel(QComboBox * cb, Input input1, int weight1, Input input2=NO_INPUT, int weight2=0);
+    int totalChannelsAvailable();
 
   private:
     QLabel *topLabel;
@@ -231,10 +232,13 @@ class TailPage: public StandardPage
 public:
   TailPage(WizardDialog *dlg, QString image, QString title, QString text, int nextPage=-1);
   void initializePage();
+  void cleanupPage();
   bool validatePage();
 private:
   QComboBox *elevatorCB;
   QComboBox *rudderCB;
+  QLayout *l;
+  QLabel *errorMessage;
 };
 
 class VTailPage: public StandardPage