in AssocDialog table disable rows that are empty data, re #7133

Code/Mantid/MantidPlot/src/AssociationsDialog.cpp

@@ -57,11 +57,11 @@ AssociationsDialog::AssociationsDialog( Graph* g, Qt::WFlags fl )
   QVBoxLayout *vl = new QVBoxLayout();
 
   QHBoxLayout *hbox1 = new QHBoxLayout ();
-    hbox1->addWidget(new QLabel(tr( "Spreadsheet: " )));
+  hbox1->addWidget(new QLabel(tr( "Spreadsheet: " )));
 
   tableCaptionLabel = new QLabel();
-    hbox1->addWidget(tableCaptionLabel);
-    vl->addLayout(hbox1);
+  hbox1->addWidget(tableCaptionLabel);
+  vl->addLayout(hbox1);
 
   table = new QTableWidget(3, 5);
   table->horizontalHeader()->setClickable( false );
@@ -70,26 +70,26 @@ AssociationsDialog::AssociationsDialog( Graph* g, Qt::WFlags fl )
   table->verticalHeader()->setResizeMode(QHeaderView::ResizeToContents);
   table->setMaximumHeight(8*table->rowHeight(0));
   table->setHorizontalHeaderLabels(QStringList() << tr("Column") << tr("X") << tr("Y") << tr("xErr") << tr("yErr"));
-    vl->addWidget(table);
+  vl->addWidget(table);
 
   connect(table, SIGNAL(itemClicked(QTableWidgetItem*)), this, SLOT(processStateChange(QTableWidgetItem*)));
   
   associations = new QListWidget();
   associations->setSelectionMode ( QListWidget::SingleSelection );
-    vl->addWidget(associations);
+  vl->addWidget(associations);
 
   btnApply = new QPushButton(tr( "&Update curves" ));
-    btnOK = new QPushButton( tr( "&OK" ) );
+  btnOK = new QPushButton( tr( "&OK" ) );
   btnOK->setDefault( true );
-    btnCancel = new QPushButton( tr( "&Cancel" ) );
+  btnCancel = new QPushButton( tr( "&Cancel" ) );
 
-    QHBoxLayout *hbox2 = new QHBoxLayout ();
+  QHBoxLayout *hbox2 = new QHBoxLayout ();
   hbox2->addStretch();
-    hbox2->addWidget(btnApply);
-    hbox2->addWidget(btnOK);
-    hbox2->addWidget(btnCancel);
-    vl->addStretch();
-    vl->addLayout(hbox2);
+  hbox2->addWidget(btnApply);
+  hbox2->addWidget(btnOK);
+  hbox2->addWidget(btnCancel);
+  vl->addStretch();
+  vl->addLayout(hbox2);
   setLayout(vl);
 
   active_table = 0;
@@ -213,35 +213,58 @@ Table * AssociationsDialog::findTable(int index)
 
 void AssociationsDialog::updateTable(int index)
 {
-Table *t = findTable(index);
-if (!t)
-  return;
-
-if (active_table != t){
-  active_table = t;
-  tableCaptionLabel->setText(t->objectName());
-  table->clearContents();
-  table->setRowCount(t->numCols());
-
-  QStringList colNames = t->colNames();
-  for (int i=0; i<table->rowCount(); i++ ){
-        QTableWidgetItem *cell = new QTableWidgetItem(colNames[i]);
-        cell->setBackground (QBrush(Qt::lightGray));
-        cell->setFlags (Qt::ItemIsEnabled);
-        table->setItem(i, 0, cell);
+  Table *t = findTable(index);
+  if (!t)
+    return;
+
+  if (active_table != t)
+  {
+    active_table = t;
+    tableCaptionLabel->setText(t->objectName());
+    table->clearContents();
+    table->setRowCount(t->numCols());
+
+    QStringList colNames = t->colNames();
+    // this vector will tell which rows should be disabled (cause there's no data in them)
+    std::vector<bool> disableRow;
+    disableRow.resize(table->rowCount(), false);
+    for (int i=0; i<table->rowCount(); i++ )
+    {
+      QTableWidgetItem *cell = new QTableWidgetItem(colNames[i]);
+      cell->setBackground (QBrush(Qt::lightGray));
+      cell->setFlags (Qt::ItemIsEnabled);
+      table->setItem(i, 0, cell);
+
+      // do we need to disable this row cause the corresponding curve it's empty?
+      // (empty curves could cause crashes in many other places)
+      bool allEmpty = true;
+      // Note possible confusion, here 'table' is the table that you see in the AssociationsDialog,
+      // whereas t is the underlying data table (spreadsheet).
+      for (int dataRow = 0; dataRow < t->numRows() && allEmpty; dataRow++)
+      {
+        // use i (row in the associations table) as column index
+        allEmpty = allEmpty & t->text(dataRow, i).isEmpty();
       }
+      if (allEmpty)
+        disableRow[i] = true;
+    }
 
-  for (int j=1; j < table->columnCount(); j++){
-    for (int i=0; i < table->rowCount(); i++ )
+    for (int j=1; j < table->columnCount(); j++)
+    {
+      for (int i=0; i < table->rowCount(); i++ )
       {
-        QTableWidgetItem *cell = new QTableWidgetItem();
-        cell->setBackground(QBrush(Qt::lightGray));
-        cell->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled);
-        table->setItem(i, j, cell);
+          QTableWidgetItem *cell = new QTableWidgetItem();
+          cell->setBackground(QBrush(Qt::lightGray));
+          cell->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled);
+          table->setItem(i, j, cell);
+
+          // disable (but keep the checkbox, as set above)
+          if (disableRow[i])
+            cell->setFlags(Qt::NoItemFlags);
       }
     }
   }
-updateColumnTypes();
+  updateColumnTypes();
 }
 
 void AssociationsDialog::updateColumnTypes()