Simple warnings

mainwindow.cpp

@@ -34,8 +34,40 @@ void MainWindow::onGridUpdated()
 
     ui->listLines->clear();
 
+    QMap<QString, QList<int>> colorCount;
     for (int i = 0; i< ui->gridPreview->getLines().size(); i++)
+    {
         ui->listLines->addItem(QString("Line #%1").arg(i + 1));
+        QString color = ui->gridPreview->getLine(i).getColor();
+        auto iter = colorCount.find(color);
+        if (iter == colorCount.end())
+            colorCount.insert(color, { i + 1 });
+        else
+            iter->push_back(i + 1);
+    }
+
+    ui->treeWarnings->clear();
+
+    for (auto iter = colorCount.begin(); iter != colorCount.end(); iter++)
+    {
+        if (iter->size() > 1)
+        {
+            QTreeWidgetItem *topItem = new QTreeWidgetItem(ui->treeWarnings, QStringList{
+                QString("Color \"%1\" is used by several lines:").arg(iter.key())
+            });
+
+            for(int i = 0; i < iter->size(); i++)
+            {
+                QTreeWidgetItem *innerItem = new QTreeWidgetItem(topItem, QStringList {
+                    QString("Line #%1").arg(iter->at(i))
+                });
+                topItem->addChild(innerItem);
+            }
+
+            ui->treeWarnings->addTopLevelItem(topItem);
+        }
+    }
+    ui->treeWarnings->expandAll();
 
     PointProbe pp = ui->gridPreview->getCapturedProbe();