Deffered SQL query when database is visible

src/databaseview.cpp

@@ -157,8 +157,19 @@ void FITSFileModel::filesUnmarked(const QModelIndexList &indexes)
     }
 }
 
+void FITSFileModel::load()
+{
+    if(!m_loaded)
+    {
+        m_loaded = true;
+        prepareQuery();
+    }
+}
+
 void FITSFileModel::prepareQuery()
 {
+    if(!m_loaded)return;
+
     QString cols;
     QString join;
     QStringList where;
@@ -427,6 +438,7 @@ bool DataBaseView::exportCSV(const QString &path)
     if(!csv.open(QIODevice::WriteOnly | QIODevice::Text))
         return false;
 
+    m_model->load();
     QSqlQuery sql(m_model->query().lastQuery());
     int colCount = m_model->columnCount();
     QStringList header;
@@ -455,3 +467,8 @@ bool DataBaseView::exportCSV(const QString &path)
     }
     return true;
 }
+
+void DataBaseView::visible(bool visible)
+{
+    if(visible)m_model->load();
+}

src/databaseview.h

@@ -30,6 +30,7 @@ class FITSFileModel : public QSqlQueryModel
     QStringList m_limit;
     QSet<QString> m_markedFiles;
     Database *m_database;
+    bool m_loaded = false;
 public:
     explicit FITSFileModel(Database *database, QObject *parent = nullptr);
     void sort(int column, Qt::SortOrder order) override;
@@ -38,6 +39,7 @@ public:
     QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
     void filesMarked(const QModelIndexList &indexes);
     void filesUnmarked(const QModelIndexList &indexes);
+    void load();
 protected:
     void prepareQuery();
 };
@@ -74,6 +76,7 @@ public slots:
     void itemActivated(const QModelIndex &index);
     void applyFilter();
     bool exportCSV(const QString &path);
+    void visible(bool visible);
 signals:
     void loadFile(QString file);
 };